Effects of the Beach Chair Position, Positive End-expiratory Pressure, and Pneumoperitoneum on Respiratory Function in Morbidly Obese Patients during Anesthesia and Paralysis |
| |
Authors: | Valenza, Franco M.D. Vagginelli, Federica M.D. Tiby, Alberto M.D. Francesconi, Silvia M.D. Ronzoni, Giulio M.D. Guglielmi, Massimiliano M.D. Zappa, Marco M.D. Lattuada, Ezio M.D. Gattinoni, Luciano M.D., F.R.C.P.
|
| |
Affiliation: | Valenza, Franco M.D.*; Vagginelli, Federica M.D.†; Tiby, Alberto M.D.†; Francesconi, Silvia M.D.†; Ronzoni, Giulio M.D.†; Guglielmi, Massimiliano M.D.†; Zappa, Marco M.D.‡; Lattuada, Ezio M.D.‡; Gattinoni, Luciano M.D., F.R.C.P.§ |
| |
Abstract: | Background: The authors studied the effects of the beach chair (BC) position, 10 cm H2O positive end-expiratory pressure (PEEP), and pneumoperitoneum on respiratory function in morbidly obese patients undergoing laparoscopic gastric banding. Methods: The authors studied 20 patients (body mass index 42 +/- 5 kg/m2) during the supine and BC positions, before and after pneumoperitoneum was instituted (13.6 +/- 1.2 mmHg). PEEP was applied during each combination of position and pneumoperitoneum. The authors measured elastance (E,rs) of the respiratory system, end-expiratory lung volume (helium technique), and arterial oxygen tension. Pressure-volume curves were also taken (occlusion technique). Patients were paralyzed during total intravenous anesthesia. Tidal volume (10.5 +/- 1 ml/kg ideal body weight) and respiratory rate (11 +/- 1 breaths/min) were kept constant throughout. Results: In the supine position, respiratory function was abnormal: E,rs was 21.71 +/- 5.26 cm H2O/l, and end-expiratory lung volume was 0.46 +/- 0.1 l. Both the BC position and PEEP improved E,rs (P < 0.01). End-expiratory lung volume almost doubled (0.83 +/- 0.3 and 0.85 +/- 0.3 l, BC and PEEP, respectively; P < 0.01 vs. supine zero end-expiratory pressure), with no evidence of lung recruitment (0.04 +/- 0.1 l in the supine and 0.07 +/- 0.2 in the BC position). PEEP was associated with higher airway pressures than the BC position (22.1 +/- 2.01 vs. 13.8 +/- 1.8 cm H2O; P < 0.01). Pneumoperitoneum further worsened E,rs (31.59 +/- 6.73; P < 0.01) and end-expiratory lung volume (0.35 +/- 0.1 l; P < 0.01). Changes of lung volume correlated with changes of oxygenation (linear regression, R2 = 0.524, P < 0.001) so that during pneumoperitoneum, only the combination of the BC position and PEEP improved oxygenation. |
| |
Keywords: | |
|
| 点击此处可从《Anesthesiology》浏览原始摘要信息 |
|