Dynamic inflation prevents and standardized lung recruitment reverts volume loss associated with percutaneous tracheostomy during volume control ventilation: results from a Neuro-ICU population.

To determine how percutaneous tracheostomy (PT) impacts on respiratory system compliance (Crs) and end-expiratory lung volume (EELV) during volume control ventilation and to test whether a recruitment maneuver (RM) at the end of PT may reverse lung derecruitment. This is a single center, prospective, applied physiology study. 25 patients with acute brain injury who underwent PT were studied. Patients were ventilated in volume control ventilation. Electrical impedance tomography (EIT) monitoring and respiratory mechanics measurements were performed in three steps: (a) baseline, (b) after PT, and (c) after a standardized RM (10 sighs of 30 cmH2O lasting 3 s each within 1 min). End-expiratory lung impedance (EELI) was used as a surrogate of EELV. PT determined a significant EELI loss (mean reduction of 432 arbitrary units p = 0.049) leading to a reduction in Crs (55 ± 13 vs. 62 ± 13 mL/cmH2O; p < 0.001) as compared to baseline. RM was able to revert EELI loss and restore Crs (68 ± 15 vs. 55 ± 13 mL/cmH2O; p < 0.001). In a subgroup of patients (N = 8, 31%), we observed a gradual but progressive increase in EELI. In this subgroup, patients did not experience a decrease of Crs after PT as compared to patients without dynamic inflation. Dynamic inflation did not cause hemodynamic impairment nor raising of intracranial pressure. We propose a novel and explorative hyperinflation risk index (HRI) formula. Volume control ventilation did not prevent the PT-induced lung derecruitment. RM could restore the baseline lung volume and mechanics. Dynamic inflation is common during PT, it can be monitored real-time by EIT and anticipated by HRI. The presence of dynamic inflation during PT may prevent lung derecruitment.

Reliability of Respiratory System Compliance Calculation During Assisted Mechanical Ventilation: A Retrospective Study.

OBJECTIVES: To compare respiratory system compliance (C rs ) calculation during controlled mechanical ventilation (MV) and, subsequently, during assisted MV. DESIGN: This is a single-center, retrospective, observational study. SETTING: This study was conducted on patients admitted to Neuro-ICU of Niguarda Hospital (tertiary referral hospital). PATIENTS: We analyzed every patient greater than or equal to 18 years old having a C rs measurement in controlled and in assisted MV within 60 minutes. Plateau pressure (P plat ) was considered reliable if it was deemed visually stable for at least 2 seconds. INTERVENTIONS: Inspiratory pause was incorporated to detect P plat in controlled and assisted MV. Calculation of C rs and driving pressure were achieved. MEASUREMENTS AND MAIN RESULTS: A total of 101 patients were studied. An acceptable agreement was found (Bland-Altman plot bias -3.9, level of agreement upper 21.6, lower -29.6). C rs in assisted MV was 64.1 (52.6-79.3) and in controlled MV it was 61.2 (50-71.2) mL/cm H 2o ( p = 0.006). No statistical difference was found in C rs (assisted vs controlled MV) when peak pressure was lower than P plat nor when peak pressure was higher than P plat . CONCLUSIONS: A P plat visually stable for at least 2 seconds leads to reliable C rs calculation during assisted MV.

Emergently planned exclusive hub-and-spoke system in the epicenter of the first wave of COVID-19 pandemic in Italy: the experience of the largest COVID-19-free ICU hub for time-dependent diseases.

BACKGROUND: Lombardy was the epicenter in Italy of the first wave of COVID-19 pandemic. To face the contagion growth, from March 8 to May 8, 2020, a regional law redesigned the hub-and-spoke system for time-dependent diseases to better allocate resources for COVID-19 patients. METHODS: We report the reorganization of the major hospital in Lombardy during COVID-19 pandemic, including the rearrangement of its ICU beds to face COVID-19 pandemic and fulfill its role as extended hub for time-dependent diseases while preserving transplant activity. To highlight the impact of the emergently planned hub-and-spoke system, all patients admitted to a COVID-19-free ICU hub for trauma, neurosurgical emergencies and stroke during the two-month period were retrospectively collected and compared to 2019 cohort. Regional data on organ procurement was retrieved. Observed-to-expected (OE) in-ICU mortality ratios were computed to test the impact of the pandemic on patients affected by time-dependent diseases. RESULTS: Dynamic changes in ICU resource allocation occurred according to local COVID-19 epidemiology/trends of patients referred for time-dependent diseases. The absolute increase of admissions for trauma, neurosurgical emergencies and stroke was roughly two-fold. Patients referred to the hub were older and characterized by more severe conditions. An increase in crude mortality was observed, though OE ratios for in-ICU mortality were not statistically different when comparing 2020 vs. 2019. An increase in local organ procurement was observed, limiting the debacle of regional transplant activity. CONCLUSIONS: We described the effects of a regional emergently planned hub-and-spoke system for time-dependent diseases settled in the epicenter of COVID-19 pandemic in Italy.