Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-19T12:26:02.570Z Has data issue: false hasContentIssue false

Respiratory effects of the kneeling prone position for low back surgery

Published online by Cambridge University Press:  23 December 2004

M. Radstrom
Affiliation:
Sahlgrenska University Hospital, Department of Anaesthesia and Intensive Care, Göteborg, Sweden
A. C. Loswick
Affiliation:
Sahlgrenska University Hospital, Department of Anaesthesia and Intensive Care, Göteborg, Sweden
J. P. Bengtsson
Affiliation:
Sahlgrenska University Hospital, Department of Anaesthesia and Intensive Care, Göteborg, Sweden
Get access

Extract

Summary

Background and objective: The kneeling prone position is often used for low back surgery in order to decrease intraoperative bleeding and increase the surgical exposure of the vertebral canal. The aim of this study was to assess effects of the kneeling prone position on respiratory gas exchange focusing on oxygen consumption and early changes in oxygenation.

Methods: Thirty ASA I–II patients scheduled for low back surgery in the kneeling prone position were studied. Anaesthesia was maintained with isoflurane, 1.2% end-tidal concentration. Respiratory gas exchange was measured with indirect calorimetry.

Results: When the patients were turned into the kneeling prone position their oxygenation was immediately improved – measured by arterial oxygen tension and arterial oxygen saturation. The oxygen uptake rate did not change from a baseline supine level of 76 mL min−1 m−2, but the carbon dioxide excretion rate decreased from a baseline supine value of 71 mL min−1 m−2 to 66 mL min−1 m−2 at 5 and 10 min after the kneeling prone position was adopted. Alveolar ventilation decreased in the kneeling prone position.

Conclusions: The present study demonstrates that the kneeling prone position improves oxygenation and that the mechanisms involved are fast in onset. Furthermore, the prone position does not change oxygen consumption although alveolar ventilation is significantly reduced. The changes in alveolar ventilation could possibly be the result of circulatory changes caused by the prone position, but further studies are needed to clarify that hypothesis.

Type
Original Article
Copyright
2004 European Society of Anaesthesiology

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ecker A. Kneeling position for operations on the lumbar spine. Especially for protruded intervertebral disc. Surgery 1949; 25: 112113.Google Scholar
Böstman O, Hyrkäs J, Hirvensalo E, Kallio E. Blood loss, operating time, and positioning of the patient in lumbar disc surgery. Spine 1990; 15: 360363.Google Scholar
Lumb AB, Nunn JF. Respiratory function and rib cage contribution to ventilation in body positions commonly used during anaesthesia. Anesth Analg 1991; 73: 422426.Google Scholar
Jolliet P, Bulpa P, Chevrolet JC. Effects of the prone position on gas exchange and hemodynamics in severe acute respiratory distress syndrome. Crit Care Med 1998; 26: 19771985.Google Scholar
Flaaten H, Aardal S, Hevroy O. Improved oxygenation using the prone position in patients with ARDS. Acta Anaesthesiol Scand 1998; 42: 329334.Google Scholar
Brazzi L, Ravagnan I, Pelosi P, Gattinoni L. Prone position in anaesthesia and intensive care. Care Crit Ill 1999; 15: 510.Google Scholar
Pelosi P, Croci M, Calappi E, et al. The prone positioning during general anesthesia minimally affects respiratory mechanics while improving functional residual capacity and increasing oxygen tension. Anesth Analg 1995; 80: 955960.Google Scholar
Nyrén S, Mure M, Jacobsson H, Larsson SA, Lindahl SGE. Pulmonary perfusion is more uniform in prone than in supine position: scintigraphy in healthy humans. J Appl Physiol 1999; 86: 11351141.Google Scholar
Mure M, Lindahl SGE. Prone position improves gas exchange – but how? Acta Anaesthesiol Scand 2001; 45: 150159.Google Scholar
Bengtsson JP, Bengtsson A, Stenqvist O. Uptake of enflurane and isoflurane during spontaneous and controlled ventilation. Anaesth Intens Care 1992; 20: 191195.Google Scholar
Bengtsson JP, Bengtsson J, Bengtsson A, Stenqvist O. Sampled gas need not be returned during low flow anesthesia. J Clin Monitor 1993; 9: 330334.Google Scholar
Nunn JF. Applied Respiratory Physiology, 4th edn. Oxford, UK: Butterworth–Heinemann, 1993: 128129, 195197.
Thomas SH. Impedance cardiography using the Sramek-Bernstein method: accuracy and variability at rest and during exercise. Br J Clin Pharmacol 1992; 34: 467476.Google Scholar
Aukburg SJ, Geer RT, Wollman H, Neufeld GR. Errors in measurement of oxygen uptake due to anesthetic gases. Anesthesiology 1985; 62: 5459.Google Scholar
Shibutani K, Muraoka M, Shirasaki S, Kubal K, Sanchala VT, Gupte P. Do changes in end-tidal PCO2 quantitatively reflect changes in cardiac output? Anesth Analg 1994; 79: 829833.Google Scholar
Wahba RWM, Tessler MJ, Béïque F, Kleiman SJ. Changes in PCO2 with acute changes in cardiac index. Can J Anesth 1996; 43: 243245.Google Scholar
Mahajan RP, Hennessy N, Aitkenhead AR, Jellinek D. Effect of three different surgical prone positions on lung volumes in healthy volunteers. Anaesthesia 1994; 49: 583586.Google Scholar
Numa AH, Hammer J, Newth CJ. Effect of prone and supine position on functional residual capacity, oxygenation, and respiratory mechanics in ventilated infants and children. Am J Respir Crit Care Med 1997; 156: 11851189.Google Scholar
Mutoh T, Guest RJ, Lamm WJE, Albert RK. Prone position alters the effect of volume overload on regional pleural pressures and improves hypoxemia in pigs in vivo. Am Rev Respir Dis 1992; 146: 300306.Google Scholar