In Study A, the incidence of arterial oxygen desaturation was studied using pulse oximetry (SaO2) in 100 sedated and 100 nonsedated patients breathing room air who underwent diagnostic upper gastrointestinal endoscopy. Hypoxia (SaO2 92% or less of at least 15 s duration) occurred in 17% and 6% of sedated patients and nonsedated patients, respectively (p < 0.03). Mild desaturation (SaO2 94% or less and less than 15 s duration) occurred in 47% of sedated patients compared with 12% of nonsedated patients (p < 0.001). In Study B, the effects of supplementary oxygen therapy and the effects of different pre-oxygenation times on arterial oxygen saturation (SaO2) in sedated patients were studied using pulse oximetry. One hundred and twenty patients who underwent diagnostic upper gastrointestinal endoscopy with intravenous sedation were studied. Patients were randomly allocated to one of four groups: Group A (n = 30) received no supplementary oxygen while Groups B-D received supplementary oxygen at 4 1 x min(-1) via nasal cannulae. The pre-oxygenation time in Group B (n = 30) was zero minutes, Group C (n = 30) was 2 min and Group D (n = 30) was 5 min before sedation and introduction of the endoscope. Hypoxia occurred in seven of the 30 patients in Group A and none in groups B, C and D (p < 0.001). We conclude that desaturation and hypoxia is common in patients undergoing upper gastrointestinal endoscopy with and without sedation. Sedation significantly increases the incidence of desaturation and hypoxia. Supplementary nasal oxygen at 4 1 x min(-1) in sedated patients abolishes desaturation and hypoxia. Pre-oxygenation confers no additional benefit.
Severe bronchiolitis requiring mechanical ventilation is uncommon and is associated with the risk of barotrauma. We report our experience with 25 (42%) of 60 infants admitted to the Paediatric Intensive Care Unit (PICU) with severe bronchiolitis who required mechanical ventilation. Eighteen patients (72%) had severe hypoxaemia (PaO2/FiO2 < 250). The mean airway pressure required ranged from 5.8 to 15.6 cmH2O with median ventilation duration of 4.0 days (range 2.0-14.0 days). Oxygenation improved significantly within 12 hours of intubation. There was only one death. Mechanical ventilation is required in a subset of patients for severe bronchiolitis and is effective and generally well tolerated.
Tolerance to colonoscopy varies between populations and data from the South East Asian region is lacking. We aimed to determine tolerance and safety with to colonoscopy; conscious sedation and identify risk factors for complications in Malaysian adults. Consecutive outpatients undergoing colonoscopy were enrolled prospectively. A combination of pethidine and midazolam were used and tolerance to colonoscopy assessed three hours post-procedure using a validated scale. All patients were monitored for cardiorespiratory depression and risk factors for complications were identified. Two hundred and eight patients (mean age 57.2 +/- 14.8 years, 48% female) were enrolled. The population ethnicity consisted of 45 (21.63%) Malays, 101 (48.56%) Chinese and 56 (26.92%) Indians. Conscious sedation was achieved with 5.0 +/- 1.1 mg of midazolam and 43.3 +/- 14.0 mg of pethidine. Thirty (14.4%) patients tolerated the procedure poorly and independent predictors included female gender (OR 2.93, 95% CI = 1.22 to 7.01) and a prolonged duration of procedure (OR 2.85, 95% CI = 1.08 to 7.48). Hypotension occurred in 13 (6.25%) patients, with age > 65 years as the only risk factor (OR 13.17, 95% CI = 1.28 to 137.92). A prolonged duration was the main cause of hypoxia (OR 5.49, 95% CI = 1.54 to 19.49), which occurred in 6 (2.88%) patients. No major complications occurred during the study period. The current practice of conscious sedation is safe and tolerated well by most adults in our population. However, poor tolerance in a notable minority may have significant clinical implications.
Study site: Division of Gastroenterology, Department of Medicine, University Malaya Medical Centre (UMMC)
The coronavirus disease 2019 (COVID-19) pandemic is an issue of global significance that has taken the lives of many across the world. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for its pathogenesis. The pulmonary manifestations of COVID-19 have been well described in the literature. Initially, it was thought to be limited to the respiratory system; however, we now recognize that COVID-19 also affects several other organs, including the nervous system. Two similar human coronaviruses (CoV) that cause severe acute respiratory syndrome (SARS-CoV-1) and Middle East respiratory syndrome (MERS-CoV) are also known to cause disease in the nervous system. The neurological manifestations of SARS-CoV-2 infection are growing rapidly, as evidenced by several reports. There are several mechanisms responsible for such manifestations in the nervous system. For instance, post-infectious immune-mediated processes, direct virus infection of the central nervous system (CNS), and virus-induced hyperinflammatory and hypercoagulable states are commonly involved. Guillain-Barré syndrome (GBS) and its variants, dysfunction of taste and smell, and muscle injury are numerous examples of COVID-19 PNS (peripheral nervous system) disease. Likewise, hemorrhagic and ischemic stroke, encephalitis, meningitis, encephalopathy acute disseminated encephalomyelitis, endothelialitis, and venous sinus thrombosis are some instances of COVID-19 CNS disease. Due to multifactorial and complicated pathogenic mechanisms, COVID-19 poses a large-scale threat to the whole nervous system. A complete understanding of SARS-CoV-2 neurological impairments is still lacking, but our knowledge base is rapidly expanding. Therefore, we anticipate that this comprehensive review will provide valuable insights and facilitate the work of neuroscientists in unfolding different neurological dimensions of COVID-19 and other CoV associated abnormalities.