Common Uses and Adverse Effects of Hyperbaric Oxygen Therapy in a Cohort of Small Animal Patients: A Retrospective Analysis of 2,792 Treatment Sessions

Hyperbaric oxygen therapy (HBOT) is commonly utilized for various human conditions<br>with a low incidence of major adverse effects (0.002–0.035%). Despite growing use in<br>veterinary patients, there remains a paucity of literature describing its use and associated<br>complications. The purpose of this study was to report clinical use of HBOT in small<br>animals and identify the rate of major adverse events at a university teaching hospital.<br>Electronic medical records were searched for small animals receiving HBOT between<br>November 2012 and February 2020. Data extracted from the medical records included<br>signalment, treatment indication, and adverse events. Treatment sessions totaled 2,792<br>in 542 dogs, 24 cats, and 10 pocket pets and exotics. Common indications included<br>neurologic injuries (50.4%), tissue healing (31.4%), control of oomycete infection (5.5%),<br>neoplasia or post-radiation injury (5.4%), and various miscellaneous conditions (7.4%).<br>Observed minor adverse events included agitation in two dogs and vomiting in three<br>dogs. The most common major adverse event was central nervous system (CNS)<br>oxygen toxicity in 19 dogs. Central nervous system oxygen toxicity, manifesting as focal<br>or generalized seizures, occurred in 0.7% of treatment sessions, with increasing age<br>(p = 0.01) and female sex (p = 0.01) identified as risk factors. One dog developed<br>pulmonary edema following HBOT which is a reported adverse event in humans or may<br>have been a manifestation of progression of the dog’s underlying disease. No adverse<br>events were noted in cats or other species. In conclusion, HBOT appeared safe across<br>various indications, although oxygen toxicity affecting the CNS was higher than reports<br>in humans. Future prospective, randomized, controlled trials should evaluate specific<br>clinical indications and outcomes.<br>

高压氧疗法（Hyperbaric Oxygen Therapy, HBOT）目前已广泛应用于多种人类疾病的治疗，其严重不良反应发生率为0.002%~0.035%。尽管该疗法在兽医患者中的应用日渐增多，但相关临床应用及伴随并发症的文献报道仍较为匮乏。本研究旨在报道小型动物高压氧疗法的临床使用情况，并明确某大学教学医院内严重不良事件的发生率。
研究人员检索了2012年11月至2020年2月期间接受HBOT治疗的小型动物电子病历，提取的病历数据包括动物个体特征、治疗适应证及不良反应情况。本次研究共纳入542只犬、24只猫以及10只小宠物和异宠，累计治疗疗程达2792次。
常见治疗适应证包括神经系统损伤（50.4%）、组织愈合（31.4%）、卵菌感染控制（5.5%）、肿瘤或放疗后损伤（5.4%），以及各类杂项病症（7.4%）。观察到的轻微不良反应包括2只犬出现躁动、3只犬出现呕吐。最常见的严重不良反应为中枢神经系统（Central Nervous System, CNS）氧中毒，共累及19只犬。
中枢神经系统氧中毒以局灶性或全身性癫痫发作为主要表现，其在治疗疗程中的发生率为0.7%，研究发现年龄增长（p=0.01）与雌性性别（p=0.01）为该不良反应的危险因素。另有1只犬在接受HBOT治疗后出现肺水肿，该不良反应在人类中已有报道，或与该犬基础疾病的进展相关。猫及其他物种未观察到任何不良反应。
综上，尽管针对中枢神经系统的氧中毒发生率高于人类相关报道，但高压氧疗法在多种适应证下均表现出良好的安全性。未来应开展前瞻性、随机对照试验，以评估特定临床适应证的治疗效果与结局。