Patient Assessment, Monitoring, and Complications
Core concepts
Assessment is cyclical: pre-dialysis weight, blood pressure (both arms, avoiding the access arm), temperature, lung sounds and edema; intradialytic vital signs at least every 30–60 minutes; post-dialysis weight compared with the estimated dry weight. Falling pressure with a rising heart rate suggests volume loss; hypotension with bradycardia should prompt a search for other causes.
Trend labs rather than reacting to single values: potassium, phosphorus, calcium, PTH, hemoglobin, albumin, Kt/V, and normalized protein catabolic rate. Persistent post-dialysis hypertension often means the dry weight is set too high.
Know the emergency syndromes. Hypotension: stop ultrafiltration, supine or Trendelenburg, saline bolus. Cramps: slow the ultrafiltration rate, give saline, apply heat. Disequilibrium syndrome - headache, nausea, confusion, seizure after a first or rapid treatment - is prevented by slowing blood flow and shortening early sessions. Air embolism: clamp the line, stop the pump, place the patient in Trendelenburg and left lateral decubitus, give 100% oxygen. Hemolysis: cherry-red blood, back pain, dyspnea - stop, do not return the blood, inspect for kinked tubing or incorrect dialysate.
Trap: blaming every intradialytic symptom on hypotension. Chest pain, arrhythmia, or a widened QRS points to potassium; fever and chills during treatment point to a pyrogen or dialyzer reaction.
Worked example: a patient becomes confused near the end of a first-ever treatment. Do not simply give more fluid - suspect disequilibrium, slow the pump, and notify the provider.