Cardiorespiratory Effects of Isoflurane Anesthesia in Crested Caracaras (Caracara plancus)

Abstract

To evaluate the cardiorespiratory changes induced by isoflurane (ISO) anesthesia in the crested caracara (Caracara plancus), eight crested caracaras that weighed 1.0 kg (range 0.9-1.1 kg) were the subjects for the study. The birds were anesthetized by face mask with ISO for brachial artery catheterization. After recovery, anesthesia was re-induced and maintained with ISO with spontaneous ventilation. Electrocardiography, direct systolic arterial blood pressure (SAP), diastolic arterial blood pressure (DAP), mean arterial blood pressure (MAP), respiratory rate (RR), end-tidal carbon dioxide (P(ET)CO2), and cloacal temperature (T degrees C) were measured before induction (baseline, under physical restraint) and after 5, 10, 15, 20, 25, 30, 35, and 40 min of ISO anesthesia. Arterial blood samples were collected for blood gas analysis at baseline, 10, 25, and 40 min. No cardiac arrhythmias were observed in the present study. RR, SAP, DAP, MAP, T degrees C and pH decreased from baseline values, whereas arterial partial pressures of oxygen and carbon dioxide, bicarbonate concentration, and P(ET)CO2 were significantly higher than baseline. Apnea was not observed in any bird. ISO anesthesia is suitable for use in healthy members of this species despite the moderate cardiovascular and respiratory depression produced.

Anaesthesia with sevoflurane in pigeons: minimal anaesthetic concentration (MAC) determination and investigation of cardiorespiratory variables at 1 MAC

“…Such mild hypercapnia is commonly observed during anaesthesia with spontaneous ventilation in birds (Ludders and others 1989, Joyner and others 2008, Escobar and others 2011, 2012, Botman and others 2016). Hypercapnia can be explained by hypoventilation due to dorsal recumbency, muscle relaxation and the effects of the volatile anaesthetic agents on the central and peripheral chemoreceptors (Gleed and Ludders 2001).…”

Physiological alteration, quality of anesthesia and economy of isoflurane in domestic chickens (Gallus domesticus)

“…The decrease in cloacal temperature during anesthesia may be due to disruption of thermoregulation and heat loss [17]. Decrease in cloacal temperature during isoflurane anesthesia have been was reported in crested serpent eagle ( Spilornis cheela hoya ) [16], red-tailed hawk ( Buteo jamaicensis ) [1], crested caracaras [5], chicken [18], and pigeon [19]. …”

“…The decrease in heart rate during anesthesia were reported in bald eagle [20], chicken [21,22], hispaniolan amazon parrot (Amazona ventralis) [14], and ostriches [23]. Whereas, nonsignificant reduction in heart rate during anesthesia was reported in pigeon [19] and crested caracaras [5]. In wild red kite ( Milvus milvus ), heart rate was maintained at 240-260 beats/min during coelioscopy under isoflurane anesthesia [24].…”

“…Decrease in respiratory rate might have resulted due to respiratory depressant activity of isoflurane further inducing hypercapnia [16]. These findings were concurrent to Hispaniolan amazon parrot ( A. ventralis ) [14], chicken [18], ostriches [23], crested caracaras [5]. However, respiration did not show a significant difference in pigeon during isoflurane anesthesia [19].…”

“…Isoflurane is the anesthetic of choice for birds [4,5] due to its relative safety and effectiveness [6], better control over the change of the anesthetic depth and recovery [7] and because of its rapid reversal resulting in a wide margin of safety and it is well tolerated by all the species [8]. Isoflurane does not produce any clinically deleterious effect on cardiorespiratory functions in pigeons [9].…”