Early administration of mucoactive agents and ventilator-free days: a propensity score-matched study.

Background: Mucoactive agents are often prescribed for the management of airway secretions. However, it is unclear whether they improve respiratory outcomes in mechanically ventilated patients. Methods: We examined the association between the early administration of mucoactive agents in ventilated patients and increased ventilator-free days (VFDs). This retrospective observational study was conducted in two intensive care units (ICUs) of a tertiary care hospital in Japan. We applied 1:1 propensity score matching between the early mucoactive agent group and the on-demand mucoactive agent group. We compared VFDs during the first 28 days of ICU stay as the primary outcome between the groups. Results: In total, 662 participants were eligible for this study, and 94 participants (47 in each group) were included in the analysis. There was no difference in the median VFDs between the groups [21 days; interquartile (IQR) 1-24 for the early group vs. 20 days; IQR 13-24 for the on-demand group; P=0.53]. The median ICU-free days were 19 (range, 12-22) days and 19 (range, 13-22) days for the early and on-demand mucoactive agent groups, respectively (P=0.72). Conclusions: Early administration of mucoactive agents was not associated with increased VFDs.

Burnout and Turnover Intention in Critical Care Professionals During the COVID-19 Pandemic in Japan: A Cross-sectional Survey.

Rationale: The prevalence of burnout among critical care professionals during the coronavirus disease (COVID-19) pandemic varies in different countries. Objectives: To investigate the prevalence of burnout and turnover intention in Japanese critical care professionals in March 2021. Methods: This cross-sectional study used a web-based survey of Japanese critical care professionals working in 15 intensive care units in 15 prefectures. Burnout was measured using the Mini Z 2.0 Survey. Intention to leave (turnover intention) was assessed by survey. Resilience was measured using the Brief Resilience Scale (Japanese version). Demographics and personal and workplace characteristics were also collected. Results: Of 1,205 critical care professionals approached, 936 (77.6%) completed the survey. Among these, 24.3%, 20.6%, and 14.2% reported symptoms of burnout, depression, and anxiety, respectively. A total of 157 respondents (16.8%) reported turnover intention. On multivariate analysis, higher resilience scores (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.84-0.95; and OR, 0.94; 95% CI, 0.91-0.96) and perceived support from the hospital (OR, 0.64; 95% CI, 0.44-0.93; and OR, 0.54; 95% CI, 0.40-0.73) were associated with a lower odds of burnout and turnover intention, respectively. Conclusions: Approximately 24% and 17% of the Japanese critical care professionals surveyed had symptoms of burnout and turnover intention from critical care, respectively, during the COVID-19 pandemic. Such professionals require organizational support to cultivate both individual and organizational resilience to reduce burnout and turnover intention.

Laboratory Risk Indicator for Necrotizing Fasciitis Score and Patient Outcomes.

CONTEXT: The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score helps to diagnose necrotizing soft-tissue infection (NSTI). The LRINEC score has been reported to be associated with poor prognosis, although few studies have evaluated this association. AIMS: We aimed to describe the characteristics of NSTI and assess whether the LRINEC score was associated with mortality and amputation. SETTINGS AND DESIGN: We conducted a retrospective observational study from January 2007 to May 2018, in a Japanese tertiary care hospital. SUBJECTS AND METHODS: Patients with NSTI were identified through our hospital database using the discharge diagnosis. We extracted data on patient characteristics, laboratory examinations, microbiological information, treatment, and in-hospital mortality. STATISTICAL ANALYSIS USED: We estimated the odds ratios (ORs) and associated 95% confidence intervals (CIs) for in-hospital mortality using logistic regression models. RESULTS: We identified 58 patients. The median LRINEC score was 8 (interquartile range [IQR]: 6-9). Forty-four patients (75.9%) scored 6 or more. The eight patients with amputations had a median score of 6 (IQR: 4.5-7.5) versus 8 (IQR: 7-9) for patients who underwent debridement (P = 0.091). Survivors and nonsurvivors had median scores of 8 (IQR: 6-9) and 6 (IQR: 5-8), respectively (P = 0.148). The OR for mortality in patients with liver cirrhosis was 10.5 (95% CI: 1.00-110.36; P = 0.050). CONCLUSIONS: There was no association between the LRINEC score and patients' outcomes: mortality and amputation. Further studies are warranted to evaluate the utility of the LRINEC score and factors associated with poor prognosis in patients with NSTI.

Body Mass Index and Ventilator Dependence in Critically Ill Subjects in Japan: A Cohort Study Using a Nationwide Database.

BACKGROUND: Body mass index (BMI) can be an important indicator for health outcomes among critically ill patients. However, the association between BMI and ventilator dependence at ICU discharge among these patients remains unknown. We aimed to evaluate the association between BMI at ICU admission and ventilator dependence at the time of ICU discharge. As secondary outcomes, we used ICU mortality, hospital mortality, and implementation of tracheostomy during ICU stay. METHODS: This is a retrospective cohort study. The data were derived from The Japanese Intensive Care Patient Database, a nationwide ICU database in Japan. We included all patients in the registry who were ≥ 16 y old, received mechanical ventilation, and were admitted to an ICU between April 2018 and March 2019. On the basis of their BMI at ICU admission, subjects were classified as underweight (< 18.5 kg/m2); normal weight (≥ 18.5 kg/m2 to < 23 kg/m2); overweight (≥ 23 kg/m2 to < 27.5 kg/m2); or obese (≥ 27.5 kg/m2). RESULTS: Among 11,801 analyzed subjects, 388 (3.3%) subjects were ventilator-dependent at ICU discharge. Compared with normal-weight subjects, the risk for ventilator dependence at ICU discharge increased among underweight subjects even after adjusting for potential confounders and inter-ICU variance in 2-level multivariable logistic regression analysis (odds ratio 1.46 [95% CI 1.18-1.79]). Although obesity was also associated with a higher risk of ventilator dependence, the association was less clear (odds ratio 1.10 [95% CI 0.99-1.22]). The risk of ICU mortality, hospital mortality, and implementation of tracheostomy also increased in underweight subjects. CONCLUSIONS: Critically ill underweight subjects had a higher risk of ventilator dependence at ICU discharge compared to normal-weight subjects, even after adjusting for potential confounders and inter-ICU variance. The association between BMI and ventilator dependence should be examined using information on subjects' nutritional status and frailty in further studies.

Persistent wheezing caused by carvedilol overdose in a non-asthmatic man.

BACKGROUND: Cardiovascular dysfunction is the main manifestation of ß-blocker intoxication; however, respiratory manifestations have rarely been reported. CASE PRESENTATION: A 41-year-old man, who had ingested 300 mg carvedilol in a suicide attempt, was transferred to our emergency department. The patient had wheezing on arrival; however, he had no known history of bronchial asthma. In the absence of signs of heart failure, we gave the patient inhaled procaterol, a short-acting ß2 agonist. The wheezing disappeared approximately 60 h after carvedilol ingestion and did not recur thereafter. CONCLUSION: We report a case of wheezing caused by carvedilol intoxication. Although rare, clinicians should recognize that wheezing or bronchospasm can develop following ß-blocker intoxication, for which a short-acting ß2 agonist could be indicated.

Urgent intubation without neuromuscular blocking agents and the risk of tracheostomy.

Neuromuscular blocking agents play a significant role in improving the success rate for urgent intubation, although there is limited evidence about the effect on subsequent outcomes, such as the incidence of tracheostomy. In this retrospective cohort study, we aimed to examine the association between avoidance of neuromuscular blocking agents for urgent tracheal intubation and incidence of tracheostomy among patients in the intensive care unit (ICU). The setting of this study was an eight-bed ICU at a tertiary-care hospital in Okayama, Japan. We included patients who underwent urgent tracheal intubation at the emergency department or the ICU and were admitted to the ICU between April 2013 and November 2017. We extracted data on methods and medications of intubation, predictors for difficult intubation, Cormack-Lehane grade, patient demographics, primary diagnoses, reintubation. We estimated odds ratios and their 95% confidence intervals for elective tracheostomy during the ICU stay using logistic regression models. Of 411 patients, 46 patients underwent intubation without neuromuscular blocking agents and 61 patients underwent tracheostomy. After adjusting for potential confounders, patients who avoided neuromuscular blocking agents had more than double the odds of tracheostomy (odds ratio 2.59, 95% confidence interval 1.06-6.34, p value = 0.04). When stratifying the subjects by risk status for tracheostomy, the association was more pronounced in high-risk group, while we observed less significant association in the low-risk group. Avoidance of neuromuscular blocking agents for urgent intubation increases the risk of tracheostomy among emergency patients, especially those who have a higher risk for tracheostomy.

Bacterial Contamination of Circuit Inner Surfaces After High-Flow Oxygen Therapy.

BACKGROUND: During high-flow oxygen therapy, heated humidified gas is delivered at high flow. Although the warmth and humidity of this gas facilitates mucociliary function in the lower airway, warm and humid conditions also promote bacterial growth. Bacterial contamination of high-flow oxygen therapy circuits has not been well investigated. We examined the incidence of bacterial contamination in high-flow oxygen therapy circuits. METHODS: This was a prospective observational study in a university hospital 10-bed general ICU. After final high-flow oxygen therapy discontinuation, samples were obtained from the interface and the chamber ends of the circuit. Initially, a half circumference of each inner surface was swabbed, after which the whole circuit was left in the ICU at room temperature for 6 h. The samples were then, in the same way, taken from the previously unswabbed arcs of the end inner surfaces. All the samples were sent to a biology laboratory and cultured. RESULTS: In all, 118 samples were collected from 31 circuits. The median duration of high-flow oxygen therapy was 48 h (interquartile range, 26-96 h). Of 31 circuits, contamination occurred in 5 circuits (16.1% [95% CI 5.5-33.7%]). CONCLUSIONS: Bacterial contamination of inner surfaces of the circuit after high-flow oxygen therapy was relatively high.

Effect of High-Flow Nasal Cannula on Thoraco-Abdominal Synchrony in Pediatric Subjects After Cardiac Surgery.

BACKGROUND: We previously reported the effects of high-flow nasal cannula (HFNC) oxygen therapy on thoraco-abdominal synchrony. This study was designed to clarify the effect of HFNC on thoraco-abdominal synchrony in pediatric subjects after cardiac surgery and to investigate HFNC optimal flow in this population. METHODS: Thoraco-abdominal synchrony was evaluated with respiratory inductive plethysmography. After extubation, we delivered oxygen via face mask for 30 min to subjects with mild to moderate respiratory failure. Each subject then randomly received either 1 or 2 L/kg/min via HFNC for 30 min, followed by the other flow level via HFNC for 30 min. After HFNC, face mask delivery was resumed. Rib cage and abdominal movement were converted into volumes and 2 quantitative indexes: maximum compartmental amplitude/tidal volume (VT) ratio and phase angle. RESULTS: Ten subjects of median (interquartile range) age 7 (6-14) months and weighing 6.5 (5.3-8.8) kg were enrolled. Compared with the first delivery via face mask, breathing frequency, maximum compartmental amplitude/VT, phase angle, and minute volume significantly decreased at 2 L/kg/min (P < .05 for all) but not at 1 L/kg/min. PaCO2 did not differ among oxygen therapies. None of the measured variables differed between first and second face mask periods. CONCLUSIONS: After cardiac surgery, HFNC oxygen therapy at 2 L/kg/min improved thoraco-abdominal synchrony and decreased breathing frequency in pediatric subjects. (Clinical trial registration: UMIN000023426.).

Humidification Performance of Passive and Active Humidification Devices Within a Spontaneously Breathing Tracheostomized Cohort.

BACKGROUND: Most heat-and-moisture exchangers (HMEs) for patients with tracheostomy and spontaneously breathing are small and have suction ports that allow some expiratory gas to escape, which loses water vapor held in the expired gas. Recently, a heated-and-humidified high-flow system for spontaneously breathing patients with tracheostomy was developed. Little is known, however, about the humidifying performance of HMEs or heated-and-humidified high-flow systems for spontaneous breathing patients with a tracheostomy. OBJECTIVE: To investigate the humidifying performance of the HMEs and heated-and-humidified high-flow systems for spontaneously breathing patients with tracheostomy. METHODS: Adult spontaneously breathing subjects with tracheostomy and were enrolled when their respiratory parameters and SpO2 were stable. We measured absolute humidity, relative humidity, and temperature by using a capacitance-type moisture sensor at the outlet of the tracheostomy tube. Heated-and-humidified high flow was delivered via the a humidifier and tracheostomy interface, and a selected HME. The subjects received heated-and-humidified high flow, after which an HME was used for humidification before switching back to a heated-and-humidified high-flow system. RESULTS: Ten subjects (5 men, 5 women; mean ± SD age, 72 ± 12 y) were enrolled. The admission diagnoses were neurologic (5 subjects), respiratory failure (3), and cardiac arrest (2). The APACHE (Acute Physiology and Chronic Health Evaluation) II score was 24 (interquartile range, 20-27). Tracheostomy was performed on day 7 (interquartile range, 5-11 d) after endotracheal intubation, and the duration of mechanical ventilation was 10 d (interquartile range, 6-11 d). The temperature with the HME was 29.9 ± 1.0°C and, during heated-and-humidified high-flow use was 35.3 ± 0.8°C (P < .001). With both the HME and the heated-and-humidified high-flow system, the relative humidity reached 100%; the absolute humidity with HME was 30.2 ± 1.8 mg/L, and, with the heated-and-humidified high-flow system, was 40.3 ± 1.8 mg/L (P < .001). CONCLUSIONS: In spontaneously breathing subjects with tracheostomy, an heated-and-humidified high-flow system achieved higher absolute humidity than did an HME.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016).

BACKGROUND AND PURPOSE: The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in February 2017 and published in the Journal of JSICM, [2017; Volume 24 (supplement 2)] 10.3918/jsicm.24S0001 and Journal of Japanese Association for Acute Medicine [2017; Volume 28, (supplement 1)] http://onlinelibrary.wiley.com/doi/10.1002/jja2.2017.28.issue-S1/issuetoc.This abridged English edition of the J-SSCG 2016 was produced with permission from the Japanese Association of Acute Medicine and the Japanese Society for Intensive Care Medicine. METHODS: Members of the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine were selected and organized into 19 committee members and 52 working group members. The guidelines were prepared in accordance with the Medical Information Network Distribution Service (Minds) creation procedures. The Academic Guidelines Promotion Team was organized to oversee and provide academic support to the respective activities allocated to each Guideline Creation Team. To improve quality assurance and workflow transparency, a mutual peer review system was established, and discussions within each team were open to the public. Public comments were collected once after the initial formulation of a clinical question (CQ) and twice during the review of the final draft. Recommendations were determined to have been adopted after obtaining support from a two-thirds (> 66.6%) majority vote of each of the 19 committee members. RESULTS: A total of 87 CQs were selected among 19 clinical areas, including pediatric topics and several other important areas not covered in the first edition of the Japanese guidelines (J-SSCG 2012). The approval rate obtained through committee voting, in addition to ratings of the strengths of the recommendation, and its supporting evidence were also added to each recommendation statement. We conducted meta-analyses for 29 CQs. Thirty-seven CQs contained recommendations in the form of an expert consensus due to insufficient evidence. No recommendations were provided for five CQs. CONCLUSIONS: Based on the evidence gathered, we were able to formulate Japanese-specific clinical practice guidelines that are tailored to the Japanese context in a highly transparent manner. These guidelines can easily be used not only by specialists, but also by non-specialists, general clinicians, nurses, pharmacists, clinical engineers, and other healthcare professionals.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016).

Background and Purpose: The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in February 2017 in Japanese. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. Methods: Members of the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine were selected and organized into 19 committee members and 52 working group members. The guidelines were prepared in accordance with the Medical Information Network Distribution Service (Minds) creation procedures. The Academic Guidelines Promotion Team was organized to oversee and provide academic support to the respective activities allocated to each Guideline Creation Team. To improve quality assurance and workflow transparency, a mutual peer review system was established, and discussions within each team were open to the public. Public comments were collected once after the initial formulation of a clinical question (CQ), and twice during the review of the final draft. Recommendations were determined to have been adopted after obtaining support from a two-thirds (>66.6%) majority vote of each of the 19 committee members. Results: A total of 87 CQs were selected among 19 clinical areas, including pediatric topics and several other important areas not covered in the first edition of the Japanese guidelines (J-SSCG 2012). The approval rate obtained through committee voting, in addition to ratings of the strengths of the recommendation and its supporting evidence were also added to each recommendation statement. We conducted meta-analyses for 29 CQs. Thirty seven CQs contained recommendations in the form of an expert consensus due to insufficient evidence. No recommendations were provided for 5 CQs. Conclusions: Based on the evidence gathered, we were able to formulate Japanese-specific clinical practice guidelines that are tailored to the Japanese context in a highly transparent manner. These guidelines can easily be used not only by specialists, but also by non-specialists, general clinicians, nurses, pharmacists, clinical engineers, and other healthcare professionals.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (JSSCG 2016), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in February 2017 in Japanese. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. Members of the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine were selected and organized into 19 committee members and 52 working group members. The guidelines were prepared in accordance with the Medical Information Network Distribution Service (Minds) creation procedures. The Academic Guidelines Promotion Team was organized to oversee and provide academic support to the respective activities allocated to each Guideline Creation Team. To improve quality assurance and workflow transparency, a mutual peer review system was established, and discussions within eachteam were open to the public. Public comments were collected once after the initial formulation of a clinical question (CQ), and twice during the review of the final draft. Recommendations were determined to have been adopted after obtaining support from a twothirds (>66.6%) majority vote of each of the 19 committee members. A total of 87 CQs were selected among 19 clinical areas, including pediatric topics and several other important areas not covered in the first edition of the Japanese guidelines (J-SSCG 2012). The approval rate obtained through committee voting, in additionto ratings of the strengths of the recommendation and its supporting evidence were also added to each recommendation statement.We conducted meta-analyses for 29 CQs. Thirty seven CQs contained recommendations in the form of an expert consensus due to insufficient evidence. No recommendations were provided for 5 CQs.Based on the evidence gathered, we were able to formulate Japanese-specific clinical practice guidelines that are tailored to the Japanese context in a highly transparent manner. These guidelines can easily be used not only by specialists, but also by non-specialists, general clinicians, nurses, pharmacists, clinical engineers, and other healthcare professionals.

FIO2 in an Adult Model Simulating High-Flow Nasal Cannula Therapy.

BACKGROUND: High-flow nasal cannula therapy (HFNC) is widely used for patients with acute respiratory failure. HFNC has a number of physiological effects. Although FIO2 is considered to be constant, because HFNC is an open system, FIO2 varies according to inspiratory flow, tidal volume (VT), and HFNC gas flow. We investigated the influence of HFNC gas flow and other respiratory parameters on FIO2 during HFNC. METHODS: We evaluated an HFNC system and, for comparison, a conventional oxygen therapy system. The HFNC apparatus was composed of an air/oxygen blender, a heated humidifier, an inspiratory limb, and small, medium, and large nasal prongs. HFNC gas flow was set at 20, 40, and 60 L/min, and FIO2 was set at 0.3, 0.5, and 0.7. We measured FIO2 for 1-min intervals using an oxygen analyzer and extracted data for the final 3 breaths of each interval. Spontaneous breathing was simulated using a mechanical ventilator connected to the muscle compartment of a model lung. The lung compartment passively moved with the muscle compartment, thus inspiring ambient air via a ventilator limb. With a decelerating flow waveform, simulated VT was set at 300, 500, and 700 mL, breathing frequency at 10 and 20 breaths/min, and inspiratory time at 1.0 s. RESULTS: With HFNC gas flow of 20 and 40 L/min, at all set FIO2 values, inspiratory oxygen concentration varied with VT (P < .001). As the set value for FIO2 increased, the difference between set FIO2 and measured FIO2 increased. Neither breathing frequency nor prong size influenced FIO2 . CONCLUSIONS: During HFNC with simulated spontaneous breathing, when HFNC gas flow was 60 L/min, measured FIO2 was similar to set FIO2 at 0.3 and 0.5, whereas at 0.7, as VT increased, measured FIO2 decreased slightly. However, at 20 or 40 L/min, changes in VT related with deviation from set FIO2 .

Hyperoxemia in mechanically ventilated, critically ill subjects: incidence and related factors.

BACKGROUND: Excessive supplemental oxygen causes injurious hyperoxemia. Before establishing the best P(aO2) targets for mechanically ventilated patients, it is important to understand the incidence of hyperoxemia and related factors. We investigated oxygenation in mechanically ventilated subjects in our ICU and evaluated factors related to hyperoxemia (P(aO2) > 120 mm Hg) at 48 h after initiation of mechanical ventilation. METHODS: We retrospectively reviewed the medical records of patients admitted to our ICU from January 2010 to May 2013. Inclusion criteria were 15 y of age or older and administration of mechanical ventilation for > 48 h. Patients at risk of imminent death on admission or who had received noninvasive ventilation were excluded. We collected subject demographics, reasons for mechanical ventilation, and during mechanical ventilation, we collected arterial blood gas data and ventilator settings on the first day of intubation (T1), 48 h after initiation of mechanical ventilation (T2), and on the day of extubation (T3). Multivariable logistic regression analysis was performed to clarify independent variables related to hyperoxemia at T2. RESULTS: For the study period, data for 328 subjects were analyzed. P(aO2) statistically significantly increased over time to 90 (interquartile range of 74-109) mm Hg at T1, 105 (89-120) mm Hg at T2, and 103 (91-119) mm Hg at T3 (P < .001), coincident with decreases in F(IO2) of 0.4 (0.3-0.5) at T1, 0.3 (0.3-0.4) at T2, and 0.3 (0.3-0.35) at T3 (P < .001). Hyperoxemia occurred in 15.6% (T1), 25.3% (T2), and 22.4% (T3) of subjects. Multivariable logistic regression analysis revealed that hyperoxemia was independently associated with age of < 40 y (odds ratio 2.6, 95% CI 1.1-6.0), Acute Physiology and Chronic Health Evaluation II scores of ≥ 30 (odds ratio 0.53, 95% CI 0.3-1.0), and decompensated heart failure (odds ratio 1.9, 95% CI 1.1 to 3.5). CONCLUSIONS: During mechanical ventilation of critically ill subjects, P(aO2) increased, and F(IO2) decreased. One in 4 subjects were hyperoxemic at T2, and hyperoxemia persisted until T3.

Performance of ventilators compatible with magnetic resonance imaging: a bench study.

BACKGROUND: Magnetic resonance imaging (MRI) is indispensable for diagnosing brain and spinal cord abnormalities. Magnetic components cannot be used during MRI procedures; therefore, patient support equipment must use MRI-compatible materials. However, little is known of the performance of MRI-compatible ventilators. METHODS: At commonly used settings, we tested the delivered tidal volume (V(T)), F(IO2), PEEP, and operation of the high-inspiratory-pressure-relief valves of 4 portable MRI-compatible ventilators (Pneupac VR1, ParaPAC 200DMRI, CAREvent MRI, iVent201) and one ICU ventilator (Servo-i). Each ventilator was set in volume control/continuous mandatory ventilation mode. Breathing frequency and V(T) were tested at 10 breaths/min and 300, 500, and 700 mL, respectively. The Pneupac VR1 has fixed V(T) and frequency combinations, so it was tested at V(T) = 300 mL and 20 breaths/min, V(T) = 500 mL and 12 breaths/min, and V(T) = 800 mL and 10 breaths/min. F(IO2) was 0.6 and 1.0. At the air-mix setting, F(IO2) was fixed at 0.5 with the Pneupac VR1, 0.45 with the ParaPAC 200DMRI, and 0.6 with the CAREvent MRI. PEEP was set at 5 and 10 cm H2O, and pressure relief was set at 30 and 40 cm H2O. RESULTS: V(T) error varied widely among ventilators (-28.1 to 25.5%). As V(T) increased, error decreased with the Pneupac VR1, ParaPAC 200DMRI, and CAREvent MRI (P < .05). F(IO2) error ranged from -13.3 to 25.3% at 0.6 (or air mix). PEEP error varied among ventilators (-29.2 to 42.5%). Only the Servo-i maintained V(T), F(IO2), and PEEP at set levels. The pressure-relief valves worked in all ventilators. CONCLUSIONS: None of the MRI-compatible ventilators maintained V(T), F(IO2), and PEEP at set levels. Vital signs of patients with unstable respiratory mechanics should be monitored during transport and MRI.

Complete bronchial obstruction by granuloma in a paediatric patient with translaryngeal endotracheal tube: a case report.

INTRODUCTION: Although continuous or frequent stimuli in tracheostomized patients may cause tracheal granulomas, little is known about management of patients with translaryngeal intubation. CASE PRESENTATION: A 1-month-old Japanese boy, weighing 3.5kg, was admitted to our hospital owing to cardiac failure caused by an atrial septal defect and intractable arrhythmia. To treat his unstable cardiovascular status, surgery was performed to close his atrial septal defect. After the operation, stenosis was detected by auscultation and flow limitation worsened. A bronchoscopy revealed granulomas completely obstructing his right bronchus and partially obstructing his left bronchus. Dexamethasone infusion partially reduced the mass, after which removal by yttrium aluminium garnet laser was tried. The airway obstruction was not resolved, however, because of granuloma reproliferation. Budesonide (aerosol liquid) inhalation was started, and tissue was reduced using an yttrium aluminium garnet laser and physically removed using forceps. After continued budesonide inhalation, he was successfully liberated from the ventilator. CONCLUSIONS: Life-threatening airway obstruction by granulomas developed in a translaryngeally intubated paediatric patient. The granuloma was detected after a couple of weeks of intubation. A bronchial granuloma is rare in paediatric patients. It should be suspected with evidence of bronchial obstruction. Treatment with corticosteroids and surgery using a laser maybe indicated.

Successful use of extracorporeal membrane oxygenation in the reversal of cardiorespiratory failure induced by atonic uterine bleeding: a case report.

INTRODUCTION: Although extracorporeal membrane oxygenation has made sufficient progress to be considered for the management of life-threatening cardiac and respiratory failure, the risk of hemorrhagic complications may outweigh the benefits for patients with bleeding tendencies. We report, to the best of our knowledge, the first case of successful treatment by extracorporeal membrane oxygenation, without any hemorrhagic complications, of postpartum cardiorespiratory failure after massive uterine bleeding. CASE PRESENTATION: A 25-year-old Japanese woman experienced massive atonic bleeding after delivering her second baby. Recovery from hemorrhagic shock was managed by conservative treatments, but she developed decompensated heart failure and refractory hypoxia. Because we could not obtain hemodynamic stability and proper oxygenation even with high doses of catecholamines and maximal ventilator settings, we administered venoarterial extracorporeal membrane oxygenation, whereupon her hemodynamic status immediately stabilized. After 72 hours of support without major bleeding, extracorporeal membrane oxygenation was successfully withdrawn. CONCLUSION: Even in cases of obstetric bleeding, if clotting status is stringently monitored, extracorporeal membrane oxygenation can be considered as an ultimate means of life support.

Humidification performance of two high-flow nasal cannula devices: a bench study.

INTRODUCTION: Delivering heated and humidified medical gas at 20-60 L/min, high-flow nasal cannula (HFNC) creates low levels of PEEP and ameliorates respiratory mechanics. It has become a common therapy for patients with respiratory failure. However, independent measurement of heat and humidity during HFNC and comparison of HFNC devices are lacking. METHODS: We evaluated 2 HFNC (Airvo 2 and Optiflow system) devices. Each HFNC was connected to simulated external nares using the manufacturer's standard circuit. The Airvo 2 outlet-chamber temperature was set at 37°C. The Optiflow system incorporated an O2/air blender and a heated humidifier, which was set at 40°C/3. For both systems, HFNC flow was tested at 20, 40, and 50 L/min. Simulating spontaneous breathing using a mechanical ventilator and TTL test lung, we tested tidal volumes (VT) of 300, 500, and 700 mL, and breathing frequencies of 10 and 20 breaths/min. The TTL was connected to the simulated external nares with a standard ventilator circuit. To prevent condensation, the circuit was placed in an incubator maintained at 37°C. Small, medium, and large nasal prongs were tested. Absolute humidity (AH) of inspired gas was measured at the simulated external nares. RESULTS: At 20, 40, and 50 L/min of flow, respective AH values for the Airvo 2 were 35.3 ± 2.0, 37.1 ± 2.2, and 37.6 ± 2.1 mg/L, and for the Optiflow system, 33.1 ± 1.5, 35.9 ± 1.7, and 36.2 ± 1.8 mg/L. AH was lower at 20 L/min of HFNC flow than at 40 and 50 L/min (P < .01). While AH remained constant at 40 and 50 L/min, at 20 L/min of HFNC flow, AH decreased as VT increased for both devices. CONCLUSIONS: During bench use of HFNC, AH increased with increasing HFNC flow. When the inspiratory flow of spontaneous breathing exceeded the HFNC flow, AH was influenced by VT. At all experimental settings, AH remained > 30 mg/L.

Hygrometric properties of inspired gas and oral dryness in patients with acute respiratory failure during noninvasive ventilation.

BACKGROUND: Because noninvasive ventilation (NIV) delivers medical gas at high flow, inadequate humidification may cause oral dryness and patient discomfort. Heated humidification can be used during NIV, but little has been reported about the effects on the hygrometric conditions inside an oronasal mask and oral dryness during 24 hours on NIV. METHODS: We measured absolute humidity (AH) inside oronasal masks on subjects with acute respiratory failure during 24 hours on NIV. A single-limb turbine ventilator and oronasal mask with an exhalation port were used for NIV. Oral moistness was evaluated using an oral moisture-checking device, and 3 times during the 24 hours the subjects subjectively scored the feeling of dryness on a 0-10 scale in which 10 was the most severe dryness. RESULTS: Sixteen subjects were enrolled. The mean ± SD AH inside the mask was 30.0 ± 2.6 mg H2O/L (range 23.1-33.3 mg H2O/L). The median oral moistness was 19.2% (IQR 4.4-24.0%), and the median oral dryness score was 5.5 (IQR 4-7). AH and inspired gas leak correlated inversely, both within the subjects (r = -0.56, P < .001) and between the subjects (r = -0.58, P = .02). AH and oral moistness correlated within the subjects (r = 0.39, P = .04). Oral breathing was associated with reduced oral moistness (P = .001) and increased oral dryness score (P = .002). CONCLUSIONS: AH varied among the subjects, and some complained of oral dryness even with heated humidifier. Oral breathing decreased oral moistness and worsened the feeling of dryness.