Early Mobility Index and Patient Outcomes: A Retrospective Study in Multiple Intensive Care Units

BACKGROUND

Early mobility interventions in intensive care units (ICUs) are safe and improve outcomes in subsets of critically ill adults. However, implementation varies, and the optimal mobility dose remains unclear.

OBJECTIVE

To test for associations between daily dose of out-of-bed mobility and patient outcomes in different ICUs.

METHODS

In this retrospective cohort study of electronic records from 7 adult ICUs in an academic quarternary hospital, multivariable linear regression was used to examine the effects of out-of-bed events per mobility-eligible day on mechanical ventilation duration and length of ICU and hospital stays.

RESULTS

In total, 8609 adults hospitalized in ICUs from 2015 through 2018 were included. Patients were mobilized out of bed on 46.5% of ICU days and were eligible for mobility interventions on a median (IQR) of 2.0 (1-3) of 2.7 (2-9) ICU days. Median (IQR) out-of-bed events per mobility-eligible day were 0.5 (0-1.2) among all patients. For every unit increase in out-of-bed events per mobility-eligible day before extubation, mechanical ventilation duration decreased by 10% (adjusted coefficient [95% CI], -0.10 [-0.18 to -0.01]). Daily mobility increased ICU stays by 4% (adjusted coefficient [95% CI], 0.04 [0.03-0.06]) and decreased hospital stays by 5% (adjusted coefficient [95% CI], -0.05 [-0.07 to -0.03]). Effect sizes differed among ICUs.

CONCLUSIONS

More daily out-of-bed mobility for ICU patients was associated with shorter mechanical ventilation duration and hospital stays, suggesting a dose-response relationship between daily mobility and patient outcomes. However, relationships differed across ICU subpopulations.

Using the ROX Index to Predict Treatment Outcome for High-Flow Nasal Cannula and/or Noninvasive Ventilation in Patients With COPD Exacerbations

BACKGROUND

The ratio of oxygen saturation index (ROX index; or SpO2 /FIO2 /breathing frequency) has been shown to predict risk of intubation after high-flow nasal cannula (HFNC) support among adults with acute hypoxemic respiratory failure primarily due to pneumonia. However, its predictive value for other subtypes of respiratory failure is unknown. This study investigated whether the ROX index predicts liberation from HFNC or noninvasive ventilation (NIV), intubation with mechanical ventilation, or death in adults admitted for respiratory failure due to an exacerbation of COPD.

METHODS

We performed a retrospective study of 260 adults hospitalized with a COPD exacerbation and treated with HFNC and/or NIV (continuous or bi-level). ROX index scores were collected at treatment initiation and predefined time intervals throughout HFNC and/or NIV treatment or until the subject was intubated or died. A ROX index score of ≥ 4.88 was applied to the cohort to determine if the same score would perform similarly in this different cohort. Accuracy of the ROX index was determined by calculating the area under the receiver operator curve.

RESULTS

A total of 47 subjects (18%) required invasive mechanical ventilation or died while on HFNC/NIV. The ROX index at treatment initiation, 1 h, and 6 h demonstrated the best prediction accuracy for avoidance of invasive mechanical ventilation or death (area under the receiver operator curve 0.73 [95% CI 0.66-0.80], 0.72 [95% CI 0.65-0.79], and 0.72 [95% CI 0.63-0.82], respectively). The optimal cutoff value for sensitivity (Sn) and specificity (Sp) was a ROX index score > 6.88 (sensitivity 62%, specificity 57%).

CONCLUSIONS

The ROX index applied to adults with COPD exacerbations treated with HFNC and/or NIV required higher scores to achieve similar prediction of low risk of treatment failure when compared to subjects with hypoxemic respiratory failure/pneumonia. ROX scores < 4.88 did not accurately predict intubation or death.

Comparing demographics, treatments, and outcomes of patients with COVID-19 lesions versus hospital-acquired pressure ulcers/injuries during the first year of COVID-19

BACKGROUND

As COVID-19 has emerged as a pandemic virus, multiple reports have surfaced to describe skin lesions that occur either associated with the virus or due to treatment.

OBJECTIVE

To compare patient demographics, treatments, and outcomes in COVID-19 symptomatic patients who developed skin lesions (COVID-19 or hospital-acquired pressure ulcer/injury [HAPU/I]) during the first year of the pandemic.

METHODS

A retrospective chart review was conducted on COVID-positive symptomatic patients admitted from March 1, 2020, through March 1, 2021. The authors analyzed the difference in patient demographics, patient skin tones, treatments, hospital length of stay (LOS), intensive care unit (ICU) LOS, death, and discharge disposition for those with COVID-19 lesions compared to those who developed HAPU/Is.

RESULTS

Of those who developed lesions, 2.3% developed COVID-19 lesions and 7.2% developed HAPU/Is. Patients with COVID-19 lesions were more likely to be male (64%), younger (median age 60), and had a higher BMI (30) than patients with no wounds and patients with HAPU/I.

CONCLUSION

This study advances the knowledge of the patient demographics and treatments that may contribute to identifying the new phenomenon of COVID lesions and how they differ from HAPU/Is.

Noninvasive vs Invasive Respiratory Support for Patients with Acute Hypoxemic Respiratory Failure

Rationale

Noninvasive respiratory support modalities are common alternatives to mechanical ventilation for patients with early acute hypoxemic respiratory failure. These modalities include noninvasive positive pressure ventilation, using either continuous or bilevel positive airway pressure, and nasal high flow using a high flow nasal cannula system. However, outcomes data historically compare noninvasive respiratory support to conventional oxygen rather than to mechanical ventilation.

Objectives

The goal of this study was to compare the outcomes of in-hospital death and alive discharge in patients with acute hypoxemic respiratory failure when treated initially with noninvasive respiratory support compared to patients treated initially with invasive mechanical ventilation.

Methods

We used a validated phenotyping algorithm to classify all patients with eligible International Classification of Diseases codes at a large healthcare network between January 1, 2018 and December 31, 2019 into noninvasive respiratory support and invasive mechanical ventilation cohorts. The primary outcome was time-to-in-hospital death analyzed using an inverse probability of treatment weighted Cox model adjusted for potential confounders, with estimated cumulative incidence curves. Secondary outcomes included time-to-hospital discharge alive. A secondary analysis was conducted to examine potential differences between noninvasive positive pressure ventilation and nasal high flow.

Results

During the study period, 3177 patients met inclusion criteria (40% invasive mechanical ventilation, 60% noninvasive respiratory support). Initial noninvasive respiratory support was not associated with a decreased hazard of in-hospital death (HR: 0.65, 95% CI: 0.35 - 1.2), but was associated with an increased hazard of discharge alive (HR: 2.26, 95% CI: 1.92 - 2.67). In-hospital death varied between the nasal high flow (HR 3.27, 95% CI: 1.43 - 7.45) and noninvasive positive pressure ventilation (HR 0.52, 95% CI 0.25 - 1.07), but both were associated with increased likelihood of discharge alive (nasal high flow HR 2.12, 95 CI: 1.25 - 3.57; noninvasive positive pressure ventilation HR 2.29, 95% CI: 1.92 - 2.74).

Conclusion

These observational data from a large healthcare network show that noninvasive respiratory support is not associated with reduced hazards of in-hospital death but is associated with hospital discharge alive. There are also potential differences between the noninvasive respiratory support modalities.

A Least Absolute Shrinkage and Selection Operator-Derived Predictive Model for Postoperative Respiratory Failure in a Heterogeneous Adult Elective Surgery Patient Population

BACKGROUND

Postoperative respiratory failure (PRF) is associated with increased hospital charges and worse patient outcomes. Reliable prediction models can help to guide postoperative planning to optimize care, to guide resource allocation, and to foster shared decision-making with patients.

RESEARCH QUESTION

Can a predictive model be developed to accurately identify patients at high risk of PRF?

STUDY DESIGN AND METHODS

In this single-site proof-of-concept study, we used structured query language to extract, transform, and load electronic health record data from 23,999 consecutive adult patients admitted for elective surgery (2014-2021). Our primary outcome was PRF, defined as mechanical ventilation after surgery of > 48 h. Predictors of interest included demographics, comorbidities, and intraoperative factors. We used logistic regression to build a predictive model and the least absolute shrinkage and selection operator procedure to select variables and to estimate model coefficients. We evaluated model performance using optimism-corrected area under the receiver operating curve and area under the precision-recall curve and calculated sensitivity, specificity, positive and negative predictive values, and Brier scores.

RESULTS

Two hundred twenty-five patients (0.94%) demonstrated PRF. The 18-variable predictive model included: operations on the cardiovascular, nervous, digestive, urinary, or musculoskeletal system; surgical specialty orthopedic (nonspine); Medicare or Medicaid (as the primary payer); race unknown; American Society of Anesthesiologists class ≥ III; BMI of 30 to 34.9 kg/m2; anesthesia duration (per hour); net fluid at end of the operation (per liter); median intraoperative FIO2, end title CO2, heart rate, and tidal volume; and intraoperative vasopressor medications. The optimism-corrected area under the receiver operating curve was 0.835 (95% CI,0.808-0.862) and the area under the precision-recall curve was 0.156 (95% CI, 0.105-0.203).

INTERPRETATION

This single-center proof-of-concept study demonstrated that a structured query language extract, transform, and load process, based on readily available patient and intraoperative variables, can be used to develop a prediction model for PRF. This PRF prediction model is scalable for multicenter research. Clinical applications include decision support to guide postoperative level of care admission and treatment decisions.

A ten-year retrospective California Poison Control System experience with possible amatoxin mushroom calls

INTRODUCTION

Mushrooms containing amatoxin are found worldwide and represent a challenging poisoning for the clinician and consulting poison center. This study evaluates the experience of a large poison system with possible amatoxin-containing mushroom ingestion calls.

METHODS

A 10-year retrospective review of the California Poison Control System database was performed for amatoxin mushroom ingestion calls resulting in hospitalization. Cases found were abstracted and data statistically analyzed for association with a composite endpoint of death, liver transplant, and/or the need for dialysis.

RESULTS

Amatoxin-containing mushroom calls are infrequent with the vast majority (98.4 percent) coming from Northern California during the rainier first and fourth quarters (October through March) of the year. Elevated initial aminotransferase activities and international normalized ratios were predictive of the composite negative outcome. The mortality plus liver transplant and hemodialysis composite rate was 8.2 percent, consistent with current literature.

CONCLUSION

The California Poison Control System has relatively few amatoxin-containing mushroom ingestion calls that result in hospitalization but those that are reported mostly occur in Northern California. Treatment bias towards the sickest patients may explain the association of intravenous fluid use or treatment with acetylcysteine or silibinin with meeting the composite outcome. The initial presence of elevated hepatic aminotransferase activity and international normalized ratios are poor prognostic indicators and are likely reflective of late presentation, an advanced toxic phase of amatoxin poisoning, and/or delays in time to obtain poison center consultation.

The 2022 Certified Flight Registered Nurse Pulse Survey

OBJECTIVE

The Certified Flight Registered Nurse (CFRN) credential independently validates a registered nurse's advanced knowledge, skills, and abilities in the unique specialty of flight nursing. Introduced in 1993 and celebrating its 30th anniversary in July 2023, the CFRN is held by over 5,500 registered nurses. The purpose of the 2022 CFRN pulse survey was to better understand the ways CFRN-certified registered nurses value this national flight nursing specialty credential. The CFRN survey is a companion to the 2022 Certified Transport Registered Nurse pulse survey, which focused on the Certified Transport Registered Nurse critical care ground transport nursing credential.

METHODS

The Board of Certification for Emergency Nursing e-mailed individuals in its database of CFRN credential holders and asked them to respond to a 14-question online survey between October 17, 2022, and November 8, 2022. Participation in the survey was voluntary. Of the 5,275 verified CFRN holders who received the survey, 992 responded, for a response rate of 18.8%. The survey instrument included discrete field and open-ended questions. Data were deidentified for analysis, and institutional review board exemption was received. Counts and percentages were reported, and descriptive statistics were used.

RESULTS

The highest percentage of flight nurses who responded have more than 10 years of experience in flight nursing (35.3%) and are employed by a stand-alone transport program (42.7%). Flight nurses reported they spent a mean of 70% of their work hours transporting via rotor wing aircraft, with a predominantly adult patient population. The top perceived benefits of being a CFRN-certified nurse were a sense of accomplishment and pride (90.7%) followed by flight physiology knowledge (85.4%), flight nursing clinical knowledge (83.4%), and confidence as a flight nurse (80.6%).

CONCLUSION

The 2022 CFRN pulse survey identified current CFRN demographics, practice environments including transport percentage by mode and patient population types, and perceived benefits of the CFRN credential. The findings suggest CFRNs are very experienced, provide care for patients across the age continuum, and perceive multiple intrinsic and extrinsic benefits of CFRN certification, all of which are essential to safe, evidence-based advanced nursing practice in the unique, complex, autonomous, and dynamic flight environment.

Work of Breathing During Proportional Assist Ventilation as a Predictor of Extubation Failure

BACKGROUND

Despite decades of research on predictors of extubation success, use of ventilatory support after extubation is common and 10-20% of patients require re-intubation. Proportional assist ventilation (PAV) mode automatically calculates estimated total work of breathing (total WOB). Here, we assessed the performance of total WOB to predict extubation failure in invasively ventilated subjects.

METHODS

This prospective observational study was conducted in 6 adult ICUs at an academic medical center. We enrolled intubated subjects who successfully completed a spontaneous breathing trial, had a rapid shallow breathing index < 105 breaths/min/L, and were deemed ready for extubation by the primary team. Total WOB values were recorded at the end of a 30-min PAV trial. Extubation failure was defined as any respiratory support and/or re-intubation within 72 h of extubation. We compared total WOB scores between groups and performance of total WOB for predicting extubation failure with receiver operating characteristic curves.

RESULTS

Of 61 subjects enrolled, 9.8% (n = 6) required re-intubation, and 50.8% (n = 31) required any respiratory support within 72 h of extubation. Median total WOB at 30 min on PAV was 0.9 J/L (interquartile range 0.7-1.3 J/L). Total WOB was significantly different between subjects who failed or were successfully extubated (median 1.1 J/L vs 0.7 J/L, P = .004). The area under the curve was 0.71 [95% CI 0.58-0.85] for predicting any requirement of respiratory support and 0.85 [95% CI 0.69-1.00] for predicting re-intubation alone within 72 h of extubation. Total WOB cutoff values maximizing sensitivity and specificity equally were 1.0 J/L for any respiratory support (positive predictive value [PPV] 70.0%, negative predictive value [NPV] 67.7%) and 1.3 J/L for re-intubation (PPV 26.3%, NPV 97.6%).

CONCLUSIONS

The discriminative performance of a PAV-derived total WOB value to predict extubation failure was good, indicating total WOB may represent an adjunctive tool for assessing extubation readiness. However, these results should be interpreted as preliminary, with specific thresholds of PAV-derived total WOB requiring further investigation in a large multi-center study.

Outcomes and risk factors for delayed-onset postoperative respiratory failure: a multi-center case-control study by the University of California Critical Care Research Collaborative (UC3RC)

BACKGROUND

Few interventions are known to reduce the incidence of respiratory failure that occurs following elective surgery (postoperative respiratory failure; PRF). We previously reported risk factors associated with PRF that occurs within the first 5 days after elective surgery (early PRF; E-PRF); however, PRF that occurs six or more days after elective surgery (late PRF; L-PRF) likely represents a different entity. We hypothesized that L-PRF would be associated with worse outcomes and different risk factors than E-PRF.

METHODS

This was a retrospective matched case-control study of 59,073 consecutive adult patients admitted for elective non-cardiac and non-pulmonary surgical procedures at one of five University of California academic medical centers between October 2012 and September 2015. We identified patients with L-PRF, confirmed by surgeon and intensivist subject matter expert review, and matched them 1:1 to patients who did not develop PRF (No-PRF) based on hospital, age, and surgical procedure. We then analyzed risk factors and outcomes associated with L-PRF compared to E-PRF and No-PRF.

RESULTS

Among 95 patients with L-PRF, 50.5% were female, 71.6% white, 27.4% Hispanic, and 53.7% Medicare recipients; the median age was 63 years (IQR 56, 70). Compared to 95 matched patients with No-PRF and 319 patients who developed E-PRF, L-PRF was associated with higher morbidity and mortality, longer hospital and intensive care unit length of stay, and increased costs. Compared to No-PRF, factors associated with L-PRF included: preexisiting neurologic disease (OR 4.36, 95% CI 1.81-10.46), anesthesia duration per hour (OR 1.22, 95% CI 1.04-1.44), and maximum intraoperative peak inspiratory pressure per cm H₂0 (OR 1.14, 95% CI 1.06-1.22).

CONCLUSIONS

We identified that pre-existing neurologic disease, longer duration of anesthesia, and greater maximum intraoperative peak inspiratory pressures were associated with respiratory failure that developed six or more days after elective surgery in adult patients (L-PRF). Interventions targeting these factors may be worthy of future evaluation.

Risk Factors Associated With Early Postoperative Respiratory Failure: A Matched Case-Control Study

BACKGROUND

Postoperative respiratory failure is the most common serious postoperative pulmonary complication, yet little is known about factors that can reduce its incidence. We sought to elucidate modifiable factors associated with respiratory failure that developed within the first 5 d after an elective operation.

MATERIALS AND METHODS

Matched case-control study of adults who had an operation at five academic medical centers between October 1, 2012 and September 30, 2015. Cases were identified using administrative data and confirmed via chart review by critical care clinicians. Controls were matched 1:1 to cases based on hospital, age, and surgical procedure.

RESULTS

Our total sample (n = 638) was 56.4% female, 71.3% white, and had a median age of 62 y (interquartile range 51, 70). Factors associated with early postoperative respiratory failure included male gender (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.12-2.63), American Society of Anesthesiologists class III or greater (OR 2.85, 95% CI 1.74-4.66), greater number of preexisting comorbidities (OR 1.14, 95% CI 1.004-1.30), increased operative duration (OR 1.14, 95% CI 1.06-1.22), increased intraoperative positive end-expiratory pressure (OR 1.23, 95% CI 1.13-1.35) and tidal volume (OR 1.13, 95% CI 1.004-1.27), and greater net fluid balance at 24 h (OR 1.17, 95% CI 1.07-1.28).

CONCLUSIONS

We found greater intraoperative ventilator volume and pressure and 24-h fluid balance to be potentially modifiable factors associated with developing early postoperative respiratory failure. Further studies are warranted to independently verify these risk factors, explore their role in development of early postoperative respiratory failure, and potentially evaluate targeted interventions.

Postoperative respiratory failure: An update on the validity of the Agency for Healthcare Research and Quality Patient Safety Indicator 11 in an era of clinical documentation improvement programs

BACKGROUND

Administrative data can be used to identify cases of postoperative respiratory failure (PRF). We aimed to determine if recent changes to the Agency for Healthcare Research and Quality Patient Safety Indicator 11 (PSI 11) and adoption of clinical documentation improvement programs have improved the validity of PSI 11. We also analyzed reasons why PSI 11 was falsely triggered.

STUDY DESIGN

Cross-sectional study of all eligible discharges using health record data from five academic medical centers between October 1, 2012 and September 30, 2015.

RESULTS

Of 437 flagged records, 434 (99.3%) were accurately coded and 414 (94.7%) represented true clinical PRF. None of the false positive records involved respiratory failure present on admission. Most (78.3%) false positive records required airway protection but did not have respiratory failure.

CONCLUSION

The validity of PSI 11 has improved with recent changes to the code criterion and adoption of clinical documentation improvement programs.