Effect of Electrical Muscle Stimulation on Upper and Lower Limb Muscles in Critically Ill Patients: A Two-Center Randomized Controlled Trial.

OBJECTIVES: Electrical muscle stimulation is widely used to enhance lower limb mobilization. Although upper limb muscle atrophy is common in critically ill patients, electrical muscle stimulation application for the upper limbs has been rarely reported. The purpose of this study was to investigate whether electrical muscle stimulation prevents upper and lower limb muscle atrophy and improves physical function. DESIGN: Randomized controlled trial. SETTING: Two-center, mixed medical/surgical ICU. PATIENTS: Adult patients who were expected to be mechanically ventilated for greater than 48 hours and stay in the ICU for greater than 5 days. INTERVENTIONS: Forty-two patients were randomly assigned to the electrical muscle stimulation (n = 17) or control group (n = 19). MEASUREMENTS AND MAIN RESULTS: Primary outcomes were change in muscle thickness and cross-sectional area of the biceps brachii and rectus femoris from day 1 to 5. Secondary outcomes included occurrence of ICU-acquired weakness, ICU mobility scale, length of hospitalization, and amino acid levels. The change in biceps brachii muscle thickness was -1.9% versus -11.2% in the electrical muscle stimulation and control (p = 0.007) groups, and the change in cross-sectional area was -2.7% versus -10.0% (p = 0.03). The change in rectus femoris muscle thickness was -0.9% versus -14.7% (p = 0.003) and cross-sectional area was -1.7% versus -10.4% (p = 0.04). No significant difference was found in ICU-acquired weakness (13% vs 40%; p = 0.20) and ICU mobility scale (3 vs 2; p = 0.42) between the groups. The length of hospitalization was shorter in the electrical muscle stimulation group (23 d [19-34 d] vs 40 d [26-64 d]) (p = 0.04). On day 3, the change in the branched-chain amino acid level was lower in the electrical muscle stimulation group (40.5% vs 71.5%; p = 0.04). CONCLUSIONS: In critically ill patients, electrical muscle stimulation prevented upper and lower limb muscle atrophy and attenuated proteolysis and decreased the length of hospitalization.

Critical Care Bed Capacity in Asian Countries and Regions.

OBJECTIVE: To assess the number of adult critical care beds in Asian countries and regions in relation to population size. DESIGN: Cross-sectional observational study. SETTING: Twenty-three Asian countries and regions, covering 92.1% of the continent's population. PARTICIPANTS: Ten low-income and lower-middle-income economies, five upper-middle-income economies, and eight high-income economies according to the World Bank classification. INTERVENTIONS: Data closest to 2017 on critical care beds, including ICU and intermediate care unit beds, were obtained through multiple means, including government sources, national critical care societies, colleges, or registries, personal contacts, and extrapolation of data. MEASUREMENTS AND MAIN RESULTS: Cumulatively, there were 3.6 critical care beds per 100,000 population. The median number of critical care beds per 100,000 population per country and region was significantly lower in low- and lower-middle-income economies (2.3; interquartile range, 1.4-2.7) than in upper-middle-income economies (4.6; interquartile range, 3.5-15.9) and high-income economies (12.3; interquartile range, 8.1-20.8) (p = 0.001), with a large variation even across countries and regions of the same World Bank income classification. This number was independently predicted by the World Bank income classification on multivariable analysis, and significantly correlated with the number of acute hospital beds per 100,000 population (r = 0.19; p = 0.047), the universal health coverage service coverage index (r = 0.35; p = 0.003), and the Human Development Index (r = 0.40; p = 0.001) on univariable analysis. CONCLUSIONS: Critical care bed capacity varies widely across Asia and is significantly lower in low- and lower-middle-income than in upper-middle-income and high-income countries and regions.

Influence of Nutritional Management and Rehabilitation on Physical Outcome in Japanese Intensive Care Unit Patients: A Multicenter Observational Study.

BACKGROUND: There is lack of evidence regarding nutritional management among intensive care unit (ICU) patients in a population with relatively low body mass index. Therefore, we conducted an observational study to assess the nutritional management in Japanese ICUs. Also, we investigated the impact of nutritional management and rehabilitation on physical outcome. METHODS: The study population comprised 389 consecutive patients who received mechanical ventilation for at least 24 h and those admitted to the ICU for > 72 h in 13 hospitals. The primary outcomes were caloric and protein intake in ICU on days 3 and 7, and at ICU discharge. The secondary outcome was the impact of nutritional management and rehabilitation on physical status at ICU discharge. We defined good physical status as more than end sitting and poor physical status as bed rest and sitting. We divided the participants into 2 groups, namely, the good physical status group (Good group) and poor physical status group (Poor group) for analysis of the secondary outcome. Data were expressed as median (interquartile range). RESULTS: The median amount of caloric intake on days 3 and 7, and at ICU discharge via enteral and parenteral routes were 8.4 (3.1-15.6), 14.9 (7.5-22.0), and 11.2 (2.5-19.1) kcal/kg/day, respectively. The median amount of protein intake on days 3 and 7, and at ICU discharge were 0.2 (0-0.5), 0.4 (0.1-0.8), and 0.3 (0-0.7) g/kg/day, respectively. The amount of caloric intake on day 3 in the Poor group was significantly higher than that of the Good group (10.1 [5.8, 16.2] vs. 5.2 [1.9, 12.4] kcal/kg/day, p < 0.001). The proportion of patients who were received rehabilitation in ICU in the Good group was significantly higher than that of the Poor group (92 vs. 63%, p < 0.001). The multivariate analysis revealed that caloric intake on day 3 and rehabilitation in ICU were considered independent factors that affect physical status (OR 1.19; 95% CI 1.05-1.34; p = 0.005 and OR 0.07; 95% CI 0.01-0.34; p = 0.001). CONCLUSIONS: The caloric and protein intakes in Japanese ICUs were 15 kcal/kg/day and 0.4 g/kg/day, respectively. In addition, critically ill patients might benefit from low caloric intake (less than 10 kcal/kg/day) until day 3 and rehabilitation during ICU stay.

End-of-Life Care in ICUs in East Asia: A Comparison Among China, Korea, and Japan.

OBJECTIVES: To compare physicians' perceptions and practice of end-of-life care in the ICU in three East Asian countries cultures similarly rooted in Confucianism. DESIGN: A structured and scenario-based survey of physicians who managed ICU patients from May 2012 to December 2012. SETTING: ICUs in China, Korea, and Japan. SUBJECTS: Specialists who are either intensivists or nonintensivist primary attending physicians in charge of patients (195 in China, 186 in Korea, 224 in Japan). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Country was independently associated with differences in the practice of limiting multiple forms of life-sustaining treatments on multivariable generalized linear model analysis. Chinese respondents were least likely to apply do-not-resuscitate orders, even if they existed (p < 0.001). Japanese respondents were most likely to practice do not resuscitate for terminally ill patients during cardiac arrest, even when no such prior order existed (p < 0.001). Korean respondents' attitudes were in between those of Chinese and Japanese respondents as far as withdrawing total parenteral nutrition, antibiotics, dialysis, and suctioning was concerned. Chinese respondents were most uncomfortable discussing end-of-life care issues with patients, while Japanese respondents were least uncomfortable (p < 0.001). Chinese respondents were more likely to consider financial burden when deciding on limiting life-sustaining treatment (p < 0.001). Japanese respondents felt least exposed to personal legal risks when limiting life-sustaining treatment (p < 0.001), and the Korean respondents most wanted legislation to guide this issue (p < 0.001). The respondents' gender, religion, clinical experience, and primary specialty were also independently associated with the different perceptions of end-of-life care. CONCLUSIONS: Despite similarities in cultures and a common emphasis on the role of family, differences exist in physician perceptions and practices of end-of-life ICU care in China, Korea, and Japan. These findings may be due to differences in the degree of Westernization, national healthcare systems, economic status, and legal climate.

Structure, Organization, and Delivery of Critical Care in Asian ICUs.

OBJECTIVES: Despite being the epicenter of recent pandemics, little is known about critical care in Asia. Our objective was to describe the structure, organization, and delivery in Asian ICUs. DESIGN: A web-based survey with the following domains: hospital organizational characteristics, ICU organizational characteristics, staffing, procedures and therapies available in the ICU and written protocols and policies. SETTING: ICUs from 20 Asian countries from April 2013 to January 2014. Countries were divided into low-, middle-, and high-income based on the 2011 World Bank Classification. SUBJECTS: ICU directors or representatives. MEASUREMENTS AND MAIN RESULTS: Of 672 representatives, 335 (50%) responded. The average number of hospital beds was 973 (SE of the mean [SEM], 271) with 9% (SEM, 3%) being ICU beds. In the index ICUs, the average number of beds was 21 (SEM, 3), of single rooms 8 (SEM, 2), of negative-pressure rooms 3 (SEM, 1), and of board-certified intensivists 7 (SEM, 3). Most ICUs (65%) functioned as closed units. The nurse-to-patient ratio was 1:1 or 1:2 in most ICUs (84%). On multivariable analysis, single rooms were less likely in low-income countries (p = 0.01) and nonreferral hospitals (p = 0.01); negative-pressure rooms were less likely in private hospitals (p = 0.03) and low-income countries (p = 0.005); 1:1 nurse-to-patient ratio was lower in private hospitals (p = 0.005); board-certified intensivists were less common in low-income countries (p < 0.0001) and closed ICUs were less likely in private (p = 0.02) and smaller hospitals (p < 0.001). CONCLUSIONS: This survey highlights considerable variation in critical care structure, organization, and delivery in Asia, which was related to hospital funding source and size, and country income. The lack of single and negative-pressure rooms in many Asian ICUs should be addressed before any future pandemic of severe respiratory illness.

The Association of Fever with Total Mechanical Ventilation Time in Critically Ill Patients.

This research aims to investigate the impact of fever on total mechanical ventilation time (TVT) in critically ill patients. Subgroup analysis was conducted using a previous prospective, multicenter observational study. We included mechanically ventilated patients for more than 24 hours from 10 Korean and 15 Japanese intensive care units (ICU), and recorded maximal body temperature under the support of mechanical ventilation (MAX(MV)). To assess the independent association of MAX(MV) with TVT, we used propensity-matched analysis in a total of 769 survived patients with medical or surgical admission, separately. Together with multiple linear regression analysis to evaluate the association between the severity of fever and TVT, the effect of MAX(MV) on ventilator-free days was also observed by quantile regression analysis in all subjects including non-survivors. After propensity score matching, a MAX(MV) ≥ 37.5°C was significantly associated with longer mean TVT by 5.4 days in medical admission, and by 1.2 days in surgical admission, compared to those with MAX(MV) of 36.5°C to 37.4°C. In multivariate linear regression analysis, patients with three categories of fever (MAX(MV) of 37.5°C to 38.4°C, 38.5°C to 39.4°C, and ≥ 39.5°C) sustained a significantly longer duration of TVT than those with normal range of MAX(MV) in both categories of ICU admission. A significant association between MAX(MV) and mechanical ventilator-free days was also observed in all enrolled subjects. Fever may be a detrimental factor to prolong TVT in mechanically ventilated patients. These findings suggest that fever in mechanically ventilated patients might be associated with worse mechanical ventilation outcome.

The relationship between sedative drug utilization and outcomes in critically ill patients undergoing mechanical ventilation.

OBJECTIVES: The objectives of this study were to describe current sedative drug utilization patterns in critically ill patients undergoing mechanical ventilation (MV) in intensive care units (ICUs) in Japanese hospitals and to elucidate the relationship of these utilization patterns with patient clinical outcomes. METHOD: Analysis of hospital claims data derived from the Quality Indicator/Improvement Project identified 12,395 critically ill adult patients who had undergone MV while hospitalized in the ICUs of 114 Japanese hospitals and had been discharged between April 2008 and March 2010. Descriptive statistics were calculated for the daily utilization of sedative drugs, opioids, and muscle relaxants in this patient sample, and the relationship between drug utilization and patient outcomes using Cox proportional hazards analysis were examined. RESULTS: Of the 12,395 patients included in the analysis, 7300 (58.9 %), 580 (4.7 %), and 671 (5.4 %) received sedative drugs, opioids, and muscle relaxants, respectively, for ≥2 days after intubation. Compared to the other patient groups, there was a higher proportion of males in the group given sedative drugs and the patients were significantly younger (P < 0.001). Propofol was the most frequently used sedative drug, followed by benzodiazepines, barbiturates, and dexmedetomidine. The mortality rate was lower and ventilator weaning was earlier among patients who received only propofol than among those who received only benzodiazepines. Muscle relaxants were associated with increased duration of MV. CONCLUSIONS: This is the first study based on a large-scale analysis in Japan to elucidate sedative drug utilization patterns and their relationship with outcomes in critically ill patients. The most commonly used sedative was propofol, which was associated with favorable patient outcomes. Further prospective research must be conducted to discern effective sedative drug utilization.

Timing of tracheotomy in ICU patients: a systematic review of randomized controlled trials.

INTRODUCTION: The optimal timing of tracheotomy in critically ill patients remains a topic of debate. We performed a systematic review to clarify the potential benefits of early versus late tracheotomy. METHODS: We searched PubMed and CENTRAL for randomized controlled trials that compared outcomes in patients managed with early and late tracheotomy. A random-effects meta-analysis, combining data from three a priori-defined categories of timing of tracheotomy (within 4 versus after 10 days, within 4 versus after 5 days, within 10 versus after 10 days), was performed to estimate the weighted mean difference (WMD) or odds ratio (OR). RESULTS: Of the 142 studies identified in the search, 12, including a total of 2,689 patients, met the inclusion criteria. The tracheotomy rate was significantly higher with early than with late tracheotomy (87 % versus 53 %, OR 16.1 (5.7-45.7); p <0.01). Early tracheotomy was associated with more ventilator-free days (WMD 2.12 (0.94, 3.30), p <0.01), a shorter ICU stay (WMD -5.14 (-9.99, -0.28), p = 0.04), a shorter duration of sedation (WMD -5.07 (-10.03, -0.10), p <0.05) and reduced long-term mortality (OR 0.83 (0.69-0.99), p = 0.04) than late tracheotomy. CONCLUSIONS: This updated meta-analysis reveals that early tracheotomy is associated with higher tracheotomy rates and better outcomes, including more ventilator-free days, shorter ICU stays, less sedation, and reduced long-term mortality, compared to late tracheotomy.

[Delayed discharge from the intensive care unit].

BACKGROUND: Delayed discharge from ICU to the general ward can exert an adverse effect. We researched whether patients are discharged smoothly from our ICU to the general ward. METHODS: We defined that patients were eligible for discharge if they are without administration of catecholamine, being assisted by mechanical ventilation and having blood purification therapy. RESULTS: Average time from actual discharge to the time patient was considered eligible for discharge was fifteen hours. This study was retrospective. CONCLUSIONS: We need to investigate further the reasons why delayed discharge occurred. It is im portant that patients are discharged from the ICU to the general ward properly. Delayed discharge can delay the recovery and expose the patient to multi-resistant microorganisms. We studied whether patients are discharged smoothly from the ICU to the general ward.

An in-hospital mortality equation for mechanically ventilated patients in intensive care units.

OBJECTIVE: To develop an equation model of in-hospital mortality for mechanically ventilated patients in adult intensive care using administrative data for the purpose of retrospective performance comparison among intensive care units (ICUs). DESIGN: Two models were developed using the split-half method, in which one test dataset and two validation datasets were used to develop and validate the prediction model, respectively. Nine candidate variables (demographics: age; gender; clinical factors hospital admission course; primary diagnosis; reason for ICU entry; Charlson score; number of organ failures; procedures and therapies administered at any time during ICU admission: renal replacement therapy; pressors/vasoconstrictors) were used for developing the equation model. SETTING: In acute-care teaching hospitals in Japan: 282 ICUs in 2008, 310 ICUs in 2009, and 364 ICUs in 2010. PARTICIPANTS: Mechanically ventilated adult patients discharged from an ICU from July 1 to December 31 in 2008, 2009, and 2010. MAIN OUTCOME MEASURES: The test dataset consisted of 5,807 patients in 2008, and the validation datasets consisted of 10,610 patients in 2009 and 7,576 patients in 2010. Two models were developed: Model 1 (using independent variables of demographics and clinical factors), Model 2 (using procedures and therapies administered at any time during ICU admission in addition to the variables in Model 1). Using the test dataset, 8 variables (except for gender) were included in multiple logistic regression analysis with in-hospital mortality as the dependent variable, and the mortality prediction equation was constructed. Coefficients from the equation were then tested in the validation model. RESULTS: Hosmer-Lemeshow χ(2) are values for the test dataset in Model 1 and Model 2, and were 11.9 (P = 0.15) and 15.6 (P = 0.05), respectively; C-statistics for the test dataset in Model 1and Model 2 were 0.70 and 0.78, respectively. In-hospital mortality prediction for the validation datasets showed low and moderate accuracy in Model 1 and Model 2, respectively. CONCLUSIONS: Model 2 may potentially serve as an alternative model for predicting mortality in mechanically ventilated patients, who have so far required physiological data for the accurate prediction of outcomes. Model 2 may facilitate the comparative evaluation of in-hospital mortality in multicenter analyses based on administrative data for mechanically ventilated patients.

Association of body temperature and antipyretic treatments with mortality of critically ill patients with and without sepsis: multi-centered prospective observational study.

INTRODUCTION: Fever is frequently observed in critically ill patients. An independent association of fever with increased mortality has been observed in non-neurological critically ill patients with mixed febrile etiology. The association of fever and antipyretics with mortality, however, may be different between infective and non-infective illness. METHODS: We designed a prospective observational study to investigate the independent association of fever and the use of antipyretic treatments with mortality in critically ill patients with and without sepsis. We included 1,425 consecutive adult critically ill patients (without neurological injury) requiring >48 hours intensive care admitted in 25 ICUs. We recorded four-hourly body temperature and all antipyretic treatments until ICU discharge or 28 days after ICU admission, whichever occurred first. For septic and non-septic patients, we separately assessed the association of maximum body temperature during ICU stay (MAXICU) and the use of antipyretic treatments with 28-day mortality. RESULTS: We recorded body temperature 63,441 times. Antipyretic treatment was given 4,863 times to 737 patients (51.7%). We found that treatment with non-steroidal anti-inflammatory drugs (NSAIDs) or acetaminophen independently increased 28-day mortality for septic patients (adjusted odds ratio: NSAIDs: 2.61, P=0.028, acetaminophen: 2.05, P=0.01), but not for non-septic patients (adjusted odds ratio: NSAIDs: 0.22, P=0.15, acetaminophen: 0.58, P=0.63). Application of physical cooling did not associate with mortality in either group. Relative to the reference range (MAXICU ≥ 39.5°C increased risk of 28-day mortality in non-septic patients (adjusted odds ratio 8.14, P=0.01), but not in septic patients (adjusted odds ratio 0.47, P=0.11) [corrected]. CONCLUSIONS: In non-septic patients, high fever (≥39.5°C) independently associated with mortality, without association of administration of NSAIDs or acetaminophen with mortality. In contrast, in septic patients, administration of NSAIDs or acetaminophen independently associated with 28-day mortality, without association of fever with mortality. These findings suggest that fever and antipyretics may have different biological or clinical or both implications for patients with and without sepsis. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00940654.

Potential inadequacy of automatic tube compensation to decrease inspiratory work load after at least 48 hours of endotracheal tube use in the clinical setting.

BACKGROUND: Endotracheal tubes (ETTs) impose a substantial respiratory work load on mechanically ventilated patients. Automatic tube compensation (ATC) should overcome this flow-dependent resistive work load; however, ETT resistance can be increased by tracheal secretions or ETT deformities. Our bench study investigated whether ATC provides effective respiratory work load relief in used ETTs. METHODS: We enrolled 20 critically ill patients requiring mechanical ventilation for longer than 48 hours. After extubation, we collected the used ETTs and measured the pressure-time products (PTPs) by using a bellows-in-a-box lung model that simulated spontaneous breathing, at a respiratory rate of 10 breaths/min, inspiratory time of 1.0 s, and tidal volumes (V(T)) of 300 mL, 500 mL, and 700 mL. The ventilator was set at ATC 100% with PEEP of 5 cm H(2)O and F(IO(2)) of 0.21. The flow and airway pressure at the proximal (P(aw)) and distal (P(tr)) ends of the ETT were recorded, and the PTP integrated from P(tr) analyzed. RESULTS: PTP values increased with V(T) during ATC. Even at 100% ATC the ventilator did not completely compensate for the PTP imposed by the ETT. In used ETTs, peak flow and peak P(aw) were lower and PTP values were greater than in new ETTs. As V(T) increased, the percentage difference in the PTP values between the new and used ETTs increased. CONCLUSIONS: ATC does not necessarily compensate for an ETT-imposed respiratory work load. ETT configuration changes and tracheal secretions can increase ETT resistance and decrease the ability of ATC to compensate for the increased respiratory work load.

Extracorporeal membrane oxygenation for 2009 influenza A(H1N1) severe respiratory failure in Japan.

PURPOSE: To evaluate procedures and outcomes of extracorporeal membrane oxygenation (ECMO) therapy applied to 2009 influenza A(H1N1) severe respiratory failure patients in Japan. METHODS: This observational study used database information about adults who received ECMO therapy for H1N1-related severe respiratory failure from April 1, 2010 to March 31, 2011. RESULTS: Fourteen patients from 12 facilities were enrolled. Anti-influenza drugs were used in all cases. Before the start of ECMO, the lowest PaO(2)/FiO(2) was median (interquartile) of 50 (40-55) mmHg, the highest peak inspiratory pressure was 30 (29-35) cmH(2)O, and mechanical ventilation had been applied for at least 7 days in 5 patients. None of the facilities had extensive experience with ECMO for respiratory failure (6 facilities, no previous experience; 5 facilities, one or two cases annually). The blood drainage cannula was smaller than 20 Fr. in 10 patients (71.4 %). The duration of ECMO was 8.5 (4.0-10.8) days. The duration of each circuit was only 4.0 (3.2-5.3) days, and the ECMO circuit had to be renewed 19 times (10 cases). Thirteen patients (92.9 %) developed adverse events associated with ECMO, such as oxygenator failure, massive bleeding, and disseminated intravascular coagulation. The survival rate was 35.7 % (5 patients). CONCLUSION: ECMO therapy for H1N1-related severe respiratory failure in Japan has very poor outcomes, and most patients developed adverse events. However, this result does not refute the effectiveness of ECMO. One possible cause of these poor outcomes is the lack of satisfactory equipment, therapeutic guidelines, and systems for patient transfer to central facilities.

The Need for an Adult Intensive Care Unit Boot Camp for Residents and Fellows: A Cross-Sectional Survey among Intensive Care Unit Directors.

BACKGROUND: The concept of "see one, do one, teach one" raises concerns regarding patient safety in the intensive care unit (ICU) and highlights the need for prior preparation of residents/fellows for ICU rotation. This study assessed the need for an adult pre-ICU "boot camp" training course. METHODS: An online questionnaire regarding the current ICU training and desirable course framework was distributed via e-mail to the ICU directors of 269 educational centers certified by the Japanese Society of Intensive Care Medicine. RESULTS: The response rate was 39% (106/269). The number of residents/fellows undergoing ICU rotation was 5.5 (IQR 2-12) /ICU/year, and the majority (63%) were second to fourth year post-graduate residents and fellows. ICU directors opined that of the fundamental critical care skills, residents/fellows performed well or very well in only seven out of 29 skills (24%). Only 18% of the ICU directors had an established ICU training curriculum. Overall, 72% of the directors were interested in the boot camp. The desirable course framework was 3-5 hours per day with simulations and lectures. The core skills that directors considered as important to acquire during ICU rotation were central venous catheter insertion, tracheal intubation, defibrillation, initiation of mechanical ventilation, physical examination of critically ill patients, and shock assessment. CONCLUSIONS: Residents/fellows began ICU rotations with suboptimal skills as reported by ICU directors. In addition, most of the ICUs had not established a training curriculum. Therefore, having an ICU boot camp is necessary to enhance critical care skills and to decrease medical errors.

A bench study of the effects of leak on ventilator performance during noninvasive ventilation.

BACKGROUND: During noninvasive ventilation (NIV), leak around the mask may cause inadequate ventilatory support or patient-ventilator asynchrony such as auto-triggering. Some NIV ventilators may be better than others at compensating for leak. METHODS: We bench studied 3 NIV ventilators (Vision, Carina, and Trilogy100) and 2 ICU ventilators (Puritan Bennett 840 and Evita XL) to assess how they coped with 2 leak levels and zero leak during NIV. With a 2-bellows-in-a-box lung model we simulated spontaneous breathing with tidal volumes of 300 mL and 500 mL, at pressure support of 0 and 10 cm H(2)O and PEEP of 5 and 10 cm H(2)O. We affixed the airway opening of the lung model to the mouth of a mannequin head and secured a mask on the mannequin face. We created a medium leak and a large leak with different size holes, and measured PEEP in the presence of leak. We also measured the actual pressure-support values and calculated the deviations from the set pressure-support value and the pressure-time product (PTP) of the airway opening pressure below and above baseline. RESULTS: With the medium leak only the Vision and Carina maintained the set PEEP and pressure support. With the large leak the pressure support was decreased with all the tested ventilators. With the larger leak and pressure support of 10 cm H(2)O the PTP below baseline for triggering increased with 2 ventilators, and the PTP above baseline for supporting the patient's inspiratory effort decreased with all 5 ventilators. The larger tidal volume increased the PTP below baseline with all 5 ventilators and at all leak sizes. CONCLUSIONS: Some of the ventilators compensated for leak better than others. With the larger leak none of the ventilators maintained the set PEEP or pressure support.

The story of critical care in Asia: a narrative review.

BACKGROUND: Asia has more critically ill people than any other part of our planet. The aim of this article is to review the development of critical care as a specialty, critical care societies and education and research, the epidemiology of critical illness as well as epidemics and pandemics, accessibility and cost and quality of critical care, culture and end-of-life care, and future directions for critical care in Asia. MAIN BODY: Although the first Asian intensive care units (ICUs) surfaced in the 1960s and the 1970s and specialisation started in the 1990s, multiple challenges still exist, including the lack of intensivists, critical care nurses, and respiratory therapists in many countries. This is aggravated by the brain drain of skilled ICU staff to high-income countries. Critical care societies have been integral to the development of the discipline and have increasingly contributed to critical care education, although critical care research is only just starting to take off through collaboration across groups. Sepsis, increasingly aggravated by multidrug resistance, contributes to a significant burden of critical illness, while epidemics and pandemics continue to haunt the continent intermittently. In particular, the coronavirus disease 2019 (COVID-19) has highlighted the central role of critical care in pandemic response. Accessibility to critical care is affected by lack of ICU beds and high costs, and quality of critical care is affected by limited capability for investigations and treatment in low- and middle-income countries. Meanwhile, there are clear cultural differences across countries, with considerable variations in end-of-life care. Demand for critical care will rise across the continent due to ageing populations and rising comorbidity burdens. Even as countries respond by increasing critical care capacity, the critical care community must continue to focus on training for ICU healthcare workers, processes anchored on evidence-based medicine, technology guided by feasibility and impact, research applicable to Asian and local settings, and rallying of governments for support for the specialty. CONCLUSIONS: Critical care in Asia has progressed through the years, but multiple challenges remain. These challenges should be addressed through a collaborative approach across disciplines, ICUs, hospitals, societies, governments, and countries.

Humidification during high-frequency oscillatory ventilation for adults: a bench study.

BACKGROUND: High-frequency oscillatory ventilation (HFOV) has recently been applied to acute respiratory distress syndrome patients. However, the issue of humidification during HFOV has not been investigated. In a bench study, we evaluated humidification during HFOV for adults to test if adequate humidification was achieved in 2 different HFOV systems. MATERIAL/METHODS: We tested 2 brands of adult HFOV ventilators, the R100 (Metran, Japan) and the 3100B (SensorMedics, CA), under identical bias flow. A heated humidifier consisting of porous hollow fiber (Hummax II, Metran) was set for the R100, and a passover-type heated humidifier (MR850, Fisher & Paykel) was set for the 3100B, while inspiratory heating wire was applied to both systems. Each ventilator was connected to a lung model in an incubator. Absolute humidity, relative humidity and temperature at the airway opening were measured using a hygrometer under a variety of ventilatory settings: 3 stroke volumes/amplitudes, 3 frequencies, and 2 mean airway pressures. RESULTS: The R100 ventilator showed higher absolute humidity, higher relative humidity, and lower temperature than the 3100B. In the R100, as stroke volume and frequency increased, absolute humidity and temperature increased. In the 3100B, amplitude, frequency, and mean airway pressure minimally affected absolute humidity and temperature. Relative humidity was almost 100% in the R100, while it was 80.5±2.3% in the 3100B. CONCLUSIONS: Humidification during HFOV for adults was affected by stroke volume and frequency in the R100, but was not in the 3100B. Absolute humidity was above 33 mgH_2 O/L in these 2 systems under a range of settings.

Effects of inspiratory rise time on triggering work load during pressure-support ventilation: a lung model study.

BACKGROUND: The rise in inspiratory flow is important during patient-triggered ventilation. Many ventilators incorporate a function to control the time to reach the targeted airway pressure (inspiratory rise time). However, it has not been clarified how inspiratory rise time affects inspiratory work load under various ventilator settings. In a bench study we investigated the effect of inspiratory rise time on inspiratory work load during pressure-support ventilation (PSV). METHODS: We studied 6 ICU ventilators. We measured flow and pressure at the airway opening (P(ao)) at PEEP of 5 cm H(2)O, pressure-support of 5 cm H(2)O and 10 cm H(2)O, 4 triggering sensitivities, and inspiratory drives 300 mL, 500 mL, and 700 mL. The inspiratory-rise-time setting was not consistent between the ventilators, and we chose 3 inspiratory-rise-time levels with each ventilator. The inspiratory delay time (DT) was defined as the time between the onset of inspiration and the return of P(ao) to baseline, and was divided into 2 parts at the point of the lowest P(ao): before the lowest P(ao) (DT(1)), and after the lowest P(ao) (DT(2)). As an indicator of inspiratory work load we calculated the pressure-time-product (PTP) of the P(ao) over the DT. PTP was also divided into PTP(1) and PTP(2), at the point of the lowest P(ao). RESULTS: Short inspiratory rise time reduced DT(2), PTP(1), and PTP(2), regardless of the pressure-support level, triggering sensitivity, or inspiratory drive. However, the inspiratory-rise-time setting did not affect DT(1). The PTP(1), PTP(2), and DT(2) values differed significantly among the ventilators. A combination of short inspiratory rise time, high PSV, and sharp triggering sensitivity resulted in the smallest PTP and DT values. CONCLUSIONS: Short inspiratory rise time decreased inspiratory work load, regardless of the pressure-support level, triggering sensitivity, or inspiratory drive. Inspiratory work load can be maximally lowered by a combination of a short inspiratory rise time, a sharp triggering sensitivity, and a high inspiratory pressure-support level for a given patient's inspiratory effort.

Evaluation of performance of two high-frequency oscillatory ventilators using a model lung with a position sensor.

PURPOSE: High-frequency oscillatory ventilation (HFOV) is thought to protect the lungs of acute respiratory distress syndrome (ARDS) patients. The performance and mechanical characteristics of high-frequency oscillatory ventilators, especially with regard to delivering appropriate tidal volume (V(T)) to compromised lungs, might affect the outcome of patients. We evaluated the performance of two such ventilators using a model lung with a position sensor. METHODS: We tested the Metran R100 and SensorMedics 3100B. V(T) was measured using the model lung with the compliance set at 20 or 50 ml/cmH2O and the resistance at 0 or 20 cmH2O/l/s. Oscillator frequency was set at 5, 7, and 9 Hz, and amplitude was set at 25%, 50%, 75%, and 100% (100% being maximum amplitude available at each setting configuration). RESULTS: At each model lung setting, R100 delivered greater V(T) at 5 Hz. V(T) differences between the ventilators decreased as frequency increased and were negligible at 9 Hz. At each model lung setting and frequency, as amplitude increased from 25% to 100%, V(T) increased proportionally more with R100. With an I:E ratio of 1:1, 3100B delivered greater V(T) than with 1:2. CONCLUSION: Because it is able to deliver comparably greater V(T), R100 may be a better choice for HFOV in critical ARDS patients. Better proportionality may be a result of more effective amplitude titration for adjusting PaCO2 during oscillation.