Pressure-flow breath representation eases asynchrony identification in mechanically ventilated patients.

Breathing asynchronies are mismatches between the requests of mechanically ventilated subjects and the support provided by mechanical ventilators. The most widespread technique in identifying these pathological conditions is the visual analysis of the intra-tracheal pressure and flow time-trends. This work considers a recently introduced pressure-flow representation technique and investigates whether it can help nurses in the early detection of anomalies that can represent asynchronies. Twenty subjects-ten Intensive Care Unit (ICU) nurses and ten persons inexperienced in medical practice-were asked to find asynchronies in 200 breaths pre-labeled by three experts. The new representation increases significantly the detection capability of the subjects-average sensitivity soared from 0.622 to 0.905-while decreasing the classification time-from 1107.0 to 567.1 s on average-at the price of a not statistically significant rise in the number of wrong identifications-specificity average descended from 0.589 to 0.52. Moreover, the differences in experience between the nurse group and the inexperienced group do not affect the sensitivity, specificity, or classification times. The pressure-flow diagram significantly increases sensitivity and decreases the response time of early asynchrony detection performed by nurses. Moreover, the data suggest that operator experience does not affect the identification results. This outcome leads us to believe that, in emergency contexts with a shortage of nurses, intensive care nurses can be supplemented, for the sole identification of possible respiratory asynchronies, by inexperienced staff.

An effective pressure-flow characterization of respiratory asynchronies in mechanical ventilation.

Ineffective effort during expiration (IEE) occurs when there is a mismatch between the demand of a mechanically ventilated patient and the support delivered by a Mechanical ventilator during the expiration. This work presents a pressure-flow characterization for respiratory asynchronies and validates a machine-learning method, based on the presented characterization, to identify IEEs. 1500 breaths produced by 8 mechanically-ventilated patients were considered: 500 of them were included into the training set and the remaining 1000 into the test set. Each of them was evaluated by 3 experts and classified as either normal, artefact, or containing inspiratory, expiratory, or cycling-off asynchronies. A software implementing the proposed method was trained by using the experts' evaluations of the training set and used to identify IEEs in the test set. The outcomes were compared with a consensus of three expert evaluations. The software classified IEEs with sensitivity 0.904, specificity 0.995, accuracy 0.983, positive and negative predictive value 0.963 and 0.986, respectively. The Cohen's kappa is 0.983 (with 95% confidence interval (CI): [0.884, 0.962]). The pressure-flow characterization of respiratory cycles and the monitoring technique proposed in this work automatically identified IEEs in real-time in close agreement with the experts.

On some factors determining the pressure drop across tracheal tubes during high-frequency percussive ventilation: a flow-independent model.

To provide an in vitro estimation of the pressure drop across tracheal tubes (ΔPTT) in the face of given pulsatile frequencies and peak pressures (Pwork) delivered by a high-frequency percussive ventilator (HFPV) applied to a lung model. Tracheal tubes (TT) 6.5, 7.5 and 8.0 were connected to a test lung simulating the respiratory system resistive (R = 5, 20, 50 cmH2O/L/s) and elastic (C = 10, 20, and 50 mL/cmH2O) loads. The model was ventilated by HFPV with a pulse inspiratory peak pressure (work pressure Pwork) augmented in 5-cmH2O steps from 20 to 45 cmH2O, yielding 6 diverse airflows. The percussive frequency (f) was set to 300, 500 and 700 cycles/min, respectively. Pressure (Paw and Ptr) and flow (V') measurements were performed for all 162 possible combinations of loads, frequencies, and work pressures for each TT size, thus yielding 486 determinations. For each respiratory cycle ΔPTT was calculated by subtracting each peak Ptr from its corresponding peak Paw. A non-linear model was constructed to assess the relationships between single parameters. Performance of the produced model was measured in terms of root mean square error (RMSE) and the coefficient of determination (r2). ΔPTT was predicted by Pwork (exponential Gaussian relationship), resistance (quadratic and linear terms), frequency (quadratic and linear terms) and tube diameter (linear term), but not by compliance. RMSE of the model on the testing dataset was 1.17 cmH2O, r2 was 0.79 and estimation error was lower than 1 cmH2O in 68% of cases. As a result, even without a flow value, the physician would be able to evaluate ΔPTT pressure. If the present results of our bench study could be clinically confirmed, the use of a nonconventional ventilatory strategy as HFPV, would be safer and easier.

Effects of sedatives and opioids on trigger and cycling asynchronies throughout mechanical ventilation: an observational study in a large dataset from critically ill patients.

BACKGROUND: In critically ill patients, poor patient-ventilator interaction may worsen outcomes. Although sedatives are often administered to improve comfort and facilitate ventilation, they can be deleterious. Whether opioids improve asynchronies with fewer negative effects is unknown. We hypothesized that opioids alone would improve asynchronies and result in more wakeful patients than sedatives alone or sedatives-plus-opioids. METHODS: This prospective multicenter observational trial enrolled critically ill adults mechanically ventilated (MV) > 24 h. We compared asynchronies and sedation depth in patients receiving sedatives, opioids, or both. We recorded sedation level and doses of sedatives and opioids. BetterCare™ software continuously registered ineffective inspiratory efforts during expiration (IEE), double cycling (DC), and asynchrony index (AI) as well as MV modes. All variables were averaged per day. We used linear mixed-effects models to analyze the relationships between asynchronies, sedation level, and sedative and opioid doses. RESULTS: In 79 patients, 14,166,469 breaths were recorded during 579 days of MV. Overall asynchronies were not significantly different in days classified as sedatives-only, opioids-only, and sedatives-plus-opioids and were more prevalent in days classified as no-drugs than in those classified as sedatives-plus-opioids, irrespective of the ventilatory mode. Sedative doses were associated with sedation level and with reduced DC (p < 0.0001) in sedatives-only days. However, on days classified as sedatives-plus-opioids, higher sedative doses and deeper sedation had more IEE (p < 0.0001) and higher AI (p = 0.0004). Opioid dosing was inversely associated with overall asynchronies (p < 0.001) without worsening sedation levels into morbid ranges. CONCLUSIONS: Sedatives, whether alone or combined with opioids, do not result in better patient-ventilator interaction than opioids alone, in any ventilatory mode. Higher opioid dose (alone or with sedatives) was associated with lower AI without depressing consciousness. Higher sedative doses administered alone were associated only with less DC. TRIAL REGISTRATION: ClinicalTrial.gov, NCT03451461.

Double Cycling During Mechanical Ventilation: Frequency, Mechanisms, and Physiologic Implications.

OBJECTIVES: Double cycling generates larger than expected tidal volumes that contribute to lung injury. We analyzed the incidence, mechanisms, and physiologic implications of double cycling during volume- and pressure-targeted mechanical ventilation in critically ill patients. DESIGN: Prospective, observational study. SETTING: Three general ICUs in Spain. PATIENTS: Sixty-seven continuously monitored adult patients undergoing volume control-continuous mandatory ventilation with constant flow, volume control-continuous mandatory ventilation with decelerated flow, or pressure control-continuous mandatory mechanical ventilation for longer than 24 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We analyzed 9,251 hours of mechanical ventilation corresponding to 9,694,573 breaths. Double cycling occurred in 0.6%. All patients had double cycling; however, the distribution of double cycling varied over time. The mean percentage (95% CI) of double cycling was higher in pressure control-continuous mandatory ventilation 0.54 (0.34-0.87) than in volume control-continuous mandatory ventilation with constant flow 0.27 (0.19-0.38) or volume control-continuous mandatory ventilation with decelerated flow 0.11 (0.06-0.20). Tidal volume in double-cycled breaths was higher in volume control-continuous mandatory ventilation with constant flow and volume control-continuous mandatory ventilation with decelerated flow than in pressure control-continuous mandatory ventilation. Double-cycled breaths were patient triggered in 65.4% and reverse triggered (diaphragmatic contraction stimulated by a previous passive ventilator breath) in 34.6% of cases; the difference was largest in volume control-continuous mandatory ventilation with decelerated flow (80.7% patient triggered and 19.3% reverse triggered). Peak pressure of the second stacked breath was highest in volume control-continuous mandatory ventilation with constant flow regardless of trigger type. Various physiologic factors, none mutually exclusive, were associated with double cycling. CONCLUSIONS: Double cycling is uncommon but occurs in all patients. Periods without double cycling alternate with periods with clusters of double cycling. The volume of the stacked breaths can double the set tidal volume in volume control-continuous mandatory ventilation with constant flow. Gas delivery must be tailored to neuroventilatory demand because interdependent ventilator setting-related physiologic factors can contribute to double cycling. One third of double-cycled breaths were reverse triggered, suggesting that repeated respiratory muscle activation after time-initiated ventilator breaths occurs more often than expected.

FLOW-i ventilator performance in the presence of a circle system leak.

Recently, the FLOW-i anaesthesia ventilator was developed based on the SERVO-i intensive care ventilator. The aim of this study was to test the FLOW-i's tidal volume delivery in the presence of a leak in the breathing circuit. We ventilated a test lung model in volume-, pressure-, and pressure-regulated volume-controlled modes (VC, PC, and PRVC, respectively) with a FLOW-i. First, the circuit remained airtight and the ventilator was tested with fresh gas flows of 6, 1, and 0.3 L/min in VC, PC, and PRVC modes and facing 4 combinations of different resistive and elastic loads. Second, a fixed leak in the breathing circuit was introduced and the measurements repeated. In the airtight system, FLOW-i maintained tidal volume (VT) and circuit pressure at approximately the set values, independently of respiratory mode, load, or fresh gas flow. In the leaking circuit, set VT = 500 mL, FLOW-i delivered higher VTs in PC (about 460 mL) than in VC and PRVC, where VTs were substantially less than 500 mL. Interestingly, VT did not differ appreciably from 6 to 0.3 L/min of fresh air flow among the 3 ventilatory modes. In the absence of leakage, peak inspiratory pressures were similar, while they were 35-45 % smaller in PRVC and VC than in PC mode in the presence of leaks. In conclusion, FLOW-i maintained VT (down to fresh gas flows of 0.3 L/min) to 90 % of its preset value in PC mode, which was 4-5 times greater than in VC or PRVC modes.

Patient-ventilator asynchrony.

PURPOSE OF REVIEW: The purpose of the review is to alert clinicians to the prevalent and frequently underrecognized problem of asynchrony in mechanically ventilated patients. To provide a mechanistic model of patient-ventilator asynchrony to help personnel understand how different asynchronies develop. To provide practical advice on how to recognize and solve different asynchronies in different contexts. RECENT FINDINGS: Patient-ventilator asynchrony is a serious problem that is associated with prolonged mechanical ventilation, prolonged ICU and hospital stays, and increased mortality. Asynchronies can occur in all modes of invasive and noninvasive ventilation in all care contexts. SUMMARY: The review provides insights into the causes of patient-ventilator asynchrony and mechanisms involved in the development of specific types of asynchrony. It explores the effects of sedation on the development of asynchrony and the impact of new ventilator modes. It also discusses the prevalence of asynchrony and its effects on outcome.

Automatic detection of ventilatory modes during invasive mechanical ventilation.

BACKGROUND: Expert systems can help alleviate problems related to the shortage of human resources in critical care, offering expert advice in complex situations. Expert systems use contextual information to provide advice to staff. In mechanical ventilation, it is crucial for an expert system to be able to determine the ventilatory mode in use. Different manufacturers have assigned different names to similar or even identical ventilatory modes so an expert system should be able to detect the ventilatory mode. The aim of this study is to evaluate the accuracy of an algorithm to detect the ventilatory mode in use. METHODS: We compared the results of a two-step algorithm designed to identify seven ventilatory modes. The algorithm was built into a software platform (BetterCare® system, Better Care SL; Barcelona, Spain) that acquires ventilatory signals through the data port of mechanical ventilators. The sample analyzed compared data from consecutive adult patients who underwent >24 h of mechanical ventilation in intensive care units (ICUs) at two hospitals. We used Cohen's kappa statistics to analyze the agreement between the results obtained with the algorithm and those recorded by ICU staff. RESULTS: We analyzed 486 records from 73 patients. The algorithm correctly labeled the ventilatory mode in 433 (89 %). We found an unweighted Cohen's kappa index of 84.5 % [CI (95 %) = (80.5 %: 88.4 %)]. CONCLUSIONS: The computerized algorithm can reliably identify ventilatory mode.

End-tidal versus manually-controlled low-flow anaesthesia.

During low-flow manually-controlled anaesthesia (MCA) the anaesthetist needs constantly adjust end-tidal oxygen (EtO2) and anaesthetic concentrations (EtAA) to assure an adequate and safe anaesthesia. Recently introduced anaesthetic machines can automatically maintain those variables at target values, avoiding the burden on the anaesthetist. End-tidal-controlled anaesthesia (EtCA) and MCA provided by the same anaesthetic machine under the same fresh gas flow were compared. Eighty patients were prospectively observed: in MCA group (n = 40) target end-tidal sevoflurane (1%) and EtO2 concentrations (≥ 35%) were manually controlled by the anaesthetist. In EtCA group (n = 40) the same anaesthetic machine with an additional end-tidal control feature was used to reach the same targets, rendering automatic the achievement and maintenance of those targets. Anaesthetic machine characteristics, amount of consumed gases, oxygen and sevoflurane efficiencies, and the amount of interventions by the anaesthetist were recorded. In EtCA group EtAA was achieved later (145 s) than in MCA (71 s) and remained controlled thereafter. Even though the target expired gas fractions were achieved faster in MCA, manual adjustments were required throughout anaesthesia for both oxygen and sevoflurane. In MCA patients the number of manual adjustments to stabilize EtAA and EtO2 were 137 and 107, respectively; no adjustment was required in EtCA. Low-flow anaesthesia delivered with an anaesthetic machine able to automatically control EtAA and EtO2 provided the same clinical stability and avoided the continuous manual adjustment of delivered sevoflurane and oxygen concentrations. Hence, the anaesthetist could dedicate more time to the patient and operating room activities.

Acute esophageal necrosis following cardiac arrest: A rare and lethal syndrome with diagnostic challenges.

INTRODUCTION AND CLINICAL RELEVANCE: Acute esophageal necrosis (AEN) is a condition characterized by the necrosis of the distal portion of the esophageal mucosa. Risk factors predisposing to this condition are associated to compromised vascular perfusion (e.g. diabetes mellitus, chronic kidney disease, advanced age, and hypertension, shock states). Complications of AEN can be severe including UGI stricture, perforation and overall increased mortality. The true incidence of AEN remains uncertain due to potential subclincal presentations and early resolution. CASE PRESENTATION: The case outlined involves a 66-years-old obese male with history of alcoholism and lymph-edema of the left leg who presented to the emergency department with hematemesis, haemodynamic instability and impaired consciousness. Shortly after initial assessment, the patient went into cardiac arrest with pulse-less electrical activity (PEA). Return of spontaneous circulation (ROSC) was achieved following instigation of ALS protocol, fluid resuscitation and the administration of a total of 5 mg of adrenaline. Following stabilization, a CT scan was performed which reported a moderately enlarged esophagus with a thickened wall, liquid hypodense material within the esophagus and stomach, and liver cirrhosis. The emergent esophagogastroduodenoscopy (EGDS) revealed extensive mucosal findings indicative of diffuse necrosis with initial scarring, which was later diagnosed as AEN. The patient unfortunately deceased in ICU after developing progression of the AEN, post-cardiac arrest syndrome and liver failure. CLINICAL DISCUSSION: The presented case highlights several crucial clinical issues and management problems related to AEN. To diagnose AEN, EGDS is still the gold-standard since it allows direct inspection of the esophageal mucosal layer. The management of AEN necessitates a multidisciplinary approach that includes aggressive resuscitation, treatment of underlying comorbidities, and supportive care (e.g. proton pump inhibitors). The mortality rate for AEN remains high despite improvements in diagnosis and treatment highlighting the need to recognize this condition early and intervene promptly in the patients affected. Moreover, long-term sequelae like stricture formation of the esophagus and impaired esophageal motility may contribute to morbidity requiring continuos monitoring. Therefore, to optimize outcomes while reducing complications among affected patients, prompt identification associated with appropriate medical measures are essential. More research needs to be done aiming to better understand the pathophysiology of AEN thereby identifying strategies for its prevention or cure. CONCLUSIONS: AEN is a rare syndrome characterized by upper gastrointestinal bleeding and hypoxic damage of the esophageal mucosa, often associated with ischemia, gastric outlet obstruction, and compromised protective barriers. Treatment involves aggressive resuscitation, proton pump inhibitors, and monitoring for infection or perforation. However, despite intensive efforts, the mortality rate for AEN remains high at 32 %.

Lung Volume and Ventilation Distribution After Bariatric Surgery: High-Flow Nasal Cannula Versus CPAP.

BACKGROUND: Patients with obesity are at increased risk of postoperative pulmonary complications. CPAP has been used successfully to prevent and treat acute respiratory failure, but in many clinical scenarios, high-flow nasal cannula (HFNC) therapy is emerging as a possible alternative. We aimed to compare HFNC and CPAP in a sequential study measuring their effects on gas exchange, lung volumes, and gas distribution within the lungs measured through electrical impedance tomography (EIT). METHODS: We enrolled 15 subjects undergoing laparoscopic bariatric surgery. Postoperatively they underwent the following oxygen therapy protocol (10 min/step): baseline air-entrainment mask, HFNC at increasing (40, 60, 80, and 100 L/min) and decreasing flows (80, 60, and 40 L/min), washout air-entrainment mask and CPAP (10 cm H2O). Primary outcome was the change in end-expiratory lung impedance (ΔEELI) measured by EIT data processing. Secondary outcomes were changes of global inhomogeneity (GI) index and tidal impedance variation (TIV) measured by EIT, arterial oxygenation, carbon dioxide content, pH, respiratory frequency, and subject's comfort. RESULTS: Thirteen subjects completed the study. Compared to baseline, ΔEELI was higher during 10 cm H2O CPAP (P = .001) and HFNC 100 L/min (P = .02), as well as during decreasing flows HFNC 80, 60, and 40 L/min (P = .008, .004, and .02, respectively). GI index was lower during HFNC 100 compared to HFNC 60increasing (P = .044), HFNC 60decreasing (P = .02) HFNC 40decreasing (P = .01), and during 10 cm H2O CPAP compared to washout period (P = .01) and HFNC 40decreasing (P = .03). TIV was higher during 10 cm H2O CPAP compared to baseline (P = .008). Compared to baseline, breathing frequency was lower at HFNC 60increasing, HFNC 100, and HFNC 80decreasing (P = .01, .02, and .03, respectively). No differences were detected regarding arterial oxygenation, carbon dioxide content, pH, and subject's comfort. CONCLUSIONS: HFNC at a flow of 100 L/min induced postoperative pulmonary recruitment in bariatric subjects, with no significant differences compared to 10 cm H2O CPAP in terms of lung recruitment and ventilation distribution.

Early short-term application of high-frequency percussive ventilation improves gas exchange in hypoxemic patients.

BACKGROUND: Hypoxemia in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) patients represents a common finding in the intensive care unit (ICU) and frequently does not respond to standard ventilatory techniques. OBJECTIVE: To study whether the early short-term application of high-frequency percussive ventilation (HFPV) can improve gas exchange in hypoxemic patients with ALI/ARDS or many other conditions in comparison to conventional ventilation (CV) using the same mean airway pressure (P(aw)), representing the main determinant of oxygenation and hemodynamics, irrespective of the mode of ventilation. METHODS: Thirty-five patients not responding to CV were studied. During the first 12 h after admission to the ICU the patients underwent CV. Thereafter HFPV was applied for 12 h with P(aw) kept constant. They were then returned to CV. Gas exchange was measured at: 12 h after admission, every 4 h during the HFPV trial, 1 h after the end of HFPV, and 12 h after HFPV. Thirty-five matched patients ventilated with CV served as the control group (CTRL). RESULTS: PaO(2)/FiO(2) and the arterial alveolar ratio (a/A PO(2)) increased during HFPV treatment and a PaO(2)/FiO(2) steady state was reached during the last 12 h of CV, whereas both did not change in CTRL. PaCO(2) decreased during the first 4 h of HFPV, but thereafter it remained unaltered; PaCO(2) did not vary in CTRL. Respiratory system compliance increased after HFPV. CONCLUSIONS: HFPV improved gas exchange in patients who did not respond to conventional treatment. This improvement remained unaltered until 12 h after the end of HFPV.

Protective ventilation for lung transplantation.

PURPOSE OF REVIEW: Lung transplantation has been one of the great medical advances as the last option for the treatment of end-stage pulmonary disease. Optimal pulmonary care of potential donors and recipients can definitely increase the number of successful lung retrievals and reduce the incidence of complications. RECENT FINDINGS: The use of a lung-protective ventilatory strategy, associated with recruitment maneuvers, has a profound clinical impact, doubling the number of lungs available for transplant. Postoperatively, it is important to use a lung-protective ventilation strategy, whereas for patients with life-threatening reperfusion injury, extracorporeal membrane oxygenation can ensure a survival rate between 50 and 80%. Pumpless extracorporeal carbon dioxide removal system allows the maintenance of normal gas exchange and can be maintained in the perioperative period. SUMMARY: Perioperative ventilatory care of the transplanted patient still represents a challenge for the ICU clinician. The lung-protective strategy and the early application of carbon dioxide removal systems can increase the number of lung donor eligibility. Further studies are needed to increase the viability of other organs and to develop new strategies that reduce the risk of ischemia-reperfusion injury, which still represents the most common complication in the postoperative period.

Neuronal desertification after a direct lightning strike: a case report.

BACKGROUND: Lightning strike is a rare but dramatic cause of injury. Patients admitted to intensive care units (ICUs) with lightning strike frequently have a high mortality and significant long-term morbidity related to a direct brain injury or induced cardiac arrest (CA). CASE PRESENTATION: A 50-year-old Caucasian man was admitted to our hospital after being struck by lightning resulting in immediate CA. Spontaneous circulation was initially restored, and the man was admitted to the ICU, but ultimately died while in hospital due to neurological injury. The computer tomography scan revealed a massive loss of grey-white matter differentiation at the fronto-temporal lobes bilaterally. Somatosensory-evoked potentials demonstrated bilateral absence of the cortical somatosensory N20-potential, and the electroencephalogram recorded minimal cerebral electrical activity. The patient died on day 10 and a post-mortem study revealed a widespread loss of neurons. CONCLUSION: This case study illustrates severe brain injury caused by a direct lighting strike, with the patient presenting an extraordinary microscopic pattern of neuronal desertification.

"Shoulder pain and limitation of motion in a young girl: think different".

BACKGROUND: Primary Synovial Chondromatosis (PSC) is a rare benign tumor of the synovial membrane in which cartilage metaplasia produces calcific loose bodies within the articular space. Only a few cases are reported in the pediatric population and its etiology remains unknown. This condition typically affects large weight-bearing joints with pain, swelling and decrease range of motion. Due to its slow progressions, delayed diagnosis is frequent and differential diagnosis should consider other chronic arthritis and malignancies. While arthroscopic removal of loose bodies is the current treatment up to now, the association of partial or complete synovectomy is debated. CASE PRESENTATION: We report about a 14-year-old girl with a long-lasting right shoulder pain, especially during movements or exercise, localized tenderness and hypotonia of the glenohumeral joint. No previous trauma was mentioned. Blood exams, Mantoux test and plain radiography of the right shoulder were unremarkable. Ultrasound imaging revealed echogenic and calcified bodies stretching the glenohumeral joint and dislocating the long head of biceps tendon. Magnetic resonance showed a "rice-grain" pattern of the right shoulder. From an arthroscopic surgery, multiple loose white bodies were removed within the synovial membrane, and synovial chondromatosis was confirmed by histological analysis. At one month follow up visit, the patient completely recovered without pain. CONCLUSION: Synovial chondromatosis is a very uncommon cause of mono articular pain in children, especially when it affects shoulder. Pediatricians should keep in mind this condition to avoid delayed diagnosis and treatment, even in consideration of the low risk of malignant transformation. Through this case, we would highlight common diagnostic pitfalls and treatment of synovial chondromatosis.

Reactivation of Herpes Simplex Virus Type 1 (HSV-1) Detected on Bronchoalveolar Lavage Fluid (BALF) Samples in Critically Ill COVID-19 Patients Undergoing Invasive Mechanical Ventilation: Preliminary Results from Two Italian Centers.

Reactivation of herpes simplex virus type 1 (HSV-1) has been described in critically ill patients with coronavirus disease 2019 (COVID-19) pneumonia. In the present two-center retrospective experience, we primarily aimed to assess the cumulative risk of HSV-1 reactivation detected on bronchoalveolar fluid (BALF) samples in invasively ventilated COVID-19 patients with worsening respiratory function. The secondary objectives were the identification of predictors for HSV-1 reactivation and the assessment of its possible prognostic impact. Overall, 41 patients met the study inclusion criteria, and 12/41 patients developed HSV-1 reactivation (29%). No independent predictors of HSV-1 reactivation were identified in the present study. No association was found between HSV-1 reactivation and mortality. Eleven out of 12 patients with HSV-1 reactivation received antiviral therapy with intravenous acyclovir. In conclusion, HSV-1 reactivation is frequently detected in intubated patients with COVID-19. An antiviral treatment in COVID-19 patients with HSV-1 reactivation and worsening respiratory function might be considered.

Comparison of noninvasive ventilation by sequential use of mask and helmet versus mask in acute exacerbation of chronic obstructive pulmonary disease: a preliminary study.

BACKGROUND: Noninvasive positive pressure ventilation (NPPV) using a face mask is the ventilatory mode of choice in selected patients experiencing acute exacerbation of chronic obstructive pulmonary disease (COPD). A high incidence of intolerance limits the use of this approach. OBJECTIVE: To evaluate the sequential use of mask and helmet during NPPV in patients with severe exacerbation of COPD in order to reduce the intolerance to these devices. METHODS: Fifty-three patients ventilated for the first 2 h with NPPV by mask were studied. If gas exchange and clinical status improved, they were randomized to continue on NPPV by mask or helmet. Physiological parameters were measured at admission, after the first 2 h on NPPV by mask, 4 h after randomization and at discharge. Need for intubation, ventilatory assistance, length of stay (LOS) and complications were recorded. RESULTS: After the first 2 h of NPPV, gas exchange and clinical parameters improved in 40 patients. Four hours after randomization, PaCO(2) was lower in the mask group than in the helmet group. Nine patients in the mask group and 2 in the helmet group failed NPPV, 8 and 1, respectively, owing to intolerance. Time of noninvasive ventilation and LOS were lower in the mask than in the helmet group. CONCLUSIONS: In patients with acute exacerbation of COPD and undergoing NPPV, the sequential use of a mask and helmet diminished the incidence of failure. Under the present experimental conditions, the use of a helmet increased LOS and the duration of artificial ventilation.

Multimodal Long-Term Predictors of Outcome in Out of Hospital Cardiac Arrest Patients Treated with Targeted Temperature Management at 36 °C.

Introduction: Early prediction of long-term outcomes in patients resuscitated after cardiac arrest (CA) is still challenging. Guidelines suggested a multimodal approach combining multiple predictors. We evaluated whether the combination of the electroencephalography (EEG) reactivity, somatosensory evoked potentials (SSEPs) cortical complex and Gray to White matter ratio (GWR) on brain computed tomography (CT) at different temperatures could predict survival and good outcome at hospital discharge and six months after the event. Methods: We performed a retrospective cohort study including consecutive adult, non-traumatic patients resuscitated from out-of-hospital CA who remained comatose on admission to our intensive care unit from 2013 to 2017. We acquired SSEPs and EEGs during the treatment at 36 °C and after rewarming at 37 °C, Gray to white matter ratio (GWR) was calculated on the brain computed tomography scan performed within six hours of the hospital admission. We primarily hypothesized that SSEP was associated with favor-able functional outcome at distance and secondarily that SSEP provides independent information from EEG and CT. Outcomes were evaluated using the Cerebral Performance Category (CPC) scale at six months from discharge. Results: Of 171 resuscitated patients, 75 were excluded due to missing data or uninterpretable neurophysiological findings. EEG reactivity at 37 °C has been shown the best single predictor of good out-come (AUC 0.803) while N20P25 was the best single predictor for survival at each time point. (AUC 0.775 at discharge and AUC 0.747 at six months follow up). The predictive value of a model including EEG reactivity, average GWR, and SSEP N20P25 amplitude was superior (AUC 0.841 for survival and 0.920 for good out-come) to any combination of two tests or any single test. Conclusions: Our study, in which life-sustaining treatments were never suspended, suggests SSEP cortical complex N20P25, after normothermia and off sedation, is a reliable predictor for survival at any time. When SSEP cortical complex N20P25 is added into a model with GWR average and EEG reactivity, the predictivity for good outcome and survival at distance is superior than each single test alone.