Anaes Cases · Measurement & monitoring physics
Damped arterial line and a falling systolic reading
The hot case — the over-damped arterial line (the bubble, the clot, the kink, the soft tubing) under-reads the systolic and slurs the waveform. The fast-flush test distinguishes the true change from the artefact; aspirate, flush, and re-slush, and verify against the cuff.
On this page
Study tools
Target exams
ANZCAFRCAABAEDAIC
Prompt
During a vascular case, the arterial line suddenly becomes slurred, the systolic reading falls from 140 to 95, and the waveform is flat. The cuff reads 145/85. Diagnose and manage.
Presentation
Midway through a carotid endarterectomy, the arterial line waveform suddenly becomes slurred and the peak falls; the systolic reading drops from 140 to 95 mmHg. The diastolic is roughly unchanged. The cuff pressure, taken a minute later, reads 145/85 mmHg. The heart rate and the capnograph are unchanged. Diagnose and manage.[42351473]
References2ShowHide
- [1]Moon K, et al. Pulse oximetry - a perioperative perspective. Diagnostics, 2026.PMID 42351472
- [42351473]Bersten AD, Soni N (eds) Oh's Intensive Care Manual. 8th edition, Elsevier, 2018.