Effects of the beach chair position, positive end-expiratory pressure, and pneumoperitoneum on respiratory function in morbidly obese patients during anesthesia and paralysis.
Anesthesiology
; 107(5): 725-32, 2007 Nov.
Article
en En
| MEDLINE
| ID: mdl-18073547
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.CONCLUSIONS:
The BC position and PEEP counteracted the major derangements of respiratory function produced by anesthesia and paralysis. During pneumoperitoneum, only the combination of the two maneuvers improved oxygenation.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Parálisis
/
Neumoperitoneo Artificial
/
Postura
/
Respiración
/
Obesidad Mórbida
/
Respiración con Presión Positiva
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Anesthesiology
Año:
2007
Tipo del documento:
Article
País de afiliación:
Italia