Intradialytic & Chronic

The contract between this chapter and the reader.

1. 1. Recognise and manage muscle cramps during dialysis.
2. 2. Identify arrhythmia risk and reduce sudden cardiac death.
3. 3. Distinguish Type A and Type B dialyzer reactions and act.
4. 4. Recognise intradialytic hemolysis and its technical causes.
5. 5. Manage air embolism.
6. 6. Diagnose access-related limb ischemia (steal) and grade its severity.
7. 7. Recognise high-output cardiac failure and acquired cystic disease.
8. 8. Differentiate pyrogenic reactions from catheter infection.

A sixty-second reading. Each bullet stands alone.

• Muscle cramps usually follow rapid ultrafiltration or hypovolemia; reduce the ultrafiltration rate, give saline, and check the dry weight is not set too low.
• Arrhythmia risk rises with rapid electrolyte shifts; avoid very low-potassium and low-calcium baths and individualize the prescription.
• Sudden cardiac death is the leading cause of death and is highest at the end of the long interdialytic interval.
• Type A dialyzer reactions are early, severe, and anaphylactoid; stop dialysis, do not return the blood, and treat anaphylaxis.
• Type B reactions are milder, with chest or back pain from complement activation, and usually allow dialysis to continue.
• Intradialytic hemolysis is a technical emergency — a kinked line, overheated or hypotonic dialysate, or a water contaminant.
• Hemolysis can cause life-threatening hyperkalemia and presents with dark blood, back pain, and dyspnea; stop and do not return the blood.
• Air embolism causes sudden dyspnea and neurological signs; clamp the line, place the patient left-side-down and head-down, and give oxygen.
• Access steal diverts arterial flow from the hand, causing pain, pallor, coldness, and — if severe — neuropathy or necrosis.
• Steal is managed by severity, from flow-reducing procedures to ligation of a limb-threatening access.
• A high-flow access can cause high-output cardiac failure, and long-standing dialysis causes acquired cystic kidney disease with a risk of renal cell carcinoma.
• Pyrogenic reactions from contaminated dialysate cause fevers and rigors during dialysis and must be distinguished from catheter infection.

The medical core. An expert should agree the dialysis complications are fully covered here.

Why it matters at the bedside

Most of what goes wrong on dialysis is recognised in seconds and fixed in minutes — if you know the pattern. A cramp, a chest pain, dark blood in the line, a cold hand: each has a short list of causes and a clear first move. This chapter is that list, plus the slower complications that accrue over years.

Cramps

• Muscle cramps, typically late in a session, usually mean too-rapid ultrafiltration or hypovolemia as the patient approaches a dry weight set too low. The immediate response is to slow or stop ultrafiltration and give saline; prevention is a lower ultrafiltration rate (more time), a realistic dry weight, and avoiding excessive interdialytic gain. (Intradialytic hypotension is covered in its own chapter.)

Arrhythmia and sudden cardiac death

• Sudden cardiac death is the single leading cause of death in dialysis, and its risk peaks at the end of the long interdialytic interval, when fluid and electrolyte loads are greatest. Rapid intradialytic shifts — a steep potassium drop, a low dialysate calcium or magnesium — on a background of left-ventricular hypertrophy provoke arrhythmia, so very low-potassium and low-calcium baths are avoided and the prescription individualised.

Dialyzer reactions: Type A and B

• Type A reactions are early (within minutes), severe, and anaphylactoid — dyspnea, hypotension, angioedema — classically linked to membrane or sterilant sensitivity (and to the bradykinin reaction of an AN69 membrane with an ACE inhibitor). They are an emergency: stop dialysis, clamp the lines and do NOT return the blood, and treat anaphylaxis. Type B reactions are milder and later, chest or back pain from complement activation, and usually allow dialysis to continue with support.

Hemolysis — the technical emergency

• Intradialytic hemolysis is almost always technical: a kinked or occluded line shearing red cells, an overheated or hypotonic dialysate, or a water contaminant such as chloramine or copper. It shows as dark, port-wine blood in the venous line, back and chest pain, and dyspnea, and it can release enough potassium to be fatal. The response is to stop immediately, not return the hemolysed blood, treat hyperkalemia, and investigate the machine and water supply.

Air embolism

• Air entering the circuit — through a broken connection or an empty infusion — causes sudden dyspnea, chest pain, and neurological signs. It is a clamp-and-position emergency: clamp the venous line, place the patient left-side-down and head-down (to trap air in the right heart apex), and give high-flow oxygen.

Access steal and limb ischemia

• An arteriovenous access can divert arterial blood away from the hand — ‘steal’ — causing pain, pallor, coldness, and, when severe, sensorimotor loss or tissue necrosis. Management is graded by severity: mild symptoms are monitored, moderate steal is treated by flow-reducing surgery (banding) or distal revascularisation with interval ligation, and a limb-threatening hand demands urgent revascularisation or ligation of the access.

High-output cardiac failure

• A high-flow access returns a large volume of blood to the heart, raising cardiac output; over time this can precipitate or worsen high-output cardiac failure. When an access flow is disproportionately high in a patient with failing cardiac function, flow-reducing surgery is considered.

Acquired cystic disease

• Years of dialysis induce acquired cystic kidney disease in the native kidneys — multiple cysts that carry a raised risk of renal cell carcinoma. It is usually asymptomatic, but new flank pain, a mass, or haematuria in a long-vintage patient prompts imaging.

Pyrogenic reactions versus infection

• Fevers and rigors during a session can be a pyrogenic reaction to endotoxin from contaminated dialysate rather than a bloodstream infection. The two are distinguished by drawing cultures and reviewing the water and dialysate — a pyrogenic reaction settles and the cultures are negative, whereas catheter-related infection (its own chapter) does not.

Five fully-built tables.

Table A — Intradialytic complications

Table B — Type A versus Type B dialyzer reactions

Table C — Intradialytic hemolysis

Table D — Access steal: severity and management

Table E — Chronic complications

Visualise & Map

Numbered rules. These numbers are the cross-reference handle for the cases and flowcharts.

Clinical Reasoning

Four cases. Each stops you at a decision before it answers it.

Exhaustive. Every rule in the chapter is here.

Safety & Evidence

Panel A — Red flags

Panel B — NEVER DO

Anti-patterns clinicians fall into. Each becomes a Level 22 distractor.

The grade reflects strength of evidence, not importance.

Apply & Test

Copy-paste chart notes that map to the real events in this chapter.

Template 1 — Intradialytic adverse-event note

• Event: cramp / reaction (Type A/B) / hemolysis / air embolism / pyrogenic / arrhythmia.
• Timing in session and presentation: ___.
• Immediate action: stopped UF / stopped dialysis (blood returned? yes/NO) / positioned / oxygen.
• Technical check: machine / water / dialysate temperature & tonicity / lines: ___.
• Cultures (if febrile): sent? ___; potassium (if hemolysis): ___.
• Outcome and prevention plan: ___.

Template 2 — Access steal / chronic-complication referral

• Symptom: hand pain / pallor / coolness / numbness / necrosis.
• Severity grade: mild / moderate / severe (limb-threatening?).
• Access type and estimated flow: ___ (high-output failure considered? ___).
• Referral: vascular surgery — flow reduction / DRIL / ligation.
• Other chronic issues flagged (acquired cystic disease, amyloid): ___.

Pre-rounds compression. Rules only.

Active recall. At least one card per objective.

Micro-teaching for rounds. Two scenarios, five steps each.

Eight items, each anchored in this chapter. At least one per objective.