Hyperbaric oxygen therapy: Can it be a novel supportive therapy in COVID-19?

The coronavirus disease 2019 (COVID-19) is a pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). Although 85% of infected patients remain asymptomatic, 5% show severe symptoms such as hypoxaemic respiratory failure and multiple end organ dysfunction (MODS) requiring intensive care unit (ICU) admission with a mortality rate of about 2.8%. Since a definitive treatment is yet to be identified, preventive and supportive strategies remain the mainstay of management. Supportive measures such as oxygen therapy with nasal cannula, face mask, noninvasive ventilation, mechanical ventilation and even extreme measures such as extracorporeal membrane oxygenation (ECMO) fail to improve oxygenation in some patients. Hence, hyperbaric oxygen therapy (HBOT) has been proposed as a supportive strategy to improve oxygenation in COVID-19 patients. HBOT is known to increase tissue oxygenation by increasing the amount of dissolved oxygen in plasma. HBOT also mitigates tissue inflammation thus reducing the ill effects of cytokine storm in COVID-19 patients. Though there is limited literature available on HBOT in COVID-19 patients, considering the present need for additional supportive therapy to improve oxygenation, HBOT has been proposed as a novel supportive treatment in COVID-19 patients.

Methemoglobinemia Unmasked by Use of Sodium Nitroprusside and Hypothermia in a Case of Chronic Thromboembolic Pulmonary Hypertension During Pulmonary Endarterectomy: A Case Report.

In performing pulmonary endarterectomy (PEA) for a patient with chronic thromboembolic pulmonary hypertension (CTEPH), we encountered methemoglobinemia that was unmasked by hypothermia while on cardiopulmonary bypass (CPB). The patient on dapsone therapy for antiphospholipid antibody syndrome had developed acquired methemoglobinemia that went undiagnosed because her cyanosis was believed to be due to CTEPH and the resulting ventilation-perfusion (V/Q) mismatch. Although pharmacological triggers for methemoglobin are well known, causation by hypothermia is not described. Monitoring saturation while on CPB was challenging because of nonpulsatile blood flow but was overcome using cerebral oximetry.

Comparing the efficacy of aprepitant and ondansetron for the prevention of postoperative nausea and vomiting (PONV): A double blinded, randomised control trial in patients undergoing breast and thyroid surgeries.

BACKGROUND AND AIMS: Aprepitant, a Neurokinin-1 receptor antagonist, has been evaluated in abdominal and neurosurgeries, but its effect is less clear in breast and thyroid surgeries, which are also known to be high risk for post-operative nausea and vomiting (PONV). This study was done to compare the antiemetic efficacy of ondansetron and aprepitant in women undergoing mastectomy and thyroidectomy. METHODS: One hundred and twenty-five ASA I and II, female patients, aged between 18 and 65 years were randomly assigned into Group I (ondansetron group, n = 62) or Group II (aprepitant group, n = 63), by computer-generated random sequencing. Per protocol analysis was done to assess the incidence and severity of PONV, use of rescue antiemetics, and patient satisfaction with PONV control between the two groups, till 24 h post-surgery. RESULTS: In the immediate postoperative period, 79.7% of patients in Group I and 85.2% in Group II were free of emesis (P value: 0.49). In Group I, the first episode of vomiting occurred within a median duration 90 min (IQR 2575: 45-147) postoperatively, whereas the median duration in Group II was 160 min (IQR 25-75: 26-490), with request for rescue antiemetic at 60 min in Group I (IQR 25-75: 27-360) and 147 min in Group II (IQR 25-75: 11-457). CONCLUSION: A single dose of oral aprepitant has comparable effects to injection ondansetron administered eighth hourly in preventing PONV, the severity of nausea, number of rescue antiemetics, and the time to first emetic episode in the 24-h postoperative period. CTRI REG NO: REF/2017/06/014637.