A comparative study on the risk factors of postoperative pulmonary atelectasis

Monica Filip¹, O.Straciuc², Ladislau Szegedi¹
1) Catedra de Anestezie-Terapie Intensivă şi Urgenţă Prespitalicească. 2) Catedra de Anatomie, Facultatea de Medicină, Universitatea Oradea

Abstract

General anesthesia promotes pulmonary atelectasis, which can by eliminated by a vital capacity maneuver (inflation of the lungs to 40 cm H2O for 15 s). High-inspired oxygen concentration favors aparition of atelectasis. We studied 33 patients with the following pathology: inguinal hernia, varicose legs, reparatory surgery of the upper extremities scheduled for surgical intervention. The purpose of the study was to evaluate the increase of atelectatic zone when we used O2 100% before extubation. Ten minutes before the presumed end of surgery, the patients were randomly assigned to three groups:
A) group with a fraction of inspired oxygen FiO2=1, n=11;
B) group with vital capacity (VC) maneuver+ FiO2=1, n=10;
C) group with VC maneuver+FiO2=0,4, n=12.
The amount of atelectasis was measured by computer tomography and the oxygenation was studied by arterial blood gas analysis. Data were analyzed by Student test and p<0.05 was considered significant. In the VC maneuver + FIO2 = 0.4 group, postoperative atelectasis was smaller (3.09% ± 1.02 of total lung surface, p < 0.05) than in the FIO2 = 1.0 group (8.32% ± 2.15) and than in the VC maneuver + FIO2 = 1.0 group (7.4% ± 1.52). Oxygen 100% at the end of general anesthesia promotes postoperative atelectasis.

Key words: atelectasis, vital capacity, FiO2

STUDII CLINICE
Studiu comparativ asupra unor factori de risc ai atelectaziei pulmonare postoperatorii

Jurnalul Român de Anestezie Terapie intensivă 2006 Vol.13 Nr.1, 5-9