Work

Laparoscopic-induced pneumoperitoneum does not impair oxygenation in large-breed dogs but worsens hypercapnia, which is improved by low positive end-expiratory pressure ventilation

Year: 2026

Type: article

Abstract: Objective: To evaluate whether laparoscopic-induced pneumoperitoneum (8 to 10 mm Hg) in reverse Trendelenburg (RT) impairs ventilation and oxygenation, and whether pressure-controlled ventilation (PCV) with low positive end-expiratory pressure (PEEP; 3 cm H2O [PEEP-3] or 5 cm H2O [PEEP-5]) improves these variables in sevoflurane-anesthetized large-breed dogs. Methods: Cardiopulmonary variables were recorded before (T0) and 15 minutes after insufflation in RT (T1) during spontaneous ventilation (SV) and again 45 minutes after initiating PCV (T2) using 20 breaths/min, an inspiratory-to-expiratory ratio of 1:2, PEEP-3 or PEEP-5, and peak inspiratory pressure (PIP) starting at 10 or 12 cm H2O, respectively, with 2-cm H2O increments every 5 minutes until end-tidal CO2 reached 35 to 40 mm Hg or PIP reached 20 cm H2O. The final dataset was collected 5 minutes after desufflation on PCV (T3). Results: During SV, pneumoperitoneum worsened Paco2 (median [range]; PEEP-3, 70.0 mm Hg [62.0 to 86.1 mm Hg]; PEEP-5, 72.0 mm Hg [61.0 to 81.9 mm Hg]) and plasma pH (mean ± SD; PEEP-3, 7.18 ± 0.04; PEEP-5, 7.18 ± 0.02). During PCV, after titrating PIP (median, 16 and 18 cm H2O, respectively), these variables improved, but in PEEP-5, pH remained lower (mean ± SD; 7.36 ± 0.03 vs 7.32 ± 0.04), and dead space-to-tidal volume higher (median [range]; 9.4% [2.2% to 16.1%] vs 16.2% [7.0% to 34.0%]). Oxygenation was unaffected, and cardiovascular changes and interventions were similar between groups. Conclusions: During SV, pneumoperitoneum in RT worsened hypercapnia and acidemia without impairing oxygenation. During PCV, PEEP-3 provided the best respiratory outcome. Clinical Relevance: Low PEEP-3 PCV improves pneumoperitoneum-induced hypoventilation in large-breed dogs without oxygenation impairment, whereas PEEP-5 may be limited by PIP.

Source: Journal of the American Veterinary Medical Association

DOI: 10.2460/javma.25.12.0797