We review the utility of serum anticholinergic activity (SAA) as a peripheral marker of anticholinergic activity (AA) in the central nervous system (CAA). We hypothesize that the compensatory mechanisms of the cholinergic system do not contribute to SAA if their system is intact and that if central cholinergic system deteriorates alone in conditions such as Alzheimer's disease or Lewy body dementia, CAA and SAA are caused by way of hyperactivity of inflammatory system and SAA is a marker of the anticholinergic burden in CNS. Taking into account the diurnal variations in the plasma levels of corticosteroids, which are thought to affect SAA, it should be measured at noon or just afterward.

AimThere are no effective, tolerable, and established medications for preventing delirium in critically ill patients admitted to the intensive care unit (ICU). We investigated whether suvorexant was effective in preventing ICU delirium.MethodsThis randomized controlled study evaluated 70 adult patients (age ≥20 years) admitted to the mixed medical ICU of the Tokyo Medical University Hospital (Tokyo, Japan) between May 2015 and February 2017. Patients were randomized using a sealed envelope method to receive either suvorexant (n = 34; 15 mg for elderly patients and 20 mg for younger adults) or conventional treatment (n = 36) for a 7‐day period. The primary outcome was delirium incidence based on the definition in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders.ResultsNo significant between‐group differences were observed in the demographic or clinical characteristics. Kaplan−Meier estimates revealed that time to delirium onset was significantly longer in the suvorexant group than in the conventional group (P < 0.05).ConclusionSuvorexant might be effective in preventing delirium in ICU patients.

AimSubsyndromal delirium is associated with prolonged intensive care unit stays, and prolonged mechanical ventilation requirements. The Prediction of Delirium for Intensive Care (PRE‐DELIRIC) model can predict delirium. This study was designed to verify if it can also predict development of subsyndromal delirium.MethodsWe undertook a single‐center, retrospective observation study in Japan. We diagnosed subsyndromal delirium based on the Intensive Care Delirium Screening Checklist. We calculated the sensitivity and specificity of the PRE‐DELIRIC model and obtained a diagnostic cut‐off value.ResultsWe evaluated data from 70 patients admitted to the mixed medical intensive care unit of the Tokyo Medical University Hospital (Tokyo, Japan) between May 2015 and February 2017. The prevalence of subsyndromal delirium by Intensive Care Delirium Screening Checklist was 31.4%. The area under the receiver operating characteristic curve was 0.83 of the PRE‐DELIRIC model for subsyndromal delirium. The calculated cut‐off value was 36 points with a sensitivity of 94.3% and specificity of 57.1%. Subsyndromal delirium was associated with a higher incidence of delirium (odds ratio, 8.81; P < 0.01).ConclusionThe PRE‐DELIRIC model could be a tool for predicting subsyndromal delirium using a cut‐off value of 36 points.

CaseSeveral successful uses of extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome in patients with novel HIV/AIDS infection have been reported; however, the therapeutic keys have not always been discussed.A 47‐year‐old man was admitted with progressive shortness of breath. He was in respiratory failure with a PaO2/FIO2 ratio of 110.8 requiring intubation. Chest computed tomography showed diffuse ground glass opacities. An HIV infection was suspected, and a diagnosis of acute respiratory distress syndrome was made. Based on clinical indications, treatment for Pneumocystis jirovecii pneumonia and concomitant bacterial infection was started.OutcomeDespite broad‐spectrum antibiotics, the patient's oxygenation deteriorated, necessitating ECMO. After 19 days of ECMO therapy, the patient was successfully decannulated and was eventually discharged.ConclusionIn acute respiratory distress syndrome in patients with HIV/AIDS refractory to treatment, ECMO should be considered. Post‐ECMO antiretroviral therapy could improve outcomes.

Case: A 71-year-old woman was admitted to the Emergency Department with severe dyspnea followed by unconsciousness. She had a history of hyperthyroidism and her anterior neck was markedly swollen. After ventilation was started, she soon became conscious with the improvement of oxygenation. Computed tomography findings indicated giant goiter surrounding the trachea. Later, we carried out a thyroidectomy for the giant goiter (800 g), and tracheostomy. Bronchoscopy carried out at the end of surgery showed a deformed tracheal wall on breathing. During inspiration, the collapsed wall of the trachea occluded the airway, although the tracheal wall recovered to normal during expiration. We diagnosed this case as acquired tracheomalacia and a tracheal stent graft made of silicon was inserted immediately after bronchoscopy.Outcome: After stent graft insertion, the patient was transferred to another hospital. Conclusion: Emergency physicians should be aware of the causes of tracheomalacia in order to safely carry out treatment, particularly in the case of patients with giant goiter.