Influence of capnoperitoneum on intraocular pressure in spontaneously breathing dogs undergoing ovariectomy

Abstract

ABSTRACT:The objective of this study was to evaluate potential changes in intraocular pressure in spontaneously breathing dogs undergoing laparoscopic ovariectomy with capnoperitoneum. Twenty bitches undergoing laparoscopic ovariectomy were enrolled in a prospective clinical trial. The dogs were under general anaesthesia and were breathing spontaneously throughout the entire period of the procedure. Capnoperitoneum was then established with an intra-abdominal pressure setting of 10 mmHg. Collected data included intraocular pressure, pupil size, heart rate, respiratory frequency, systolic and diastolic arterial pressure, end-tidal CO 2 , oxygen saturation of haemoglobin and tidal volume. Data were recorded 5 min before starting CO 2 -insufflation (baseline), after capnoperitoneum establishment (T0), and at further 5-min intervals (T5, T10, T15, T20, T25, T30). Compared to baseline, pupil size was increased at T30 (P = 0.03) and respiratory frequency at T25 (P < 0.01) and T30 (P = 0.02). No other significant changes were found regarding intraocular pressure. Our data show that the induction of an intra-abdominal pressure of 10 mmHg for a 30-min laparoscopy with the use of medetomidine-butorfanolpropofol-isoflurane in spontaneously breathing dogs in the horizontal position does not result in any important changes in intraocular pressure or end-tidal CO 2 .Keywords: laparoscopy; veterinary ophthalmology; pupil size; heart rate, respiratory frequency; systolic and diastolic arterial pressure; oxygen saturation of haemoglobin; tidal volume; end-tidal CO 2 List of abbreviations DAP = diastolic arterial pressure, EtCO 2 = end-tidal CO 2 , f R = respiratory frequency, HR = heart rate, IOP = intraocular pressure, PS = pupil size, SAP = systolic arterial pressure, SpO 2 = oxygen saturation of haemoglobin, V T = tidal volume