Practical Trends in Anesthesia and Intensive Care 2020-2021

This book offers an essential guide to managing the most-debated hot topics of practical interest in anesthesia and intensive care. Part I reviews the state of the art in issues concerning both intensive care medicine and anesthesia, such as perioperative medicine, acute liver failure, anesthesia monitoring and ERAS in hepatic surgery. Part II focuses on microbiome in critically ill patients, on COVID-19 aspects and related issues, on sepsis in pediatric patients and ventilatory management in obese patients. Written by leading experts and including updated references, it provides a comprehensive, easy-to-follow update on anesthesia and intensive care. The book clearly explains complex topics, offering practicing clinicians valuable insights into the latest recommendations and evidence in the field while, at the same time, making it a vital resource for students new to the fields of anesthesia and intensive care. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

CPAP-associated changes in oxygenation and clinical outcomes in severe COVID-19 pneumonia

Background: Continuous positive airway pressure (CPAP) can improve oxygenation in severe COVID-19 pneumonia. Objective(s): To assess whether CPAP-associated improvements in oxygenation can inform clinical outcomes in patients with severe COVID-19 pneumonia. Method(s): Retrospective study in patients with severe COVID-19 pneumonia treated with CPAP in three academic respiratory units in Milan, Italy. Arterial gas analysis obtained before and 1 hour after starting CPAP. CPAP failure defined as either death in the respiratory units while on CPAP or need for intubation. Result(s): 211 patients (mean age 64 years, 74% males) were included. Baseline median PaO2was 68 (57-83) mmHg, PaO2/FiO2(P/F) ratio was 129 (91-179) mmHg and alveolar-arterial (A-a) O2 gradient was 310 (177-559) mmHg. On CPAP, PaO2and P/F increased to 100 (79-141) (p<0.001) and 195 (132-257;p<0.001) mmHg and A-a gradient decreased to 240 (188-308;p<0.001) mmHg. 42 (19.9%) patients died in the respiratory units while on CPAP and 51 (24.2%) required intubation. There was a substantial overlap of baseline and CPAP-associated values of PaO2, P/F ratio and A-a gradient in CPAP failures and successes (Figure). CPAP-associated changes in PaO2, P/F ratio and A-a gradient in both groups were similar. Conclusion(s): CPAP-associated improvements in oxygenation cannot be used to inform clinical outcomes of the individual patient with severe COVID-19 pneumonia.

WE-159. Critical Illness Neuropathy in Severe COVID-19: a case series

Introduction: Neurological complications of SARS-CoV-2 disease have received growing attention, but only few studies have described to date clinical and neurophysiological findings in COVID patients during their stay in intensive care units (ICUs). Here, we assessed the presence of either critical illness neuropathy (CIP) or myopathy (CIM) in ICU patients. Method(s): Patients underwent a neurophysiological assessment, including bilateral examination of the median, ulnar, deep peroneal and tibial motor nerves and of the median, ulnar, radial, and sural sensory nerves. Needle electromyography (EMG) was performed for both distal and proximal muscles of the lower and upper limbs. The technique of Direct Muscle Stimulation (DMS) was applied either to the deltoid or tibialis anterior muscles. Peak to peak amplitudes and onset latencies of the responses evoked by DMS (DMSamp, DMSlat) or by motor nerve stimulation (MNSamp, MNSlat) were compared. The ratio MNSamp to DMSamp (NMR) and the MNSlat to DMSlat difference (NMD: MNSlat-DMSlat) were also evaluated. Result(s): Nerve conduction studies showed a sensory-motor polyneuropathy with axonal neurogenic pattern, as confirmed by needle EMG. Both MNSamp and NMR were significantly reduced when compared to controls (p < 0.0001), whereas MNSlat and NMD were markedly increased (p = 0.0049). Conclusion(s): We have described COVID patients in the ICU with critical illness neuropathy (CIP). The predominance of CIP as compared to critical illness myopathy (CIM) has implications for the functional recovery and rehabilitation strategies in severe COVID-19. Copyright © 2022

Hemorrhagic, coagulopathic, and thrombotic (HECTOR) complications among critically-ill patients with COVID-19: An International COVID-19 critical care consortium study

Background: Hemorrhage, coagulopathy and thrombosis (HECTOR) are reported complications of coronavirus disease 2019 (COVID-19) however, more information is needed on the prevalence of these complications and their associated outcomes in intensive care unit (ICU) settings. Aim(s): To determine the prevalence and outcomes of HECTOR complications in ICU patients with COVID-19. Method(s): Observational cohort study spanning 229 ICUs across 32 countries. Patients >=16 years admitted for severe COVID-19 from 1st January 2020, through 31st December 2021 were included. Patient characteristics and clinical data were collected. Survival analysis estimated the instantaneous impact of HECTOR complications on ICU-mortality and discharge. Result(s): HECTOR complications occurred in 1,735 (14%) of 11,972 study-eligible patients. Acute thrombosis occurred in 1,249 (10%) patients, including 712 (57%) with pulmonary embolism, 413 (33%) with myocardial infarction, 93 (7.4%) with deep vein thrombosis, and 49 (3.9%) with ischemic stroke. Hemorrhagic complications were reported in 582 (4.9%) patients, including 276 (48%) with gastrointestinal hemorrhage, 83 (14%) with hemorrhagic stroke, and 77 (13%) with pulmonary hemorrhage. Disseminated intravascular coagulation occurred in 11 (0.09%) patients. Univariate analysis identified diabetes, hypertension, cardiac and kidney disease and ECMO as statistically-significant risk factors for HECTOR complications. Patients with versus without HECTOR complications suffered higher ICU-mortality at 28 days (25%vs.13%, p < 0.001), 90 days (32%vs.15%, p < 0.0001) and overall (44%vs.36%, p < 0.001). Among ICU survivors, the ICU stay was longer (median days 19vs.12, p < 0.001). ICU mortality was similar between patients with and without HECTOR complications (HR = 1.01, 95%CI 0.92-1.12, p = 0.783) where an increased hazard of ICU mortality with hemorrhage (HR = 1.26, 1.09-1.45, p = 0.002) was balanced by a reduced hazard of thrombosis (HR = 0.88, 0.79-0.99, p = 0.03). Kaplan-Meier curves are presented in the Figure. Conclusion(s): HECTOR events are frequent complications of severe COVID-19 in ICU patients. Hemorrhagic, but not thrombotic complications are associated with increased ICU-mortality.

Respiratory and peripheral muscular ultrasound characteristics in ICU COVID 19 ARDS patients.

PURPOSE: Severe cases of coronavirus disease 2019 develop ARDS requiring admission to the ICU. This study aimed to investigate the ultrasound characteristics of respiratory and peripheral muscles of patients affected by COVID19 who require mechanical ventilation. MATERIALS AND METHODS: This is a prospective observational study. We performed muscle ultrasound at the admission of ICU in 32 intubated patients with ARDS COVID19. The ultrasound was comprehensive of thickness and echogenicity of both parasternal intercostal and diaphragm muscles, and cross-sectional area and echogenicity of the rectus femoris. RESULTS: Patients who survived showed a significantly lower echogenicity score as compared with those who did not survive for both parasternal intercostal muscles. Similarly, the diaphragmatic echogenicity was significantly different between alive or dead patients. There was a significant correlation between right parasternal intercostal or diaphragm echogenicity and the cumulative fluid balance and urine protein output. Similar results were detected for rectus femoris echogenicity. CONCLUSIONS: The early changes detected by echogenicity ultrasound suggest a potential benefit of proactive early therapies designed to preserve respiratory and peripheral muscle architecture to reduce days on MV, although what constitutes a clinically significant change in muscle echogenicity remains unknown.

Brainstem damage in COVID-19

Background and aims: It has recently been proposed that SARS-CoV-2 might spread through the nervous system in a prion-like way, reaching respiratory centers in the brainstem. Here, we evaluated neuropathologically, neurophysiologically and clinically the brainstem involvement in COVID-19. Methods: Neuropathological data were acquired from patients died for COVID-19 and COVID-19 negative;neuronal damage and the number of corpora amylacea (CA)/mm2 were assessed. The expression of the nuclear proteinof SARS-Cov-2 was also evaluated. To clarify whether neuropathological findings had a functional correlate, we studied the blink reflex (BR) in 11 COVID-19 patients, admitted to our Intensive Care Unit (ICU), and compared data both with healthy subjects and non COVID- 19 ICU patients. An extensive neurological examination, comprising the corneal and glabellar reflexes, was also performed. Results: Autopsies showed a high percentage of neuronal damage and a higher number of CA in the medulla oblongata of COVID-19 patients;immunohistochemistry revealed the presence of SARS-Cov-2 virus in the brainstem. Neurophysiologically, the RII component of the BR was selectively impaired in COVID-19 and, clinically, the glabellar reflex reduced or absent. Conclusion: Our findings provide the first combined neuropathological, neurophysiological and clinical evidence of SARS-Cov-2-related brainstem involvement, especially at the medullary level, suggesting a neurogenic component of respiratory failure.

An appraisal of respiratory system compliance in mechanically ventilated COVID-19 patients

Rationale Heterogeneous respiratory system static compliance (CRS) values and levels of hypoxemia in patients with novel coronavirus disease (COVID-19) requiring mechanical ventilation have been reported in previous smallcase series or studies conducted at a national level.Methods We designed a retrospective observational cohort study with rapid data gathering from the international COVID-19 Critical Care Consortium study to comprehensively describe the impact of CRS on the ventilatory management and outcomes of COVID-19 patients on mechanical ventilation (MV), admitted to intensive care units (ICU) worldwide.Results We enrolled 318 COVID-19 patients enrolled into the study from January 14th through September 31th, 2020 in 19 countries and stratified into two CRS groups. CRS was calculated as: tidal volume/[airway plateau pressure-positive endexpiratory pressure (PEEP)] and available within 48h from commencement of MV in 318 patients. Patients were mean±SD of 58.0±12.2, predominantly from Europe (54%) and males (68%). Median CRS (IQR) was 34.1 mL/cmH2O (26.5-45.5) and PaO2/FiO2 was 119 mmHg (87.1-164) and was not correlated with CRS. Female sex presented lower CRS than in males (95% CI:-13.8 to-8.5 P<0.001) and higher body mass index (34.7±10.9 vs 29.1±6.0, p<0.001). Median (IQR) PEEP was 12 cmH2O (10-15), throughout the range of CRS, while median (IQR) driving pressure was 12.3 (10-15) cmH2O and significantly decreased as CRS improved (p<0.001). No differences were found in comorbidities and clinical management between CRS strata. In addition, 28-day ICU mortality and hospital mortality did not differ between CRSgroups.Conclusions This multicentre report provides a comprehensive account of CRS in COVID-19 patients on MV-predominantly males or overweight females, in their late 50s-admitted to ICU during the first international outbreaks. Phenotypes associated with different CRS upon commencement of MV could not be identified.

Factors associated with mortality in patients with COVID-19 requiring mechanical ventilation: An international cohort study from 139 intensive care unit across 6 continents

Rationale: Patients with COVID-19 commonly develop severe hypoxemic respiratory failure and require invasive mechanical ventilation (MV). The disease burden and predictors of mortality in this population remain uncertain. Methods: Prospective observational cohort study from 139 intensive care units of the international COVID-19 Critical Care Consortium. Patients enrolled from January 14th through November 31st 2020 were included in the analysis. Patient's characteristics and clinical data were assessed. Multivariable Cox proportional hazards analysis was conducted to identify indipendent predictors of mortality within 28 days from commencement of MV. Results: 1578 patients on MV were included into the analysis. Mean±SD age was 59 years±13 and patients were predominantly males (66%). 542 Patients (34.4%) died within 28 days from commencement of MV. Nonsurvivors were slightly older (mean age±SD 62±13 vs. 59±13) and presented more frequently hypertension, chronic cardiac disease and diabetes. Median (IQR) PaO2/FiO2 upon commencement of MV was 96 (68-135) and 111 (81-173) in patients who did not survive vs. survivors, respectively (p=0.04). ECMO (13% vs 25%, p<0.01), inhaled nitric oxide (11% vs 15%, p=0.02) and recruitment manoeauvres (26% vs 31%, p<0.01) were used less frequently in patients who did not survive. Independent risk factors associated with 28-day mortality included age older than 70 years (hazard ratio [HR], 2.83;95% CI, 1.32-6.07), higher creatinine levels upon ICU admission (HR, 1.20;95% CI, 1.03-1.40), and lower pH within 24h from commencement of MV (HR, 0.12;95% CI, 0.02-0.62), while a shorter period (day) from early symptoms to hospitalisation reduced mortality risks (HR, 0.96;95% CI, 0.93-0.99). Conclusions: Our findings from a large international cohort of critically-ill COVID-19 patients on mechanical ventilation emphasises that elderly patients, not promptly admitted to the hospital, and who present higher creatinine levels and acidosis are at higher risk of mortality.