Abstract
Purpose
The literature describing the pulmonary mechanisms of increasedPA-PaO2 during general anaesthesia was examined to define the role of airway closure and sub-radiological atelectasis.
Source
A Medline search was designed to include articles dealing with the stated purpose, which is thus selective rather than a meta-analysis. The MeSH consisted of the following words: Anesthesia: general / inhalational; Pulmonary gas exchange; Ventilation.perfusion ratio; Lung Physiology; Lung Volume measurements; Closing Volume/Capacity; Functional Residual Capacity; Atelectasis; Diaphragm. Also, Dr H. Rothen and Prof. G. Hedenstierna supplied raw data.
Principal findings
Changes in shape and dimensions of the thorax and abdomen immediately after induction of anaesthesia result in marked alterations in the efficiency of oxygenation. Three pathways can be described: increased effects of airway closure, increased low ventilation: perfusion in dependent lung zones, and frank atelectasis. The magnitude of the alterations is determined by the patients’ age and body habitus. Some of the changes may carry-over into the postoperative period. The data suggest that increasing tidal volume during anaesthesia will reduce the effects of airway closure and that vital capacity breaths will re-expand atelectatic areas.
Conclusion
Airway closure and atelectasis contribute equally to the increased ventilation: perfusion mismatching that occurs during general anaesthesia.
Résumé
Objectif
La littérature médicale portant sur les mécanismes pulmonaires de l’augmentation de laPA-PaO2 pendant l’anesthésie a été révisée dans le but de préciser le rôle de la fermeture des voies aériennes et de l’atélectasie indétectable par examen radiologique.
Source
La recherche sur Medline était destinée à inclure tous les articles traitant du sujet, donc plutôt une sélection qu ’une méta-analyse. Les mots clés étaient les suivants: Anesthésie: générale par inhalation; Échanges gazeux pulmonaires; Rapport ventilation/perfusion; Physiologie pulmonaire; Mesures des volumes pulmonaires; Volume/capacité de fermeture; Capacité résiduelle fonctionnelle; Atélectasie; Diaphragme. En outre, le Dr H Rothen et le Pr G Hedenstierna ont fourni des données brutes.
Principales observations
Les changements morphologiques et dimensionnels thoraciques survenant immédiatement après l’induction de l’anesthésie altèrent profondément l’efficacité de l’oxygénation. Trois étapes sont décrites: augmentation des effets de la fermeture des voies aériennes, augmentation de la restriction ventilatoire; perfusion des zones pulmonaires inférieures; atélectasie évidente. L’importance des altérations est déterminée par l’âge du patient et son habitus physique. Quelques uns des changements peuvent se perpétuer dans la période postopératoire. Ces données suggèrent que l’augmentation du volume courant pendant l’anesthésie peut réduire les effets de la fermeture des voies aériennes et que les inspirations égales à la capacité vitale permettent la ré-expansion des zones atélectasiées.
Conlusion
La fermeture des voies aériennes et l’atélectasie contribuent également à la perturbation du rapport ventilation/perfusion pendant l’anesthésie générale.
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References
Craig DB, Wahba WM, Don H. Airway closure and lung volumes in surgical positions. Can Anaesth Soc J 1971; 18: 92–9.
Lundh R, Hedenstierna G. Ventilation-perfusion relationships during anaesthesia and abdominal surgery. Acta Anaesthesiol Scand 1983; 27: 167–73.
Gunnarsson L, Tokics L, Gustavsson H, Hedenstierna G. Influence of age on atelectasis formation and gas exchange impairment during general anaesthesia. Br J Anaesth 1991; 66: 423–32.
Wahba RWM. Perioperative functional residual capacity. Can J Anaesth 1991; 38: 384–400.
Wahba WM. Influence of aging on lung function — clinical significance of changes from age twenty. Anesth Analg 1983; 62: 764–76.
Craig DB, Wahba WM, Don HF, Couture JG, Becklake MR. “Closing volume” and its relationship to gas exchange in seated and supine positions. J Appl Physiol 1971; 31: 717–21.
Don HF, Craig DB, Wahba WM, Couture JG. The measurement of gas trapped in the lungs at functional residual capacity and the effects of posture. Anesthesiology 1971; 35: 582–90.
Don HF, Wahba WM, Craig DB. Airway closure, gas trapping, and the functional residual capacity during anesthesia. Anesthesiology 1972; 36: 533–9.
Weenig CS, Pietak S, Hickey RF, Fairley HB. Relationship of preoperative closing volume to functional residual capacity and alveolar — arterial oxygen difference during anesthesia with controlled ventilation. Anesthesiology 1974; 41: 3–7.
Gilmour I, Burnham M, Craig DB. Closing capacity measurement during general anesthesia. Anesthesiology 1976; 45: 477–82.
Hedenstierna G, McCarthy G, Bergström M. Airway closure during mechanical ventilation. Anesthesiology 1976; 44: 114–23.
Hedenstierna G, Santesson J. Airway closure during anesthesia: a comparison between resident-gas and argon-bolus techniques. J Appl Physiol 1979; 47: 874–81.
Hedenstierna G, Santesson J, Norlander O. Airway closure and distribution of inspired gas in the extremely obese, breathing spontaneously and during anaesthesia with intermittent positive pressure ventilation. Acta Anaesthesiol Scand 1976; 20: 334–42.
Juno P, Marsh HM, Knopp TJ, Rehder K. Closing capacity in awake and anesthetized-paralyzed man. J Appl Physiol 1978; 44: 238–44.
Bindslev L, Hedenstierna G, Santesson J, Norlander O, Gram I. Airway closure during anaesthesia, and its prevention by positive end expiratory pressure. Acta Anaesthesiol Scand 1980; 24: 199–205.
Bergman NA, Tien YK. Contribution of the closure of pulmonary units to impaired oxygenation during anesthesia. Anesthesiology 1983; 59: 395–401.
Dueck R, Prutow RJ, Davies NJH, Clausen JL, Davidson TM. The lung volume at which shunting occurs with inhalation anesthesia. Anesthesiology 1988; 69: 854–61.
Bindslev L, Hedenstierna G, Santesson J, Gottlieb I, Carvallhas A. Ventilation-perfusion distribution during inhalation anaesthesia. Effects of spontaneous breathing, mechanical ventilation and positive endexpiratory pressure. Acta Anaesthiol Scand 1981; 25: 360–71.
Craig DB, McCarthy DS. Airway closure and lung volumes during breathing with maintained airway positive pressures. Anesthesiology 1972; 36: 540–3.
Craig DB, Toole MA. Airway closure in pregnancy. Can Anaesth Soc J 1975; 22: 665–72.
Bevan DR, HoldcroftA, Loh L, MacGregor WG, O’Sullivan JC, Sykes MK. Closing volume and pregnancy. BMJ 1974; 1: 13–5.
Drummond GB, Wildsmith JAW, Masson AHB. Impairment of oxygen transfer in the lung by increasing oxygen concentration during halothane and trichloroethylene anaesthesia. Br J Anaesth 1978; 50: 255–60.
Rothen HU, Sporre B, Engberg G, Wegenius G, Hedenstierna G. Re-expansion of atelectasis during general anaesthesia: a computed tomography study. Br J Anaesth 1993; 71: 788–95.
Rothen HU, Sporre B, Engberg G, Wegenius G, Högman M, Hedenstierna G. Influence of gas composition on recurrence of atelectasis after a re-expansion maneuver during general anesthesia. Anesthesiology 1995; 82: 832–42.
Brismar B, Hedenstierna G, Lundquist H, Strandberg Å, Svensson L, Tokics L. Pulmonary densities during anesthesia with muscular relaxation — a proposal of atelectasis. Anesthesiology 1985; 62: 422–8.
Strandberg A, Hedenstierna G, Tokics L, Lundquist H, Brismar B. Densities in dependent lung regions during anaesthesia: atelectasis or fluid accumulation? Acta Anaesthesiol Scand 1986; 30: 256–9.
Tokics L, Strandberg A, Brismar B, Lundquist H, Hedenstierna G. Computerized tomography of the chest and gas exchange measurements during ketatnine anaesthesia. Acta Anaesthesiol Scand 1987; 31: 684–92.
Strandberg A, Tokics L, Brismar B, Lundquist H, Hedenstierna G. Constitutional factors promoting development of atelectasis during anaesthesia. Acta Anaesthesiol Scand 1987; 31: 21–4.
Hedenstierna G, Tokics L, Strandberg A, Lundquist H, Brismar B. Correlation of gas exchange impairment to development of atelectasis during anaesthesia and muscle paralysis. Acta Anaesthesiol Scand 1986; 30: 183–91.
Strandberg A, Tokics L, Brismar B, Lundquist H, Hedenstierna G. Atelectasis during anaesthesia and in the postoperative period. Acta Anaesthesiol Scand 1986; 30: 154–8.
Tokics L, Hedenstierna G, Strandberg Å, Brismar BO, Lundquist H. Lung collapse and gas exchange during general anesthesia: effects of spontaneous breathing, muscle paralysis and positive end-expiratory pressure. Anesthesiology 1987; 66: 157–67.
Rothen HU, Sporre B, Engberg G, Wegenius G, Hedenstierna G. Airway closure, atelectasis and gas exchange during general anesthesia. Br J Anaesth 1995; 74: A148.
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Wahba, R.M. Airway closure and intraoperative hypoxaemia: twenty-five years later. Can J Anaesth 43, 1144–1149 (1996). https://doi.org/10.1007/BF03011842
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DOI: https://doi.org/10.1007/BF03011842