Optimal inspiratory pressure for face mask ventilation in paralyzed and unparalyzed children to prevent gastric insufflation: a prospective, randomized, non-blinded study

  • Ji-Hyun Lee
  • Haesun Jung
  • Eun-Hee Kim
  • In-Kyung Song
  • Hee-Soo Kim
  • Jin-Tae KimEmail author
Reports of Original Investigations



Gastric insufflation is common during face mask ventilation and results in unfavourable respiratory events in children. The purpose of this study was to evaluate the effect of a muscle relaxant on gastric insufflation and determine the optimal inspiratory pressure during face mask ventilation in children.


Children aged one month to five years were randomly assigned to neuromuscular blocker (NM) or non-neuromuscular blocker (non-NM) groups. After administering intravenous anesthetics, face mask ventilation commenced via pressure-controlled mechanical ventilator. Initial inspiratory pressure was 10 cmH2O and was increased by 2 cmH2O until gastric insufflation was detected via gastric ultrasonography or epigastric auscultation. The primary outcome was the difference in the inspiratory pressure that causes gastric insufflation between the two groups. Diagnostic methods that detect gastric insufflation first were also evaluated.


There was no significant difference in the median [interquartile range] inspiratory pressure inducing gastric insufflation between the non-NM (n = 52) and NM groups (n = 60) (18 [16-18] cmH2O vs 18.0 [16-20] cmH2O; median difference, 0 cmH2O; 95% confidence interval [CI], 0 to 2; P = 0.57). The incidence of gastric insufflation increased with increasing inspiratory pressure. Gastric insufflation was detected first by ultrasonography in 44% and by epigastric auscultation in 19% of the non-NM group (difference in percentage, 25%; 95% CI, 6 to 42; P = 0.006) and by ultrasonography in 73% and by epigastric auscultation in 7% of the NM group (difference in percentage, 66%; 95% CI, 50 to 78; P < 0.001).


A neuromuscular blocking agent has minimal effect on the inspiratory pressure that causes gastric insufflation during face mask ventilation in children.

Trial Registration (NCT02471521); registered 15 June 2015.

Pression inspiratoire optimale pour ventilation au masque facial évitant l’insufflation gastrique chez des enfants paralysés et non paralysés: une étude randomisée sans insu



L’insufflation gastrique est fréquente au cours de la ventilation au masque et entraîne des événements respiratoires délétères chez les enfants. L’objectif de cette étude était d’évaluer l’effet d’un relaxant musculaire sur l’insufflation gastrique et de déterminer la pression inspiratoire optimale pendant la ventilation au masque des enfants.


Des enfants âgées d’un mois à cinq ans ont été affectés de manière aléatoire dans un groupe recevant un bloqueur neuromusculaire (groupe NM) ou dans un groupe n’en recevant pas (groupe non-NM). La ventilation au masque avec un ventilateur mécanique à contrôle de pression a commencé après l’administration intraveineuse des anesthésiques. La pression inspiratoire initiale était de 10 cmH2O et a été augmentée par incréments de 2 cmH2O jusqu’à ce qu’une insufflation gastrique soit détectée par échographie gastrique ou auscultation épigastrique. Le critère d’évaluation principal était la différence de pression inspiratoire entraînant une insufflation entre les deux groupes. Les méthodes diagnostiques de détection précoce de l’insufflation gastrique ont été également évaluées.


Il n’y a pas eu de différence significative concernant la valeur médiane [écart interquartile] de la pression inspiratoire induisant une insufflation gastrique entre le groupe non-NM (n = 52) et le groupe NM (n = 60) (18 [16-18] cmH2O contre 18,0 [16-20] cmH2O; différence des médianes, 0 cmH2O; intervalle de confiance [IC] à 95 %: 0 à 2; P = 0,57). L’incidence de l’insufflation gastrique a augmenté avec l’augmentation de la pression inspiratoire. L’insufflation gastrique a d’abord été détectée par l’échographie dans 44 % des cas, et par auscultation épigastrique dans 19 % des cas dans le groupe non-NM (différence en pourcentage, 25 %; IC à 95 %, 6 à 42; P = 0,006) et par échographie dans 73 % et par auscultation épigastrique dans 7 % des cas dans le groupe NM (différence en pourcentage, 66 %; IC à 95 %, 50 à 78; P = 0,001).


Un agent bloqueur neuromusculaire n’a qu’un effet minime sur la pression inspiratoire entraînant une insufflation gastrique au cours de la ventilation au masque chez des enfants.

Enregistrement de l’essai clinique (NCT02471521); enregistré le 15 juin 2015.


Conflict of interest

None declared.

Editorial responsibility

This submission was handled by Dr. Gregory L. Bryson, Deputy Editor-in-Chief, Canadian Journal of Anesthesia.

Author Contributions

Jin-Tae Kim and Ji-Hyun Lee contributed substantially to all aspects of this manuscript, including conception and design; acquisition, analysis, and interpretation of data; and drafting the article. Eun-Hee Kim contributed substantially to the conception and design of the manuscript. In-Kyung Song contributed substantially to the acquisition of data. Hee-Soo Kim contributed to the analysis of data. Haesun Jung contributed substantially to the interpretation of data.


Support was provided solely from institutional and/or department sources.


  1. 1.
    Weiler N, Heinrichs W, Dick W. Assessment of pulmonary mechanics and gastric inflation pressure during mask ventilation. Prehosp Disaster Med 1995; 10: 101-5.CrossRefGoogle Scholar
  2. 2.
    Weiler N, Latorre F, Eberle B, Goedecke R, Heinrichs W. Respiratory mechanics, gastric insufflation pressure, and air leakage of the laryngeal mask airway. Anesth Analg 1997; 84: 1025-8.CrossRefGoogle Scholar
  3. 3.
    Ho-Tai LM, Devitt JH, Noel AG, O’Donnell MP. Gas leak and gastric insufflation during controlled ventilation: face mask versus laryngeal mask airway. Can J Anaesth 1998; 45: 206-11.CrossRefGoogle Scholar
  4. 4.
    Neelakanta G, Chikyarappa A. A review of patients with pulmonary aspiration of gastric contents during anesthesia reported to the Departmental Quality Assurance Committee. J Clin Anesth 2006; 18: 102-7.CrossRefGoogle Scholar
  5. 5.
    Seet MM, Soliman KM, Sbeih ZF. Comparison of three modes of positive pressure mask ventilation during induction of anaesthesia: a prospective, randomized, crossover study. Eur J Anaesthesiol 2009; 26: 913-6.CrossRefGoogle Scholar
  6. 6.
    Paal P, Neurauter A, Loedl M, et al. Effects of stomach inflation on haemodynamic and pulmonary function during cardiopulmonary resuscitation in pigs. Resuscitation 2009; 80: 365-71.CrossRefGoogle Scholar
  7. 7.
    Brimacomb J, Keller C, Kurian S, Myles J. Reliability of epigastric auscultation to detect gastric insufflation. Br J Anaesth 2002; 88: 127-9.CrossRefGoogle Scholar
  8. 8.
    Perlas A, Chan VW, Lupu CM, Mitsakakis N, Hanbidge A. Ultrasound assessment of gastric content and volume. Anesthesiology 2009; 111: 82-9.CrossRefGoogle Scholar
  9. 9.
    Perlas A, Davis L, Khan M, Mitsakakis N, Chan VW. Gastric sonography in the fasted surgical patient: a prospective descriptive study. Anesth Analg 2011; 113: 93-7.CrossRefGoogle Scholar
  10. 10.
    Bouvet L, Albert ML, Augris C, et al. Real-time detection of gastric insufflation related to facemask pressure-controlled ventilation using ultrasonography of the antrum and epigastric auscultation in nonparalyzed patients: a prospective, randomized, double-blind study. Anesthesiology 2014; 120: 326-34.CrossRefGoogle Scholar
  11. 11.
    Wilson EB. Probable inference, the law of succession, and statistical inference. J Am Stat Assoc 1927; 22: 209-12.CrossRefGoogle Scholar
  12. 12.
    Newcombe RG. Interval estimation for the difference between independent proportions: comparison of eleven methods. Stat Med 1998; 17: 873-90.CrossRefGoogle Scholar
  13. 13.
    Qian X, Hu Q, Zhao H, et al. Determination of the optimal inspiratory pressure providing adequate ventilation while minimizing gastric insufflation using real-time ultrasonography in Chinese children: a prospective, randomized, double-blind study. BMC Anesthesiol 2017; 17: 126.CrossRefGoogle Scholar
  14. 14.
    Thorn K, Thorn SE, Wattwil M. The effects on the lower esophageal sphincter of sevoflurane induction and increased intra-abdominal pressure during laparoscopy. Acta Anaesthesiol Scand 2006; 50: 978-81.CrossRefGoogle Scholar
  15. 15.
    Vanner RG, Pryle BJ, O’Dwyer JP, Reynolds F. Upper oesophageal sphincter pressure and the intravenous induction of anaesthesia. Anaesthesia 1992; 47: 371-5.CrossRefGoogle Scholar
  16. 16.
    McGrath JP, McCaul C, Byrne PJ, Walsh TN, Hennessy TP. Upper oesophageal sphincter function during general anaesthesia. Br J Surg 1996; 83: 1276-8.CrossRefGoogle Scholar
  17. 17.
    Hunt PC, Cotton BR, Smith G. Barrier pressure and muscle relaxants. Comparison of the effects of pancuronium and vecuronium on the lower oesophageal sphincter. Anaesthesia 1984; 39: 412-5.CrossRefGoogle Scholar
  18. 18.
    Ahlstrand R, Thorn SE, Wattwil M. High-resolution solid-state manometry of the effect of rocuronium on barrierpressure. Acta Anaesthesiol Scand 2011; 55: 1098-105.CrossRefGoogle Scholar
  19. 19.
    Lagarde S, Semjen F, Nouette-Gaulain K, et al. Facemask pressure-controlled ventilation in children: what is the pressure limit? Anesth Analg 2010; 110: 1676-9.CrossRefGoogle Scholar
  20. 20.
    Moroz SP, Espinoza J, Cumming WA, Diamant NE. Lower esophageal sphincter function in children with and without gastroesophageal reflux. Gastroenterology 1976; 71: 236-41.PubMedGoogle Scholar
  21. 21.
    Park JH, Kim JY, Lee JM, Kim YH, Jeong HW, Kil HK. Manual vs. pressure-controlled facemask ventilation for anaesthetic induction in paralysed children: a randomised controlled trial. Acta Anaesthesiol Scand 2016; 60: 1075-83.CrossRefGoogle Scholar

Copyright information

© Canadian Anesthesiologists' Society 2018

Authors and Affiliations

  1. 1.Department of Anesthesiology and Pain MedicineSeoul National University Hospital, Seoul National University College of MedicineSeoulRepublic of Korea
  2. 2.Department of Anesthesiology and Pain Medicine, Asan Medical CenterUniversity of Ulsan College of MedicineSeoulRepublic of Korea

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