Transpulmonary Pressure-Guided Lung-Protective Ventilation Improves Pulmonary Mechanics and Oxygenation Among Obese Subjects on Mechanical Ventilation.

BACKGROUND: Transpulmonary pressure (PL) is used to assess pulmonary mechanics and guide lung-protective mechanical ventilation (LPV). PL is recommended to individualize LPV settings for patients with high pleural pressures and hypoxemia. We aimed to determine whether PL-guided LPV settings, pulmonary mechanics, and oxygenation improve and differ from non-PL-guided LPV among obese patients after 24 h on mechanical ventilation. Secondary outcomes included classification of hypoxemia severity, count of ventilator-free days, ICU length of stay, and overall ICU mortality. METHODS: This is a retrospective analysis of data. Ventilator settings, pulmonary mechanics, and oxygenation were recorded on the initial day of PL measurement and 24 h later. PL-guided LPV targeted inspiratory PL < 20 cm H2O and expiratory PL of 0-6 cm H2O. Comparisons were made to repeat measurements. RESULTS: Twenty subjects (13 male) with median age of 49 y, body mass index 47.5 kg/m2, and SOFA score of 8 were included in our analysis. Fourteen subjects received care in a medical ICU. PL measurement occurred 16 h after initiating non-PL-guided LPV. PL-guided LPV resulted in higher median PEEP (14 vs 18 cm H2O, P = .009), expiratory PL (-3 vs 1 cm H2O, P = .02), respiratory system compliance (30.7 vs 44.6 mL/cm H2O, P = .001), and [Formula: see text] (156 vs 240 mm Hg, P = .002) at 24 h. PL-guided LPV resulted in lower [Formula: see text] (0.53 vs 0.33, P < .001) and lower PL driving pressure (10 vs 6 cm H2O, P = .001). Tidal volume (420 vs 435 mL, P = .64) and inspiratory PL (7 vs 7 cm H2O, P = .90) were similar. Subjects had a median of 7 ventilator-free days, and median ICU length of stay was 14 d. Three of 20 subjects died within 28 d after ICU admission. CONCLUSIONS: PL-guided LPV resulted in higher PEEP, lower [Formula: see text], improved pulmonary mechanics, and greater oxygenation when compared to non-PL-guided LPV settings in adult obese subjects.

Proactive Use of High-Flow Nasal Cannula With Critically Ill Subjects.

INTRODUCTION: It has been suggested that use of a high-flow nasal cannula (HFNC) could be a first-line therapy for patients with acute hypoxic respiratory failure. The purpose of this study was to determine if protocolized use of HFNC decreases unplanned intubation and adverse outcomes in an ICU population. METHODS: The study was a prospective evaluation of 2 cohorts who received HFNC per protocol. Control groups were retrospective selections of subjects who received HFNC in the pre-protocol period. Cohort 1 (n = 88) received mechanical ventilation for ≥ 24 h and was extubated directly to HFNC following strict protocol criteria. Cohort 2 (n = 83) were placed on HFNC when oxygen requirements escalated (>4 L/min). RESULTS: Cohort 1 did not differ from its control group in mortality, hospital stay, or ICU days, but there were significant decreases in incidence of Gram-negative pulmonary infection (30% vs 9%, P = .001) and use of bronchodilator therapy (81% vs 61%, P = .008). Failed extubation rates were nearly identical across groups, but time to re-intubation was shorter in the protocol group (24 vs 13 h, P = .19). Cohort 2 did not differ significantly from its control group in intubation rates or mortality, but subjects managed by protocol experienced significant decreases in ICU days (4 vs 3 d, P = .03) and hospital days (12 vs 8 d, P = .007). There was a trend toward fewer hours on HFNC (33 vs 24 h, P = .10) and faster time to intubation when HFNC failed (19 vs 9 h, P = .08). CONCLUSIONS: Extubation to HFNC led to a significant decrease in pulmonary infections and bronchodilator therapy in Cohort 1 but did not reduce length of stay or rates of failed extubation. When HFNC was used early and per protocol (Cohort 2), ICU and hospital lengths of stay were reduced and HFNC was initiated more quickly when the need for respiratory support escalated.

A Preventative Respiratory Protocol to Identify Trauma Subjects at Risk for Respiratory Compromise on a General In-Patient Ward.

BACKGROUND: Patients are at risk for respiratory complications after sustaining blunt chest trauma, yet contradictory evidence exists about the utility of prophylactic respiratory therapy to reduce respiratory complications in this population. This study assessed the effectiveness of a proactive respiratory protocol on an in-patient ward to identify trauma patients at risk for pulmonary complications, administer appropriate therapies, and prevent deterioration requiring transfer to the ICU. METHODS: Trauma patients received a respiratory therapy evaluation at the time of admission to a general in-patient ward at a Level 1 trauma center. If subjects met protocol inclusion criteria, they received prophylactic respiratory treatments, primarily MetaNeb therapy, Vest therapy, or EzPAP. Multiple phases were included to evaluate the effectiveness of the protocol, with 50 subjects in each phase: a pre-protocol phase before adoption of the protocol; phase 1, which was found to have low physician adherence and overly broad inclusion criteria; and phase 2, with improved adherence and narrower inclusion criteria. Study inclusion criteria mirror the protocol criteria from phase 2: ≥3 rib fractures; pulmonary contusion; exacerbation of COPD, asthma, or other lung disease; or age ≥65 y with expected immobility of ≥48 h. RESULTS: The respiratory protocol was associated with an elimination of unplanned admissions to the ICU. After controlling for injury severity and other important clinical factors, receiving the protocol significantly decreased hospital stay by approximately 1.5 d. More subjects were admitted from the emergency department directly to the ward, avoiding the ICU. Bronchodilator use also decreased, although the result did not reach statistical significance. CONCLUSIONS: Study results suggest that a preventive respiratory protocol had a beneficial effect on patient outcomes; receiving the protocol reduced hospital days and eliminated unplanned admission to the ICU.

High-flow nasal cannula therapy for patients with blunt thoracic injury: A retrospective study.

OBJECTIVE: High-flow nasal cannula (HFNC) has been shown to reduce the need for mechanical ventilation (MV) and to decrease hospital and ICU days for patients with severe respiratory compromise. HFNC has not been evaluated in trauma patients, thus the goal of this study is to describe the use of HFNC in a chest-injured population. METHODS: A retrospective study examined trauma patients with moderate to severe thoracic injury admitted to the ICU at a tertiary hospital between March 2012 and August 2015. HFNC was delivered by the Fisher & Paykel Optiflow system. Primary outcomes were the need for intubation after HFNC for respiratory failure, length of hospitalization, and mortality. RESULTS: During the study period, 105 patients with blunt chest trauma were admitted to the ICU and received HFNC therapy. Eighteen percent received MV prior to HFNC. Overall, 69% of patients who received HFNC never received MV, and 92% of patients were discharged alive. The intubation rate for respiratory failure after HFNC was 18%. For patients who did not receive MV prior to HFNC, delay to first HFNC was correlated with increased hospital days (r s = 0.41, p = 0.001) and ICU days (r s = 0.41, p < 0.001). CONCLUSIONS: Study results suggest that HFNC is comparable with other methods of noninvasive ventilation and may be beneficial for patients with thoracic injury. Additional investigation is warranted to determine if early use of HFNC can deliver effective respiratory support and prevent intubation in this population.

High-Flow Nasal Cannula in a Mixed Adult ICU.

BACKGROUND: Humidified, high-flow nasal cannula (HFNC) enables mucociliary clearance, accurate oxygen measurement, precise control of flow, and low-level positive airway pressure. There is sparse information concerning the timing of HFNC on patient outcomes such as incidence of adverse events during hospitalization, ICU stay, and post-ICU stay. METHODS: This is a retrospective analysis of a heterogeneous population of medical and trauma ICU patients who received HFNC therapy in a critical care setting. The study sample included 145 subjects who were admitted to the ICU and received HFNC therapy between March 2012 and February 2014. HFNC was delivered by the Fisher & Paykel Optiflow system. RESULTS: Of the 145 subjects who received HFNC, 35 (24.1%) received mechanical ventilation before HFNC, 21 (14.5%) received mechanical ventilation after HFNC, and 89 (61.3%) never received mechanical ventilation. Delay to first HFNC was moderately associated with unplanned ICU admission and was strongly correlated with the development of ventilator-associated pneumonia. Subjects with a greater length of time between ICU admission and first use of HFNC experienced significantly longer stays in the ICU and post-ICU periods, even after controlling for adverse events and mechanical ventilation. CONCLUSIONS: Study results provide preliminary evidence that early use of HFNC is beneficial in a medical and trauma ICU population, as it was associated with decreased ICU and post-ICU lengths of stay and reduced incidence of adverse events. This suggests that HFNC should be considered early in the ICU as first-line oxygen therapy.

Year in review 2014: mechanical ventilation.

Mechanical ventilation is an important and ever-evolving component of everyday critical care. Clinicians can struggle to keep up with current literature and descriptions of advancement in a way that they can apply these changes to their bedside patient care. This article serves as a review of important recent findings related to invasive mechanical ventilation and describes their relevance to bedside critical care.