Contents

Medical Complications

Mechanical Complications

Management of Medical and Mechanical Complications

a. Medical Complications

Common Complications during Hemodialysis

Serious complications during hemodialysis

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b. Mechanical Complications

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• Management of Medical and Mechanical Complications During Hemodialysis

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• Disequilibrium syndrome

Definition: It is a set of systemic & neurological symptoms and EEG finding that occur during or soon after acute  dialysis

Pathogenesis:

1-Rappid removal of solute from the extracellular fluid  compartment  results  in an osmolar gradient between brain and blood  hence results in cerebral edema.

2-A fall in pH of spinal fluid has been also noted to occur.

Clinical manifestations :

Prevention:

1-Limit the amount and rate of dialysis.

2-Use  of high dialysate sodium levels.

3-Use bicarbonate dialysis.

4-Intavenous infusion of:

Hypertonic dextrose

Hypertonic saline

Mannitol

Management:

In mild cases :

Treat the symptoms,

Reduce blood flow rate,

Hypertonic saline or dextrose solution can be administered.

In severe cases:

Stop dialysis, treat the seizures

Supportive measures of coma

Mechanical ventilation if necessary,

IV mannitol may be of benefit.

N.B. If coma is due to disequilibrium, the patient should improve within  24 hours.

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•  Intradialytic Hypotension

 Causes

A-Decreased Plasma Volume :

1-High ultrfiltration rate

2-Fluctuation in the ultrafiltration rate.

3-Target dry weight set low

4-Low dialysate  sodium.

5-Dialyzers with large surface area

6-Increased blood flow rate.

7-Increased dialysate flow rate

B-Decreased Compensatory Related Vaso Constriction:

1-Acetate dialysate.

2-Dialysate temperature 37-38’c.

3-Low dial ysate calcium.

4-Antihypertensive medications.

5-Biocompatible dialyzer membrane

C-Cardiac Related Factors:

1-Failure to increase cardiac rate :

Ingestion of B blockers.

Uremic autonomic neuropathy.

Aging

  2-Inability to increase cardiac output :

Poor myocardial contractility due to aging.

Hypertension.

Atherosclerosis.

Myocardial calcification.

Valve disease.

Amylodosis.

D-Other Causes:

1-Pericardial  temponade.

2-Myocardial infarction.

3-Occult hemorrhage.

4-Septicemia.

5-Arrhythmia.

6-Anaphylaxis.

7-Hemolysis.

8-Air embolism.

 Management of Intradialytic Hypotension

A-Measures to Ameliorate :

1-Accurate evaluation of dry weight ; is the most important step in minimizing intradialytic hypotension . limit weight gain to less than 1 kg / day .

2-Dosing of antihypertensive drugs . Give the daily dose after dialysis ( not before ) .

3-Adequate dialysate sodium concentration (or high sodium) has been effective in reducing intradialytic hypotension.

4-Bicarbonate dialysis & avoid acetate dialysis in those patient.

5-Cooled dialysate ; in some patient ; dialysate temperature of 35.5’c may be adequate to overcome the predisposition to hypotension.

6-Sequential UF is less likely to cause hypotension.

7-Oxygen supplementation during  dialysis specially in elderly is valuable to overcome predisposition to hypotension (to avoid hypoxemia).

8-Dialysate calcium concentration of 7.5 mg /dl may prevent hypotension

9-Infusion of Human Albumin before dialysis is also helpful.

10-The use of biocompatible dialyser decrease the incidence of hypotension 

11-Placement of pressurized leg boos in patients with sever peripheral edema.

12-Treatment of anemia by EPO.

B-Treatment of Acute hypotension:

1-The patient should be placed in trendlenberg position (if respiratory status allows this ).

2-A bolus of 0.9 saline (100-250 ml) should be administered through the venous line.

Alternative to 0,9 saline :

3% saline :50-100 ml

Dextrose  50 % : 25-50 ml.

Human Albumin 20 % :50-100 ml.

Mannitol.

Pressor agents e,g Dopamine.

3-Rreduce the UF rate near to zero.

4-Discontinue dialysis in severe cases.

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• Membrane Reactions

(Dialyzer reactions-Membrane Hypersensitivity-First use Syndrome)

Reactions occur with new dialyzer were grouped under the term first use syndrome. However , similar reactions occur with reused dialyzer.These reactions appear to be two varieties :

1-Anaphylactic type (type A)

2-Non specific type (type B)

1-Anaphylactic type (type A)

This type of reaction occur at the first 20-30 minutes of dialysis, usually first 5 minutes. It occur in less than 15% of patients when new dialyzer is used or with 5/100,000 dialyzer sold. Atopic patient are prone to develop these reaction.

Manifestations

Severe reaction: Dyspnea -Sense of impending doom-Heat sensation at fistula site and throughout the body-Cardiac arrest and death may supervene.

Mild reaction: Itching-urticaria - Cough- sneezing-Coryza or watery eye-Abdominal pain and Diarrhea

Etiology

1-Ethylene oxide (used to sterilize HF dialyzers) hypersensitivity, often after inadequate rinising. High IgE antibodies were found in those patient. It is uncommon nowadays.

2-Polyacrylonitrile membrane associated reactions mediated by bradykinin system .

3-ACE inhibitors magnify the effect of the membrane because ACE participate in bradykinin inactivation.

4-Contaminated dialysate with bacteria when high flux dialyzer is used with less frequent cleaning and sterilization.

5-Reuse probably due to bacterial or endotoxin contamination of the water used during the reuse procedure further more formaldehyde and glutaradehyde can cause allergic reaction.

6-Complement activation ; it is conceivable that complement activating membranes and acetate dialysate  may act as co factor in precipitating reaction in some patients, especially those with history of atopy.

7-Heparin allergic reaction should be suspected when other causes reasonably excluded.

6-Others -Azide substances used to package some water pretreatment ultrafiltrers .Acetate causes adenosine release when metabolized can exacerbate bronchoconstriction

Management:

1-Stop dialysis

2-Clamp the blood lines

3-Do not reinfuse the blood

4-Discard the dialyzer and the lines

5-Cardiorespiratory resuscitation

6-Antihistaminic, Steroids ,Epinephrine can be given

Prevention:

1-Proper rinsing of dialyzer prior to use

2-Change suspected ethylene oxide sensitized patient to gamma or steam sterilized dialyzer

3-Stop ACE inhibitor therapy in affected patients.

4-Change the membrane if the reaction occur while using it.

2-Non specific type (type B)

The non specific type of membrane reactions are more common than anaphylactic type but less severe.

Manifestations:

1-It occur within several minutes to one hour

2-Chest pain which may be associated with backache.

Etiology:

Complement activation is the most likely cause .It is less common with reused dialyzer. In reused filters the membrane will be coated with protein layer ,furthermore the toxic substances are washed during the previous dialysis

Prevention

Change the dialyzer membrane to characterized by release of activated complement fragments such as cellulose or Hemophan may be of benefit.

Management:

1-Oxygen therapy

2-Treat as in angina during dialysis

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• Muscle cramps during hemodialysis

Etiology

1-Hypotension and significant volume of fluid removal by UF

Cramps most commonly occur in association with hypotension & may persist after restoring BP. UF reduce extracellular volume ->>>>>skeletal muscle irritability.

2-Patient below dry weight:

Sever prolonged cramps beginning during the later part of dialysis and persisting after dialysis occur when the patient has been dehydrated to below dry weight.

3-Electrolyte disturbance:

Acute decrease of plasma sodium (due to the use of low sodium dialysate) will result in constriction of blood vesseles, subsequently muscle cramps occur. Hypokalemia also can cause muscle cramps.

Prevention

1- Prevention of hypotension episodes & excessive UF(previous tip).

2-Increasing the dialysis solution sodium level to 140mEq/L or more.     

3-Other strategies:\

a) Qunine  sulphate tab 180-300mg ,2 hr. predialysis. 

b)Diazepam or Oxazepam   2 hrs pre dialysis .

c)Stretching excercise. to the affected muscle group.

N.B. Side effect of the drugs limit its use.

Management:

1-Concomitant occurrence of hypotension and cramps may respond to treatment with  100 ml  of 0.9 % saline

2-Hypertonic saline or dextrose >>>>>dilatation of the  muscle bed blood vessels and restore blood volume.

 *Hypertonic dextrose( 50 ml of  10 % dextrose.) is preferred for treating non diabetic patient to avoid  thirst  produced by saline.

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• Skin disorders in dialysis patient

• Pruritus (Itching)

Pruritis is present at some time in 80-90% of dialyzed patients. It may appear as a symptom of early uremia, but is also troublesome and  persistent in some  patients  on long-term dialysis therapy. Overall, itching was often most severe during or after hemodialysis session but was also increased during periods of inactivity or bed rest.

ETIOLOGY:   

1-Circulating uremic toxins.

2-Elevated calcium-phosphorous product.

3-High para thyroid hormone

4-Dry skin aggravate the pruritus.

5-Allergic patients to:  

Heparin

Plasticizers used to soften hemodialysis tubing.

Ethylene Oxide gas used  to sterilize hemodialyzers &blood line

DIAGNOSIS:

Pruritis may involve the entire skin surface, predominantly on the face, back, trunk & extremities

Telltale signs of scratching include:

Excoriation , Heemorrhgic crusts , Pustule , Lichenification , Nodule formation

TREATMENT: 

A- General measures.

1- Relieve the dry skin with topical emollients e.g. Lubricating solutions, Camphor and Menthol containing creams

2-Switch from ethylene oxide to gamma ray-sterilized dialyzer.

B-Phototherapy:

Ultraviolet light-B delivered in a conventional light box giving 2 treatments per week for 4 weeks..

C-Control of calcium and phosphorous metabolism:

Treat hyperphosphtemia, Control hyperparathyroidism, including vitamin D therapy and partial parathyroidectomy.

D-Drug therapy :   -

Antihistamines,e.g. Diphenhydramine ,Hydroxyzine

Parenteral lidocaine infusion

Oral activated charcoal

E- Renal transplantation

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• Causes of Chest pain in ESRD  patients

Cardiovascular

Angina pectoris

Pericarditis   

Valvular heart disease Aortic dissection

Pleuropulmonary

Pneumonia

Pleuritis

Hemothorax

Pulmonary embolism/infarction

Gastrointestinal

Esophageal spasm/reflux

Acid peptic disease

Pancreatitis

Cholecystitis/Cholelithiasis

Musculoskeletal

Rib fracture

Renal osteodystrophy

Muscle cramps

Neurologic

Spinal disease with nerve root compression

Herpes zoster

Miscellaneous

Anaphylactic reaction

Air Embolism

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• Hemodialysis associated angina

a)Causes:

-Hemodynamic stress caused by hemodialysis

-Reduction of blood Po2 Particularly with acetate dialysate bath and or complement activating cuprophane dialyzers that can cause; pulmonary leukocyte sequestration , change hemoglobin-oxygen affinity, arrhythmia and hypotension (First use syndrome). It occurs in ~5% of dialysis treatment given with fresh unused dialyzers

-Thus hemodialysis reduce coronary artery filling time ,perfusion pressure , and myocardial oxygenation.

-Potential causes of chest pain (e.g. hemolysis ,air embolism) must be considered

-These events coupled with anemia and the possible loss of coronary vasodilator reserve may be responsible for hemodialysis associated angina in patients with or without significant coronary stenosis.

 b)Hemodialysis as  a risk factors for angina :

1.Hypotension and Hypertension during dialysis

2.Anemia

3.Hypoxemia during dialysis

4.Chronic volume overload

5.Hyperlipdaemia

6.Acetate intolerance

7.Atherosclerosis

The use of glucose in dialysis fluid may cause hyprlipidemia and thereby atherosclerosis. Acetate dialysis solutions can facilitate synthesis of cholesterol and triglyceride.

c) Management of angina during hemodialysis:

1. Nasal oxygen should be initiated.

2. Reduce blood flow rate and stop ultrafiltration.

3. Sublingual nitroglycerin if blood pressure is maintained.

4. Sedation.

5. Treat the possible cause.

6.Dialysis with bicarbonate dialysate bath.

7.In severe cases discontinue the procedure .

8.ECG and Further investigation may be required to exclude myocardial infarction.

Predialysis administration of nitroglycerin 1houre prior to hemodialysis session may be be of benefit

d) Dialysis after acute myocardial infarction:

1.Postpone dialysis for 24 hours when possible.

2.Such patients are best dialysed peritonealy (if possible) to avoid the attendant     hemodynamic      instability

3.If peritoneal dialysis is impossible -Hemofiltration or Bicarbonate dialysate bath with close monitoring ,oxygen therapy .,blood transfusion if Hct is less than 30% , along with all measures to avoid hypotension (review the previous tips)

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• Air Embolism

Air embolism is a serious complication of the dialysis procedure. Air can be introduced via the segment  of the blood circuit that operates in the negative pressure range-the portion between the arterial fistula needle and the blood pump.

Routes of air introduction:

 a-Air leaks around tubing joints (saline and heparin infusion sites placed before the pump)

 b-Excessive undetected or unmonitored negative pressure, related to inadequate fistula flow rate for the pump demand ,or malposition of the arterial needle.

c-Unattended intravenous solution administration.

d-The use of prepump arterial drip chamber

e-The use of air to return blood to the patient at the completion of dialysis.

To avoid that venous  air trap and air detector are located just distal to the venous pressure monitor. The air detector is attached to a relay switch which automatically clamps the venous blood line and shuts off the blood pump if air is detected.

Manifestations

a-In seated patient: Air migrates to cerebral venous system (not to the heart) causing obstruction to cerebral venous return with loss of consciousness , convulsion , even death.

b-In recumbent position: The air tends to enter the heart and generate foam in the right ventricle and pass into the lungs manifested by dyspnea, cough, chest tightness. Further passage of air across the capillary bed into the left ventricle can result in air immobilization to the arteries of the brain and the heart with acute neurological and cardiac dysfunction.

c-Foam will often seen in the venous blood line.

d-A peculiar churning sound may be heard on auscultation ,if the air gone into the heart.

Management

a-Clamp the venous line and stop the blood pump.

b-Place the patient in Trendelenberg position on the left side with the chest and head tilted downward to trap the air at the apex of right ventricle away from the outflow tract.

c-Cardiorespiratory support, Oxygen 100%.

d-Occasionally percutaneous aspiration of the air foam from the heart may be necessary.

e-Other measures include IV Dexamthsone to reduce brain edema ,Heparin /Dextran to improve the microcirculation.

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• Ruptured  Dialyzer

Causes of dialyzer rupture

1-Improper priming

2-Improper or inadequate heparinization.

3-Damaged dialyzer.

4-Accidental tubing kink; causing high venous pressure

5-Clotting

Management:

 Dialyzer rupture is uncommon, if it occurs , an immediate decision must be made to

1- Reinfuse the blood (or not)

2-Change the ruptured dialyzer as quickly as possible.

3-Cleaning the dialysate circuit or reset up.

4-Resume dialysis if safe to do so .

When the rupture is extensive and the pressure in the dialysate compartment is greater than the pressure inside the blood compartment, dialysate can rapidly enter the blood compartment and the patient. To avoid that, the machine should always be set to at least 25-50 mm Hg negative pressure.

[Usually less than 1% of blood present in dialysate trigger the blood leak alarm

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• Clotted dialyzer

Causes

a. High venous Pressure

b. Slow blood flow

c.Turbulence of air that may have been infused during priming

eTurbulence of air and blood while using single needle machine

f. Blood transfusion during dialysis

Mechanism:

Platelet activation upon contact with the dialyzer membrane is the primary mechanism responsible for clotting during dialysis.

Management:

When a dialyzer clots , the dialyzer, the arterial line, the venous line may need to be replaced. In clotted dialyzer without rupture, the entire dialysate circuit does not need to be set up again or recleaned

Dialyzers need not to clot even if no heparin is used during dialysis.The procedure consisted of clamping the arterial line every 20-30 minutes, and rinsing the blood circuit with normal saline to clear the dialyzer and blood lines. Negative pressure  to be adjusted to compensate  for the excess fluid  administered. Saline rinsing interferes with platelet aggregation and prevents overproduction of active coagulation factors. Thus the formation of stable fibrin network is prevented.

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• Needle-Site Bleeding

 Needle-site bleeding may occur after venipuncture as a result of:

 1-capillary trauma or trauma occurring when rotating the needle or manipulating the needle side to side during insertion.

 2-Multiple puncture at the same site

 3-Overheparinization

 Management:

 1-Direct pressure is the simplest and effective measure. It should be aseptically and with extreme care to avoid AV access occlusion.

 2-Apply gel foam to the puncture site

 3-Adjust heparin dose

 4-Change the puncture site every dialysis

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• High Venous Pressure

High venous pressure is seen on almost daily basis. The purpose of monitoring venous pressure is to identify any pressure changes within venous return line during dialysis. Venous pressure of +50 to +100 mmHg above the atmospheric pressure is acceptable during dialysis(preset pressure -100 to +100 ). If venous pressure moves out of limits an audible alarm is heard and the blood pump stopped until the problem is corrected.

Causes of high venous pressure:

1-Needle related –

Needle may have infiltrated the access wall

Needle hole may be resting against the side wall of the access

Needle may have been inserted into scar tissue inside the access

Needle may be to short and the hole is not completely inside the access

Needle with small gouge (16) when blood flow rate is high.

2-Clotting

Clotting of venous needle

Clotting of venous side of AV shunt

Clotting of venous blood line

Clotting of the filter

3-Access related

Stenosis or spasm at the venous limb of the access

Clotting at the venous limb of the access

AV graft have naturally high venous pressure(150-200mmHg)

4-Lines related

Kinked venous line

Management  ( See also alarm problem solving)

1-Manipulate the needle and or the line. If the access is small, a tourniquet must be used, being certain the blood pump is off.. Recannulation with new needle if needed ,the original one should be left in place until the end of dialysis. to avoid undue bleeding as the patient is heparinized

2-Adjust the blood flow rate, Proper heparnization, Treat access problem, and Proper needle and needling

3-Extreme care must be exercised when dialyzing a patient with high venous pressure

This increases the baseline TMP and obligatory ultrafiltration will occur

Single-needle device is occasionally impossible to use, because with high venouspressure ,venous return will be impaired and blood recirculation will be high.

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• Abnormal Arterial Pressure

The arterial pressure monitor reads in negative pressure because it measures the partial vacuum resulting from the roller pump withdrawal of the whole blood at a relatively high rate through the small bore needle inserted into the arterial end of the access. It identifies how much suction is being placed on the arterial wall. When the pressure becomes very negative (-150 &-200mmHg) the access will collapse and the blood flow will be discontinued to the machine. Furthermore very high negative pressure may cause air bubbles to enter around the needle causing air embolism and or clotting of the dialyzer.

 Causes of an increase  in negative pressure:

 1-Needle related –

Needle may have infiltrated the access wall

Needle hole may be resting against the side wall of the access

Needle may have been inserted into scar tissue or flap inside the access

2-Clotting

Clotted arterial needle

Clotted arterial side of AV shunt

3-Access related  -

Stenosis within the access

Spasm of the access.

Positional in acute access

4-Patient related   -Low blood pressure

 Management:   ( See also alarm problem solving)

1 Manipulation of the arterial needle is similar to that of venous needle. In most cases the needle may have to be replaced with the same precaution as with venous needle

2-Treat the cause.

3- Proper needling

4-Asses the access

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• Hemolysis

Acute hemolysis during hemodialysis is rare  but must be immediately identified and emergency management initiated to minimize the patient morbidity.

Technical causes:

1-Hypotonic dialysate

2-Overheated dialysate

3-Formaldehyde in the dialysate

4-Hypochlorite in dialysate

5-Copper or Nitrates in the dialysate

6-Overoccluded blood pump

7-Severe foaming in the roller clamp segment

Manifestations

1-Port-wine appearance of blood in the venous return line

2-Presence of pink plasma in centrifuged blood sample.

3-Patient Manifestations :Headache , Arm pain , Chest pain, Drowsiness Dyspnea , Back pain, Diaphoresis  ,  Pallor, Arrhythmia ,Cardiac arrest

4-Laboratory studies, Drop in Hemoglobin and Hematocrit ,Hyperkalemia, Arrhythmias ,Cardiac arrest

Management

1-Clamp the blood lines

2-Turn the blood pump off

3-Do not reunifies  the blood

4-Leave the needle in place

5-Draw blood for: Type and crossmatch    CBC    Electrolyte  Trace metal

6-Save dialysate and blood samples for further evaluation

7-Discard the dialyzer lines

8-Evaluate the problem by reviewing the following

a. Check conductivity

b.Check the dialysate temperature

c. Look for kinks in the blood line in the pump

d. Check dialysate for ;Electrolyte Formaldehyde-Chlorine-Trace metal

9-Check the IV priming solution

!0-Resume dialysis to prevent hyperkalemia and blood transfusion  if necessary

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• Conductivity

Conductivity is a property of electrolyte solutions to conduct an electric current. It is measured in units called mhos or milli mohos (1mhos =1000 milli mhos). A mho is the conductivity of body through which 1 A of current flows when potential difference is 1 V. It is important to be aware that the display meter of clinical dialysis machines does not read in milli mhos, but displays an entirely arbitrary scale intended to present a clinically understandable reading approximately equal to mEq/L chloride ions  in the dialysate solution. Because dialysate chloride  concentration is usually 105 mEq/L, the scale deviation from the ideal set line are, therefore, approximately % deviation from the desired reading. All recent dialysis machine have factory-set conductivity meters with alarm system. When conductivity meter detects high or low conductivity  the machine automatically sounds an alarm and puts the dialysate into bypass mode so that  no dialysate flow to the dialyzer.

Usually conductivity is adjusted between 13-14 in single bath system. In Redy Sorbent hemodialysis the initial dialysis solution conductivity adjusted according to patient natremic status (it will be discussed in later tips). The newer computerized dialysis machine display the actual sodium and electrolyte concentration in dialysate (profiling)

High-Conductivity Alarm:

Causes : High-conductivity is a dialysate production complication caused by too much concentrate and not enough treated water

Management :   (See also alarm problem solving)

Evaluate the incoming water and check for kink the line.

The water pressure and filters should be also checked

Recheck the conductivity:

If normal, there is malfunction in the machine itself (change it)

If high again concentrate should be changed

Check the conductivity before resuming dialysis   

Low-Conductivity Alarm:

Causes : Low conductivity is a dialysate machine mixing complication that occurs when the machine receives insufficient dialysate concentrate within the mixing chamber. The result is a hypotonic dialysate that cause hemolysis. The usual reasons are :

1-The concentrate container runs dry

2-Leakage at the concentrate pump .

3-Malfunction in the concentrate pump feedback circuit

Management : (See also alarm problem solving)

Change the concentrate container if it is dry

If the concentrate container has not run dry, a sample of dialysate should sent to the      laboratory for sodium and chloride

Recheck the conductivity with second conductivity meter:

If low conductivity is confirmed  ; change the concentrate bottle (recheck again)

If the conductivity still low after changing the concentrate , a different machine should be  tried

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