2022 Update of the consensus on the rational use of antithrombotics and thrombolytics in Veterinary Critical Care (CURATIVE) Domain 6: Defining rational use of thrombolytics

Objectives To systematically review available evidence and establish guidelines related to the use of thrombolytics for the management of small animals with suspected or confirmed thrombosis. Design PICO (Population, Intervention, Control, and Outcome) questions were formulated, and worksheets completed as part of a standardized and systematic literature evaluation. The population of interest included dogs and cats (considered separately) and arterial and venous thrombosis. The interventions assessed were the use of thrombolytics, compared to no thrombolytics, with or without anticoagulants or antiplatelet agents. Specific protocols for recombinant tissue plasminogen activator were also evaluated. Outcomes assessed included efficacy and safety. Relevant articles were categorized according to level of evidence, quality, and as to whether they supported, were neutral to, or opposed the PICO questions. Conclusions from the PICO worksheets were used to draft guidelines, which were subsequently refined via Delphi surveys undertaken by the Consensus on the Rational Use of Antithrombotics and Thrombolytics in Veterinary Critical Care (CURATIVE) working group. Results Fourteen PICO questions were developed, generating 14 guidelines. The majority of the literature addressing the PICO questions in dogs is experimental studies (level of evidence 3), thus providing insufficient evidence to determine if thrombolysis improves patient-centered outcomes. In cats, literature was more limited and often neutral to the PICO questions, precluding strong evidence-based recommendations for thrombolytic use. Rather, for both species, suggestions are made regarding considerations for when thrombolytic drugs may be considered, the combination of thrombolytics with anticoagulant or antiplatelet drugs, and the choice of thrombolytic agent. Conclusions Substantial additional research is needed to address the role of thrombolytics for the treatment of arterial and venous thrombosis in dogs and cats. Clinical trials with patient-centered outcomes will be most valuable for addressing knowledge gaps in the field

Physical examination of the respiratory system

This article reviews the approach to a patient with respiratory distress, with a focus on clues obtained from the physical examination. Respiratory distress is a common reason for presentation of a companion animal to a veterinarian on an emergency basis, and thus the clinician should have a comfort level with the approach to these patients. Our discussion includes a basic review of respiratory pathophysiology and the differential diagnoses for hypoxemia. In the majority of cases, physical examination should allow localization of the cause of the respiratory problem to the upper airways, lower airways, pleural space, or pulmonary parenchyma. Such localization, coupled with signalment and historical clues, guides additional diagnostics and therapeutics based on the most likely differential diagnoses. Although managing a patient with respiratory distress can be challenging, a systematic approach such as the one presented here should ensure appropriate intervention in a timely fashion and maximize the chance of a good outcome

Cardiovascular and systemic effects of gastric dilatation and volvulus in dogs

Gastric dilatation and volvulus (GDV) is a common emergency condition in large and giant breed dogs that is associated with high morbidity and mortality. Dogs with GDV classically fulfill the criteria for the systemic inflammatory response syndrome (SIRS) and can go on to develop multiple organ dysfunction syndrome (MODS). Previously reported organ dysfunctions in dogs with GDV include cardiovascular, respiratory, gastrointestinal, coagulation and renal dysfunction. Cardiovascular manifestations of GDV include shock, cardiac arrhythmias and myocardial dysfunction. Respiratory dysfunction is also multifactorial, with contributory factors including decreased respiratory excursion due to gastric dilatation, decreased pulmonary perfusion and aspiration pneumonia. Gastrointestinal dysfunction includes gastric necrosis and post-operative gastrointestinal upset such as regurgitation, vomiting, and ileus. Coagulation dysfunction is another common feature of MODS in dogs with GDV. Disseminated intravascular coagulation can occur, putting them at risk of complications associated with thrombosis in the early hypercoagulable state and hemorrhage in the subsequent hypocoagulable state. Acute kidney injury, acid-base and electrolyte disturbances are also reported in dogs with GDV. Understanding the potential for systemic effects of GDV allows the clinician to monitor patients astutely and detect such complications early, facilitating early intervention to maximize the chance of successful management

The pattern of mortality in dogs with gastric dilatation and volvulus

Introduction The primary study objective was to characterize the pattern of in‐hospital mortality in dogs with gastric dilatation and volvulus (GDV), with a focus on preoperative nonsurvival. Materials and Methods A retrospective review of medical records from a 10‐year period was undertaken at a university teaching hospital. Data collected included signalment, physical examination parameters at hospital presentation, blood lactate concentration, and outcome. Results A total of 498 dogs were included. Overall, 319 (64.1%) survived to discharge and 179 (35.9%) were nonsurvivors. Of the nonsurvivors, 149 (31.3% of all dogs) were euthanized and 30 (6%) died. Of those dogs euthanized, the majority (n = 116) were euthanized at the time of hospital presentation prior to surgery (ie, without intent to treat). When dogs that were euthanized prior to surgery were excluded, 83.5% of dogs survived to discharge. Median group age was higher in those euthanized than in the group of dogs that survived to discharge. Conclusions Preoperative euthanasia and hence nonsurvival without intent to treat accounted for the majority of GDV mortality in this study. Given the high rate of nonsurvival without intent to treat it is likely that efforts focused at disease prevention will ultimately affect a much greater improvement in overall disease mortality than those focused on improving treatment

Spontaneous pneumothorax in 35 cats (2001–2010)

Thirty-five cases of spontaneous pneumothorax were reviewed. In contrast to dogs, cats with an established etiology all had spontaneous pneumothorax associated with lung disease. Underlying diseases identified in affected cats included inflammatory airway disease, neoplasia, heartworm infection, pulmonary abscess and lungworm infection. Many cats were managed successfully with observation alone or needle thoracocentesis and specific therapy for their primary lung disease. Cats who present with spontaneous pneumothorax may be treated successfully with non-surgical therapies and appear to have a better prognosis than previously extrapolated from canine studies

The effect of storage on ammonia, cytokine, and chemokine concentrations in feline whole blood

Objective To determine if the concentrations of ammonia and inflammatory mediators in feline stored whole blood (SWB) increase with duration of storage. Design Prospective ex vivo study. Setting University Teaching Hospital. Animals Thirteen cats, recruited from the hospital feline donor pool, deemed healthy based on the predonation donor screening process. Interventions One unit (30 mL) of whole blood was collected from 13 unique blood donor cats, anticoagulated with citrate‐phosphate‐dextrose, and stored at 4°C. Concentrations of ammonia, interleukin (IL) 6, and IL‐10 were measured in 5 units weekly for 4 weeks. Presence of chemokine ligand (CXCL) 8 was measured weekly in 8 other units in the same manner. Measurements and Main Results The ammonia concentration increased nonlinearly with duration of storage, from a median of 48 μmol/L (range 25–74 μmol/L) on day 0 and 417 μmol/L (324–457 μmol/L) on day 28. IL‐6 and IL‐10 concentrations were below the lower limits of detection of the assay used (IL‐6 < 31.2 pg/mL and IL‐10 < 125 pg/mL). CXCL‐8 was detected in 4 of 8 SWB units at all time points. Conclusions and Clinical Importance Ammonia concentration increases with storage time in feline SWB. The clinical significance of this finding is yet to be determined. The presence of the proinflammatory chemokine CXCL‐8 in feline SWB warrants further research to determine whether it can incite an inflammatory response in the recipient. Further research evaluating the epidemiology of transfusion reactions in cats should evaluate the effect of unit age, and should include the possible impact of the presence of CXCL‐8

Cardiopulmonary resuscitation in hospitalized Rabbits: 15 cases

Cardiopulmonary arrest is relatively common in hospitalized rabbits. The purpose of this study was to assess whether cardiopulmonary resuscitation (CPR) was effective in rabbits with cardiopulmonary arrest. Rabbit patients were evaluated on patient characteristics, treatment, and outcome after CPR. Only rabbits with complete medical records were included in this retrospective study. The complete files were obtained after a thorough search of the hospital medical records system and anesthesia morbidity and mortality records for rabbits undergoing CPR. Fifteen complete records were identified that matched the criteria of the study, which included 5 intact does, 4 spayed does, 1 intact buck, and 5 neutered bucks. Ages ranged from 6 months to 10 years (median age, 39 months). Fourteen of the 15 cardiac arrest patients in the study were witnessed. Five arrests occurred during anesthesia, 5 within 24 hours of anesthesia, and 5 were unassociated with anesthesia. Two rabbits were intubated before CPR, 3 during CPR, facemasks were used in 7 animals, tracheostomy in 1, and the method of ventilation was unknown in 2 rabbits. Treatments included epinephrine 0.006-0.26 mg/kg (median, 0.09 mg/kg), atropine 0.015-0.18 mg/kg (median, 0.04 mg/kg), and glycopyrrolate 0.002-0.045 mg/kg (median, 0.01 mg/kg). Other treatments included vasopressin, dextrose, yohimbine, naloxone, fluids, and oxyglobin. Return of spontaneous circulation (ROSC) occurred in 7 animals (2 with intubation, 5 with facemask ventilation). Two of the rabbit patients experienced only transient ROSC, 5 had longer survival, 1 was later euthanized, and 3 died. One rabbit that experienced 3 cardiac arrests in rapid succession made a full recovery and was discharged. Three out of the 5 rabbits that experienced long- or medium-term survival after ROSC experienced an anesthesia-related arrest. The prognosis associated with CPR in rabbits is similar to that reported in other species. Tight-fitting facemasks can provide effective respiratory support in rabbits during CPR. Conventional CPR techniques for other species appear effective in rabbits

The use of deep oral swabs as a surrogate for transoral tracheal wash to obtain bacterial cultures in dogs with pneumonia

Objective To determine agreement in bacterial culture and susceptibility (BC&S) between deep oral swab (DOS) and routine transoral tracheal wash (TOTW) in dogs with pneumonia. Design Prospective study, performed between 2008 and 2010 with no follow‐up period. Setting University teaching hospital. Animals Five puppies and 5 adult dogs with community or hospital‐acquired pneumonia. Measurements and Main Results A DOS was collected from each patient; dogs were then briefly anesthetized with propofola for a routine TOTW. Routine microbiology techniques were used for culture. Positive culture results were obtained from all 20 swabs. Results of BC&S were compared between the 2 sites. In all puppies, there was no agreement between DOS and TOTW. In adult dogs, 2 patients with hospital‐acquired infection (HAI) had complete agreement between the BC&S results from DOS and TOTW. Two adult dogs had some similarity in BC&S results, and the final dog had no relationship between cultures. Conclusions DOS is not an appropriate alternative to TOTW to obtain samples for BC&S in puppies with pneumonia. In adult dogs, traditional TOTW remains the gold standard, but DOS may be considered in dogs with suspected HAI. Further work is needed to confirm this preliminary finding

Outcome and medical management in dogs with lower motor neuron disease undergoing mechanical ventilation: 14 cases (2003-2009)

Objective To describe the application of intermittent positive pressure ventilation (IIPV) in dogs with lower motor neuron disease (LMND). Design Multi‐institutional, retrospective study (2003–2009). Setting Intensive care units at multiple university teaching hospitals. Animals Fourteen dogs with LMND that underwent IIPV. Interventions None. Measurements and Main Results The ventilatory logs of 4 teaching hospitals were searched for dogs undergoing IIPV in association with a diagnosis of acute LMND. The medical records were evaluated for signalment, specific LMND, ventilatory management and duration, complications associated with ventilation, duration of hospitalization, and outcome. Descriptive statistics were used as indicated. Fifteen records were evaluated, 1 dog was excluded since it experienced cardiopulmonary arrest (CPA) before commencement of IIPV. The median age was 7.0 years (range 10 mo to 12 y). There were 5 Labrador retrievers, 4 mixed breeds, and 5 other breeds were each represented once. Five dogs were diagnosed with myasthenia gravis, 4 dogs with polyradiculoneuritis, and 5 dogs had an undetermined LMND. Clinical signs of weakness before ventilation were present for a median of 36 hours (range 6 h to 14 d). Dogs were ventilated for a median of 109 hours (range 5–261 h). Nine dogs had temporary tracheostomies performed, and 8 dogs received nutritional support. Five dogs developed ventilator associated pneumonia. Six dogs were successfully weaned from the ventilator with a median ventilatory time of 49 hours (range 25–192 h). Three dogs survived to discharge. No single LMND was associated with a better outcome. Conclusions High euthanasia rates and iatrogenic complications limit the ability to accurately prognosticate for affected dogs in this retrospective study, but in dogs with LMND that is severe enough to require IIPV, support may be required days to weeks

Evaluation of thromboelastography in bitches with pyometra

We investigated the effect of pyometra on kaolin-activated thromboelastography (TEG). Eighteen client-owned dogs with pyometra and 8 healthy spayed dogs were recruited. TEG parameters and packed cell volume were determined. Results from spayed females and from intact females with pyometra were compared using a Student t-test and Wilcoxon rank sum test. Bitches with pyometra were hypercoagulable compared to spayed bitches as evidenced by elevated maximum amplitude, G, and alpha angle. There were no significant group differences in R time, K time, or clot lysis at 30 or 60 min. Dogs with pyometra should be anticipated to have hypercoagulable TEG variables, and this should be addressed when planning surgical and medical therapy