Renal Bone Disease: 200 Hours Dialysis Training

I will never look at an AV fistula the same again.

Not after this 6 months training.

I was looking at my own arm thinking, yeah, I think I would certainly qualify for an AV fistula. That's how it was when starting work too, you look at veins and see how beautiful they are and how easy it would be to cannulate them. Only doctors and vampires would understand.

So we were in ICU during the nephrology grand rounds and there was a patient who had had a parathyroidectomy.

So it's a good time to read up on renal bone disease.

Management of Renal Bone Disease Disease
Dr. Sunita Bavanandan Dept of Nephrology Hospital Kuala Lumpur

Mineral Bone Disease in Renal Failure
•Synonyms
–Renal osteodystrophy
–CKD-mineral bone disease (CKD-MBD)
•Common complication of renal failure

•Mineral bone disturbance:
–Low serum calcium
–High serum phosphate
–Parathyroid hormone
–Alkaline phosphatase

Types of Renal Bone Disease
1.High bone turn-over disease
–Secondary hyperparathyroidism
2.Low bone turn-over disease
–Adynamic bone disease
–Osteomalacia including aluminium bone disease
3.Mixed bone disease

Secondary hyperparathyroidism
•Most common form of renal bone disease
•Synonyms
–Osteitis fibrosa
–Hyperparathyroid bone disease
•Characterised by elevated PTH level

Pathogenesis
•Hypocalcaemia
–Low levels of active Vitamin D
–Kidneys are required for activation of Vitamin D
•Hyperphosphataemia
–Reduced renal clearance
•High iPTH (secondary hyperparathyroidism)
–Hypocalcaemia
–Hyperphosphataemia

Vitamin D
•Vitamin D (cholecalciferol) is inactive
•Needs to be converted to 1,25 DHCC
–DHCC = dihydroxycholecalciferol
•2 step activation
–Liver adds 25-hydroxy
–Liver adds 25-hydroxy
–Kidney adds 1-hydroxy
•Active Vitamin D (1,25DHCC)
–increases serum calcium and phosphate absorption from intestines
–calcifies bones
–suppresses PTH secretion

Pathogenesis of secondary hyperparathryodisim
•PTH regulates calcium homeostasis
•PTH increase stimulated by
–hypocalcaemia
–hyperphosphataemia
•PTH increases serum calcium
–increasing efflux of calcium from bones & increase GI & renal absorption

Features of RBD
Type      PTH      SAP      Calcium
SHPT     ↑           ↑           ↓
THPT     ↑↑         ↑↑         ↑
ABD       ↓↔       ↔         ↑      
SAP = serum alkaline phosphatase
SHPT = secondary hyperparathyroidism,
THPT = tertiary hyperparathyroidism
ABD = adynamic/aluminium bone disease

Features of tertiary hyperparathyroidism
•Hyperplastic parathryoid glands autonomous
•Non-suppressible by Vitamin D analogues
•Hypercalcaemia
•Very high alkaline phosphate level

CONSEQUENCES OF
Lab abnormalities
Bone abnormalities
Vascular calcification
CVD
Fractures
Mortality

Consequences of CKD -MBD
1.Bone disease
–Proximal muscle weakness
–Bone erosions, bone pain
–Fractures
–Marrow Fibrosis
–Erythropoietin resistance

Consequences of CKD-MBD
2.Systemic complications
–Vascular calcification, Calciphylaxis
–Soft tissue calcification
–Cardiovascular disease
–Increased mortality

At slide 16/50 suddenly can't copy and paste. Will read up and maybe continue later.

Tetiba boleh pulak copy paste slide 27/50...

                                                  2009           2003 NKF KDOQI  KDIGO
Calcium (mmol/l)                     2.1-2.37      2.1-2.37                   Normal range
Phosphate (mmol/l)                  1.13-1.78    1.13-1.78                 Toward normal range

range CaP product (mmol2/l2) <  4.54     < 4.54
Intact PTH (pg/mL)                  150 -300  150 -300                     2-9x ULN

Conversion for iPTH 1pmol/l = 9.5pg/ml
Corrected Calcium = Serum calcium + (40-serum albumin)x0.02
CaP product = Correct calcium x Phosphate

Baby pulak dah bangun...to be continued

200 Hours Haemodialysis Training: Access

So today I had bedside teaching with the final years. I think they are either getting better or I am getting more patient. Anyhow, after that, in the afternoon, I had to come to collect more signatures for my logbook and make progress in the haemodialysis training.

It's interesting that one of the friendlier sisters asked "are you still here doc? Not finished yet?" Well, I'm not the only one who thinks this thing is taking forever. Thank God.

Today is also my eldest sons birthday. Nearing the end of October so I have less than two months to go and the pressure is on. That's a good thing because before this it was getting a bit difficult to make myself move. Now its internal motivation (ok la, external, who am I kidding, dateline is getting closer).

The logbook sort of starts with vascular access so tonight will try to cover the lecture notes on this topic.

Care of AV Grafts and Hemodialysis Catheters
Dr. Yudisthra M. Ganeshadeva MBBS (Mal), MRCP (UK and London), Fellowship in Nephrology (Malaysia)

AV Grafts
What is an AV Graft?
•A Synthetic Tube used to connect an artery to a Vein •Usually made of PTFE or Dacron •Used primarily as access in patients with difficult veins

Surgical Placement
•Can be placed on –Forearm (Forearm loop graft) –Arm –Neck (Necklace graft) –AxilaryArtery to Femoral Vein •The longer the graft –the less likely it is to last.

Time to Maturation
•AV Grafts are usually ready to use within 2-4 weeks from placement •May be used earlier if not much soft tissue swelling.

Determining the Direction of Flow AV Grafts
•Compress the graft in the middle with 2 fingers –milk it both  ways with pressure •Release one finger •If the graft fills up again-the limb proximal to  that finger is the arterial end.

Determining the Direction of Flow AV Grafts
•Ultrasound  technique -can also use dopplerto look at flow •Most surgeons include a diagram

Post Operative Care of AV Graft
•Patient advice –If bleeding –pressure with gauze/kleenexfor 10 mins –Do not get wound soaked or wet for a week post op –Check operation site for redness, swelling, discharge or warmth which  may signify infection –First week –need to keep arm elevated above level of heart to minimise
swelling.

Chronic Care of AV Graft
•Avoid on the side of the graft –Taking Blood Pressure –Taking Blood tests •Thrill should be palpable on working AV Grafts

Cannulation of AV Grafts
•Staff : –If hands are visibly soiled, use soap and water. –If not visibly soiled, use an alcohol-based hand rub or soap and water. –Decontaminate hands before and after patient contact, rubbing hands together vigorously for 15 seconds then rinsing. –Staff members who closely follow the policies and procedures of their respective facilities will always use and change gloves when indicated.

Cannulation of AV Grafts
•It is important not to try to cannulate the same site with each treatment as this weakens the access wall –puncture graft in step ladder fashion.
•Patient: It is recommended that patients wash their site arm carefully with soap and water when arriving at dialysis..

Cannulation of AV Graft
•Skin prep –for grafts, best to wash graft arm with non drying soap and water first before skin prep with povidone/chlorhexidine. •Skin pulled taut in opposite direction to needle •Needle inserted at 45 degree angle –once in rotated 180 degrees so that cutting edge faces downwards •Taped in angle of insertion

Removal of needle
•Needle pulled out –then pressure applied to puncture site. •Do not apply pressure before needle removed.

Care of Hemodialysis Catheters

Anatomy of the Neck •The internal jugular is the preferred site of cannulationfor insertion of hemodialysis catheters.
•The Right internal jugular offers a straight path to the atrium.
•The left internal jugular has a more tortuous path
Final Position of the catheter in the right artium

Ultrasound Guidance
•Ultrasound guidance is mandatory cannulationof the internal jugular veins due to markedly variable anatomy. •Realtimeultrasound guidance preferred.

Lin, BS, Huang, TP, Tang, GJ, et al. Ultrasound-guided cannulationof the internal jugular vein for dialysis vascular access in uremicpatients. Nephron1998; 78:423.190 patients undergoing percutaneousinsertion of a temporary catheter into the internal jugular vein compared the complication rates among those using ultrasound-guided placement (104 patients) to those using landmarkguided insertion (86 patients). Significantly superior results were obtained with ultrasound guidance with respect to overall success rate (99 versus 86 percent, P<0 .01="" 11.6="" 2.58="" 35="" and="" attempt="" complication="" first="" of="" p="0.015). </div" percent="" puncture="" rate="" success="" the="" traumatic="" trials="" versus="">

Anatomy of The SubclavianVein

•The subclavian anatomy is more fixed than that of the internal jugular vein.

•Higher risk of pneumothorax as well as bleeding and hemothorax as a result of this being a non compressible site.

•Subclavian cannulation can result in brachiocephalic stenosis on the ipsilateral site obviating the possibility of successful fistula creation on the arm on  the same side.

Catheter Care

Care of the Catheter-Patient Info

•No showers for the first 24 hours. •Showers requires catheter and dressing to be wrapped with plastic wrap. •If the catheter comes  off –compress the insertion point with a finger until bleeding stops.

Handling the Catheter

•Hemodialysis catheter dressing changes and catheter manipulations that access the patient’s bloodstream should only be performed by trained dialysis staff. •The catheter exit site should be examined at each hemodialysis treatment for signs of infection. •Catheter exit site dressings should be changed at each hemodialysis treatment

Handling the Catheter

•Use of dry gauze dressing combined with skin disinfection, using either chlorhexidine or povidone iodine solution, followed by povidone iodine ointment or mupirocin ointment at the catheter exit site are recommended after catheter placement and at the end of each dialysis session. •Manipulating a catheter and accessing the patient’s bloodstream should be performed in a manner that minimizes contamination.

Decontaminating the Catheter

•Dressing for the catheter at each visit •Povidone soak/ Chlorhexidine soak for hubs prior to dialysis procedure.

Decontamination procedure

•Catheter hubs should be soaked for 3-5 minsin povidoneiodine and allowed to dry prior to seperation •Catheter lumens should be kept sterile. •Catheter tips should remain capped or attached to a syringe while maintaining a clean field. •Patients should wear a mask for all catheter procedures •Dialysis staff should wear a mask and gloves for any procedure related to the catheter. •Gloves need to be changed for each patient.

Other infection prevention methods 

•Do not recycle blood lines. •Keep the dialysis unit clean.

Troubleshooting AV Grafts and Fistulas

When to Refer Infected AV Graft

AV Graft Infection –May present with following over graft •Pus •Inflammation •New Onset Pain •Needs inpatient intravenous antibiotics ±debridement/ removal of part or all of graft.

When to refer Graft Thrombosis

•Graft thrombosis is common –no thrill over graft, graft hardened & unable to use for dialysis. •Need to refer early to salvage graft-best to return to surgeon who created graft. •Graft salvage may be done endovascularly or through surgery

When to refer Graft Hematoma

•Graft hematomascan occur due to tears of the graft during needling. •Usually resolve spontaneously •AV graft different from vessels as tears in material cannot seal off.

When to Refer Graft Pseudoaneurysm

•Present with localised pain and swelling. •Pulsatile–external to graft •Usually due to poor needling technique. •Will require referral for repair of graft –if numerous or large. •Avoid areas of pseudoaneurysm for cannulation.

When to refer Infection of AV Grafts •Characterised by –Redness –Pus –Skin Erosion –Exposure of the graft •Associated with –Tenderness over graft –Fever –±fluctuance

When to refer Infection of Grafts

•Entire graft should be removed in the following conditions: –the graft is less than one month old, –graft involvement by infection is extensive and graft infection is accompanied by sepsis or hemorrhage. 

When to refer Dialysis Associated Steal Syndrome

•DASS occurs in 2.78% of PTFE grafts. •Subjectively coldness, numbness, tingling, and impairment of motor function (not limited by postoperative pain) •Objectively –Cold peripheries, decreased sensation.

When to refer Dialysis Associated Steal Syndrome

•Left untreated –potential of gangrene •Usually needs surgical procedure to reduce steal by cutting down arterial inflow. •In grafts may occur immediately post surgery when compared to  AV fistula where  steal may develop over time.

Troubleshooting Hemodialysis Catheters

Immediate Problems

Hematoma

•Hematomascan arise from tears in the jugular  vein wall or from punctures into the carotid artery. •Hematomarisk is higher in patients with coagulopathies and uraemia.

Management

•Usually conservative •Cold compress at site of hematoma may help.

Carotid Artery Puncture
•Carotid artery punctures can result in dissection of the artery and formation of pseudoaneurysms •May require placement of covered stentif large or can be filled in with coils

Carotid Artery Dissection
•Carotid artery dissection is as a result of traumatic accidental puncture of the carotid artery and can even result in strokes as well as bleeding.


Carotidojugular Fistulas
•Carotidojugular fistulas can result from the accidental puncture of the carotid and jugular at the same insertion.
•They are usually significant if a dilator or catheter has been passed from the carotid into the jugular or vice versa.
•Treatment can be conservative if the fistula is small –may seal up spontaneously
•Covered endovascular stentmay be needed in some patients where the fistula is large.
•Stent placement will require patients to be on clopidrogrelfor 3 months and aspirin for life.


Pneumothorax
•Rare but dreaded complication of catheter insertion. •More common with subclavian catheters •Usually present within minutes or hours of insertion


Hemothorax
•Can occur with catheter insertion. •Usually accompanied by fall in blood pressure, pallor, tachycardia and difficulty breathing •Can occur within hours to days of catheter insertion

Arrythmias
•Ventricular arrythmiascan arise from catheters placed deep in the ventricles and can be fatal if not identified and terminated immeadiately.
•They can also arise from guidewiresthat irritate the ventricular myocardium

Chronic Problems Flow Issues

Troubleshooting HD Catheters
•Poor flow Red Lumen –May be due to sideholes resting against vessel wall – usually in a narrowed vessel –May be due to intravascular Sheath formation –this is a fibrinous sock that covers the catheter.

Troubleshooting HD Catheters
•Poor flow Blue Lumen –May be due to position of catheter tip –May be abutting structure e.gTricuspid Valve or vessel wall (left sided catheters)

When To Refer Poor Flow Both or Either Lumen

•Can be due to intraluminal thrombus or external thrombus abutting openings •No flow both lumens-new catheter –May be due to catheter malposition –May have dissected through vessel wall during insertion for new catheters. –Needs Exchange

Management

•Rotate Catheter gently until flow improved. •Withdraw catheter 1-2 cm •Still no improvement? Refer –may need urokinase or intraluminal brushing if cuffed catheter •Cathetogram if new catheter or old catheter failing urokinase/intraluminal brushing.

Management

•Usually involves exchange of catheter or reposition of catheter over guidewire for non cuffed catheters.

Other Issues

When to refer Exit site bleeding •Bleeding from the sides of the catheter insertion point •May be due to  crack in the Catheter •May be due to downstream stenosis •May be due to large catheter insertion wound – for new catheters •Risk of Infection

Management

•Deeper re-position of catheter  for downstream stenosis –May require  fluroscopy •Purse String Suture at exit site –usually first line of  management

When to refer Central Vein Stenosis
•Long term HD catheter use can result in central vein stenosis. •Difficult to treat –can confound future fistula creation

When to Refer Central Vein Stenosis

•May require plastyin the event arm having  fistula is swollen and distressing to patient •May require plastyif  stridoror breathing difficulty in patient.

Infections

Infections of Catheters

Exit Site Infections(ESI)

Definition: 

•Localized Catheter Colonization 

Significant growth of a microorganism (>15 CFU) from the catheter tip, subcutaneous segment of the catheter, or catheter hub 

•Exit Site Infection 

Erythema or induration within 2 cm of the catheter exit site, in the absence of concomitant bloodstream infection (BSI) and without concomitant purulence 

•Clinical Exit Site Infection 

Tenderness, erythema, or site induration>2 cm from the catheter site along the subcutaneous tract of a tunneled catheter, in the absence of concomitant BSI

ESI Prevention:Topicalantiobiotic

Polysporintriple antibiotic (Lok2003) –169 patients with TCD, 6 months

Mupirocin(Johnson 2002) –50 HD patients with TCD catheters, 20 months

Topical antibiotics –meta analysis 

•Topical antibiotics reduced the rate of: 

–Bacteremia •rate ratio, 0.22 [95% CI, 0.12 to 0.40]; •0.10 vs. 0.45 case of bacteremiaper 100 catheter-days, 

–Exit-site infection •rate ratio, 0.17 [CI, 0.08 to 0.38]; •0.06 vs. 0.41 case of infection per 100 catheter-days, 

–Need for catheter removal, and 

–Hospitalization for infection

Tunnel Infections

•Tunnel Infection 

Purulent fluid in the subcutaneous tunnel of a totally implanted intravascular catheter that might or might not be associated with spontaneous rupture and drainage or necrosis of the overlaying skin, in the absence of concomitant BSI (blood stream infection)

Blood Stream Infections

•Infusate-Related BSI 

Concordant growth of the same organism from the infusate and blood cultures (preferably percutaneously drawn) with no other identifiable source of infection

•Catheter-Related BSI 

Bacteremia/fungemia in a patient with an intravascular catheter with at least one positive blood culture obtained from a peripheral vein, clinical manifestations of infections (i.e., fever, chills, and/or hypotension), and no apparent source for the BSI except the catheter. 

Vascular access Part 2

PATIENT ASSESSMENT

• History
• Hx of CVC (central venous catheter?)
• Arm dominance
• DM
• Physical Examination
• Venous caliber and patency
• Character of pulse
• DM
• Congestive HF
• Previous vascular access
• Previous arm, neck or chest surgery/trauma
• Anticipated renal transplant
• Allen’s test
• Scar of previous CVC placement
• Presence of collateral veins
• Signs of cardiac failure

What is a arteriovenous fistula?

• 1st preference Radiocephalic
• 2ndpreference Brachialcephalic
• 3rd preference Brachialbasilic

DOPPS 2007


Access by Etiology of Disease

KI 2009; 76: 1040-1048 Hemodialysis Access Failure A call to action -revisited

Why a Native Fistula?

Fewer infectious complications: AVFs: 4.4 -12 x less infection rates than AVGrafts

Fewer interventional procedures to keep patency: AVFs: 2.4 -7.1 x less salvage procedures than AVGs

Better 1 year primary patency in incident HD patients: 68% for AVFs &  49% for AVGs

Lower Risk of CV deaths For patients starting AVF By 90 days of HD

Non Infected Catheters Increases Inflammation

When to Create a Fistula?

30-20-10 GFR guidelines

GFR < 30ml/min, discussions on RRT options 

GFR < 20ml/min, strongly advocate placement of vascular access.  

4-6 months prior to anticipated use of fistula GFR < 10ml/min, mature fistula should be ready 

Role of Mapping 

Vascular mapping Pulse examination Differential BP measurement Assessment of palmar arch Arterial Diameter by Dupplex Ultrasonography Arterial Diameter by Dupplex Ultrasonography

Diameter of at least 2mm a/w better success

Functional Fistulas

Rule of 6s’ Flow of at least 600ml/s Diameter of 0.6cm Depth of no more than 0.6cm (0.5-1.0cm)

Straight segment

Accessible in sitting position

Sufficient time for maturation

Mature Arteriovenous Fistula

During AVF Maturation Process

Look, listen, and feel the new AVF at every dialysis treatment

After the scar heals, begin assessing AVF using a “gentle” tourniquet placed high in the axilla area

Instruct patient to start access exercises after healing (check with surgeon first) 

Document patient education as well as condition and maturation of the AVF

Fact

Experienced dialysis nurses have an 80% success rate for identifying fistula maturity.

Clinical Clarification

Several studies suggest that performing access exercises after surgery may contribute to the development of the fistula.1-3However, it is important to note that exercise alone will not turn a poor fistula into a good, functional fistula. 

During Maturation

Feel for strong thrill at arterial anastomosis

Listen for continuous low-pitched bruit 

Document fistula maturation, patient education 

During Physical Examination

• Assess AVF for complications 
• Thrombosis 
• Stenosis 
• Infection 
• Steal syndrome 
• Aneurysms

Select cannulation sites

Fistula Maturation

What diagnostic tools or techniques can be used to determine if an AVF is ready for cannulation?

Can the same tools or techniques be  used to select the cannulation sites?

Diagnostic Tools/Techniques to Determine If an AVF Is Ready

• Duplex Doppler study 
• Physical exam by the: 
• Nephrologist 
• Nephrology nurse 
• Surgeon
• Angiogram (fistulogram)

Best Tool/Technique?

Physical Exam!

Look, Listen, and Feel

Use Your:   

Eyes

Ears

Fingertips

Maturing Fistula Physical Exam

Firm, no longer mushy

Vessel wall thickening

Vessel diameter enlargement (to 4–6 mm)

Absence of prominent collateral veins

If in doubt, “Just Say No”

Inspection

Look for: Changes compared to opposite extremity Skin color/circulation Skin integrity Edema Edema Drainage Vessel size/cannulation areas Aneurysm Hematoma Bruising

Look for Complications

Changes in access 

• Redness 
• Abscess
• Infection 
• Cannulation sites

Distal Areas of Access Extremity

Hands/Feet:

Cold

PainfulSteal   

Changes in access extremities •Skin color •Edema •Small blue  or purple           veins •Hematoma •Bruising

PainfulSteal   

Numb         Syndrome 

Fingers/Toes:

Discolored

Central or outflow vein stenosis

Stenosis

Frequent cause of early fistula failure Juxta-anastomotic stenosis most stenosis most common 

26

Juxta-Anastomotic Stenoses 

Most common AVF stenosis Vein segment immediately above the arterial anastomosis Stenosis also may be present in artery

Caused by Caused by ? Trauma to segment of vein mobilized and manipulated by the surgeon in creating the AVF

Observe Access Extremity for Stenosis

Before the patient has needles inserted Make a fist with access arm dependent; observe vein filling Raise access arm; entire AVF should flatten/ collapse if no stenosis/obstruction

If a segment of the AVF has not collapsed, stenosis is located at junction between collapsed and noncollapsed segment 

Instruct patient to perform this at home

Infection

Lower rate with AVF compared with other access types1,2

Staphylococcusaureusthemost commonpathogen2

Patients and dialysis team personnel have high rates of Staphylococcuson skin3 Staphylococcuson skin3

Handwashing before, after, and between patients is critical4

Steal Syndrome

Shortage of blood to hand

Rare but can be serious

Regularly evaluate sensory-motor changes to hand and condition of skin, especially in diabetic patients 

Aneurysm
Localized ballooning

Signs and Symptoms of Complications

Differences in extremities 

Edema or changes in skin color = stenosis or infection 

Access Redness, drainage, abscess = infection 

Aneurysms 

Aneurysms 

Access extremities Small, blue/purple veins = stenosis 

Discolored fingers = steal syndrome

Signs and Symptoms of Complications (cont’d)

Temperature Changes 

Warmth of extremity = infection 

Coldness of extremity may = steal syndrome

Thrill for Stenosis

Abrupt change or loss

Pulse-like

Narrowing of vein = stenosis

Feel for Cannulation Sites

Superficial, straight vein section 

Adequate and consistent vein diameter

Palpation

Temperature Change 

Warmth = possible infection 

Cold = decreased blood supply 

Thrill Thrill 

Palpation can be started at the anastomosis 

Thrill diminishes evenly along access length 

Change can be felt at the site of a stenosis; becomes “pulse-like” at the site of a stenosis 

Stenosis may also be identified as a narrowed area

Palpation(cont’d)

Feel for Size, Depth, Diameter,and Straightness of AVF

Feel the entire AVF from arterial anastomosis all the way up the vein  

Evaluate for possible cannulation sites = superficial, straight vein section with adequate and consistent vein diameter

Auscultation                            Listenfor the Nature of the Bruit

Auscultation (cont’d)

Listen for Bruit Listen to entire access every treatment 

Note changes in sound characteristics (bruit): 

A well-functioning fistula should have a continuous, A well-functioning fistula should have a continuous, machinery-like bruit on auscultation 

An obstructed (stenotic) fistula may have a discontinuous and pulse-like bruit rather than a continuous one—and also may be louder and high-pitched or “whistling” 

Louder at stenosis than at anastomosis 

Requirements for Cannulation

Physician order

Experienced, qualified staff person

Tourniquet

Post-Op Follow-up

Communicate assessment findings with access team, including surgeon

Check maturity progress every session

Assure evaluation by surgeon 4 weeks post-op Assure evaluation by surgeon 4 weeks post-op Intervene if there is no progress at 4 weeks or AVF is not mature and ready for cannulation at 6–8 weeks

COMPLICATIONS

Bleeding

Bleeding during treatment (oozing around needle or infiltration) = fragile vessel wall or back wall penetration; don’t flip the needles

Bleeding post–needle removal = fragile vessel wall or needle trauma or inadequate pressure at puncture sites

Review needle-removal technique. Improper pressure with needle withdrawal = vessel damage

A pattern of prolonged bleeding post–needle removal may indicate stenosis or clotting disorder. Evaluate bleeding after 20 minutes

Educate patients about post-treatment hemostasis and what to do at home should the needle site re-bleed

Infiltration = Hematoma

Prevent Cannulation Infiltrations
Don’t flip needle
Don’t lift needle in vein
Flush with NSS

Prevent Postdialysis Infiltrations

Apply gauze without pressure

Remove needle at insertion angle

Apply pressure with 2 fingers

Hold pressure 10–12 minutes

Treating Infiltrations

Elevate arm above heart

Ice 20 minutes on/20 minutes off for 24 hours

Warm compresses after 24 hours

Let fistula rest

Second infiltration: Notify vascular access team

Don’t use AVF until directed

Infiltrations in New AVF

Elevate arm above the level of heart 

While protecting the skin over access area with a clean cloth, gently apply: 

Ice 20 minutes on/20 minutes off for first 24 hours

Warm compresses after 24 hours

Infiltrations in New AVF(cont’d)

If the fistula infiltrates, let it “rest” until the swelling is resolved 

If the fistula infiltrates a second time, the staff should notify the vascular access team, including the surgeon, as soon as possible for intervention 

Don’t use that AVF until further directed

How to Prevent Infiltrations

Check for flashback and aspirate 

Flush with NSS to ensure the needle flushes with ease and there are no signs or symptoms of infiltration 

Saline causes much less damage and discomfort than blood if an infiltration occurs 

Post-Cannulation Bruising and  Hematoma 

If bruising or hematoma occurs after dialysis, the surface skin site has sealed but the needle hole in the vessel wall has not 

Use 2 fingers per site for hemostasis 

It is crucial to apply pressure to both the skin and access wall puncture sites

AVF Bleeding Emergency Kit for Dialysis Patients 

Gauze pads to apply to the bleeding site

Tape to apply once the bleeding has stopped

Information Card: 

1.Vascular access type/location

2.Name and phone number of the vascular access surgeon and address of the closest hospital, should the bleeding not stop and further assistance be required 

Poor Flow

May be due to location or position of needle(s) 

May need to change direction of arterial needle  

If poor flow persists after next session despite changing needle locations, refer to surgeon for evaluation and possible treatment options 

NOTE: Use tourniquet for cannulation only!   Do not leave in place for entire treatment!!!

Aneurysm

Caused by stenosis as vessel narrowing increases “back pressure,” causing vessel distension and weakening of vessel wall 

May also be caused or aggravated by frequent cannulations in the same area

Stenosis

Most common complication

Causes: IV, CVC, PICC lines 

Surgery to create AVF 

Aneurysms 

May  be caused by the back pressure associated with stenosis 

Needle-stick injury 

Types of Stenoses

Juxta-anastomotic (most common stenosis in AVF) 

Mid-access

Outflow

Central-vein

Mid-access 

Outflow 

Central vessel

Central-vein Stenosis

Distended, Obstructed Left Shoulder Veins Indicative of Central-vein Stenosis

Clues to Stenosis

Clotting of the extracorporeal circuit 2 or more times/month

Persistently swollen access extremity

Changes in bruit or thrill (ie, becomes pulse-like) 

Difficult needle placement

Blood squirts out during cannulation

Elevated venous pressures 

Clues to Stenosis (cont’d)

Excessively negative pre-pump AP

Decreased blood pump speeds

Inability to achieve BFR

Changes in Kt/V and URR 

Recirculation

Prolonged postdialysis bleeding 

Frequent episodes of access thrombosis

Observe Access Extremity for Evidence of Stenosis

Perform a physical exam for AVF stenosis Perform before patient has needles inserted Have patient keep access arm dependent and make a fist—observe vein filling Have patient slowly raise the access arm—the entire AVF should collapse if no stenosis; if entire vein is not flat, indicative of stenosis If a segment of the AVF has not collapsed, stenosis is located at junction between collapsed and noncollapsed segment Patient can do this at home

Thrombosis

Surgical/technical problems

Preexisting anatomic lesions (eg, old IV injury)

Premature use

Poor blood flow

Hypotension

Hypercoagulation

Fistula compression

Infection

AV fistulas have lowest risk of infection of any vascular access type. 

However… Each pre-and post-treatment exam should include: 

Checking for signs/symptoms of infection, including: 

Changes of skin over access area 

Redness 

Increase in temperature 

Swelling, 

hardness 

Drainage from incision, needle sites 

Tenderness or pain 

Patient complaints without other indications of Malaise Fever 

Prevention of Infection

Prevention General hygiene 

Pretreatment washing of access extremity 

Hand washing, before and after cannulation 

No scratching, irritation of skin of access extremity 

Precannulation 

Appropriate skin antisepsis 

Sufficient antiseptic-skin contact time 

Cannulate while antiseptic is wet or dry, as directed 

Cannulation 

Maintain needle sterility 

Do not cannulate through scabs or abraded areas

Steal Syndrome/Ischemia

Steal syndrome is a constellation of symptoms related to ischemia (inadequate blood supply to the hand) caused by the AVF “stealing” blood away from the extremity

Steal causes hypoxia (lack of oxygen) to the tissues of the hand, resulting in severe pain and identified by nail bed discoloration, a cool hand, and a weak or absent pulse hand, and a weak or absent pulse

Neurological and soft tissue damage to the hand can occur, resulting in mobility limitations (eg, grip strength, dexterity), loss of function, ulcerations, necrosis

Steal syndrome/ischemia is estimated to occur in approximately 5% of vascular access patients, mostly those with diabetes and peripheral vascular disease (PVD)

Clinical Clarification

Steal syndrome is estimated to occur in approximately 5% of vascular access patients, mostly those with diabetes and peripheral vascular disease. 

“Claw Hand” Contracture From Steal Syndrome

Steal Syndrome/Ischemia

Steal symptoms may improve due to the development of collateral circulation 

Procedures, such as the DRIL (distal revascularizationinterval ligation), can successfully treat steal and ischemia 

Individuals who are at high risk for developing acute steal are: Patients with diabetic neuropathy Patients with PVD

Is Steal Syndrome Serious?

Steal/ischemia may lead to loss of function and amputation if not recognized and treated quickly Necrotic tissue cannot be “fixed”—it must be removed 

Steal/ischemia places patients at risk for infection 

Infection increases their risk for hospitalization 

Hospitalization increases their risk for death!

Patient education

Check fistula daily for a thrill and bruit 

Check for signs and symptoms of infection or other complications 

Write instructions for infiltrations 

Call Nephrologist

Thrill is weak
Signs of obstruction
Patient becomes feverish, dehydrated, or experiences low blood pressure

Thank you

Acknowledgement to www.fistulafirst.org

Finished!

200 Hours Haemodialysis Training: Principles Of Haemodialysis

PRINCIPLES OF HEMODIALYSIS

Lecture Outline
•Introduction •History of Hemodialysis •Back To Basics: Mechanism of Solute Removal •Hemodialysis Circuit •Hemodialysis Circuit •Modalities of  Renal Replacement Therapies Intermittent hemodialysis –High flux dialysis –Hemodiafitration •Summary

History of hemodialysis

John J. Abel & colleagues at Johns Hopkins develops a dialysis system and tests it on animals.

1913

Georg Haas, German physician dialyzes patients with ARF in Giessen, Patient died

Dutchman Willem Kolff 

The first hollow-fiber dialyzers 

SkeggsLeonards developed the parallel plate dialyzer, 

Production of disposable parallel plate dialyzers in Europe. Hollow fiber kidneys were developed 

History of hemodialysis

192319451948

John J. Abel & colleagues at Johns Hopkins develops a dialysis system and tests it on animals.

1913

Georg Haas, German physician dialyzes patients with ARF in Giessen, Patient died

Willem Kolff achieves a breakthrough when a patient with ARF survives therapy for the first time.

History of hemodialysis

1960’s Haemodialysis was performed  for 8-10 hours, every other day

Early dialysis machines were cumbersome

Dialysis membranes

1980’s … Dialysis hours rapidly contracted to  a ‘standard’ 4 hrs per session, 3 times per week

NCDS 1983

1970’s: Drive for shorter dialysis with high urea clearance rate lead to high efficiency dialysis 

Equipment/expertise was improving fast

1990’s…. The use of conventional low efficiency membrane has declined.

The search for more biocompatible features & the  desire 

1980’s1990’s

Dialysis ‘membranes’ were re-usable ‘slabs’ called Kiil plates

Dialysis was confined to only a few centers

Dialysis was available to only a few people

1970’s

NCDS 1983 Urea considered to be an appropriate surrogate marker for small molecule clearance

Kt/V was introduced

Increased the dialysis membrane surface area (KoA)

They succeeded in reducing dialysis time to ~4 hrs, 3 times/wk

1990’s…. The use of conventional low efficiency membrane has declined.

The search for more biocompatible features & the  desire 

1980’s1990’s

Dialysis ‘membranes’ were re-usable ‘slabs’ called Kiil plates

Dialysis was confined to only a few centers

Dialysis was available to only a few people

1970’s

NCDS 1983 Urea considered to be an appropriate surrogate marker for small molecule clearance

Kt/V was introduced

Increased the dialysis membrane surface area (KoA)

They succeeded in reducing dialysis time to ~4 hrs, 3 times/wk

features & the  desire to remove amyloidogenic  B2 M has led to high flux dialysis

BASIC CONCEPTS 

Mechanisms of Solute and fluid Removal

•Diffusion

•Ultra-filtration

•Convection

•Adsorption

Mechanisms of Solute Removal: DIFFUSION

Solute transport in hemodialysis Primary mechanism: diffusion

Small solute pass through the dialysis membrane down a concentration gradient from a higher plasma concentration to a lower dialysate concentration

Mechanisms of Solute Removal: DIFFUSION

Ultrafiltration

•Movement of FLUIDSthrough a membrane caused by pressure gradient

•Positive, negative and osmotic pressure from non•Positive, negative and osmotic pressure from nonpermeable

Ultrafiltration - removal of fluid from patients blood

Mechanisms of Solute Removal: CONVECTION

CONVECTION Convection is a process where solutes pass across the semipermeable membrane along with the solvent (“solvent drag”) in response to a positive 

Mechanisms of Solute Removal: CONVECTION

response to a positive transmembrane pressure

CONVECTION (“ ““ “solvent-drag” ”” ”)

Fluid Flux is a pre-requisite for the removal of solutes, whereas concentration gradient is not.

Note: All these slides have beautiful pictures which will take time for me to incorporate here. Perhaps one day I will add videos or other visuals to make it more easy to understand.

Solute Classes by Molecular Weight

Theres large for example albumin, middle and small for example urea

Mechanisms of Solute Removal: DIFFUSION/CONVECTION

Clearance for Diffusion and Convection

Clearance Profiles by Modality

HEMODIALYSIS CIRCUIT 

Hemodialysis Circuit

Main Functions of Hemodialysis Machines 

Blood Related functions:

To transport blood from the patient via blood pump to dialyser and back to the patient safely Dialysate Related functions Dialysate Related functions

To prepare dialysis fluid by heating, deaerating and appropriate proportioning of dialysate and treated water and ensuring conductivity and temp of dialysate is maintained

Components of Hemodialysis Machine

The standard machine consists of: •Blood pump •Heparin infusion pump •Dialysis solution delivery system •Dialysis solution delivery system •Heating and degassing •Ultra-filtration controller

Components of Hemodialysis Machine

Monitoring Devices: Blood circuit •Arterial pressure monitoring •Venous pressure monitoring •Venous pressure monitoring •Air bubble detector

Components of Hemodialysis Machine

Monitoring Devices: Dialysis solution circuit •Conductivity •Temperature •Temperature •Bypass valve •Blood leak detector •UF controller

Options available for hemodialysis machine

•Bicarbonate  dialysate

•Sodium profiling

•Ultrafiltration controller 

•High Flux dialyser

•Hemodiafiltration (HDF) 

Criteria to determine if Hemodialysis Machine is safe for use

•Air bubble detector should be able to detect micro bubbles /air passing through the devise  and clamp immediately 

•All audible and visual alarms should be in working order order 

•Blood  and dialysate flow rates should be accurate 

•Conductivity and temp readings should be within acceptable limits 

•All monitoring devices should be in good working order

Definition Definition Efficiency/Flux/Permeability

Efficiency

•Measure of urea clearance

•KoA=urea mass transfer co-efficient

•High efficiency is achieved by increasing surface •High efficiency is achieved by increasing surface area (A) of dialysis membrane

Efficiency

Qb =200 300 400 urea (ml/min) 195 267 315

Polyflux 21 s: KoA 1238 ml/min Qd=500 ml/min

Low efficiency: KoA <450 div="" min="" ml="">

High efficiency: KoA >450 mL/min

Flux 

•Measure of  UF capacity 

•based on the ultrafiltration coefficient (Kuf) 

•Kuf= the volume removed (in ml) perhour per mmHg of applied transmembrane pressure(TMP) of applied transmembrane pressure(TMP) 

•Low flux: •Kuf < 15mL/h/mm Hg 

•High flux: •Kuf > 20 mL/h/mm Hg 

Permeability

•Measure of the clearance of the middle molecular weight 

molecule (eg, B2-microglobulin)

•General correlation between flux and permeability •General correlation between flux and permeability

•Low permeability: B2-microglobulin clearance <10 div="" min="" ml="">

•High permeability: B2-microglobulin clearance >20 mL/min

General correlation exists between the (water) flux and the (middle molecular weight molecule) permeability of dialysis membrane but the are not synonymous

FLUX , EFFICIENCY, PERMEABILITY

A : numerous small pores –allows water flux but not B2 M

B: fewer pores with pore size large enough to allow B2-M transport

The KUf of the 2 membranes are equivalent

Low Efficiency (Conventional) Versus Versus High Efficiency

Efficiency of dialysis

Rate of small solute transfer across membrane 

•KoA Urea –urea mass transfer co-efficient. –urea mass transfer co-efficient. –Theoretical maximum urea clearance at infinite  blood and dialysate flow rate

Dialyzer urea clearance as a function of KoA and Qb

High Efficiency Dialysis : Technical Requirements

•High Efficiency Dialyser

–Large surface area (A)

–High mass transfer coeeficient (K0) –High mass transfer coeeficient (K0)

•High Blood Flow

•High Dialysate Flow

•Bicarbonate dialysate

CONVENTIONAL/HIGH EFFICIENCY

CharacteristicLow EfficiencyHigh Efficiency

KoA (ml/min)

                     <500 nbsp="">600 

Urea Clearance (ml/min)

                       <200 nbsp="">200

Blood Flow (ml/min)

                       <350 nbsp="">350

Dialysate Flow (ml/min)

                       <500 nbsp="">500

Bicarbonate Dialysate

                       optimal            necessary

Benefits of high efficiency dialysis:

Higher clearance of small solutes, such as urea compared with conventional dialysis without increase in treatment time

•Better control of chemistry •Better control of chemistry

•Potentially reduced morbidity

•Potentially higher patient survival rates

CAUSES OF FAILURE OF HIGH EFFICIENCY     DIALYSIS

Access-related

•Low blood flow rate

•High recirculation rate

Time-related

•Patient not adherent to prescribed time

•Staff not adherent to prescribed time

Failure to adjust time for conditions such as alarm, dialysate bypass, and hypotension

Low Flux  Versus Versus High Flux

FLUX ,EFFICIENCY AND PERMEABILITY

Flux •Measure of  UF capacity •based on the ultrafiltration coefficient (Kuf) •Kuf= the volume removed (in ml) perhour per mmHg •Kuf= the volume removed (in ml) perhour per mmHg of applied transmembrane pressure(TMP) •Low flux: •Kuf < 15mL/h/mm Hg •High flux: •Kuf > 20 mL/h/mm Hg

Hemodialysis

Solute transport in    conventional hemodialysis

•Primary mechanism: Diffusion

Low flux dialyser 

Hemodialysis Typical Prescription

Conventional HD treatment : 3x per week, 4 hrs/session

Blood pump250-350 ml/min 

Dialysate Flow500 ml/min –700 ml/min 

Ultrafiltration : 3% of   dry weight 

Up to 3.9 lit over 4 hrs

Lecture Outlines

•History of hemodialysis •Back To Basic: Mechanism of Solute Removal •Term Definition: Flux/ Permeability •High Flux Hemodialysis –Technical Requirement –Technical Requirement –Potential Benefit •Hemofiltration/Hemodiafiltration (HF/HDF) –Technical Requirement –Potential Benefit •Summary

High Flux

•High flux membranes are all High Efficiency membranes ( as defined by KoA urea)

•In addition, larger pore size and water permeability •In addition, larger pore size and water permeability lead to a high ultrafiltration (Kuf) co-efficient

•Kuf = volume removed in ml/hr/mmHg of applied TMP

High Flux Dialysis

High permeability to solutes: larger pore size High permeability  to water: UF co-efficient (Kuf) Large surface area (high KoA)

Kuf •= volume removed in ml/hr/mmHg of applied TMP •Low flux:  Kuf < 15mL/hr/mm Hg •High flux: Kuf > 20mL/hr/mm Hg 

Characteristic Conventional  (High Efficiency)

                                                                             High flux

KoA (ml/min)

                       >600                                             >600

Urea Clearance>200                                            >200 

Urea Clearance (ml/min) >200                            >200 

Kuf ( ml/mm Hg/h)           variable                      >20 

B2 M Clearance (ml/min) variable                      >20

High Flux Dialysis

Low Flux & high efficiency

ManufacturerModelMembraneKoAKUfSurface Area

TorayB3 1.6 Apolymethylacrylate71881.0

FreseniusF8polysulfone71671.0

BaxterPSN 210polysynthane1044102.0

High Flux

ManufacturerModelMembraneKoAKUfSurface Area

GambroPolyflux 14spolyamide711.7

GambroPolyflux 21spolyamide1238832

FreseniusF80polysulfone945651.8

High Flux: Characteristics

Because of high KUf, high flux HD requires an automated UF control system to avoid accidental profound intravascular volume depletion (which is standard in current HD machines)

High Flux Dialysis

Potential“reverse filtration”: movement of fluid from dialysate to the blood compartment, 

•Therefore, need pyrogen free water

•The dialysis membranes are impermeable to intact Endotoxin to intact Endotoxin

•However, their fragments (some of which still are pyrogenic) may be small enough to traverse the membrane. 

•Although the membrane is impermeable to bacteria and blood cells, a mechanical break in the membrane could result in bacteremia.

High Flux Dialyser

•Automated UF control system

•Potential “reverse filtration”: movement of fluid 

from dialysate to the blood compartment, use of 

pyrogen free dialysate is preferred

Potential benefit high flux dialysis: 

β2microglobulin clearance

β2microglobulin

100 amino acids •Single polypeptide chains, globular structure β ββ β2microglobulin globular structure •11 815 Dalton •Daily production = 150-200 mg (3 mg/kg/D) •Normal serum level = 1.2-2.7 mg/l •95% metabolized by the kidneys 

Potential benefit of high flux dialysis: Dialysis related amyloidosis

RR of carpal tunnel syndrome in patients receiving high flux treatment is 40% lower than those receiving conventional therapy

Until slide 56 of 71...now its become slow again.

To be continued...

200 Hours Dialysis Training: Assessing Haemodialysis Adequacy

So it looks like with my current new timetable I can sort of squeeze one or two blog posts per week. Alright. Better than nothing.

So today finally I got to read one of the 15 lecture notes for the 15 hours of the 200 hours training for dialysis PIC.

Tried to print out the CD but couldn't, or else I could easily read it on my phone. Would have been done by now, seriously.

Anyway, in the mean time, I did read it already I think but at that point, the very beginning, it was difficult and the theory didn't quite make sense. Of course if you attend the lecture and there is someone explaining it, the experience would probably be a bit different.

This is an important lecture and I will share what I can here.

ADEQUACY OF HEMODIALYSIS
Dr Keng Tee Chau UMMC

These slides are prepared by
Dr. Keng Tee Chau
MBBS(MAL), MRCP(UK) Consultant Nephrologist & Senior Lecture Consultant Nephrologist & Senior Lecture Division of Nephrology Department of Medicine University Malaya Medical Centre

OUTLINE
•Marker for hemodialysis adequacy •Measurement of hemodialysis adequacy •Blood sampling method •Inadequate delivery of dialysis : What to do? •Inadequate delivery of dialysis : What to do?

HOW TO DEFINE HEMODIALYSIS ADEQUACY ?
•The ultimate goal of hemodialysis is removal of solutes or ‘uremic toxins’.
•Uremic toxins encompass a long list of solutes •Uremic toxins encompass a long list of solutes of different molecular weights.

CHARACTERISTICS OF AN IDEAL MARKER OF DIALYSIS ADEQUACY •Accumulated in renal failure •Eliminated by dialysis •Proven toxicity •Generation and elimination representative for •Generation and elimination representative for other solutes •Easily measured
Vanholder and Ringoir 1992

UREA AS A MARKER OF DIALYSER CLEARANCE •Traditionally urea has been used as ‘representative’ solute for measurement of dialysis adequacy •Urea, as a small solute, is effectively removed •Urea, as a small solute, is effectively removed during dialysis. •Dialyzer clearance of urea (Kt/V or URR) has been proven to be a measure of clinical outcome.

MEASUREMENT OF UREA CLEARANCE •Urea clearance (rather than its absolute value) is a sensitive marker of dialysis adequacy. •Urea clearance can be expressed in a few ways : :

1)Kt/V
2)URR

UREA REDUCTION RATIO (URR)
•URR = ( 1 –[postdialysis BUN / predialysis BUN] )

DILEMMA WITH URR
•Easy to calculate•Represent only a single snapshot in time of the patient’s adequacy of dialysis •Doesn’t include contraction •Doesn’t include contraction of body water volume and urea generation during dialysis •Inability to adjust the prescription accurately when the value is off target (by adjusting K or t)

Kt/V
•K = dilayser clearance (ml/min) •T = time on dialysis (min) •V = total body water (ml)

MEASUREMENT OF Kt/V
1)Formal Urea Kinetic Modeling (UKM) ** 2)Natural log formula Kt/V = -Ln(R -0.008 ×t)+(4 -3.5 ×R) ×UF/W 3)On line clearance 3)On line clearance
** KDOQI gold standard R = the ratio of postdialysis BUN to predialysis BUN, t= time on dialysis in hours W= body weight UF = ultrafiltration

FORMAL UREA KINETIC MODELING (UKM) •Computer software is needed to compute Kt/V using UKM •Data requires for calculation : 1.Pre/post dialysis BUN (Either 2 or 3 BUN 1.Pre/post dialysis BUN (Either 2 or 3 BUN samples method) 2.Patient’s data : weight, height 3.Treatment data : actual treatment time, effective dialyser clearance, pre/post dialysis weight, blood/dialysate flow rate.

EXPRESSION OF Kt/V
Single poolspKt/V
Double pooldpKt/V
EquilibratedeKt/V EquilibratedeKt/V
StandardstdKt/V
NormalizednKt/V
continuousEKR (t/V)

Dose expression for Kt/V
•Prescribed dose -calculated from doctor’s order for Qb, Qd, dialyzer and treatment time •Predicted dose -calculated from actual Qb, Qd, treatment time -calculated from actual Qb, Qd, treatment time recorded •Delivered dose -calculated from pre/post dialysis BUN and other variables -actual results based on how the patient really dialysed the blood samples are drawn

KDOQI GUIDELINES
•The preferred method of measurement of dialysis adequacy is Kt/V calculation using Formal Urea Kinetic Modelling (UKM), employing single pool model. employing single pool model. •Delivered dialysis dose should be measured at regular intervals no less than monthly.

KDOQI GUIDELINES
•For a patient on HD 3 times a week Kt/V -minimal : 1.2 per dialysis -target : 1.4 per dialysis -target : 1.4 per dialysis URR -minimal : 65% per dialysis -target : 70% per dialysis

BLOOD SAMPLING
•Both pre & post BUN should be taken during the same HD session (mid week)
PRE BUN SAMPLING -KDOQI GUIDELINES 2006
PRE BUN BLOOD SAMPLING FROM FISTULA Blood drawn as soon as cannulation done Before starting blood pump or bolus dose of heparin Ensure not mixed with heparin or saline

PRE BUN BLOOD SAMPLING FROM CATHETER Remove heparin block/saline (first * 5mlof blood). *Discardthe blood. Then use new syringe to draw * 5mlof blood sample sample
* New amendment in latest KDOQI 2006 guidelines

POST BUN BLOOD SAMPLING
•To avoid dilution of post BUN sample by recirculatingpost dialysis blood and to  minimise effects of urea rebound , the blood should be taken by using SLOW FLOW/STOP PUMP sampling method PUMP sampling method
Non adherence will lead to over/underestimation of Kt/V or URR

UREA REBOUND
Fig I-2. Components of urea rebound. This illustration shows a total of 65% urea rebound of which over half is secondary to access recirculation (A→B). The contribution from cardiopulmonary recirculation is 15% (B→C), and the remaining 31% (C→D) is a consequence of flow and diffusion limitations

POST BUN BLOOD SAMPLINGKDOQI GUIDELINES

POST HD BLOOD SAMPLING RECOMMENDED BY KDOQI -SLOW FLOW/STOP PUMP METHOD
•Turn off dialysate pump •Reduce UF to 50ml/H or off •Widen pressure alarm limit •Widen pressure alarm limit •Reduce blood pump to 50-100ml/min for at least 15 s •Blood pump can be then either stopped or kept running at 50-100ml/min •Clamp venous needle tubing •Take blood from arterial port

POST BUN BLOOD SAMPLING RECOMMENDED BY KDOQI -STOP DIALYSATE FLOW METHOD

INADEQUATE Kt/V : What to do?
•CHECKLIST : 1.Vascular access 2.Dialyser 3.Blood flow rate 3.Blood flow rate 4.Dialysate flow rate 5.Treatment time 6.Blood sampling method

VASCULAR ACCESS
•Check for access recirculation (AR)
•Review needle placement -inadvertent needle placement -inadvertent needle placement -close promixity of both needle •Poor access flow -fistula stenosis (low prepump pressure < 200mmHg or high venous pressure)

RECIRCULATION
•A fully functional AVF should have blood flow > 600ml/min •If AVF blood flow is poor (due to either stenosis or poorly mature fistula) blood returning to patients from dialyser will be “sucked” back to arterial line from dialyser will be “sucked” back to arterial line and dialysed again. inadequate dialysis •Significant recirculation happens when blood pump (Qb) demands more blood supply than the AVF can deliver •Recirculation >10% will result in poor URR/Kt/V

DETECTION OF ACCESS RECIRCULATION
1)Urea based method (S BUN –A BUN )/ (S BUN -V BUN)x 100% SBUN = systemic BUN A= Arterial BUN ABUN= Arterial BUN VBUN= Venous BUN
2)Non urea based method, examples: Ultrasound dilution Thermal dilution

CAUSES FOR RECIRCULATION
1.Poor AVF flow (requires fistulogram for assessment) 2.Error in placement of cannulation needles : -reversed needle cannulation -reversed needle cannulation -distance of both arterial/venous needles too close

DIALYSER
•Low surface area -bigger size patient needs bigger dialyser •Excessive reuse of dialyser can significantly reduce its performance reduce its performance -Review dialyser reuse log to evaluate total cell volume (TCV) -TCV should not be allowed to drop more than 20%

BLOOD FLOW RATE
•Compare prescribed versus actual blood flow rate •If prescribed blood flow rate can not be achieved, look for the possible causes : achieved, look for the possible causes : Inadequate setting of blood flow rate Small needle size Fistula stenosis (requires fistulogram for assesment) Hemodynamic instability eg cardiac failure

DIALYSATE FLOW RATE
•Review dialysis log book to compare prescribed versus actual dialysate rate

TREATMENT TIME
•Actual treatment time may be shorter than prescribed time -late arrival of patient -early termination of dialysis -early termination of dialysis -interruption of dialysis due to intradialytic events eg hypotension, cramp -others

THANK YOU

That's basically what can be copied from the lecture notes in point form. There are some cool pics and diagrams that aren't included. Maybe in future if I have the time I will upload them.

The most important terms are the URR and KtV which sounded very foreign. After spending some time on the wards observing that 'which needs to be observed' according to the logbook, things begin to 'fall in place' just like final medical year.

My First Official Run After Delivering My Fourth Baby

Alhamdulillah, today was an exhilarating experience that must be blogged about. I never thought I could run again since having baby no4. Life has been hectic and there was hardly any time to run. Somehow, we managed.

I think my husband had emailed information about the run and when we came across the booth in the usual running place, we decided to sign up on the dot. It was a 6 km run and there was no time limit. Certificate and medal award to all finishers. A bit expensive though, RM50 registration but the medal was nice enough.

There was also a 3km run for family and the other kids were dying to participate, but without the yes from hubby, based on the previous run earlier this year where I was the only parent with two kids in another event, it wasn't going to work. So it was just me and son no1.

For the most part, for the past one year or so I have cycled at home on alternate evenings using the exercise home-bike. Some people asked about which brand to invest in, I can't compare as this is the same indoor static exercise bike I have used for many years (I think 4 now). We'd only go jogging during the weekends.

Rebuilding stamina has not been easy. Recovery after my third caesarean and fourth delivery was snail's pace compared to all the previous pregnancies. Maybe it's age, I'm not sure. Certainly I did not plan to have a child after the age of 35 but we humans can only plan, God ultimately decides what is best.

Sometimes its hard for me to believe that I used to run 5km alternate week days and 10km-15km long distance run at the weekend. I really hope that I can go back to this level of fitness. I had initially planned to run my first marathon in 2014 after my first half marathon in 2013, until I got pregnant. Ah well, life goes on. Now that baby is nearing 2 years of age, I can slowly go back to a more predictable training and sleep pattern, both not achieved as I write this but certainly hoping it to transpire in the next one year.

The main question is:
1) How to start or restart?
2) How to maintain momentum?

Change is always difficult because staying in one place requires no effort. I had to set goals. My goals were weight loss, to get back to the weight I was before I was pregnant, and to finish that goal of running a marathon that I had set many years back.

I think it's important to write the goals down, and then come up with a plan.

Running a half marathon (21 km) isn't something like going shopping or buying a book. You don't just wake up one day and say 'I think I'm going to run a half marathon', sign up for one the following month, and then do it. Ok, it might work for people who are fit and accustomed to running certain distance but for the majority of normal people, half marathon and any running event regardless of distance requires some thought, preparation and advanced planning.

There were many setbacks. Full time job didn't leave me with much energy to pursue exercise in the beginning (after many months of time off work completely, so I did enjoy returning to work but it had some drawbacks). Baby was also still small and sleep was fragmented at best. So I either didn't exercise or just used the exercise bike.

Cycling has to be roughly twice the distance to get the same amount of work out as a run, if I'm not mistaken. It is a good form of exercise, especially when I was pregnant, and in the early months when my weight was still on the heavy side. I went from 66 kg to 50 kg in about 6 months. Mostly through a bit of mindful eating, a bit of exercise and also nursing my baby.

Then I decided, for many reasons unrelated to exercise, more personal and family reasons then anything else, to move back to Kelantan which also involved taking up a part time job. This was an opportunity to spend more time on my work-out but again, didn't translate. It was painful, running, after not running for so long. My knees hurt as it had when I over-trained for the half marathon in the past.

But at least I did get to cycle more regularly then before. I also ran but not more than 3 km at one go. It was only after signing up for the LTK or Larian Terbuka Kelantan, that I made conscious effort to run, and measure the distance and speed, and make sure that we built enough stamina towards the event. We means me and my son.

Motivating oneself can be an issue, but once I sign up for a race it becomes automatic. I look at the date of the race and then plan ahead how to build up distance from running 3 km to 5 km and making sure we 'peak' at the time of the event.

I felt like a beginner again, struggling with:
1) Breathing
2) Mental strength

The best way to breath is to take deep breaths and to inhale or exhale for as long as possible, shallow breaths will make one tired more quickly.

I also found myself thinking about all sorts of negative things while running which was not an empowering experience.

It was a morning run and I had not done any morning runs in a while. That was another mistake.

I wish there was someone else who would be a cheerleader for me, as I had to be for my son. I had to train him, be his pacesetter, made sure he ate and drank right, plan out the training for him, now I realize that doing something challenging is half as hard as coaching others to do the same.

Today's finisher medal.

Just wanted to share the picture of the medal. When I crossed the line, the girls said, you were so close! Never had that reaction yet. Of course now I am in the women's senior category, there is less competition.