Heart rate and indirect blood pressure responses to four different field anesthetic protocols in wild born captive chimpanzees (pan troglodytes)

Abstract

Limited data are available on hemodynamic responses to anesthetic protocols in wild-born chimpanzees (Pan troglodytes). Accordingly, this study characterized the heart rate (HR) and blood pressure responses to four anesthetic protocols in 176 clinically healthy, wild-born chimpanzees undergoing routine health assessments. Animals were anesthetized with medetomidine–ketamine (MK) (n = 101), tiletamine–zolazepam (TZ) (n = 30), tiletamine–zolazepam–medetomidine (TZM) (n = 24), or medetomidine–ketamine (maintained with isoflurane) (MKI) (n = 21). During each procedure, HR, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were regularly recorded. Data were grouped according to anesthetic protocol, and mean HR, SBP, and DBP were calculated. Differences between mean HR, SBP, and DBP for each anesthetic protocol were assessed using the Kruskall–Wallis test and a Dunn multiple comparisons post hoc analysis. To assess the hemodynamic time course response to each anesthetic protocol, group mean data (±95% confidence interval [CI]) were plotted against time postanesthetic induction. Mean HR (beats/min [CI]) was significantly higher in TZ (86 [80–92]) compared to MKI (69 [61–78]) and MK (62 [60–64]) and in TZM (73 [68–78]) compared to MK. The average SBP and DBP values (mm Hg [CI]) were significantly higher in MK (130 [126–134] and 94 [91–97]) compared to TZ (104 [96–112] and 58 [53–93]) and MKI (113 [103–123] and 78 [69–87]) and in TZM (128 [120–135] and 88 [83–93]) compared to TZ. Time course data were markedly different between protocols, with MKI showing the greatest decline over time. Both the anesthetic protocol adopted and the timing of measurement after injection influence hemodynamic recordings in wild-born chimpanzees and need to be considered when monitoring or assessing cardiovascular health.