To the Editor:—

With great interest, I read the excellent article about systemic air embolism (SAE) after lung trauma by Ho and Ling. 1Although I have not found any case report in the literature, liquid ventilation might be a theoretically beneficial approach in treating this condition. Total or partial liquid ventilation is used in many studies for the treatment of patients with severe acute respiratory distress syndrome (ARDS) and studied in various animal studies with different design. 2–4These studies show a marked reduction in peak airway pressures, which are identified by Ho and Ling 1as detrimental in the setting of systemic air embolism in lung trauma. The used perfluorocarbon liquid does not seem to be toxic even if absorbed in larger quantities, as shown in a study in which it was used as a supplement for cardioplegic solution. 5Starting total liquid ventilation immediately after the diagnosis of systemic air embolism in lung trauma might therefore be a possibility to stop the entrance of gas in the systemic circulation until surgical repair of the leakage is completed. The spontaneous closure of small leaks might also be enhanced by changing the surface contact from gas to liquid. Especially in patients in whom an isolation of the injured lung is not possible, liquid ventilation offers a treatment opportunity for the complete organ. This “flooding of the field” might be accompanied by a significant entrance of perfluorocarbon in the systemic circulation and, if partial liquid ventilation is used, might not prevent air entrance completely. Before using this concept clinically, animal studies in a lung injury model should be initiated to assess the feasibility and possible side effects of liquid ventilation for treatment or prevention of systemic air embolism after lung trauma.

Ho AMH, Ling E: Systemic air embolism after lung trauma. Anesth 1999; 90: 564–75
Hirschl RB, Tooley R, Parent A, Johnson K, Bartlett RH: Evaluation of gas exchange, pulmonary compliance and lung injury during total and partial liquid ventilation in the acute respiratory distress syndrome. Crit Care Med 1996; 24: 1001–8
Tutuncu AS, Faithful NS, Lachmann B: Intratracheal perfluorocarbon administration combined with mechanical ventilation in experimental respiratory distress syndrome: Dose dependent improvement of gas exchange. Crit Care Med 1993; 21 (7): 962–9
Hirsch RB, Pranikoff T, Gauger P, Schreiner RJ, Dechert R, Bartlett RH: Liquid ventilation in adults, children, and full-term neonates. Lancet 1995; 346: 1201–2
Mosca RS, Rohs TJ, Waterford RR, Child KF, Brunsting LA, Bolling SF: Perfluorocarbon supplementation and postischemic cardiac function. Surgery 1996; 120: 197–204