Influence of pneumoperitoneum and patient positioning on respiratory system compliance.
OBJECTIVE
To investigate the influence of pneumoperitoneum (PP) and posture on respiratory compliance and ventilation pressures.


METHODS
Prospective, single blind trial.


METHODS
10 female ASA physical status I and II patients scheduled for elective gynecologic laparoscopy.


METHODS
University medical center.


METHODS
Anesthesia was performed as total IV anesthesia (TIVA) with propofol, alfentanil, and atracurium. After induction of anesthesia and orotracheal intubation, the lungs were ventilated to maintain partial pressure of CO(2) (P(ET)CO(2)) of 30 +/- 3 mmHg. Ventilation was kept constant. As gas mixture oxygen and air 1:1 was used without positive end-expiratory pressure (PEEP).


METHODS
Measurements were taken before and after creation of pneumoperitoneum with an intraabdominal pressure (IAP) of 10 mmHg, of 15 mmHg in 20 degrees head-down tilt, then in 20 degrees head-up tilt, and after deflation of PP. We determined peak inspiratory pressure (PIP), mean airway pressure (mPaw), P(ET)CO(2), expiratory minute volume (V(E)), heart rate (HR), and systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP). Respiratory system compliance (C(eff rs)) was calculated as quotient of tidal volume (V(T)) and PIP.


RESULTS
After creation of PP (IAP 10 mmHg), there was a significant increase of median PIP (3 cmH(2)O), mPaw (1 cm H(2)O) and arterial pressure (BP), (MAP by 7 mmHg), C(eff rs) decreased by 6 mL. cm H(2)O(-1). Increase of IAP to 15 mmHg led to a further increase of PIP (2 cm H(2)O) and mPaw (1 cm H(2)O), and a further decrease of C(eff rs) by 5 mL cm H(2)O(-1); BP decreased (MAP by 5.5 mmHg). Head-up or head down positions showed no significant hemodynamic or pulmonary changes. P(ET)CO(2)increased from 29.5 to 36 mmHg at an IAP of 15 mmHg, but then no further changes were noticed. Five minutes after deflation of pneumoperitoneum all values returned to baseline levels.


CONCLUSIONS
Creation of PP at an IAP of 15 mmHg reduced respiratory system compliance, and increased peak inspiratory and mean airway pressures, which quickly returned to normal values after deflation. Head-down or head-up position did not further alter those parameters.
Rauh
R
R
Department of Anesthesiology, University of Erlangen-Nuremberg, Nuremberg, Germany.
Hemmerling
T M
TM
Rist
M
M
Jacobi
K E
KE
D000328:Adult; D000771:Anesthesia, Intravenous; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D013509:Gynecologic Surgical Procedures; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics; D006801:Humans; D010535:Laparoscopy; D008170:Lung Compliance / Q000502:physiology*; D011027:Pneumoperitoneum / Q000503:physiopathology*; D011187:Posture / Q000502:physiology*; D012121:Respiration, Artificial; D015656:Respiratory Mechanics / Q000502:physiology