Pulmonary Vein Stenosis After Single Lung Transplantation.

A 72-year-old man with interstitial lung disease underwent a planned single lung transplantation. His late postoperative course was notable for hemodynamic deterioration, after which severe right pulmonary vein anastomotic stenosis was identified via echocardiogram. The case highlights a rare complication of lung transplantation diagnosed by using transesophageal echocardiogram.

Combined Percutaneous Tracheostomy and Endoscopic Gastrostomy Tubes in COVID-19: A Prospective Series of Patient Outcomes.

Background: A significant number of patients with severe respiratory failure related to COVID-19 require prolonged mechanical ventilation. Minimal data exists regarding the timing, safety, and efficacy of combined bedside percutaneous tracheostomy and endoscopy gastrostomy tube placement in these patients. The safety for healthcare providers is also in question. This study's objective was to evaluate the effectiveness and safety of combined bedside tracheostomy and gastrostomy tube placement in COVID-19 patients. Design and Methods: This is a single arm, prospective cohort study in patients with COVID-19 and acute respiratory failure requiring prolonged mechanical ventilation who underwent bedside tracheostomy and percutaneous endoscopic gastrostomy placement. Detailed clinical and procedural data were collected. Descriptive statistics were employed and time to event curves were estimated and plotted using the Kaplan Meier method for clinically relevant prespecified endpoints. Results: Among 58 patients, the median total intensive care unit (ICU) length of stay was 29 days (24.7-33.3) with a median of 10 days (6.3-13.7) postprocedure. Nearly 88% of patients were weaned from mechanical ventilation postprocedure at a median of 9 days (6-12); 94% of these were decannulated. Sixty-day mortality was 10.3%. Almost 90% of patients were discharged alive from the hospital. All procedures were done at bedside with no patient transfer required out of the ICU. A median of 3.0 healthcare personnel total were present in the room per procedure. Conclusion: This study shows that survival of critically ill COVID-19 patients after tracheostomy and gastrostomy was nearly 90%. The time-to-event curves are encouraging regarding time to weaning, downsizing, decannulation, and discharge. A combined procedure minimizes the risk of virus transmission to healthcare providers in addition to decreasing the number of anesthetic episodes, transfusions, and transfers patients must undergo. This approach should be considered in critically ill COVID-19 patients requiring prolonged mechanical ventilation.

Dexmedetomidine-Associated Hyperpyrexia in Three Critically Ill Patients With Coronavirus Disease 2019.

OBJECTIVES: To present three patients with severe coronavirus disease 2019 infection who developed life-threatening hyperpyrexia while being treated with dexmedetomidine for sedation. DATA SOURCES: Clinical records. STUDY SELECTION: Case report. DATA EXTRACTION: Relevant clinical information. DATA SYNTHESIS: We describe three patients, a 60-year-old female, 43-year-old female, and 46-year-old male, who were hospitalized in surge ICUs during the coronavirus disease 2019 pandemic in the early spring of 2020. All developed hyperpyrexia, defined as a temperature above 41.1°C, following an increase in dexmedetomidine dosing to above 1.5 µg/kg/hr. Fevers resolved following discontinuation of dexmedetomidine. CONCLUSIONS: While the exact mechanism of hyperpyrexia remains unclear, findings in this study suggest that high doses of dexmedetomidine infusion are associated with hyperpyrexia in a seemingly dose-dependent fashion in critically ill patients with coronavirus disease 2019. Coronavirus disease 2019 infection causes a hyperinflammatory state characterized by pro-inflammatory cytokine dysregulation. Dexmedetomidine, a centrally acting alpha-2 agonist, may alter hypothalamic temperature regulation through disturbances in neurotransmitter expression and metabolism. We postulate that the use of high-dose dexmedetomidine in a hyperinflammatory state may increase the risk of developing hyperpyrexia in this severe disease state.

Effects of Opioids Given to Facilitate Mechanical Ventilation on Sleep Apnea After Extubation in the Intensive Care Unit.

Study Objectives: Following extubation in the intensive care unit (ICU), upper airway (UA) edema and respiratory depressants may promote UA dysfunction. We tested the hypothesis that opioids increase the risk of sleep apnea early after extubation. Methods: Fifty-six ICU patients underwent polysomnography the night after extubation. Airflow limitation during wakefulness was identified using bedside spirometry. Correlation and ordinal regression analyses were used to quantify the effects of preextubation opioid dose on postextubation apnea-hypopnea index (AHI) and severity of sleep apnea and whether or not inspiratory airway obstruction (ratio of maximum expiratory and inspiratory airflows at 50% of vital capacity [MEF50/MIF50] ≥ 1) during wakefulness predicts airway obstruction during sleep. Data were adjusted for age, gender, body mass index, as well as a generalized propensity score balanced for APACHE II, score for preoperative prediction of obstructive sleep apnea, duration of mechanical ventilation, chronic obstructive pulmonary disease, and a procedural severity score for morbidity. Results: Sleep apnea (AHI ≥ 5) was present in 40 (71%) of the 56 patients. Morphine equivalent dose given 24 hours prior extubation predicted obstructive respiratory events during sleep (r = 0.35, p = .01) and sleep apnea (odds ratio [OR] 1.17; 95% confidence interval [CI] 1.02-1.34). Signs of inspiratory UA obstruction (MEF50/MIF50 ≥ 1) assessed by bedside spirometry were strongly associated with sleep apnea (OR 5.93; 95% CI 1.16-30.33). Conclusions: High opioid dose given 24 hours prior to extubation increases the likelihood of postextubation sleep apnea in the ICU, particularly in patients with anatomical vulnerability following extubation.

Clinical predictors of central sleep apnea evoked by positive airway pressure titration.

PURPOSE: Treatment-emergent central sleep apnea (TECSA), also called complex apnea, occurs in 5%-15% of sleep apnea patients during positive airway pressure (PAP) therapy, but the clinical predictors are not well understood. The goal of this study was to explore possible predictors in a clinical sleep laboratory cohort, which may highlight those at risk during clinical management. METHODS: We retrospectively analyzed 728 patients who underwent PAP titration (n=422 split-night; n=306 two-night). Demographics and self-reported medical comorbidities, medications, and behaviors as well as standard physiological parameters from the polysomnography (PSG) data were analyzed. We used regression analysis to assess predictors of binary presence or absence of central apnea index (CAI) ≥5 during split-night PSG (SN-PSG) versus full-night PSG (FN-PSG) titrations. RESULTS: CAI ≥5 was present in 24.2% of SN-PSG and 11.4% of FN-PSG patients during titration. Male sex, maximum continuous positive airway pressure, and use of bilevel positive airway pressure were predictors of TECSA, and rapid eye movement dominance was a negative predictor, for both SN-PSG and FN-PSG patients. Self-reported narcotics were a positive predictor of TECSA, and the time spent in stage N2 sleep was a negative predictor only for SN-PSG patients. Self-reported history of stroke and the CAI during the diagnostic recording predicted TECSA only for FN-PSG patients. CONCLUSION: Clinical predictors of treatment-evoked central apnea spanned demographic, medical history, sleep physiology, and titration factors. Improved predictive models may be increasingly important as diagnostic and therapeutic modalities move away from the laboratory setting, even as PSG remains the gold standard for characterizing primary central apnea and TECSA.

Perioperative sleep apnea: a real problem or did we invent a new disease?

Depending on the subpopulation, obstructive sleep apnea (OSA) can affect more than 75% of surgical patients. An increasing body of evidence supports the association between OSA  and perioperative complications, but some data indicate important perioperative outcomes do not differ between patients with and without OSA. In this review we will provide an overview of the pathophysiology of sleep apnea and the risk factors for perioperative complications related to sleep apnea. We also discuss a clinical algorithm for the identification and management of OSA patients facing surgery.

Apnea burden: efficacy versus effectiveness in patients using positive airway pressure.

BACKGROUND: Modern continuous positive airway pressure (PAP) machines track hours of use and residual respiratory events while on treatment. A substantial portion of sleep apnea patients are partially compliant, emphasizing the need to distinguish between PAP efficacy and PAP effectiveness in chronic management of patients with sleep apnea. METHODS: We used a combination of three data sources to estimate the sleep apnea burden in a convenience cohort of PAP users from our clinics that were compliant based on Medicare criteria: self-reported habitual total sleep time, and PAP usage times with residual apnea-hypopnea index (AHI) from compliance downloads. RESULTS: Assuming that the off-PAP time consists of baseline AHI severity, an estimated apnea burden was calculated to estimate PAP effectiveness. Whereas 70% of patients in our cohort showed machine AHI values <5/h, the apnea burden calculations revealed that only one-third of patients are predicted to have an effective AHI <5. CONCLUSION: Estimating PAP effectiveness through the concept of apnea burden has implications for clinical care as well as research trials.