Downs, John B.

Importance An estimated 70% to 80% of older adults develop delirium in the intensive care unit (ICU). Objective To determine if a slow-tempo music (60-80 beats/min) listening intervention decreases delirium duration, delirium severity, pain, or anxiety in older adults undergoing mechanical ventilation. Design, Setting, and Participants This multicenter randomized clinical trial with concealed outcomes assessments was conducted in older adults undergoing mechanical ventilation from February 2020 to December 2023. Patients were enrolled from the ICUs of 2 hospitals affiliated with the Indiana University School of Medicine and from the Mayo Clinic in Rochester, Minnesota. Intervention A music intervention comprising classical and contemporary tracks, delivered twice daily through noise-canceling headphones and tablets for up to 7 days, was compared to active control listening to a silence track delivered under identical conditions. Main Outcomes and Measures The primary outcome was delirium/coma-free days during the 7-day intervention period assessed by the Confusion Assessment Method for the ICU (CAM-ICU) and the Richmond Agitation-Sedation Scale. The secondary outcomes were delirium severity assessed by the CAM-ICU-7, pain assessed by the Critical Care Pain Observation Tool, and anxiety assessed by the visual analog scale for anxiety (VAS-A). Results A total of 158 patients were randomized (mean [SD] age, 68 (9.2) years; 72 [45.5%] female and 86 [54.4%] male). In an intention-to-treat analysis, no differences were found in the number of delirium/coma-free days in the music intervention group compared with control (median [IQR] days, 2.5 [0-5] vs 3 [0-5]; P = .66). There were also no statistically significant differences in the mean CAM-ICU-7 scores, mean pain scores, or mean VAS-A scores over the 7-day intervention period. By end of the 7-day period, both music intervention and control groups had similar mean (SD) CAM-ICU-7 scores (2.72 [2.80] vs 2.56 [2.72]), Critical Care Pain Observation Tool scores (0.20 [0.55] vs 0.61 [1.29]), and VAS-A scores (43.6 [24.7] vs 28.8 [38.4]). Conclusions and Relevance In this randomized clinical trial among older adults undergoing mechanical ventilation, a slow-tempo music intervention did not demonstrate a statistically significant decrease in delirium duration, delirium severity, pain, or anxiety symptoms. Trial Registration ClinicalTrials.gov Identifier: NCT04182334

AbstractAimWe investigated whether a commercial bi‐level positive airway pressure (BPAP) device, would improve peripheral oxygen saturation (SpO2) during recreational aviation up to 12,500 feet without supplemental oxygen. Ten adults with recreational flight experience (age:47 ± 14; female = 5) completed a standardized flight profile in an unpressurised aircraft, involving randomized crossover design at 8,000 feet and 12,500 feet with BPAP or control. SpO2, middle cerebral artery velocity (MCAv), heart rate (HR), respiratory rate (RR), and relative tidal volume (TV) index were measured continuously. Psychomotor vigilance test (3‐min) assessed reaction time halfway through taxi and altitude stages. Altitude significantly (p < 0.05) decreased mean SpO2, MCAv, and RR, and increased TV index and HR. There was no effect of altitude (p > 0.05) on reaction time. BPAP increased mean SpO2 at 8,000 feet [Control: 92 ± 1%; BPAP: 94 ± 2%; mean difference (MD) = 2 ± 2%; p = 0.002] and 12,500 feet [Control: 86 ± 4%; BPAP: 89 ± 4%; MD = 2 ± 3%; p = 0.013]. BPAP lowered MCAv at 8,000 feet [Control: 53 ± 10 cm/s; BPAP: 50 ± 9 cm/s; MD = ‐3 ± 2 cm/s; p = 0.001] and 12,500 feet [Control: 52 ± 10 cm/s; BPAP: 50 ± 8 cm/s; MD = ‐2 ± 3 cm/s; p = 0.041]. BPAP increased TV index at 8,000 feet (Control: 6.6 ± 1.3; BPAP:8.1 ± 1.8; MD = 1.9 ± 0.8; p < 0.001) but not 12,500 feet, without effect on RR or reaction time. This study provides preliminary results that BPAP may improve mean SpO2 for recreational aviators up to 12,500 feet without supplemental oxygen.

Setting: The coronavirus disease 2019 pandemic has raised fear throughout the nation. Current news and social media predictions of ventilator, medication, and personnel shortages are rampant. Patients: Patients with coronavirus disease 2019 are presenting with early respiratory distress and hypoxemia, but not hypercapnia. Interventions: Patients who maintain adequate alveolar ventilation, normocapnia, and adequate oxygenation may avoid the need for tracheal intubation. Facemask continuous positive airway pressure has been used to treat patients with respiratory distress for decades, including those with severe acute respiratory syndrome. Of importance, protocols were successful in protecting caregivers from contracting the virus, obviating the need for tracheal intubation just to limit the spread of potentially infectious particles. Conclusions: During a pandemic, with limited resources, we should provide the safest and most effective care, while protecting caregivers. Continuous positive airway pressure titrated to an effective level and applied early with a facemask may spare ventilator usage. Allowing spontaneous ventilation will decrease the need for sedative and paralytic drugs and may decrease the need for highly skilled nurses and respiratory therapists. These goals can be accomplished with devices that are readily available and easier to obtain than mechanical ventilators, which then can be reserved for the sickest patients.

Background Rapid recovery and weaning from ventilatory support and cardiovascular stability are suggested advantages of isoflurane inhalation, in concentrations ranging from 0.1 to 0.6 vol%, for long-term sedation in mechanical ventilated patients. This study was designed to determine whether isoflurane in low concentrations impairs pulmonary gas exchange by increasing ventilation and perfusion (V(A)/Q) mismatch during lung injury. Methods Fourteen anesthetized dogs received in random order 0, 0.25, or 0.5 vol% end-tidal isoflurane before and after induction of lung injury with oleic acid. Gas exchange was assessed by blood gas analysis and by estimating the V(A)/Q distributions using the multiple inert gas elimination technique. Results Administration of oleic acid produced a lung injury with severe V(A)/Q mismatch and 38 +/- 4% intrapulmonary shunting of blood. During lung injury, isoflurane accounted for a dose-related increase in blood flow to shunt units from 38 +/- 4 to 42 +/- 3 (0.25 vol%) and 48 +/- 4% (0.5 vol%) (P < 0.05), dispersion pulmonary blood flow distribution from 0.94 +/- 0.07 to 1.01 +/- 0.09 (0.25 vol%) and 1.11 +/- 0.11% (0.5 vol%) (P < 0.05), and a decrease in perfusion of normal V(A)/Q units from 58 +/- 5 to 55 +/- 4 (0.25 vol%) and 50 +/- 4% (0.5 vol%) (P < 0.05) (mean +/- SE). Isoflurane decreased arterial oxygen partial pressure from 72 +/- 4 to 62 +/- 4 mmHg (0.25 vol%) and 56 +/- 4 mmHg (0.5 vol%) (P < 0.05) and oxygen delivery from 573 +/- 21 to 529 +/- 19 ml. kg. min (0.25 vol%) and 505 +/- 22 ml. kg. min (0.5 vol%) (P < 0.05). Gas exchange, perfusion of shunt and normal V(A)/Q units, and pulmonary blood flow distribution was similar in absence of lung injury with and without isoflurane. Isoflurane 0.5 vol% lowered cardiac output during all conditions (P < 0.05). CONCLUSIONS Inhalation of low concentrations of isoflurane contributed to increased V(A)/Q mismatch and decreased systemic blood flow and oxygen delivery in mechanically ventilated animals with injured lungs.