Chapter 35 — Air and Circuit Emergencies

Published 2026-09-24. 16 sections, 26 callouts, 8 tables, ~62 kB. Anchor read as COMPLETE FULL TEXT: Franco D, Krasna N, Novak R, Esposito G, Izzo R, Belohlavek J, Noc M, Goslar T. Prevention of Air Embolism in ECMO Systems: An In Vitro Study on Protection of Central Venous Catheter Lumen. Medicina (Kaunas) 2024;60(11):1883. DOI 10.3390/medicina60111883, PMC11596159. Hadano 2023 reused for air events (12/178; clamp release 33%, stopcock 33%, machine 17%; circuit change 6/12). STRUCTURAL CLAIM: the pump divides the circuit into a side that sucks (breach draws air) and a side that pushes (breach sprays blood); the membrane lung divides the positive side again (Red Book venous vs arterial air). Three-zone rule. Patient's central veins are part of the drainage limb; PFO turns VV air into arterial air. Franco: open CVC lumen drew air at 2500 rpm tips touching and 3500+ otherwise; closed stopcock/clave prevented all; pump hiss at 1 mL; air passed membrane at 1 mL at 4500 rpm and 5-25 mL at 3500+; 25-50 mL stopped flow at every speed; never raise speed in airlock. Red Book sequence: call, decide whether air will enter patient, clamp return limb if so, otherwise maintain reduced flow with one person at return limb with clamp, locate by circuit check, remove, change circuit if not quickly resolved. De-airing techniques table. Chan 2022 (4/116, source always found, 3 venous, 2 airlocks, backflush). Air in patient: clamp, head down, CPR, aspirate venous air, consider hypothermia (ISCCM); no hyperbaric guidance. Rupture: temporise (finger, bone wax, tape, clamp pigtail) then controlled separation; return-side needs clamp. ECPR text emergent (CLAMP STOP RESCUE) and controlled separation (clamp return then drainage; restart ~1500 rpm; unclamp drainage then return) plus bridge sequences. Preparation: primed backup circuit 30+ days, backup pump, cart, training 4-8 h every 6 months. CONTROVERSY 1: bubble detector auto-stop vs alarm-only (position and action chosen together; central VA auto-stop defensible, VV alarm-only defensible). CONTROVERSY 2: stop vs slow-and-watch for small venous air (Red Book vs ECPR text; slow only if someone free to hold clamp). Worked case: open CVC lumen, hiss, air in membrane, silent detector. Owed items in 35.13 to Ch 31, 32, 33, 34, 38a, 55, 60, 88-90.