Retrospective evaluation of the utility of shock index to determine the presence of congestive heart failure in dogs with myxomatous mitral valve disease (2019-2021): 98 cases.

OBJECTIVES: To calculate the shock index (SI) in dogs with myxomatous mitral valve disease (MMVD) and to evaluate its use to predict the presence of congestive heart failure (CHF). DESIGN: Retrospective study. SETTING: Small animal university veterinary teaching hospital. ANIMALS: Ninety-eight dogs with MMVD and 20 healthy dogs as part of a control group. INTERVENTIONS: Heart rate (HR) and systolic blood pressure (SBP) were recorded, and SI was calculated by dividing HR by SBP for each dog. MEASUREMENTS AND MAIN RESULTS: The mean (SD) HR, SBP, and SI were 123/min (32.6), 147 mm Hg (21.5), and 0.86 (0.3), respectively, for dogs with MMVD and 98/min (20.9), 145 mm Hg (18.7), and 0.68 (0.13), respectively, for control dogs. Dogs with MMVD had a significantly higher HR compared with control dogs (P < 0.01), and an elevation in HR was seen as the severity of MMVD increased. Dogs in stage B2 and C/D MMVD had a significantly higher SI value compared with control dogs (P = 0.04 and P < 0.01, respectively). SI was significantly higher in dogs in stage C/D MMVD compared with dogs in stage B2 MMVD (P < 0.01). Ten of 98 (10%) dogs had an arrhythmia. HR, SBP, and SI were not significantly different between dogs with and without arrhythmias (P = 0.13, P = 0.57, and P = 0.07, respectively), but significantly more dogs with CHF had an arrhythmia (P = 0.01). SI (area under the curve [AUC]: 0.98) and HR (AUC: 0.95) were excellent indicators for the presence of CHF. An optimal SI cutoff value ≥1.1 had 92% sensitivity and 95% specificity for predicting the presence of CHF, and an optimal HR cutoff value of ≥157/min had 92% sensitivity and 93% specificity for the prediction of CHF. CONCLUSIONS: When there are compatible clinical signs, SI values ≥1.1 may suggest the presence of CHF in dogs with MMVD.

The use of High-Flow Nasal Oxygen Therapy in 4 dogs undergoing bronchoscopy.

Introduction: High-Flow Nasal Oxygen Therapy is a method to deliver warmed, humidified air-oxygen blended at high flow rates to patients through a nasal cannula using a specialized, commercially available machine. This is a well-tolerated, safe and effective method for oxygen delivery to healthy and hypoxemic dogs. Patients undergoing bronchoscopic procedures frequently develop hypoxemia. Human trials have shown a reduction in incidents of hypoxemic events and higher pulse oximeter oxygen saturation during bronchoscopies in patients on High-Flow Nasal Oxygen. Materials and methods: This is a single-centre, prospective case series. All dogs weighing between 5 and 15 kg and undergoing bronchoscopy during the study period (03/07/2022-01/10/2022) were eligible. Results: Twelve patients were eligible for inclusion of which four were enrolled. No clinically significant complications related to the use of High-Flow Nasal Oxygen Therapy were recorded. Two of the patients were re-intubated post bronchoscopy due to clinician preference for recovery. One of the patients had a self-limiting period of severe hypoxemia with a pulse oximeter oxygen saturation of 84% for < 1 min during bronchoalveolar lavage, and whilst undergoing High-Flow Nasal Oxygen administration. Another patient had a self-limiting episode of mild hypoxemia (SpO2 of 94% lasting < 1 min) 5 min after completion of bronchoalveolar lavage. Conclusion: No clinically relevant complications relating to High-Flow Nasal Oxygen Therapy were recorded in this case series, although further studies are required to confirm this conclusion. This initial data suggests that the use of High-Flow Nasal Oxygen therapy during bronchoscopy is feasible and potentially safe, although it may not prevent hypoxemia in these patients. The use of High-Flow Nasal Oxygen Therapy during bronchoscopy in small patients carries multiple potential benefits and further studies to compare its efficacy against other traditional oxygen delivery systems are warranted in this patient population.

Real-world, multicentre evaluation of the incidence and risk factors for non-susceptible Stenotrophomonas maltophilia isolates.

BACKGROUND: Stenotrophomonas maltophilia is a cause of infection most commonly in the opportunistic host. Trimethoprim-sulfamethoxazole and levofloxacin are considered first-line treatment agents. With reports of increasing resistance to these first-line agents, it is important to determine risk factors associated with a non-susceptible isolate. METHODS: This was a real-world, multicentre, retrospective case-control study from five centres in the southeast United States evaluating S. maltophilia. The primary outcome was risk factors associated with non-susceptibility of S. maltophilia isolates to ≥1 antimicrobial agents. Secondary outcomes include incidence of S. maltophilia non-susceptibility, all-cause mortality, and 30-day readmission rates. RESULTS: There were 325 patients included in the study. For the primary outcome, the only factor associated with non-susceptibility per univariate analysis was isolation from urine culture (13.3% vs. 5.4%; P = 0.014), whereas the presence of mechanical ventilation (37.7% vs. 21.5%) and intensive care unit admission (35.3% vs. 18.4%) were associated with susceptibility (P < 0.001). For the secondary outcomes, non-susceptibility was present in 49% of isolates with 43 of 325 (13.2%), 53 of 324 (16.4%), and 105 of 172 (61%) to TMP-SMX, levofloxacin, and ceftazidime, respectively. Resistance to chloramphenicol and tigecycline was observed among 5/26 and 11/16 of tested isolates, respectively. Sixty-six patients (20%) experienced all-cause, inpatient mortality (18% susceptible vs. 23% non-susceptible; P = 0.280) and 44 patients (17%) were readmitted within 30 days of discharge (16% susceptible vs. 18% non-susceptible; P = 0.673). CONCLUSION: S. maltophilia non-susceptibility had a prevalence of ∼50% to at least one first-line or commonly used agent. More research is needed to delineate risk factors for non-susceptible isolates.