Extracorporeal life support for severe acute respiratory distress syndrome in adults.
OBJECTIVE
Severe acute respiratory distress syndrome (ARDS) is associated with a high level of mortality. Extracorporeal life support (ECLS) during severe ARDS maintains oxygen and carbon dioxide gas exchange while providing an optimal environment for recovery of pulmonary function. Since 1989, we have used a protocol-driven algorithm for treatment of severe ARDS, which includes the use of ECLS when standard therapy fails. The objective of this study was to evaluate our experience with ECLS in adult patients with severe ARDS with respect to mortality and morbidity.


METHODS
We reviewed our complete experience with ELCS in adults from January 1, 1989, through December 31, 2003. Severe ARDS was defined as acute onset pulmonary failure, with bilateral infiltrates on chest x-ray, and PaO2/fraction of inspired oxygen (FiO2) ratio < or =100 or A-aDO2 >600 mm Hg despite maximal ventilator settings. The indication for ECLS was acute severe ARDS unresponsive to optimal conventional treatment. The technique of ECLS included veno-venous or veno-arterial vascular access, lung "rest" at low FiO2 and inspiratory pressure, minimal anticoagulation, and optimization of systemic oxygen delivery.


RESULTS
During the study period, ECLS was used for 405 adult patients age 17 or older. Of these 405 patients, 255 were placed on ECLS for severe ARDS refractory to all other treatment. Sixty-seven percent were weaned off ECLS, and 52% survived to hospital discharge. Multivariate logistic regression analysis identified the following pre-ELCS variables as significant independent predictors of survival: (1) age (P = 0.01); (2) gender (P = 0.048); (3) pH < or =7.10 (P = 0.01); (4) PaO2/FiO2 ratio (P = 0.03); and (5) days of mechanical ventilation (P < 0.001). None of the patients who survived required permanent mechanical ventilation or supplemental oxygen therapy.


CONCLUSIONS
Extracorporeal life support for severe ARDS in adults is a successful therapeutic option in those patients who do not respond to conventional mechanical ventilator strategies.
Hemmila
Mark R
MR
Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, USA. mhemmila@umich.edu
Rowe
Stephen A
SA
Boules
Tamer N
TN
Miskulin
Judiann
J
McGillicuddy
John W
JW
Schuerer
Douglas J
DJ
Haft
Jonathan W
JW
Swaniker
Fresca
F
Arbabi
Saman
S
Hirschl
Ronald B
RB
Bartlett
Robert H
RH
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D002408:Catheters, Indwelling; D002985:Clinical Protocols; D015199:Extracorporeal Membrane Oxygenation; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010102:Oxygen Inhalation Therapy; D010351:Patient Discharge; D011175:Positive-Pressure Respiration; D011659:Pulmonary Gas Exchange / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D012128:Respiratory Distress Syndrome / Q000628:therapy*; D012189:Retrospective Studies; D012737:Sex Factors; D015996:Survival Rate; D013997:Time Factors
D000925:Anticoagulants