Spontaneous breathing during anaesthesia: first, do no harm

Controlled respiration and mechanical ventilation have long been part of anaesthetic practice. Modern surgery, anaesthetic techniques, and new agents require a reappraisal of this established habit. In many circumstances the adverse effects of mechanical ventilation can be avoided by the use of the laryngeal mask and allowing spontaneous ventilation. In addition to the more prominent advantages, such as less sore throat, reliable assessment of anaesthetic depth, and good recovery, there may be more subtle advantages such as improved cardiopulmonary interaction, better distribution of ventilation, and reduced mechanically induced lung damage. Some of these advantages may be also applied during mechanical ventilation, by allowing continued muscle activity or continuously varying the size of the tidal breaths.Mechanical ventilation is often unnecessary and may be harmful.

respiration, neuromuscular blockade, artificial respiration, pul-monary gas exchange  

1. Bodman R, Gillies D. Ethylene and endotracheal anaesthesia. In: Harold Griffith, editor. The evolution of modern anaesthesia. Toronto: Hannah and Dundurn; 1992;4:39-48.

2. Bernard C. Introduction à l’étude de la médecine expérimentale. 1865

Accessed at www.gutenberg.org/etext/16234.

3. Gillies J. Physiological trespass in anaesthesia. Proc Roy Soc Med 2007; 45:1-6.

4. Marsh HM, Rehder K, Sessler AD, Fowler WS. Effects of mechanical ventilation, Muscle Paralysis, and Posture on Ventilation-Perfusion relationships in Anesthetized man. Anesthesiol 1973;38:59-67.

5. Nunn JF, Hill DW. Respiratory deadspace and arterial to end tidal CO2 tension difference in anesthetized man. J Appl Physiol 1960;15:383-9.

6. Tokics L, Hedenstierna G, Strandberg A, Brismar B, Lundquist H. Lung collapse and gas exchange during general anesthesia: effects of spontaneous breathing, muscle paralysis, and positive end-expiratory pressure. Anesthesiol 1987; 66:157-67.

7. Hayano J, Yasuma F, Okada A, Mukai S, Fujinami T. Respiratory sinus arrhythmia - phenomenon improving pulmonary gas- exchange and circulatory efficiency. Circulation 1996;94:842-7.

8. Larsen PD, Tzeng YC, Galletly DC. Quantal ventilatory variability during spontaneous breathing anaesthesia. Br J Anaesth 2003;91:184-9.

9. Dreyfuss D, Saumon G. Role of tidal volume, FRC and end-inspiratory volume in the development of pulmonary edema following mechanical ventilation. Am Rev Respir Dis 1993;148:1194-203.

10. Nucci G, Suki B, Lutchen K. Modeling airflow-related shear stress during heterogeneous constriction and mechanical ventilation. J Appl Physiol 2003; 95:348-56.

11. D’Angelo E, Pecchiari M, Saetta M, Balestro E, Milic-Emili J. Dependence of lung injury on inflation rate during low-volume ventilation in normal open-chest rabbits. J Appl Physiol 2004;97:260-8.

12. Mutch WAC, Eschun GM, Kowalski SE, Graham MR, Girling LG, Lefevre GR. Biologically variable ventilation prevents deterioration of gas exchange during prolonged anaesthesia. Br J Anaesth 2000;84:197-203.

13. Boker A, Haberman CJ, Girling L, Guzman RP, Louridas G, Tanner JR et al. Variable ventilation improves perioperative lung function in patients undergoing abdominal aortic aneurysmectomy. Anesthesiol 2004;100:608-16.

14. Hedenstierna G, Tokics L, Lundquist H, Adresson T, Strandberg A, Brismar B. Phrenic-nerve stimulation during halothane anesthesia. Anesthesiol 1994;80:751-60.

15. Bregeon F, Delpierre S, Roch A, Kajikawa O, Martin TR, Utillo-Touati A et al. Persistence of diaphragmatic contraction influences the pulmonary inflammatory response to mechanical ventilation. Respiratory Physiology & Neurobiology 2004;142:185-95.

16. Natalini G, Franceschetti ME, Pletti C, Recupero D, Lanza G, Bernardini A. Impact of laryngeal mask airway and tracheal tube on pulmonary function during the early postoperative period. Acta Anaesth Scand 2002;46:525-8.

17. Maltby JR, Beriault MT, Watson NC, Liepert DJ, Fick GH. LMA-Classic (TM) and LMA-ProSeal (TM) are effective alternatives to endotracheal intubation for gynaecologic laparoscopy. Canadian Journal of Anaesthesia-Journal Canadien D Anesthesie 2003;50:71-7.

18. Viby-Mogensen J. Editorial I - Postoperative residual curarization and evidence-based anaesthesia. Br J Anaesth 2000;84:301-3.

19. Baillard C, Clec’h C, Catineau J, Salhi F, Gehan G, Cupa M et al. Postoperative residual neuromuscular block: a survey of management. Br J Anaesth 2005;95:622-6.

20. Warner MA, Warner ME, Weber JG. Clinical significance of pulmonary aspiration during the perioperative period. Anesthesiol 1993;78:56-62.

21. Practice advisory for intraoperative awareness and brain function monitoring - A report by the American Society of Anaesthesiologists task force on intraoperative awareness. Anesthesiol 2006;104:847-64.

22. Strickland TL, Drummond GB. Comparison of pattern of breathing with other measures of induction of anaesthesia, using propofol, methohexital, and sevoflurane. Br J Anaesth 2001;86:639-44.

23. Thompson S, Drummond GB. Loss of volition and pain response during induction of anaesthesia with propofol or sevoflurane. Br J Anaesth 2001;87:283-6.

24. Payne K, Moore EW, Elliott RA, Pollard BJ, McHugh GA. Anaesthesia for day case surgery: a survey of adult clinical practice in the UK. Eur J Anaesth 2003;20:311-7.

25. Simpson RB, Russell D. Anaesthesia for daycase gynaecological laparoscopy: a survey of clinical practice in the United Kingdom. Anae 1999; 54:72-6.

26. Hager H, Reddy D, Mandadi G, Pulley D, Eagon JC, Sessler DI et al. Hypercapnia improves tissue oxygenation in morbidly obese surgical patients. Anesthesia and Analgesia 2006;103:677-81.