BACKGROUND:Cervical spinal cord injury (CSCI) often results in respiratory muscle weakness, requiring prolonged mechanical ventilation and tracheostomy. However, the frequency and timing of ventilator-weaning milestones after acute hospitalization are not well described. This study assessed the rates and timing of daytime ventilator weaning, liberation from invasive ventilator support, and decannulation among adults with CSCI managed under a standardized weaning protocol at a rehabilitation center, and the associations of weaning milestones with discharge disposition. METHODS:We retrospectively analyzed data from adults with CSCI admitted to the University of Utah Craig H. Neilsen Rehabilitation Hospital between 2015 and 2022. All subjects required continuous mechanical ventilation via tracheostomy upon admission and underwent a standardized ventilator weaning protocol. We tracked the time to reach key ventilator-weaning milestones-daytime wean, liberation from invasive mechanical ventilation, and decannulation-and categorized discharge destinations based on required respiratory support intensity. Predictors of milestone achievement and discharge outcomes were assessed using Fine-Gray competing-risk and proportional odds logistic regression models. RESULTS:Among 39 subjects, 76% were weaned from daytime ventilator support (median day 20), 62% were liberated from invasive ventilatory support (median day 23), and 48% were decannulated (median day 36) by discharge. Subjects with lower-level injuries (C5-C8) were more likely to achieve further weaning and decannulation compared with those with high-level injuries (C1-C4) (odds ratio [OR] 5.54 [1.51-20.38]). Increasing age was associated with discharge to more intensive care settings (OR 0.68 per decade [0.48-0.95]). Decannulated subjects had higher odds of being discharged home (OR 22.84 [2.84-183.57]). No significant differences in weaning status based on discharge disposition were observed. CONCLUSIONS:Most subjects with CSCI initially on continuous mechanical ventilation achieved partial or full ventilatory independence during rehabilitation, although these milestones were often reached several weeks into their stay.

Intensive care unit (ICU) patients often face stress and sensory deprivation, contributing to poor recovery outcomes. This study investigated the impact of distraction therapy delivered using immersive virtual reality (VR). The impact on the autonomic nervous system was measured by electrodermal activity (EDA) before and after the VR sessions. Statistical analysis revealed significant changes in skin conductance responses (p < 0.001), indicating increased parasympathetic nervous system activity. These findings suggest VR-based distraction therapy as a promising therapeutic intervention to reduce ICU-related stress and enhance recovery. Further research should explore long-term effects and optimized applications in critical care.

BACKGROUND:Several studies suggest a high prevalence and disease burden associated with hypercapnic respiratory failure of any cause in emergency department (ED) and inpatient settings. However, these studies use different case definitions. The consistency and validity of these case definitions have not been assessed. RESEARCH QUESTIONS:Do the various case definitions from health record-based studies of adults with hypercapnic respiratory failure identify the same, or similar, patients? METHODS:We identified case definitions for hypercapnic respiratory failure from the peer-reviewed literature. We constructed an emulation data set enriched for the presence of hypercapnic respiratory failure from TriNetX (TriNetX, LLC), which aggregates health records from 76 hospitals in the United States. Adult ED and inpatient encounters occurring in 2022 were eligible for inclusion. We assessed consistency among case definitions by applying them to the emulation data set on the day of ED or hospital admission. We calculated Cohen's κ value and compared the patient characteristics and short-term outcomes for the cohorts defined by each case definition. We evaluated the accuracy of hypercapnic respiratory failure diagnosis codes for capturing hypercapnia demonstrated on first-day arterial blood gas samples. RESULTS:Ten case definitions for hypercapnic respiratory failure were identified and were amenable to emulation. The emulation data set contained 515,286 encounters. Case definitions showed limited agreement (median κ = 0.35; interquartile range, 0.21-0.56) for hypercapnic respiratory failure identification. Key demographic characteristics, comorbidities, and outcomes such as receiving ventilatory support (range, 29%-100%) and 60-day mortality (range, 12%-28%) varied substantially among the resulting cohorts. Diagnosis codes were insensitive for capturing first-day arterial blood gas-demonstrated hypercapnia (sensitivity, 23.5%; 95% CI, 23.1%-23.8%). INTERPRETATION:Case definitions from studies of hypercapnic respiratory failure identify patients with widely different attributes and outcomes, thereby hampering interpretation of associated study findings. Standardization of case definitions is necessary to improve the rigor and generalizability of research on hypercapnic respiratory failure.

Rationale: A method to reliably identify which patients have an elevated arterial partial pressure of CO2 (PaCO2) is required to rigorously study hypercapnic respiratory failure. Arterial blood gas (ABG) sampling is the reference standard, but it is painful, can cause complications, and is therefore not always obtained in usual care. Requiring ABG sampling may dissuade patients from participating in prospective studies, and may result in biased detection of hypercapnia in studies using passive detection. We sought to combine previously reported estimates of transcutaneous CO2 (TcCO2) sensor accuracy with the distribution of PaCO2 results to evaluate whether TcCO2 monitors might be accurate enough to identify hypercapnia among hospitalized adults. Methods: Inpatient encounters occurring Jan 1 to Dec 31, 2022, in which an ABG was drawn on the day of admission were requested from the TriNetX research network, which aggregates electronic health record data from 76 medical centers and roughly 115 million patients across the United States. We simulated a TcCO2 reading for each PaCO2 measurement using test agreement estimates from the meta-analysis by Conway et al. (Thorax, 2017) which estimated a mean bias of TcCO2 0.09 mmHg lower than PaCO2 and a population standard deviation (accounting for both within- and between-study variance) of 4.60 mmHg. Results were classified as true negatives (PaCO2 and TcCO2 < 45mmHg), false positives (PaCO2 < 45mmHg, TcCO2 ≥ 45mmHg), true positives (PaCO2 and TcCO2 ≥ 45mmHg), or false negatives (PaCO2 ≥ 45mmHg, TcCO2 < 45mmHg). Operating characteristics were subsequently calculated. Results: 158,228 ABGs were included (57.8% critical care; 54.9% male; 35.3% ventilated; 65.4% non-Hispanic white, 14.4% Black, 5.5% Hispanic; mean age 62.1 ± 16.4 years) showing a mean PaCO2 of 42.6 ±17.3mmHg. Hypercapnia was present in 47,995 (30.3%). Simulated TcCO2 measurements yielded the following operating characteristic estimates: sensitivity 84.2%, specificity 91.0%, negative predictive value 93.0%, and positive predictive value 80.4%. Conclusions: Our simulation suggests the accuracy of TcCO2 for binary classification of hypercapnia is likely to be high because many admitted patients have PaCO2 values sufficiently far from the threshold to make classification errors unlikely, given reported limits of agreement. Two limitations of this work are that patients receiving ABGs may have more extreme PaCO2 derangements than those without ABGs and disagreements between TcCO2-PaCO2 might be non-Gaussian. Nonetheless, TcCO2 may be a useful tool to capture the occurrence of hypercapnia more reliably among inpatients.

An emerging body of literature describes the prevalence and consequences of hypercapnic respiratory failure. While device qualifications, documentation practices, and previously performed clinical studies often encourage conceptualizing patients as having a single "cause" of hypercapnia, many patients encountered in practice have several contributing conditions. Physiologic and epidemiologic data suggest that sleep-disordered breathing-particularly obstructive sleep apnea (OSA)-often contributes to the development of hypercapnia. In this review, the authors summarize the frequency of contributing conditions to hypercapnic respiratory failure among patients identified in critical care, emergency, and inpatient settings with an aim toward understanding the contribution of OSA to the development of hypercapnia.

Background Immersive virtual reality (VR) is a promising therapy to improve the experience of patients with critical illness and may help avoid postdischarge functional impairments. However, the determinants of interest and usability may vary locally and reports of uptake in the literature are variable. Objective The aim of this mixed methods feasibility study was to assess the acceptability and potential utility of immersive VR in critically ill patients at a single institution. Methods Adults without delirium who were admitted to 1 of 2 intensive care units were offered the opportunity to participate in 5-15 minutes of immersive VR delivered by a VR headset. Patient vital signs, heart rate variability, mood, and pain were assessed before and after the VR experience. Pre-post comparisons were performed using paired 2-sided t tests. A semistructured interview was administered after the VR experience. Patient descriptions of the experience, issues, and potential uses were summarized with thematic analysis. Results Of the 35 patients offered the chance to participate, 20 (57%) agreed to partake in the immersive VR experience, with no difference in participation rate by age. Improvements were observed in overall mood (mean difference 1.8 points, 95% CI 0.6-3.0; P=.002), anxiety (difference of 1.7 points, 95% CI 0.8-2.7; P=.001), and pain (difference of 1.3 points, 95% CI 0.5-2.1; P=.003) assessed on 1-10 scales. The heart rate changed by a mean of –1.1 (95% CI –0.3 to –1.9; P=.008) beats per minute (bpm) from a baseline of 86.1 (SD 11.8) bpm and heart rate variability, assessed by the stress index (SI), changed by a mean of –5.0 (95% CI –1.5 to –8.5; P=.004) seconds–2 from a baseline SI of 40.0 (SD 23) seconds–2. Patients commented on the potential for the therapy to address pain, lessen anxiety, and facilitate calmness. Technical challenges were minimal and there were no adverse effects observed. Conclusions Patient acceptance of immersive VR was high in a mostly medical intensive care population with little prior VR experience. Patients commented on the potential of immersive VR to ameliorate cognitive and emotional symptoms. Investigators can consider integrating minimally modified commercial VR headsets into the existing intensive care unit workflow to further assess VR’s efficacy for a variety of endpoints.

Hypercapnic respiratory failure (an accumulation of carbon dioxide, CO2, in the blood) is often missed in clinical practice. Arterial blood gas is the standard diagnostic test, but it is painful and not routine. When clinicians fail to make the diagnosis, it is often because an arterial blood gas was not obtained. This 'partial verification' of CO2 levels presents a challenge for machine learning algorithms. We assessed the accuracy of two machine learning methods using demographics and routine lab work to estimate the likelihood that a patient has hypercapnic respiratory failure at hospital admission. Hospitalized patients who received an arterial blood gas sample constituted the training (n = 111,015) and geographic validation (n = 20,834) sets. Acceptance of "silver standard" diagnostic criteria and weighting observations by their modeled likelihood of receiving arterial blood gas sampling were used to assess the stability of findings in the presence of partial verification. Both regularized logistic regression and randomforest-based models resulted in acceptable performance (area under the curve: 0.763 and 0.758 respectively), with minimal changes in the auxiliary analyses. This work suggests that routinely available health record data can stratify the likelihood of hypercapnic respiratory failure among hospitalized adults, and findings may generalize to patients who have not received arterial blood gas sampling in clinical practice.

Hickam’s dictum (“a patient can have as many diseases as he damn well pleases”) has been touted as a counterargument to Ockham’s razor, which enjoins clinicians to seek a single, simple, or unifying diagnosis. Yet the phenomenon of multiple diagnoses has not been formally analyzed. We evaluated multiple diagnoses using three methods of inquiry: (1) a review of 83 case reports; (2) a review of 220 cases from the New England Journal of Medicine; and (3) an online survey of providers’ intuitions. Eighty-three published case reports claimed to instantiate Hickam’s dictum or violate Ockham’s razor. All reported a primary diagnosis that explained the presenting illness, and one or more additional diagnoses which could be classified into four categories: (1) an incidentaloma (n = 21; 25.3

Summary Introduction Weight loss is recommended for individuals with obstructive sleep apnea (OSA) and overweight or obesity, but there is limited evidence to guide the selection of weight management strategies for patients who do not lose sufficient weight with diet and lifestyle changes. We evaluated the relationship between weight loss caused by pharmacologic or surgical interventions and subsequent improvement in OSA by the apnea‐hypopnea index (AHI). Methods PubMed, Cochrane CENTRAL, and EMBASE were searched for randomized trials comparing pharmacologic or surgical obesity interventions to usual care, placebo, or no treatment in adults with OSA. The association between percentage weight loss and AHI change between randomization and last follow‐up was evaluated using meta‐regression. PROSPERO: CRD42022378853. Results Ten eligible trials ( n = 854 patients) were included. Four ( n = 211) assessed bariatric surgery, and 6 ( n = 643) assessed pharmacologic interventions over a median follow‐up of 13 months (interquartile range 6–26 months). The linear best estimate of the change in AHI is 0.45 events per hour (95% Confidence Interval 0.18 to 0.73 events per hour) for every 1% body weight lost. Conclusions Weight loss caused by medication or surgery caused a proportionate improvement of the AHI. Providers could consider extrapolating from this relationship when advising patients of the expected effects of other pharmacologic or surgical interventions without direct evidence in OSA.

PURPOSE: Individuals with cervical level Spinal Cord Injuries (SCI) have severely compromised respiratory function due to paralysis of ventilatory muscles resulting in impaired cough and inefficient ventilation.As a result, respiratory dysfunction is the leading cause of morbidity and mortality for patients with acute and chronic cervical SCI.At the University of Utah Neilson Rehabilitation Hospital, many cervical SCI patients are admitted requiring tracheostomy and mechanical ventilation.Thus, mechanical ventilation becomes part of the rehab course and may potentially effect rehab outcomes.METHODS: Medical records were obtained from SCI patients who were admitted to the University of Utah Rehab department between 2015-2022, with a tracheostomy, and required mechanical ventilation at the time of admission.The initial search identified 237 possible patients, which were manually reviewed, and 42 met the criteria noted above.Injuries were classified based on documented AISA scores.All patients had been subject to standard ventilator weaning practices at the University of Utah.Ordinal logistic regression was used to assess odds of weaning, which were ordered as "Fully Ventilator Dependent", "Daytime Wean", "Complete Wean", "Decannulated".RESULTS: 42 patients with SCI requiring mechanical ventilation via tracheostomy were identified.Median age was 44 (Interquartile Range [IQR] 28-59) years, 79% were male, and patients were admitted to rehab median 16 (IQR 13-25) days after their injury.Median days from injury to intubation was 0 (IQR 0-4) and tracheostomy occurred median 7 days (IQR 4-9) after.[BL1] C4 (n¼15),C5 (n¼9) injuries, and AIS A (n¼29) injuries were most common.Median length of stay was 64 [BL2] [CF3] days (IQR 56-76).Overall, 76% of patients weaned from daytime ventilator support (median day 20), 62% weaned from any ventilator support (median day 22), and 48% were decannulated.17% discharged to home, 19% went home with home health, 45% discharged to a skilled nursing facility, and 19% discharged to a long-term acute facility.Even amongst high cervical injuries (C1-4), 48% were able to wean from any ventilatory support, 28% decannulated, and 28% discharged to home +/-home health.In the regression analysis, age, days from injury to rehab admission, prior attempts at weaning were not associated with weaning success.However, high cervical (C1-4) conferred an odds ratio of 4.2 (p ¼ 0.45) of higher ventilatory support needs on discharge.CONCLUSIONS: Many patients with SCI who are initially dependent on mechanical ventilation via tracheostomy are able to wean from ventilation and discharge home, even amongst patients with high injuries.High cervical injury predicted more need for ventilatory support on discharge, but pre-rehab attempts at weaning, time from injury, and age did not.CLINICAL IMPLICATIONS: Previous unsuccessful attemtps at weaning high spinal cord patients should not limit future weaning attemtps if the patient currently appears ready to wean.

PurposeGuidelines recommend considering an initial trial of continuous positive airway pressure (CPAP) to treat central sleep apnea (CSA). However, practice patterns vary widely. This study investigated predictors for an initial trial of CPAP in patients with central apneas and whether those factors predict adequate treatment response in patients receiving an initial CPAP trial.MethodsCharts of patients receiving a diagnostic code for CSA following a sleep study during 2016-2018 at a single center were reviewed. Patient factors, initial treatment prescriptions, and subsequent changes to therapy were extracted from electronic health records. Regression models were used to estimate factors associated with an initial CPAP prescription and the likelihood of an adequate CPAP response (no subsequent therapy change and no discontinuation of therapy) among patients prescribed CPAP.Results429/588 (73%) patients with central apneas received an initial trial of CPAP. Younger age, diagnosis by home sleep testing, non-opiate etiology of central apneas, and a lower proportion of central apneas at diagnosis were independently associated with a higher likelihood of an initial CPAP trial. A lower proportion of central apneas was associated with a higher probability of adequate response, while current smoking and opiate-related central apneas predicted an unsuccessful CPAP trial. A new finding was that older age predicted a lower likelihood of an initial CPAP prescription but did not predict an unsatisfactory response to CPAP.ConclusionClinicians may incorrectly weigh certain clinical and sleep study characteristics when deciding whether to trial CPAP for patients with central apneas.

Abstract Introduction High rates of poor sleep quality have been reported among patients of Native Hawaiian/Pacific Islander (NHPI) race. Unrestful sleep might be attributable to short sleep times or to elevated rates of obstructive sleep apnea among NHPIs. We aimed to evaluate factors associated with self-reported poor sleep quality among NHPIs in a nationwide, representative community sample. Methods Using the 2014 National Health Interview Survey (NHIS), we used logistic regression to model the odds of individuals reporting that they did not awake feeling rested at least two out of the prior seven days. NHPIs from the NHPI-NHIS and non-NHPIs from the general sample were compared. Age, sex, BMI, smoking status, report of heavy drinking, employment status, marital status, and reported average hours of sleep time were evaluated in terms of their effects on self-reported sleep quality. Results Data from 36,697 non-NHPI and 2,590 NHPI individuals was available for analysis. There were significant differences in age, BMI, marital and current employment status between NHPIs vs. non-NHPIs. NHPI patients reported less sleep (mean 6.86±1.41 hours) in contrast to non-NHPIs (mean 7.12±1.42 hours) (P< 0.001). NHPIs were more likely to report two or more days awakening not feeling rested (Odds Ratio (OR) 1.22, 95% confidence interval (95CI) 1.12–1.32) as compared to non-NHPIs. After adjusting for demographics, BMI, alcohol, smoking, and marital and employment status, the relationship persisted (OR 1.17, 95CI 1.07-1.28). When additionally controlling for sleep time, which was strongly associated with the likelihood of awakening unrested (OR 3.1 95CI 2.9-3.2 for six or fewer average hours of sleep), there was no significant relationship between race and likelihood of awakening unrested (OR 1.02, 95CI 0.93-1.13). Findings were similar when evaluating different thresholds of unrestful nights per week. Conclusion NHPIs are more likely to awake feeling unrested than non-NHPIs. The higher rate of unrestful sleep is associated with higher reports of short (6 hours or less) sleep time. Therefore, future research to improve sleep quality in NHPIs should also investigate the cultural and social factors leading to short sleep time. Support (if any) BWL: NIH Ruth L. Kirschstein National Research Service Award 5T32HL105321 and the ATS ASPIRE Fellowship

PURPOSE: An enlarged pulmonary artery (PA) on CT imaging has been associated with mortality risk in several cohorts.Two measures of abnormal PA size have been defined based on the distribution of sizes in healthy individuals: PA diameter (PAd; abnormal >27mm [female], >29mm [male]) and PAd ratio to the ascending aorta (PA:AA; abnormal > 0.9).It is not known if these thresholds correspond to the PA size beyond which risk of adverse outcomes increases.We hypothesized that mortality risk would increase in a size-dependent manner for both metrics.The average AA diameter increases faster with age; thus we also hypothesized that higher PA:AA ratios would be needed to confer excess mortality risk in younger patients. METHODS:We reviewed 1000 randomly-selected CTPAs completed in 2009-2010 in two EDs within an integrated healthcare system in Utah.Patients with acute pulmonary emboli and duplicate scans were excluded.We measured the PAd and AA at the same level on each CTPA.Mortality status was obtained from the EHR and death registries.Restricted cubic splines were used to model the association of PA:AA and PAd with death in Cox regression models that also control for age and sex.Hazard Ratios (HR) are compared to the healthy population median value (PA:AA 0.77; PAd 25.1mm). RESULTS:The median age (n¼912 included) was 51y (interquartile range [IQR] 37-67) and 36.5% were male.28.8% died during follow-up (median 7 years).The median age of the n¼318 patients with high PA:AA was 41.5 (IQR.30-61).Patients with enlarged PAd were older (n¼ 258, median age 62 IQR 46-77).The PA:AA ratio associated with the lowest mortality risk was higher in younger patients.For the entire sample, all ratios below 0.75 predicted equivalent and minimized risk, while patients <50y had mortality risk nadir at PA:AA of 0.83.Similarly, the PA:AA conferring a HR of 1.5 was higher in younger patients (PA:AA ratio of 0.96 entire sample; PA:AA 1.05 under age 50y) with near log-linear increase for further size increase in all ages.The PAd associated with lowest risk of death was also smaller in the entire cohort (PAd of 22.1 mm [F] and 24.1 mm [M]) than in patients <50y (25.6 mm [F] and 27.6 mm [M]).The size associated with HR 1.5 was also larger in younger patients (entire cohort: PAd of 28.8 mm [F] and 30.8 mm [M]; under 50y: 30.7 mm [F] and 32.7 mm [M]) CONCLUSIONS: We found that both enlarged PAd and elevated PA:AA confer excess mortality risk in a dose-dependent manner for patients receiving CTPAs in the ED.Therefore, dichotomization as "normal or abnormal" may discard prognostic information.For both PAd and PA:AA, a larger PA size was required in younger patients before mortality risk increased.Whether this is due to differing timelines of mortality risk, increased vascular compliance in younger adults, or other mechanisms warrants further investigation.CLINICAL IMPLICATIONS: Dichotomized classification of pulmonary artery size on CTPA has previously been shown to predict mortality risk, but we show that age adjustment and accounting for the degree of enlargement may improve predictive performance.

Findings of an enlarged pulmonary artery diameter (PAd) and increased pulmonary artery to ascending aorta ratio (PA:AA) on contrast-enhanced computed tomography pulmonary angiography (CTPA) are associated with increased mortality in particular groups of patients with cardiopulmonary disease. However, the frequency and prognostic significance of these incidental findings has not been studied in unselected patients evaluated in the Emergency Department (ED). This study aims to determine the prevalence and associated prognosis of enlarged pulmonary artery measurements in an ED cohort. We measured PA and AA diameters on 990 CTPA studies performed in the ED. An enlarged PA diameter was defined as >27 mm in females and >29 mm in males, while an increased PA:AA was defined as >0.9. Poisson regression was performed to calculate prevalence ratios for relevant comorbidities, and multivariable Cox regression was performed to calculate hazard ratios (HR) for mortality of patients with enlarged pulmonary artery measurements. An enlarged PAd was observed in 27.9% of 990 patients and was more commonly observed in older patients and in patients with obesity or heart failure. Conversely, PA:AA was increased in 34.2% of subjects, and was more common in younger patients and those with peripheral vascular disease or obesity. After controlling for age, sex, and comorbidities, both enlarged PAd (HR 1.29, 95% CI 1.00-1.68, p = 0.05) and PA:AA (HR 1.70, 95% CI 1.31-2.22 p < 0.01) were independently associated with mortality. In sum, enlarged PAd and increased PA:AA are common in patients undergoing CTPAs in the ED setting and both are independently associated with mortality.