Outcomes and Complications Associated With Caudal Thoracic and Abdominal Air Sac Cannulation in 68 Birds

Air sac cannulation is used both as an emergency procedure in avian patients with severe upper respiratory compromise, as well as a means of routine ventilation for surgery of the head and neck. The objective of this retrospective study was to describe and quantify the complications associated with air sac cannulation in birds. Medical records were retrieved for all patients that underwent caudal thoracic or abdominal air sac cannulation at a single center between August 2004 and October 2020. Patient signalment, indication for air sac cannulation, location of air sac cannula (ASC) placement, occurrence and category of complications encountered, and survival data were recorded. Eighty-four ASCs were placed in 68 birds across 6 orders; 95.2% (80/84) of cases survived general anesthesia for initial ASC placement. The side and position of ASC placement were known in 33.3% (28/84) and 21.4% (18/84) of cases, respectively. Survival to ASC removal was known in 91.3% (73/80) of cases; 43 (58.9%) of these 73 cases survived to ASC removal. Complications were observed in 32.5% (26/80) of cases, and 11.5% (3/26) of cases died as a direct result of the complication. The most common reported ASC complication was loss of patency in 23.8% (19/80) of cases. Increased likelihoods for complications were seen in cases where exercise intolerance (P = 0.04) or abnormal respiratory sounds (P = 0.04) were reported at presentation. Increased likelihoods for survival to ASC removal were seen with intercostal placements (P = 0.049) and peri-interventional antibiotic therapy (P = 0.005). Decreased likelihood for survival to ASC removal was seen in cases where voice change was reported at presentation (P = 0.02). This study demonstrates a moderate risk of ASC complication, with a guarded overall prognosis for survival to ASC removal.

Raptor Sedation and Anesthesia

Sedation and/or anesthesia is routinely and successfully used in raptors for a wide variety of procedures from the routine such as physical examination, radiographs, or venipuncture, to the more complex, such as orthopedic surgeries. Understanding the anatomy and physiology of raptor patients who present for care, and being fully prepared before the start of any procedure, can increase the success of anesthetic procedures. Recent advances in raptor sedation and anesthesia continue to improve the health and welfare of these avian patients.

Psittacine Sedation and Anesthesia

Successful management of sedation/anesthesia of psittacine species relies on familiarity with their specific anatomy and physiology, and detailed knowledge of the recent advancements in applied pharmacology of the anesthetics and perianesthetic monitoring of cardiovascular and respiratory functions. Each sedation/anesthetic plan should be patient-specific, developed based on preexisting conditions, size, species, age, and estimated risk. Other key factors to improve safety, quality of perioperative care, and client satisfaction are anticipation of complications, extension of close monitoring to the recovery phase, multimodal analgesic approach, stress prevention/reduction, and transparent communication with the owner.

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

Aim:

Aim of the study was to evaluate the effect of isoflurane anesthesia on physiological parameters, assessment of anesthetic qualities, and economy of use of isoflurane in domestic chickens (Gallus domesticus).

Materials and Methods:

In this study, 18 apparently healthy adult domestic chickens were selected randomly and divided into three groups. The birds were anesthetized by masked induction with isoflurane at a dose rate of 3.5%, 4%, and 5% and were maintained with 1.5%, 2%, and 2.5% isoflurane with oxygen by endotracheal intubation in Groups I, II, and III, respectively. Physiological parameters, viz., cloacal temperature, heart rate, and respiration rate were recorded at 0, 5, 10, 20, 30, 40, 50, and 60 min. The quality of anesthesia was assessed on the basis of induction time, induction behavior, quality of sedation, production of analgesia, degree of muscle relaxation, palpebral reflex, recovery time, and recovery behavior. The economy of anesthesia was calculated in terms of quantity of isoflurane utilized during 60 min of study. Statistical analysis was performed by analysis of variance, Duncan’s multiple range tests.

Results:

There was significant decrease (p<0.01) in physiological parameters such as in cloacal temperature, heart rate and respiration rate in the birds of all the groups from 0 to 60 min. The induction time was 5.83±0.33, 2.37±0.18, and 0.87±0.15 min, respectively, in Groups I, II, and III. Induction behavior was smooth in Group III, whereas mildly stormy in Group II and I. Quality of sedation was excellent in Group III, better in Group II as compared to Group I. Analgesia was moderate in Group III whereas poor in Group II and I. Degree of muscle relaxation was excellent in Group III, whereas good in Group I and II. Palpebral reflexes were absent in all the groups. Recovery time was 15.33±0.84, 18.83±0.94, and 26.50±0.85 in Groups I, II, and III respectively. Recovery behavior was smooth in birds of all the groups. The cost of the anesthesia was 158.22±1.04, 194.27±0.66, and 236.84±0.60 Indian National Rupee in Groups I, II, and III, respectively. Quantity of anesthesia utilized in each group was 7.62±0.05, 9.35±0.03, and 11.41±0.03 ml in Groups I, II, and III, respectively.

Conclusion:

The use of isoflurane at different concentration produces different level of physiological changes, quality of anesthesia and economy without causing any deleterious effect on the birds. The physiological parameters observed in this study can serve as reference values for the wild and endangered birds.

Effect of Intermittent Positive Pressure Ventilation on Depth of Anaesthesia during and after Isoflurane Anaesthesia in Sulphur-Crested Cockatoos (Cacatua galerita galerita)

This study aimed to determine the effect of intermittent positive pressure ventilation (IPPV) on the depth of inhalation anaesthesia in parrots. Anaesthesia was induced with 3.0% isoflurane in six Sulphur-crested Cockatoos (Cacatua galerita galerita) and maintained using either 1.5% or 3.0% during spontaneous ventilation (SV) or IPPV at 6 (IPPV-6) or 12 (IPPV-12) breaths per minute. The time taken for the appearance of somatic reflexes and the return of SV after IPPV was recorded. During recovery, the body jerk, beak, eye, and shivering reflexes appeared after 126 ± 27 s, 133 ± 26 s, 165 ± 34 s, and 165 ± 44 s, respectively. All cockatoos developed apnoea after IPPV-12 and only some did after IPPV-6. Return of SV after IPPV-12 was delayed compared to IPPV-6. Recovery times after the SV runs were significantly different between 1.5% and 3.0% isoflurane anaesthesia. Similarly, after IPPV, the recovery times were significantly different between 1.5% and 3.0% isoflurane anaesthesia. Recovery times after 3.0% inhaled isoflurane were longer than those of 1.5% inhaled isoflurane. In conclusion, cockatoos recovering from isoflurane anaesthesia are likely to exhibit body jerk, beak, eye, and shivering reflexes in that order. IPPV increases the depth of anaesthesia in a rate and dose-related manner and prolongs recovery.

Caudal thoracic air sac cannulation in zebra finches for isoflurane anesthesia

Small songbirds such as the zebra finch are commonly used for studies on the neural mechanisms that underlie vocal learning. For these studies, survival surgeries are often performed that involve animal anesthesia and stereotaxic stabilization for localization of specific brain regions. Here we describe air sac cannulation as a novel method for delivering isoflurane gas to zebra finches for anesthesia during neurosurgery. Advantages of this method include that it leaves the bird's head free for stereotaxic targeting and does not interfere with the beak clamps that are often used to position and stabilize the head. It additionally allows for the use of the inhalant anesthetic, isoflurane, which is an appealing alternative to injectable anesthetics because it provides fast, minimally stressful induction, and low subject and personnel toxicity. The use of isoflurane also prevents overdosing and lengthy postoperative recovery times.