The Effect of the Prone Position on Pulmonary Mechanics Is Frame-Dependent

• Published in: Anesthesia and analgesia Vol. 87; no. 5; pp. 1175 - 1180
• Main Authors: Palmon, Sally C, Kirsch, Jeffrey R, Depper, Jane A, Toung, Thomas J. K
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD International Anesthesia Research Society 01.11.1998; Lippincott
• Subjects: Anesthesia; Anesthesia depending on type of surgery; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Female; Hemodynamics - physiology; Humans; Intraoperative Period; Male; Medical sciences; Middle Aged; Neurosurgery; Obesity - physiopathology; Prone Position - physiology; Respiratory Function Tests; Respiratory Mechanics - physiology; Smoking - physiopathology; Space life sciences; Human; Body mass index; Compression; Spinal cord; Lung function; Surgical equipment; Surgery; General anesthesia; Corporal biometry; Pulmonary ventilation; Patient position; Compliance(volume pressure)
• ISSN: 0003-2999; 1526-7598
• DOI: 10.1097/00000539-199811000-00037

By compressing the abdomen and restricting chest wall movement, the prone position compromises pulmonary compliance.For spine surgery, placing the anesthetized patient into the prone position increases the risk of improper ventilation. In this study, we tested the hypothesis that the compromise in pulmonary compliance is related to the patient's body habitus and the surgical frame used to support the patient while in the prone position. Seventy-seven adult patients were divided into three groups according to body mass indexnormal (n = 36) <or=to27 kg/m, heavy (n = 21) 28-31 kg/m, and obese (n = 20) >or=to32 kg/m. Patients were placed in the prone position supported by chest rolls, a Wilson frame, or the Jackson spinal surgery table (Jackson table) according to the surgeon's preferences. Peak airway pressure (at the proximal endotracheal tube), pleural pressure (esophageal balloon), and mean arterial pressure were recorded in the supine position and prone position within 15 min of the turn. Dynamic mean (+/- SD) pulmonary compliance (mL/cm H2 O) decreased when turning from the supine to the prone position in all three body mass groups when using chest rolls (normal 37 +/- 5 to 29 +/- 6; heavy 43 +/- 2 to 34 +/- 4; obese 42 +/- 8 to 32 +/- 6) or the Wilson frame (normal 39 +/- 6 to 32 +/- 7; heavy 43 +/- 16 to 34 +/- 10; obese 36 +/- 11 to 28 +/- 9). The dynamic pulmonary compliance was not altered in patients positioned on the Jackson table. Regardless of body habitus, using the Jackson Table forprone positioning was not associated with a significant alteration in pulmonary or hemodynamic variables. We conclude that moving patients from the supine to the prone position during anesthesia results in a decrease in pulmonary compliance that is frame-dependent but that is not affected by body habitus. ImplicationsWe hypothesized that compromise in pulmonary compliance in the prone position is related to the patient's body mass index and the surgical frame used. In this study, we demonstrated that prone positioning during anesthesia results in a decrease in pulmonary compliance that is frame-dependent but that is not affected by body mass index.(Anesth Analg 1998;87:1175-80)