Faculty Bibliography

BACKGROUND:In patients with acute respiratory distress syndrome undergoing mechanical ventilation, positive end-expiratory pressure (PEEP) can lead to recruitment or overdistension. Current strategies utilized for PEEP titration do not permit the distinction. Electric impedance tomography (EIT) detects and quantifies the presence of both collapse and overdistension. We investigated whether using EIT-guided PEEP titration leads to decreased mechanical power compared to high-PEEP/FiO2 tables. METHODS:ratio, and static compliance. RESULTS:O, p = 0.008). CONCLUSIONS:In patients with moderate-severe acute respiratory distress syndrome, EIT-guided PEEP titration reduces mechanical power mainly through a reduction in elastic-dynamic power. Trial registration This trial was prospectively registered on Clinicaltrials.gov (NCT03793842) on January 4th, 2019.

OBJECTIVE:To describe, through a narrative review, the physiologic principles underlying electrical impedance tomography, and its potential applications in managing acute respiratory distress syndrome (ARDS). To address the current evidence supporting its use in different clinical scenarios along the ARDS management continuum. DATA SOURCES:We performed an online search in Pubmed to review articles. We searched MEDLINE, Cochrane Central Register, and clinicaltrials.gov for controlled trials databases. STUDY SELECTION:Selected publications included case series, pilot-physiologic studies, observational cohorts, and randomized controlled trials. To describe the rationale underlying physiologic principles, we included experimental studies. DATA EXTRACTION:Data from relevant publications were reviewed, analyzed, and its content summarized. DATA SYNTHESIS:Electrical impedance tomography is an imaging technique that has aided in understanding the mechanisms underlying multiple interventions used in ARDS management. It has the potential to monitor and predict the response to prone positioning, aid in the dosage of flow rate in high-flow nasal cannula, and guide the titration of positive-end expiratory pressure during invasive mechanical ventilation. The latter has been demonstrated to improve physiologic and mechanical parameters correlating with lung recruitment. Similarly, its use in detecting pneumothorax and harmful patient-ventilator interactions such as pendelluft has been proven effective. Nonetheless, its impact on clinically meaningful outcomes remains to be determined. CONCLUSIONS:Electrical impedance tomography is a potential tool for the individualized management of ARDS throughout its different stages. Clinical trials should aim to determine whether a specific approach can improve clinical outcomes in ARDS management.

INTRODUCTION/AIMS:) to assess the need for inpatient initiation of NIV. METHODS:Eight patients from the University of Michigan Pranger ALS clinic were directly admitted to the hospital for urgent initiation of NIV between May 2020-May 2021. A retrospective review of electronic medical records, including pre-hospital pulmonary function assessments, hospitalization blood gases, and NIV use metrics was performed. RESULTS: > 45 mmHg. Seven of eight patients had worsening hypercapnia after admission, indicating advanced respiratory failure. All patients were titrated to tolerance of continuous nocturnal NIV while in the hospital, with an average length of stay of 6.5 days (range, 3-8). All patients demonstrated compliance with NIV, >4 h, at post-hospital follow-up. DISCUSSION:measurements can serve as a useful screening tool to identify ALS patients who would benefit from inpatient initiation and titration of NIV.

Hemidiaphragm paralysis (HP) is a potential complication of cardiac surgery. While most patients are either asymptomatic or have mild symptoms, some are at risk of developing life-threatening hypercapnia. We present a case of a patient who developed HP after tricuspid valve replacement. Diaphragm plication was deferred due to underlying comorbidities, but over time she developed severe hypercapnic respiratory failure requiring intensive care unit admission. Chronic noninvasive ventilation therapy (NIV) was initiated, which improved her symptoms and hypercapnia and prevented further hospitalizations. For patients with iatrogenic HP unable to undergo diaphragm plication, Pulmonology referral for initiation of NIV should be strongly considered.

BACKGROUND:Amyotrophic Lateral Sclerosis (ALS) is a terminal neuromuscular disease with patients dying within 3-5 years of diagnosis. Most patients choose to forego invasive life sustaining measures. Timing of hospice referral can be challenging given the advancement of non-invasive ventilation (NIV) technology. OBJECTIVE:To describe the characteristics of patients enrolled in hospice from an ALS clinic at 1 academic medical center and to perform a cost analysis for patients who remained on ventilator support. METHODS:Retrospective cross-sectional study of patients enrolled in hospice over a 2-year period. Clinical characteristics included ALS Functional Rating Scale Revised (ALSFRS-R) score, Forced Vital Capacity (FVC), use of NIV and mechanical insufflation-exsufflation (MIE), riluzole use, and length of stay in hospice. A cost analysis was performed for patients enrolled in Duke Home Care and Hospice. RESULTS:85 of 104 patients who died were enrolled in hospice. Median days enrolled in hospice was 84. Patients who continued on NIV had similar hospice length of stay as those on no respiratory support (88 versus 80 days, p = 0.83). Bulbar patients had a trend toward shorter length of stay in hospice than limb onset patients (71 versus 101 days, p = 0.49). Cost analysis showed that hospice maintained a mean net operating revenue of $3234.50 per patient who continued on NIV. CONCLUSIONS:Hospice referrals for ALS patients on NIV can be challenging. This study shows that even with continued NIV use, most ALS patients die within the expected 6 months on home hospice, and care remains cost effective for hospice agencies.

OBJECTIVES/OBJECTIVE:Though critical care physicians feel responsible to address spiritual and religious needs with patients and families, and feel comfortable in doing so, they rarely address these needs in practice. We seek to explore this discrepancy through a qualitative interview process among physicians in the intensive care unit (ICU). METHODS:A qualitative research design was constructed using semi-structured interviews among 11 volunteer critical care physicians at a single institution in the Midwest. The physicians discussed barriers to addressing spiritual and religious needs in the ICU. A code book of themes was created and developed through a regular and iterative process involving 4 investigators. Data saturation was reached as no new themes emerged. RESULTS:Physicians reported feeling uncomfortable in addressing the spiritual needs of patients with different religious views. Physicians reported time limitations, and prioritized biomedical needs over spiritual needs. Many physicians delegate these conversations to more experienced spiritual care providers. Physicians cited uncertainty into how to access spiritual care services when they were desired. Additionally, physicians reported a lack of reminders to meet these needs, mentioning frequently the ICU bundle as one example. CONCLUSIONS:Barriers were identified among critical care physicians as to why spiritual and religious needs are rarely addressed. This may help inform institutions on how to better meet these needs in practice.

"Home noninvasive ventilation (NIV) is indicated for numerous conditions including neuromuscular disease, thoracic cage disorders, chronic obstructive pulmonary disease, and hypoventilation syndromes. Effective management of patients on home NIV requires clinicians to interpret data downloads from NIV devices. Clinicians must first look at adherence and factors that may impact this including mask comfort and fit. Next, leak assessment is undertaken. Once these are addressed, such information as apnea-hypopnea index, exhaled tidal volume, and percent triggered breaths help clinicians troubleshoot setting changes. Finally, overnight oximetry and transcutaneous CO2 monitoring are useful adjuncts to the data download to optimize NIV settings."