Analysis of different levels of positive end-expiratory pressure during lung retrieval for transplantation: an experimental study

Atelectasis and inadequate oxygenation in lung donors is a common problem during the retrieval of these organs. Nevertheless, the use of high positive end-expiratory pressure (PEEP) is not habitual during procedures of lung retrieval. Twenty-one Sprague-Dawley male consanguineous rats were used in the study. The animals were divided into 3 groups according to the level of PEEP used: low (2 cmH2O), moderate (5 cmH2O), and high (10 cmH2O). Animals were ventilated with a tidal volume of 6 mL/kg. Before lung removal, the lungs were inspected for the presence of atelectasis. When atelectasis was detected, alveolar recruitment maneuvers were performed. Blood gasometric analysis was performed immediately. Finally, the lungs were retrieved, weighed, and submitted to histological analysis. The animals submitted to higher PEEP showed higher levels of oxygenation with the same tidal volumes PO2=262.14 (PEEP 2), 382.4 (PEEP 5), and 477.0 (PEEP 10). The occurrence of atelectasis was rare in animals with a PEEP of 10 cmH2O, which therefore required less frequent recruitment maneuvers (need for recruitment: PEEP 2=100%, PEEP 5 =100%, and PEEP 10=14.3%). There was no change in hemodynamic stability, occurrence of pulmonary edema, or other histological injuries with the use of high PEEP. The use of high PEEP (10 cmH2O) was feasible and probably a beneficial strategy for the prevention of atelectasis and the optimization of oxygenation during lung retrieval. Clinical studies should be performed to confirm this hypothesis.

Inalação de solução salina hipertônica como coadjuvante da fisioterapia respiratória para reversão de atelectasia no pós-operatório de cirurgia cardíaca pediátrica / Inhalation of hypertonic saline solution as coadjuvant in respiratory physiotherapy to reverse atelectasis in the postoperative of pediatric heart surgery

Criança de 11 meses, sexo feminino, submetida à operação de fechamento de comunicação interventricular, comunicação interatrial e ligadura de canal arterial. Evoluiu no pós-operatório com atelectasia persistente em base pulmonar à direita, não respondendo às manobras fisioterapêuticas convencionais, efetuadas seis vezes ao dia. Após associação, como coadjuvante, da inalação de solução salina hipertônica com NaCl a 6 por cento, imediatamente antes e após o atendimento fisioterápico, observou-se crises de tosse produtiva, com maior indução do escarro e resolução completa da atelectasia, com três dias de tratamento.

The case of an eleven-month-old female child is presented diagnosed as having congenital heart disease with pulmonary hyperflow, who was submitted to a surgery to close an interventricular communication, interatrial communication and arterial canal ligature. The infant evolved with persistent atelectasis at the right lung base in the postoperative period which did not respond to conventional physiotherapeutic measures. Inhalation of hypertonic saline solution with 6 percent NaCl was associated as a coadjuvant therapy, giving a total cure of the atelectasis after three days of treatment.