High Airway Pressures Research Articles

Anaphylactic shock reaction caused by the anesthetic drug cyclopofol during general anesthesia: case report and literature review

Introduction: Cyclopofol, as an alternative to propofol, is theoretically known as a safe drug and is widely used as a sedative. However, it is important to note that the short history of clinical application of cyclopofol and the rarity of systemic anaphylaxis, there is a lack of understanding that cyclopofol can cause systemic anaphylaxis. To our knowledge, there have been no reported allergic reactions associated with cyclopofol, but we should always be aware of this risk. Case presentation: A 47-year-old male patient developed severe hypotension, high airway pressure, decreased oxygen saturation, and rash after intravenous and pump administration of cyclopofol during general anesthesia, and a diagnosis of anaphylactic shock was made based on a skin test 6 weeks later. Discussion: This case serves as a reminder that although allergic reactions to cyclopofol are rare, it is important to be aware of such incidents. Therefore, the possibility of an allergic reaction caused by cyclopofol should be considered and always prepared for treatment. Conclusion: As a new drug substitute for propofol, cyclopofol should still be used with caution in people with a history of allergies or the possibility of allergies or other uncertain situations on patients.

A systematic review on the use of sevoflurane in the management of status asthmaticus in adults

BackgroundTo conduct a systematic review looking into the use of sevoflurane in the management of status asthmaticus (SA) in adults.MethodsWe performed a systematic search on PubMed, EMBASE, and The Cochrane Library – CENTRAL through 23rd August 2023, restricting to studies reported in English. We included studies reporting use of sevoflurane in asthmatics beyond its use as an anaesthetic agent in surgeries i.e. in the emergency department (ED) and critical care setting, and focused on patient’s clinical parameters, ventilation pressures and weaning of invasive ventilation.ResultsA total of 13 publications fulfilled the inclusion criteria, comprising of 18 cases. All publications were of case reports/ series and conference abstracts, and no randomised trials were available. Most patients required intubation despite best medical management before sevoflurane administration, and high airway pressures and respiratory acidosis were apparent. There was significant heterogeneity regarding severity of asthma, treatment instituted, and the delivery, duration and concentration of sevoflurane administered. Many of the studies also did not quantify the changes in parameters pre- and post-sevoflurane. Sixteen patients experienced improvements in clinical status with sevoflurane administration—one required escalation to extracorporeal membrane oxygenation (ECMO), and another did not survive.ConclusionThe systematic review suggests sevoflurane can be a valuable treatment option in SA. As these cases are rare and heterogenous, further prospective case series are needed to support this.

Sleep apnea-specific hypoxic burden and pulse rate response in children using high flow nasal cannula therapy compared with continuous positive airway pressure

BackgroundElevated sleep apnea-specific hypoxic burden (HB) and pulse rate response (ΔHR) are associated with a higher cardiovascular risk in adults. The clinical significance of HB and ΔHR in children with obstructive sleep apnea (OSA) and their responses to therapy have not yet been investigated. This study aimed to compare the efficacy of high flow nasal cannula (HFNC) and continuous positive airway pressure (CPAP) in reducing HB and ΔHR in children. MethodsThis analysis included 17 children (11 males, mean age: 12.6 ± 3.9 years) with obesity and/or medical complexity and moderate-to-severe OSA. Each participant underwent two additional sleep studies: one for HFNC titration and another for CPAP titration. HB and ΔHR were derived from the oximetry and pulse rate signals from overnight sleep studies, respectively. ResultsBoth HFNC and CPAP demonstrated significant reductions in HB from baseline, with similar magnitudes [HFNC: −129 (standard error, SE 55) %min/h, p = 0.003; CPAP: −138 (SE 53) %min/h, p = 0.005]. However, for ΔHR, a significant reduction from baseline was observed only in the CPAP group [–2.7 (SE 1.1) beats/min, p = 0.049], not the HFNC group [–1.0 (SE 1.4) beats/min, p = 0.67]. ConclusionsHFNC is as effective as CPAP in treating hypoxia in children with OSA, but HFNC might be less effective than CPAP in mitigating cardiovascular stress from autonomic disturbances during obstructive events.

High flow nasal cannula versus continuous positive airway pressure on incidence of postoperative pulmonary complications after bariatric surgery

ABSTRACT Background High flow nasal cannula (HFNC) and continuous positive airway pressure (CPAP) can be used postoperatively to decrease postoperative pulmonary complications. Aim This study evaluated and compared the effect of HFNC versus CPAP on postoperative pulmonary complications in bariatric surgery. Patients and Methods Sixty adult ASA class II and III patients scheduled for bariatric operations were divided into two equal groups: the HFNC and CPAP groups. Results No significant variations in HR and MABP were observed between groups. Mean SpO2% and PaO2/FiO2 readings were lower on ICU admission than pre-induction (p < 0.001). However, after the intervention, readings significantly increased (p < 0.001). Respiratory rate and PaCO2 levels were higher upon ICU admission than pre-induction in both groups (p < 0.001). After the intervention, they decreased significantly during all assessment times compared to ICU admission time (p < 0.001). Both groups had lower lung ultrasound scores at ICU discharge than on admission (p < 0.001). Still, no significant variations in scores observed between groups upon admission and before discharge. No significant variations were found in the incidence of postoperative pulmonary complications and duration of stay in hospital. Conclusion HFNC and CPAP decrease atelectasis and improve respiratory parameters postoperatively in morbidly obese persons after bariatric operation.

Tracheal gas insufflation for refractory hypercapnia

A 65 year male patient got admitted to ICU after alleged intake of ~ 250 ml of Chlorpyrifos (Organophosphate insecticides which cause cholinergic toxidrome) and cypermethrin (Synthetic pyrethroid) and presented with cholinergic toxidrome with severe hypercapnia (supercarbia). All conventional and advanced modes of ventilation failed to ventilate the patient because of severe bronchospasm and a prolonged expiratory time constant with high airway pressures and high auto-peep. As a last resort, we resorted to unconventional modes, as the patient could not afford ECMO. Tracheal gas insufflation was done using a coaxial flow of humidified oxygen at 8 lpm with a suction catheter and ventilator parameter were adjusted to match the added gas flows. Tracheal gas insufflation can be delivered by a thin catheter placed through the endotracheal tube (terminating within 1 to 2 cm of the main carina) or via a modified endotracheal tube with channels embedded in the walls of the tube. Tracheal gas insufflation flow can be forward (toward the alveoli) or reversed in direction toward the proximal end of the endotracheal tube. Keywords: TGI, Hypercapnia, organophosphate toxicity

Assessing the predictors for paediatric intensive care unit for inter-hospital transfer patients on high-flow nasal cannula or continuous positive airway pressure ventilation at a tertiary Australian paediatric hospital.

The aim of the present study was to assess the predictors of need for paediatric intensive care unit (PICU) admission for inter-hospital transfer patients to a tertiary paediatric hospital ED on high flow (HF) or continuous positive airway pressure (CPAP) ventilation. Single-centre retrospective study of patients transferred to the state's tertiary paediatric hospital. Demographic information and disease management information was obtained. Between October 2021 and September 2022, 53 patients were transferred to the tertiary hospital on HF or CPAP. Of these, 23 required admission to PICU. Those admitted to PICU had a higher median fraction of inspired oxygen than those not admitted (0.4 vs 0.3, respectively, P = 0.013). Patients transported by road (vs flight) were more likely (20/23 patients, RR = 3.15, P = 0.016) to be admitted to PICU (56% vs 18%). Those who had received CPAP prior to or during transfer were more likely to require PICU admission (P = 0.012). We have demonstrated that children who require CPAP to manage their respiratory disease are more likely to require PICU care on transfer to the tertiary paediatric hospital. In addition, those patients being transferred from secondary metropolitan hospitals after a trial of HF are also likely to require PICU care. This suggests that these patients should be directly admitted to PICU, allowing for improved patient experience and flow as well as reducing unnecessary ED resource utilisation.

Non-Invasive High Frequency Oscillatory Ventilation versus Continuous Positive Airway Pressure in Preterm Neonates With Respiratory Distress Syndrome

Abstract Background Respiratory distress syndrome (RDS) is the main cause of respiratory failure in preterm neonates, its incidence varies from 80% to 25% depending on gestational age. When optimal prenatal care is provided, the best approach to treat RDS, according to several recent trials, consists of providing continuous positive airway pressure (CPAP) from the first minutes of life using short binasal prongs or masks, followed by early selective surfactant administration for babies with worsening oxygenation and/or increasing work of breathing. Any effort must be done to minimize the time under invasive mechanical ventilation (IMV). Non-invasive high-frequency oscillatory ventilation (nHFOV) is a new mode of non-invasive ventilation that connects non-invasive circuits to high-frequency ventilators, through which gas exchange is achieved by the superposition of high-frequency oscillation over continuous positive flow. Compared with other non-invasive ventilation modes, nHFOV combines the advantages of nCPAP and high-frequency ventilation, making it more effective at maintaining alveolar stability, eliminating CO2, and limiting barotrauma. Objective To investigate the effectiveness of nasal high frequency oscillatory ventilation in comparison to nCPAP as a primary mode of respiratory support in preterm neonates with respiratory distress syndrome. Methods This randomized controlled trial that was conducted on 90 neonates diagnosed with RDS at the Neonatal Intensive Care Units (NICUs), Ain Shams University Hospitals throughout six months. Results In the current study, there was a significant decrease in FiO2 needs in nHFOV group vs. nCPAP group, the median (IQR) (30% (21 to 37) vs. 31% (30 to 40) respectively, P-value=0.030), but non significant difference in RDS according to total Silverman score in nHFOV group vs. nCPAP group with median (IQR) total Silverman score (4 (4 to 5)vs. 4 (3 to 6) respectively, P-value= 0.474). Conclusion Using nHFOV is better than nCPAP in decreasing the need of FiO2.

Does ‘sub-threshold’ ventilatory stress promote healing after lung injury?

Excessive tidal stretching may initiate damage or retard healing after lung injury. However, it is seldom considered whether intracycle power and ventilatory forces of lesser magnitude than those required to cross an injury threshold might stimulate or accelerate beneficial adaptive responses. Acute lung injury is a dynamic process that may exhibit phase-dependent reparative responses to mechanical stress broadly similar to physical training, body trauma or sepsis. We propose that lower stress may not always be better through all phases of ARDS; moderately high tidal airway pressures that stay below the threshold of global injury may have potential to speed healing of the injured lung.

Remimazolam anaphylaxis in a patient not allergic to brotizolam: a case report and literature review

BackgroundRemimazolam is a recently developed, ultrashort-acting benzodiazepine that is used as a general anesthetic. Some cases of remimazolam anaphylaxis have been reported, but its characteristics are not fully understood. We present an interesting case report and review of the literature to better understand remimazolam anaphylaxis.Case presentationA 75-year-old man scheduled for robot-assisted gastrectomy was administered remimazolam for the induction of general anesthesia. After intubation, low end-expiratory CO2, high airway pressure and concurrent circulatory collapse were observed. Bronchoscopy revealed marked tracheal and bronchial edema, which we diagnosed as anaphylaxis. The patient suffered cardiac arrest after bronchoscopy but recovered immediately with intravenous adrenaline administration and chest compressions. We performed skin prick tests for the drugs used during induction except for remimazolam, considering the high risk of systemic adverse reactions to remimazolam. We diagnosed remimazolam anaphylaxis because the skin prick test results for the other drugs used during anesthesia were negative, and these drugs could have been used without allergic reactions during the subsequent surgery. Furthermore, this patient had experienced severe anaphylactic-like reactions when he underwent cardiac surgery a year earlier, in which midazolam had been used, but it was not thought to be the allergen at that time. Based on these findings, cross-reactivity to remimazolam and midazolam was suspected. However, the patient had previously received another benzodiazepine, brotizolam, to which he was not allergic, suggesting that cross-reactivity of remimazolam may vary among benzodiazepines. In this article, we reviewed the 11 cases of remimazolam anaphylaxis that have been described in the literature.ConclusionsRemimazolam is an ultrashort-acting sedative; however, it can cause life-threatening anaphylaxis. In addition, its cross-reactivity with other benzodiazepines is not fully understood. To increase the safety of this drug, further research and more experience in its use are needed.

Inconsistent Methods Used to Set Airway Pressure Release Ventilation in Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Regression Analysis.

Airway pressure release ventilation (APRV) is a protective mechanical ventilation mode for patients with acute respiratory distress syndrome (ARDS) that theoretically may reduce ventilator-induced lung injury (VILI) and ARDS-related mortality. However, there is no standard method to set and adjust the APRV mode shown to be optimal. Therefore, we performed a meta-regression analysis to evaluate how the four individual APRV settings impacted the outcome in these patients. Methods: Studies investigating the use of the APRV mode for ARDS patients were searched from electronic databases. We tested individual settings, including (1) high airway pressure (PHigh); (2) low airway pressure (PLow); (3) time at high airway pressure (THigh); and (4) time at low pressure (TLow) for association with PaO2/FiO2 ratio and ICU length of stay. Results: There was no significant difference in PaO2/FiO2 ratio between the groups in any of the four settings (PHigh difference -12.0 [95% CI -100.4, 86.4]; PLow difference 54.3 [95% CI -52.6, 161.1]; TLow difference -27.19 [95% CI -127.0, 72.6]; THigh difference -51.4 [95% CI -170.3, 67.5]). There was high heterogeneity across all parameters (PhHgh I2 = 99.46%, PLow I2 = 99.16%, TLow I2 = 99.31%, THigh I2 = 99.29%). Conclusions: None of the four individual APRV settings independently were associated with differences in outcome. A holistic approach, analyzing all settings in combination, may improve APRV efficacy since it is known that small differences in ventilator settings can significantly alter mortality. Future clinical trials should set and adjust APRV based on the best current scientific evidence available.

Restoration of Pulmonary Compliance after Laparoscopic Gynecologic Surgery Using a Recruitment Maneuver.

This study aimed to investigate the hypothesis that an alveolar recruitment maneuver can restore lung compliance to initial values after laparoscopic gynecological surgery. A total of 31 patients who underwent laparoscopic gynecological surgery were enrolled. Protective mechanical ventilation was applied, and the radial artery was catheterized in all patients. An alveolar recruitment maneuver (incremental and decremental positive end-expiratory pressure) was applied ten minutes after the release of pneumoperitoneum. The respiratory mechanics and blood gas results were recorded at eight different time points: after induction of anesthesia (T1), in the lithotomy position (T2), in the Trendelenburg position (T3), 10 and 90 min after insufflation of carbon dioxide (T4 and T5), in the supine position (T6), after desufflation (T7), and 10 min after an alveolar recruitment maneuver at the end of surgery (T8). Pneumoperitoneum and the Trendelenburg position caused a decline of 15 units in compliance (T7 vs. T1; p < 0.05) compared to baseline. After the alveolar recruitment maneuver, compliance increased by 17.5% compared with the mean value of compliance at time T1 (T8 vs. T1; p < 0.05). The recruitment maneuver had favorable results in patients with low initial compliance (41.5 mL/cmH2O, IQR: 9.75 mL/cmH2O), high Body Mass Index 30.32 kg/m2 (IQR: 1.05 kg/m2), and high initial plateau airway pressure (16.5 cmH2O, IQR: 0.75 cmH2O). Lung compliance does not return to initial values after performing laparoscopic gynecological procedures. However, after the release of pneumoperitoneum, an alveolar recruitment maneuver is beneficial as it improves compliance and gas exchange.

Ultrasound Differentiation of Twins with Discordant Congenital Diaphragmatic Hernia in the Delivery Room

AbstractMost infants with prenatally diagnosed congenital diaphragmatic hernia (CDH) are intubated rapidly after birth to optimize oxygenation and ventilation while avoiding abdominal distention and high mean airway pressures. A twin pregnancy complicated by one twin with a CDH diagnosis is a rare event and is associated with preterm delivery and low birth weight compared to singletons with CDH. In rare cases of discordant CDH in twin pregnancies with an absence of external distinguishing features (similar weights, fetal presentation, and sex), it may be difficult to quickly determine which twin has CDH in the delivery room (DR), raising ambiguity about the best management of both infants. This case describes the successful use of ultrasound (US) in the DR to rapidly diagnose the presence or absence of CDH in discordant twins. By developing a resuscitation algorithm and using in situ simulations prior to delivery, the twin with CDH was rapidly identified, intubated, and transported to the neonatal intensive care unit (NICU) for further management. The twin without CDH received routine care and was transferred to the well-baby nursery. Interprofessional planning and simulation may be used to design a safe resuscitation plan incorporating US diagnosis of diaphragmatic anomalies into the Neonatal Resuscitation Program (NRP) algorithm.

Effect of high flow nasal cannula and continuous positive airway pressure on the sleep apnea-specific hypoxic burden and pulse rate response in children with Obstructive Sleep Apnea

Effect of high flow nasal cannula and continuous positive airway pressure on the sleep apnea-specific hypoxic burden and pulse rate response in children with Obstructive Sleep Apnea

The use of protective mechanical ventilation during extracorporeal membrane oxygenation for the treatment of acute respiratory failure.

Acute respiratory failure (ARF) strikes an estimated two million people in the United States each year, with care exceeding US$50 billion. The hallmark of ARF is a heterogeneous injury, with normal tissue intermingled with a large volume of low compliance and collapsed tissue. Mechanical ventilation is necessary to oxygenate and ventilate patients with ARF, but if set inappropriately, it can cause an unintended ventilator-induced lung injury (VILI). The mechanism of VILI is believed to be overdistension of the remaining normal tissue known as the 'baby' lung, causing volutrauma, repetitive collapse and reopening of lung tissue with each breath, causing atelectrauma, and inflammation secondary to this mechanical damage, causing biotrauma. To avoid VILI, extracorporeal membrane oxygenation (ECMO) can temporally replace the pulmonary function of gas exchange without requiring high tidal volumes (VT) or airway pressures. In theory, the lower VT and airway pressure will minimize all three VILI mechanisms, allowing the lung to 'rest' and heal in the collapsed state. The optimal method of mechanical ventilation for the patient on ECMO is unknown. The ARDSNetwork Acute Respiratory Management Approach (ARMA) is a Rest Lung Approach (RLA) that attempts to reduce the excessive stress and strain on the remaining normal lung tissue and buys time for the lung to heal in the collapsed state. Theoretically, excessive tissue stress and strain can also be avoided if the lung is fully open, as long as the alveolar re-collapse is prevented during expiration, an approach known as the Open Lung Approach (OLA). A third lung-protective strategy is the Stabilize Lung Approach (SLA), in which the lung is initially stabilized and gradually reopened over time. This review will analyze the physiologic efficacy and pathophysiologic potential of the above lung-protective approaches.

A real-world observational study assessing relationships between excessive daytime sleepiness and patient satisfaction in obstructive sleep apnea

Objectives/BackgroundTo estimate prevalence and severity of excessive daytime sleepiness among patients with obstructive sleep apnea (OSA) who were prescribed treatment; assess perception and satisfaction of OSA-related care; describe relationships between excessive daytime sleepiness, treatment adherence, and patient satisfaction. Patients/methodsA national population-based cross-sectional sample of US adults with clinician-diagnosed OSA was surveyed in January 2021 via Evidation Health's Achievement App. Patients completed the Epworth Sleepiness Scale, rated satisfaction with healthcare provider and overall OSA care, and reported treatment adherence. Covariates affecting excessive daytime sleepiness (average weekly sleep duration, treatment adherence, sleepiness-inducing medications, age, sex, body mass index, nasal congestion, smoking status, and comorbidities) were adjusted in multivariate regression models. ResultsIn 2289 participants (50.3 % women; 44.8 ± 11.1 years), EDS was highly prevalent (42 %), and was experienced by 36 % of patients with high positive airway pressure (PAP) therapy adherence. Each additional hour of nightly PAP use was associated with improved sleepiness (a 0.28-point lower Epworth score; p < 0.001). Excessive daytime sleepiness was associated with lower patient satisfaction with healthcare providers and overall care (OR [95 % CI] 0.62 [0.48–0.80] and 0.50 [0.39–0.64], respectively; p < 0.0001), whereas PAP adherence was associated with higher patient satisfaction (OR [95 % CI] 2.37 [1.64–3.43] and 2.91 [2.03–4.17]; p < 0.0001), after adjusting for confounders. ConclusionsIn a real-world population-based study of patients with OSA, excessive daytime sleepiness was highly prevalent and associated with poor patient satisfaction ratings. Better patient-centered care among patients with OSA may require interventions aimed at addressing excessive daytime sleepiness and treatment adherence.

Expert consensus on management of pain, agitation and related issues in adult patients with critical respiratory diseases

As patients with critical respiratory diseases suffer from the discomfort of disease, frequent medical and nursing procedures, and the noise disturbance of the ICU environment, it is necessary to implement analgesia and sedation to reduce their negative stress and oxygen consumption. Special emphasis will be placed on the clinical practice of analgesia, sedation and rehabilitation in critically ill patients with respiratory diseases, as different pathophysiological features of the respective pulmonary diseases are presented, such as severe asthma and acute exacerbations of chronic obstructive pulmonary disease, as well as the exclusive situations during respiratory therapy, such as recruitment maneuvers, bedside bronchoscopy and operation of extracorporeal membrane oxygenators. To standardize the prevention and management of pain, agitation, delirium, immobility, and sleep disturbance in adult patients with critical respiratory diseases, the Chinese Thoracic Society and Critical Care Medicine Group of Chinese Association of Chest Physicians, Chinese Medical Doctor Association organized pulmonary and critical care experts to discuss 19 important issues and ultimately provided 20 recommendations based on the best available evidence.Assessment, prevention and management of pain should be prioritized before the administration of continuous infused sedatives in all patients with critical respiratory diseases. Bundles that include multiple strategies of non-pharmacological interventions to prevent and manage delirium and sleep disruption are encouraged. For the patients with stable respiratory and hemodynamic status, early mobility and exercise could be safe and beneficial. Respiratory drive control by addressing patient and ventilator factors should be the priority before administration of analog-sedation protocol in the ARDS patients. Deep sedation could be necessary in the early stage of ARDS with high respiratory drive, and during the recruitment maneuver, prone position and measurement of the respiratory mechanics. Maintaining spontaneous breathing with a lower level of sedation is recommended in COPD patients on invasive mechanical ventilation, while a deeper level of sedation, even with a short course of neuromuscular blockade, may be beneficial among severe asthma patients with high peak airway pressure. Pharmacokinetic alterations in patients with critical respiratory diseases during ECMO support are complicated as varied factors are involved, including ECMO circuit factors, drug factors, and patient factors. Therefore, the dosage of analgesics and sedatives should be adjusted according to the target of analog-sedation protocol in the respective disease.

The Pitfalls of Using Pop-Off Valves in Adult Emergency Airway Management

BackgroundAlthough common in pediatric airway equipment, positive-pressure relief (“pop-off”) valves are also present on some adult resuscitator bags. These valves are designed to decrease barotrauma but, in doing so, limit the airway pressure provided during manual bag-assisted ventilation. In critically ill adult patients with high airway pressures, these valves can be detrimental and result in hypoventilation and subsequent hypoxemia. Case ReportsIn the 7 days after an unannounced introduction of new resuscitator bags with pop-off valves in the emergency department, there were 3 adult patients for whom an open pop-off valve resulted in hypoventilation and hypoxemia. These cases involved both medical and traumatic pathologies. In each case, there was a delay in discovering the change to a resuscitator bag equipped with a pop-off valve. Once the emergency physicians noticed the pop-off valve and closed them, there was significant improvement in ventilation and oxygenation. Why Should an Emergency Physician Be Aware of This?Hand-operated resuscitator bags are an essential tool for airway management. These cases represent two main lessons: changing airway equipment without notifying staff is dangerous, and an open pop-off valve will result in inadequate ventilation when patients have high airway pressures, without the tactile feedback of difficult bagging. Emergency physicians should be aware of equipment changes and know to disable the pop-off valve on resuscitator bags if they find them in their departments.

Impact on cerebral hemodynamics of the use of volume guarantee combined with high frequency oscillatory ventilation in a neonatal animal respiratory distress model.

No differences were observed at cerebral hemodynamic between respiratory assistance in HFOV with and without VG, being the latter ventilatory strategy equally safe. • Preterm have a situation of fragility of cerebral perfusion wich means that any mechanical ventilation strategy can have a significant influence. High-frequency oscillatory ventilation (HFOV) is an alternative to conventional mechanical ventilation (CMV). Recently, the use of volume guarantee (VG) combined with HFOV has been suggested as a safe strategy capable of reducing the damage induced by ventilation in immature lungs. Several studies have compared CMV and HFOV and their effects at hemodynamic level. It is known that the use of high mean airway pressure in HFOV can cause an increase in pulmonary vascular resistance with a decrease in thoracic venous return. • The possible impact of VAFO + VG on cerebral hemodynamics is unknown. Due the lack of studies and the existing controversy, we have carried out this research project in an experimental animal model with the aim of evaluating the cerebral hemodynamic repercussion of the use of VG in HFOV compared to the classic strategy without VG.

A Case of Asymptomatic Tracheoesophageal Fistula.

The tracheoesophageal fistula (TEF) is an abnormal flow between the esophagus and the trachea. Most patients with TEF experience severe symptoms. Asymptomatic TEF is rare. In this case report, a 47-year-old woman planned to undergo orthopedic surgery under general anesthesia. She had no symptoms related to TEF, and the preoperative chest computed tomography was also normal. However, there was significant airway resistance after induction. Using a fiber bronchoscope, a TEF was discovered. The TEF found after anesthesia due to high airway pressure is unusual, and the outcome and treatment of these patients need to be further discussed.

Comparison of High Flow Nasal Cannula and Continuous Positive Airway Pressure in COVID-19 Patients With Acute Respiratory Distress Syndrome in Critical Care Unit: A Randomized Control Study.

Background and objective Acute hypoxic respiratory failure in coronavirus disease 2019 (COVID-19) pneumonia has been treated with oxygen delivered by oxygen masks and non-invasive ventilation (NIV) with continuous positive airway pressure (CPAP), and more recently with high-flow nasal cannula (HFNC) devices. There is a paucity of randomized controlled trials to compare the efficacy of CPAP with HFNC in COVID-19 pneumonia. We conceptualized a randomized control study to compare the efficacy of HFNC and CPAP in reducing the need for invasive mechanical ventilation, estimation of mechanical ventilation-free days, and risk of intubation in COVID-19 patients with hypoxic respiratory failure. Methodology One hundred consecutive patients who satisfied the inclusion criteria were included in the trial. The patients were then randomly allocated to receive either CPAP or HFNC with settings as per the study protocol. The patients were deemed to have achieved the study endpoint when they were intubated due to any reason or successfully weaned from NIV to conventional oxygen therapies. The number of patients who required invasive ventilation and the number of invasive ventilation-free days were recorded and analyzed. Results Nineteen (38%) patients in the CPAP group and 30 (60%) patients in the HFNC group required invasive mechanical ventilation and the difference was statistically significant (p = 0.03, 95%CI: 0.1829-0.9129). The median number of days free of invasive mechanical ventilation in the CPAP group (median=5 (interquartile range (IQR(=5,6)) was more than in the HFNC group (median=4 (IQR=3,4)) and this difference was statistically significant (p<0.000). The secondary analysis of risk evaluation for intubation done using the Cox regression model showed no significant factors that could have contributed to intubation in the study population. The Kaplan-Meyer curve was used to express the probability of a patient getting intubated and the calculated hazard ratio was 2.29. Conclusion The administration of CPAP significantly reduced the intubation rate and prolonged invasive mechanical ventilation-free period in COVID-19 patients with hypoxic respiratory failure. We also inferred a two-fold increase in the risk of intubation in patients receiving HFNC compared to CPAP.