Effects of lung recruitment maneuver and positiveend‐expiratory pressure on lung volume, respiratory mechanics and alveolar gas mixing in patients ventilated after cardiac surgery

Acta Anaesthesiologica Scandinavica - Tập 46 Số 6 - Trang 717-725 - 2002
Thomas Dyhr1, N. Laursen2, Anders Larsson1
1Departments of *Anesthesiology and
2Radiology, Gentofte University Hospital, Denmark

Tóm tắt

Background: It is unclear whether positive end‐expiratory pressure (PEEP) is needed to maintain the improved oxygenation and lung volume achieved after a lung recruitment maneuver in patients ventilated after cardiac surgery performed in the cardiopulmonary bypass (CPB).Methods: A prospective, randomized, controlled study in a university hospital intensive care unit. Sixteen patients who had undergone cardiac surgery in CPB were studied during the recovery phase while still being mechanically ventilated with an inspired fraction of oxygen (FiO2) 1.0. Eight patients were randomized to lung recruitment (two 20‐s inflations to 45 cmH2O), after which PEEP was set and kept for 2.5 h at 1 cmH2O above the pressure at the lower inflexion point (14±3 cmH2O, mean ±SD) obtained from a static pressure‐volume (PV) curve (PEEP group). The remaining eight patients were randomized to a recruitment maneuver only (ZEEP group). End‐expiratory lung volume (EELV), series dead space, ventilation homogeneity, hemodynamics and PaO2 (oxygenation) were measured every 30 min during a 3‐h period. PV curves were obtained at baseline, after 2.5 h, and in the PEEP group at 3 h.Results: In the ZEEP group all measures were unchanged. In the PEEP group the EELV increased with 1220±254 ml (P<0.001) and PaO2 with 16±16 kPa (P<0.05) after lung recruitment. When PEEP was discontinued EELV decreased but PaO2 was maintained. The PV curve at 2.5 h coincided with the curve obtained at 3 h, and both curves were both steeper than and located above the baseline curve.Conclusions:  Positive end‐expiratory pressure is required after a lung recruitment maneuver in patients ventilated with high FiO2 after cardiac surgery to maintain lung volumes and the improved oxygenation.

Từ khóa


Tài liệu tham khảo

10.1007/BF03039447

10.1111/j.1399-6576.1992.tb03568.x

10.1097/00003246-199908000-00008

10.1016/0003-4975(92)91447-H

10.1161/01.CIR.52.3.483

10.1097/00000542-199808000-00013

10.1093/bja/71.6.788

10.1097/00000542-199504000-00004

10.1034/j.1399-6576.1999.430309.x

10.1164/ajrccm.159.3.9802090

10.1016/S0954-6111(98)90388-2

10.1007/s001340050104

10.1097/00000542-198710000-00016

10.1097/00000542-198507000-00014

10.1152/jappl.1988.65.5.2030

10.1042/cs0620541

10.1023/A:1009916905078

10.1378/chest.93.4.693

10.1097/00003246-199304000-00019

10.1203/00006450-199601000-00019

10.1056/NEJM199802053380602

10.1164/ajrccm.163.1.9905084

10.1034/j.1399-6576.2001.045006690.x

10.1164/ajrccm.158.1.9708049

10.1136/thx.54.1.82

10.1164/ajrccm.156.4.97-01052

10.1164/ajrccm.158.1.9708031

10.1164/ajrccm.159.4.9801088

Lumb A, 2000, Nunn's Applied Respiratory Physiology., 37

10.1016/0034-5687(75)90109-7

10.1152/jappl.1999.86.4.1116

10.1152/jappl.1998.85.4.1533

10.1378/chest.102.1.227

10.1164/ajrccm.164.1.2007011

10.1164/ajrccm.164.1.2007010

10.1007/s001340051196

Muller N, 1979, Diaphragmatic muscle tone, J Appl Physiol, 47, 279, 10.1152/jappl.1979.47.2.279

10.1164/ajrccm/138.3.720

Thông tin
Thông tin xuất bản

Acta Anaesthesiologica Scandinavica

Tập 46 Số 6

717-725

Thông tin tác giả