Assessment of adequacy of mechanical ventilation in morbid obese patients during laparotomy for bariatric surgery

O.V. Vynnychenko


Background. In order to assess the adequacy of ventilation, the ratio of the dead space volume (Vd) to alveolar volume (Va) was calculated for all patients. Gas in airways does not take part in gas exchange. The tidal volume (Vt) is equal to the indices of Vd and Va. Integrated index is the ratio Vd/Vt = РаСО2 – ЕtCO2/РаСО2, where РаСО2 is a partial pressure of СО2 in arterial blood. In the norm, Vd/Vt equals 0.3–0.35. Materials and methods. In accordance with the tasks, all patients were divided into two groups depending on the mode of mechanical ventilation. The group 1 included 46 patients, which underwent mandatory volume-controlled ventilation. The group 2 consisted of 44 patients, who underwent mandatory pressure-controlled ventilation. Taking into account BMI, all patients had a high risk of development of hypoxemia. All patients underwent bariatric surgery and were performed an indirect pulse oximetry before surgery. Results. Eight patients experienced oxygen saturation of capillary blood under 90 %; 27 patients — 90–95 % and 9 persons — 96–100 %. During operation, the patients of both groups were monitored for arterial blood gases (RaО2, mmHg, and RaCO2, mmHg). Also, all patients were peerformed an indirect spirometry. Conclusions. No statistically significant dependence between the RaО2 level and Vd/Vt ratio was established; ρ = 0.155 (P > 0.05). At the same time, RaCO2 level and Vd/Vt ratio demonstrate a directly proportional correlation.


obesity; mechanical ventilation; dead space; alveolar ventilation; blood gases


Buchwald H., Oien D.M. Metabolic/bariatric surgery worldwide // Obes. Surg. — 2011 Apr. — 23(4). — Р. 427-36. Doi: 10.1007/s11695-012-0864-0.

Hensrud D.D., Klein S. Extreme obesity: A new medical crisis in the United States // Mayo Clin. Proc. — 2006 Oct. — 81 (10 Suppl.). — Р. S5-10. Doi: 10.1016/S0025-6196(11)61175-0.

Canoy D., Buchan I. Challenges in obesity epidemio­logy // Obes. Rev. — 2007 Feb. — 8(1 Suppl.). — Р. S1-11. Doi: 10.1111/j.1467-789X.2007.00310.x.

Bamgbade O.A., Rutter T.W., Nafiu O.O., Dorje P. Postoperative complications in obese and nonobese patients // World J. Surg. — 2007 Mar. — 31(3). — Р. 556-560; discussion 561. Doi: 10.1007/s00268-006-0305-0.

Matadial C.M., Slonin J.H. Surgery in morbidly obese // Complication in Anesthesia Elsevier. — 2007 Dec. — 1(4). — Р. 810-813. Doi: 10.1016/B978-1-4160-2215-2.50207-6.

Kaw R., Pasupuleti V., Walker E., Ramaswamy A., Foldvary-Schafer N. Postoperative complications in patients with obstructive sleep apnea // Chest. — 2012 Feb. — 141(2). — Р. 436-441. Doi: 10.1378/chest.11-0283.

Katyal N., Bollu P.C. Ventilation, Obesity-Hypoventilation Syndrome. — Treasure Island (FL): StatPearls Publishing, 2018.

Singh M., Liao P., Kobah S., Wijeysundera D.N., Shapiro C., Chung F. Proportion of surgical patients with undiagnosed obstructive sleep apnoea // Br. J. Anaesth. — 2013 Apr. — 110(4). — Р. 629-636. doi: 10.1093/bja/aes465.

Al-Alwan A., Bates J.H., Chapman D.G., Kaminsky D.A., DeSarno M.J., Irvin C.G. et al. The non-allergic asthma of obesity. A matter of distal lung compliance // Crit. Care Med. — 2014 Dec. — 189(12). — Р. 1494-1502.

Pulmonary atelectasis: a pathogenic perioperative entity / M. Duggan, B.P. Kavanagh // Anesthesiology. — 2005. — Vol. 102. — P. 838-854.

Wang C., Zhao N., Wang W. Intraoperative mechanical ventilation strategies for obese patients: a systematic review and network meta-analysis // Obes. Rev. — 2015 Jun. — 16(6). — P. 508-517.

Hemmes S.N., Serpa Neto A., Schultz M.J. Intrao­perative ventilatory strategies to prevent postoperative pulmonary complications: a meta-analysis // Curr. Opin. Anaesthesiol. — 2013 Feb. — 26(2). — Р. 126-133.

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