Clinical Practice: Monitoring, Complications, and Vascular Access
Clinical practice: monitoring and troubleshooting
Most clinical-practice items test whether you can link a patient's signs to a cause and a first action. Know the baseline: full vital signs and weight before treatment, then per facility protocol during treatment (commonly every 30 minutes), and more often when the patient is unstable or the ultrafiltration rate is high.
Intradialytic hypotension is the most common complication. Signs include a fall of at least 20 mmHg systolic (or 10 mmHg mean arterial pressure) or a systolic below 90, with yawning, restlessness, cramping, nausea, diaphoresis, or a declining level of consciousness. First actions are usually to stop or slow ultrafiltration, lay the patient flat (Trendelenburg if needed), and give saline per protocol - not simply to recheck in 30 minutes.
Cramping often follows a high ultrafiltration rate or low dialysate sodium; slow the rate and follow protocol for saline. Disequilibrium syndrome (headache, confusion, seizure) calls for slowing blood and dialysate flow, not more aggressive clearance. Air embolism is an emergency: stop the pump, clamp the line, place the patient in Trendelenburg on the left side, and give 100 percent oxygen.
For access, palpate the thrill and auscultate the bruit of a fistula or graft before cannulation. If an infiltration occurs, stop the pump, withdraw the needle, apply firm pressure, and use a cold compress initially. Never use the access arm for blood pressure or venipuncture.
Rule of thumb: keep ultrafiltration near or below about 13 mL/kg/hour. A 70 kg patient with 3 kg to remove over 4 hours needs 0.75 L/h, about 10.7 mL/kg/h - acceptable; the same 3 kg over 2 hours is about 21 mL/kg/h and invites hypotension and cramping.