Seasonality of Radon-222 near the surface at King Sejong Station (62°S), Antarctic Peninsula, and the role of atmospheric circulation based on observations and CAM-Chem model

We examined the seasonal cycle of radon concentration observed at King Sejong Station (KSG, 62°S), Antarctic Peninsula, during the period 2013-2016. The distribution of monthly radon concentration was found to be highly positively skewed from March through October (austral autumn to spring) due to large numbers of short-lived periods of high radon concentration. The global atmospheric chemistry model (CAM-Chem), which includes all global terrestrial sources of radon except for those in Antarctica, well reproduces the observed seasonal cycle of monthly-mean radon concentration at KSG. Further offline experiments suggest that uncertainties in radon emissions over South America and the Southern Ocean should be improved for the simulations of radon in Antarctica. The results demonstrate that seasonally varying transport of radon in the boundary layer from South America substantially affects the seasonality of monthly mean radon concentration at KSG. The composite analyses further reveal that high radon events at KSG are the result of a distinct east-west dipole-like structure associated with surface cyclonic circulation over the Bellingshausen Sea and anticyclonic circulation in the Weddell Sea. This atmospheric pattern provides favorable conditions for radon transport into KSG from the northwest. The relationship between radon concentration at KSG and climate variability is also discussed in this study.

Continuous Piperacillin-Tazobactam Infusion Improves Clinical Outcomes in Critically Ill Patients with Sepsis: A Retrospective, Single-Centre Study

Continuous infusion of beta-lactam antibiotics has emerged as an alternative for the treatment of sepsis because of the favourable pharmacokinetics of continuous infusion. This study aimed to evaluate the survival benefits of continuous vs. intermittent infusion of piperacillin-tazobactam in critically ill patients with sepsis. We retrospectively conducted a single-centre study of continuous infusion vs. intermittent infusion of piperacillin-tazobactam for adult patients who met the Sepsis-3 criteria and were treated at a medical ICU within 48 h after hospitalisation between 1 May 2018 and 30 April 2020. The primary outcome was mortality at 28 days. A total of 157 patients (47 in the continuous group and 110 in the intermittent group) met the inclusion criteria for evaluation. The 28-day mortality rates were 12.8% in the continuous group and 27.3% in the intermittent group (p = 0.07). However, after adjustment for potential covariables, patients in the continuous group (12.8%) showed significantly lower mortality at 28 days than those in the intermittent group (27.3%; adjusted hazard ratio (HR), 0.31; 95% confidence interval (CI), 0.13-0.79; p = 0.013). In sepsis patients, continuous infusion of piperacillin-tazobactam may confer a benefit regarding the avoidance of mortality at 28 days compared with intermittent infusion.

Impact of nutrition and physical activity on outcomes of hospital-acquired pneumonia

Frailty is an important risk factor for adverse health-related outcomes. It is classified into several phenotypes according to nutritional state and physical activity. In this context, we investigated whether frailty phenotypes were related to clinical outcome of hospital-acquired pneumonia (HAP). During the study period, a total of 526 patients were screened for HAP and 480 of whom were analyzed. The patients were divided into four groups according to physical inactivity and malnutrition: nutritional frailty (Geriatric Nutritional Risk Index [GNRI] < 82 and Clinical Frailty Scale [CFS] ≥ 4), malnutrition (GNRI < 82 and CFS < 4), physical frailty (GNRI ≥ 82 and CFS ≥ 4), and normal (GNRI ≥ 82 and CFS < 4). Among the phenotypes, physical frailty without malnutrition was the most common (39.4%), followed by nutritional frailty (30.2%), normal (20.6%), and malnutrition (9.8%). There was a significant difference in hospital survival and home discharge among the four phenotypes (p = 0.009), and the nutritional frailty group had the poorest in-hospital survival and home discharge (64.8% and 34.6%, respectively). In conclusion, there were differences in clinical outcomes according to the four phenotypes of HAP. Assessment of frailty phenotypes during hospitalization may improve outcomes through adequate nutrition and rehabilitation treatment of patients with HAP.

Mortality of patients with hospital-onset sepsis in hospitals with all-day and non-all-day rapid response teams: a prospective nationwide multicenter cohort study

Background

Hospital-onset sepsis is associated with a higher in-hospital mortality rate than community-onset sepsis. Many hospitals have implemented rapid response teams (RRTs) for early detection and timely management of at-risk hospitalized patients. However, the effectiveness of an all-day RRT over a non-all-day RRT in reducing the risk of in-hospital mortality in patient with hospital-onset sepsis is unclear. We aimed to determine the effect of the RRT’s operating hours on in-hospital mortality in inpatient patients with sepsis.

Methods

We conducted a nationwide cohort study of adult patients with hospital-onset sepsis prospectively collected from the Korean Sepsis Alliance (KSA) Database from 16 tertiary referral or university-affiliated hospitals in South Korea between September of 2019 and February of 2020. RRT was implemented in 11 hospitals, of which 5 (45.5%) operated 24-h RRT (all-day RRT) and the remaining 6 (54.5%) had part-day RRT (non-all-day RRT). The primary outcome was in-hospital mortality between the two groups.

Results

Of the 405 patients with hospital-onset sepsis, 206 (50.9%) were admitted to hospitals operating all-day RRT, whereas 199 (49.1%) were hospitalized in hospitals with non-all-day RRT. A total of 73 of the 206 patients in the all-day group (35.4%) and 85 of the 199 patients in the non-all-day group (42.7%) died in the hospital (P = 0.133). After adjustments for co-variables, the implementation of all-day RRT was associated with a significant reduction in in-hospital mortality (adjusted odds ratio 0.57; 95% confidence interval 0.35–0.93; P = 0.024).

Conclusions

In comparison with non-all-day RRTs, the availability of all-day RRTs was associated with reduced in-hospital mortality among patients with hospital-onset sepsis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04149-z.

Comparison of the Outcomes of Patients Starting Mechanical Ventilation in the General Ward Versus the Intensive Care Unit

OBJECTIVE

Mechanical ventilation is sometimes initiated in the general ward (GW) due to the shortage of intensive care unit (ICU) beds. We investigated whether invasive mechanical ventilation (MV) started in the GW affects the patient's prognosis compared with its initiation in the ICU.

METHODS

From January 2016 to December 2018, medical records of patients who started MV in the GW or ICU were collected. The 28-day mortality, ICU mortality, ventilator-free days, and complications related to the ventilator and the ventilator-free days were analyzed as outcomes.

RESULTS

A total of 673 patients were enrolled. Among these, 268 patients (39.8%) started MV in the GW and 405 patients (60.2%) started MV within 24 hours after admittance to the ICU. There was no difference in 28-day mortality between the 2 groups (27.2% versus 27.2%, P = 0.997). In addition, there was no difference between ventilator-related complication rates, ventilator-free days, or the length of hospital stay. A high Acute Physiology and Chronic Health Evaluation II score, the presence of solid tumor, the absence of chronic kidney diseases, and low platelet count were associated with higher 28-day mortality. However, the initiation of MV in the GW was not associated with an increase in 28-day mortality compared with the initiation in the ICU.

CONCLUSIONS

Starting MV in the GW was not a risk factor for 28-day mortality. Therefore, prompt application of a ventilator if medically indicated, regardless of the patient's location, is desirable if a skilled airway team and appropriate monitoring are available.

Characteristics and prognostic factors of very elderly patients admitted to the intensive care unit

Background

Korea is rapidly becoming a super aging society and is facing the increased burden of critical care for the elderly people. Traditionally, far-advanced age has been regarded as a triage criterion for intensive care unit (ICU) admission. We evaluated how the characteristics and prognostic factors of very elderly patients (≥85 years) admitted to the ICU changed over the last decade.

Methods

We retrospectively evaluated the data of patients admitted to the ICU over 11 years (2007–2017). The clinical characteristics and outcomes of the very elderly-patients group were evaluated. Factors associated with mortality were assessed by a cox regression analysis.

Results

Comparing the first half (2007–2012) and the second half (2013–2017) of the study period, the proportion of very elderly group increased from 603/47,657 (1.3%), to 697/37,756 (1.8%) (P<0.001). Among 1,294 very elderly patients, 1,274 patients were analyzed excluding hopeless discharge (n=20). The non-surgical reasons for ICU admission (67.0% vs. 76.1%, P<0.001) and the percentage of patients with co-morbidities (78.3% vs. 82.7%, P=0.048) were increased. Nevertheless, the hospital mortality decreased (21.3% vs. 14.9%, P=0.001). High creatinine levels, use of vasopressors and ventilator weaning failure were associated with in-hospital mortality.

Conclusions

The proportion of very elderly people in the ICU increased over the last decade. The non-surgical causes of ICU admission increased compared with the surgical causes. Despite an increasement in ICU admissions of very elderly patients, in-hospital mortality of very elderly ICU patients decreased.

Reliability of Central Venous Blood Gas Values Compared With Arterial Blood Gas Values in Critically Ill Patients

BACKGROUND

Central venous blood gas (cVBG) values are correlated with arterial blood gas (ABG) values. However, the substitution of cVBG values for ABG values in critically ill patients remains uninvestigated. Thus, we investigated the reliability between cVBG and ABG values and sought to define the conditions that could improve the reliability of cVBG values as a substitute.

METHODS

We conducted a prospective comparison of 292 sets of cVBG values and ABG values from 82 subjects admitted to the medical ICU between October 2017-July 2018. Paired cVBG and ABG samples were collected daily during the first 5 d of ICU treatment and on days 8, 15, 22, and 29. Intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement (LOA) were obtained.

RESULTS

The ICC between ABG and cVBG was 0.626 for pH, 0.696 for P_CO2 , 0.869 for bicarbonate, 0.866 for base excess, and 0.989 for lactic acid. Bland-Altman plots showed clinically unacceptable LOA between all parameters. Subgroup analysis indicated a significant increase in the ICCs of P_CO2 in samples with mechanical ventilation (0.0574-0.735, P = .02) and central venous oxygen saturation (ScvO₂) ≥ 70% (0.611-0.763, P = .008). After adjustment, the 95% LOA between ABG and cVBG was -0.06 to 0.07 for pH and -7.09 to 7.05 for P_CO2 in mechanically ventilated subjects with ScvO₂ ≥ 70%.

CONCLUSIONS

ABG and cVBG values showed clinically acceptable agreements and improved reliability in mechanically ventilated subjects with ScvO₂ ≥ 70%. cVBG analysis may be a substitute for ABG analysis in mechanically ventilated patients once tissue perfusion is restored.

Microbiologic pattern and clinical outcome of non-ICU-acquired pneumonia: Korean HAP registry analysis

BACKGROUND/AIMS

Most studies on hospital-acquired pneumonia (HAP) have been conducted in intensive care unit (ICU) settings. This study aimed to investigate the microbiological and clinical characteristics of non-ICU-acquired pneumonia (NIAP) and to identify the factors affecting clinical outcomes in Korea.

METHODS

This multicenter retrospective cohort study was conducted in patients admitted to 13 tertiary hospitals between July 1, 2019 and December 31, 2019. Patients diagnosed with NIAP were included in this study. To assess the prognostic factors of NIAP, the study population was classified into treatment success and failure groups.

RESULTS

Of 526 patients with HAP, 379 were diagnosed with NIAP. Overall, the identified causative pathogen rate was 34.6% in the study population. Among the isolated organisms (n = 113), gram-negative bacilli were common pathogens (n = 91), such as Pseudomonas aeruginosa (n = 25), Acinetobacter baumannii (n = 23), and Klebsiella pneumoniae (n = 21). The multidrug resistance rates of A. baumannii, P. aeruginosa, and K. pneumoniae were 91.3%, 76.0%, and 57.1%, respectively. Treatment failure was significantly associated with K. pneumoniae (odds ratio [OR], 3.50; 95% confidence interval [CI], 1.35 to 9.05; p = 0.010), respiratory viruses (OR, 3.81; 95% CI, 1.34 to 10.82; p = 0.012), hematological malignancies (OR, 3.54; 95% CI, 1.57 to 8.00; p = 0.002), and adjunctive corticosteroid treatment (OR, 2.40; 95% CI, 1.27 to 4.52; p = 0.007).

CONCLUSION

The causative pathogens of NIAP in Korea are predominantly gram-negative bacilli with a high rate of multidrug resistance. These were not different from the common pathogens of ICU-acquired pneumonia.

Treatment of acute respiratory failure: extracorporeal membrane oxygenation

Background: Extracorporeal membrane oxygenation (ECMO) support for tissue oxygenation can improve the survival of patients with life-threatening respiratory distress syndrome or cardiac failure.Current Concepts: Recently, the use of ECMO in acute respiratory distress syndrome has first been reported by a multicenter randomized controlled trial, known as the conventional ventilation or ECMO for severe adult respiratory failure trial. The ECMO application is dramatically increasing with the increasing number of patients experiencing acute respiratory failure due to coronavirus disease 2019 pneumonia. In this review, we explain the indications of the ECMO application and ECMO-associated complications.Discussion and Conclusion: The ECMO application in lung diseases, such as coronavirus disease 2019 and acute respiratory distress syndrome, has significant outcomes in securing the treatment periods and reducing mortality. Therefore, accumulating knowledge and experience in the ECMO application can produce positive outcomes.

The feasibility of extracorporeal cardiopulmonary resuscitation for patients with active cancer who undergo in-hospital cardiac arrest

Indications of extracorporeal cardiopulmonary resuscitation (ECPR) are still debatable, particularly in patients with cancer. Prediction of the prognosis of in-hospital cardiac arrest (IHCA) in patients with cancer receiving ECPR is important given the increasing prevalence and survival rate of cancer. We compared the neurologic outcomes and survival rates of IHCA patients with and without cancer receiving ECPR. Data from the extracorporeal membrane oxygenation registry between 2015 and 2019 were used in a retrospective manner. The primary outcome was 6-month good neurologic outcome, defined as a Cerebral performance category score of 1 or 2. The secondary outcomes were 1- and 3-month good neurologic outcome, and 6-month survival. Among 247 IHCA patients with ECPR, 43 had active cancer. The 6-month good neurologic outcome rate was 27.9% and 32.4% in patients with and without active cancer, respectively (P > 0.05). Good neurologic outcomes at 1-month (30.2% vs. 20.6%) and 3-month (30.2% vs. 28.4%), and the survival rate at 6-month (39.5% vs. 36.5%) were not significantly different (all P > 0.05) Active cancer was not associated with 6-month good neurologic outcome by logistic regression analyses. Therefore, patients with IHCA should not be excluded from ECPR solely for the presence of cancer itself.

Neurological Emergencies in Patients Hospitalized With Nonneurological Illness

OBJECTIVE

We aimed to present neurological profiles and clinical outcomes of patients with acute neurological symptoms, which developed during hospitalization with nonneurological illness.

METHODS

We organized the neurological alert team (NAT), a neurological rapid response team, to manage in-hospital neurological emergencies. In this registry-based study, we analyzed the clinical profiles and outcomes of patients who were consulted to the NAT. We also compared the 3-month mortality of patients with acute neurological symptoms with that of patients without acute neurological symptoms.

RESULTS

Among the 85,507 adult patients, 591 (0.7%) activated the NAT. The most common reason for NAT activation was stroke symptoms (37.6%), followed by seizures (28.6%), and sudden unresponsiveness (24.0%). The most common diagnosis by the NAT neurologists was metabolic encephalopathy (45.5%), followed by ischemic stroke (21.2%) and seizures or status epilepticus (21.0%). Patients with NAT activation had high rates in mortality before hospital discharge (22.5%) and at 3 months (34.7%), transfer to intensive care units (39.6%), and length of hospital stay (43.1 ± 57.1 days). They also had high prevalence of poor functional status (78.1%) and recurrence of neurological symptoms at 3 months (27.2%). In a Cox proportional hazards model, patients with in-hospital neurological emergencies had a hazard ratio of 13.2 in terms of mortality at 3 months (95% confidence interval, 11.5-15.3; P < 0.001).

CONCLUSIONS

Occurrence of acute neurological symptoms during hospital admission was associated with high rate of mortality and poor functional status. These results call for enhanced awareness and hospital-wide strategies for managing in-hospital neurological emergencies.

The Distribution of Multidrug-resistant Microorganisms and Treatment Status of Hospital-acquired Pneumonia/Ventilator-associated Pneumonia in Adult Intensive Care Units: a Prospective Cohort Observational Study

BACKGROUND

It is essential to determine the distribution of the causative microorganisms in the region and the status of local antibiotic resistance for the proper treatment of hospital-acquired pneumonia/ventilator-associated pneumonia (HAP/VAP). This study aimed to investigate the occurrence and causative strains of HAP/VAP, distribution of resistant bacteria, use of antibiotics, and the ensuing outcomes of patients in Korea.

METHODS

A multicenter prospective observational cohort study was conducted among patients with HAP/VAP admitted to the medical intensive care unit of 5 tertiary referral centers between August 2012 and June 2015. Patients' demographic and clinical data were collected.

RESULTS

A total of 381 patients were diagnosed with HAP/VAP. Their median age was 69 (59-76) years and 71% were males. A majority of the patients (88%) had late-onset (> 5 days) HAP/VAP. One-quarter of the patients (n = 99) had at least one risk factor for multidrug-resistant (MDR) pathogens, such as prior intravenous antibiotic use within the last 90 days. Microbiological specimens were mostly obtained noninvasively (87%) using sputum or endotracheal aspirates. Pathogens were identified in 235 (62%) of the 381 patients. The most common bacterial pathogen was Acinetobacter baumannii (n = 89), followed by Staphylococcus aureus (n = 52), Klebsiella pneumoniae (n = 25) and Pseudomonas aeruginosa (n = 22). Most of isolated A. baumannii (97%) and S. aureus (88%) were multidrug resistant. The most commonly used empirical antibiotic regimens were carbapenem-based antibiotics (38%), followed by extended-spectrum penicillin/β-lactamase inhibitor (34%). Glycopeptide or linezolid were also used in combination in 54% of patients. The 28-day mortality rate of the patients with HAP/VAP was 30% and the 60-day mortality was 46%. Patients who used empirical antibiotics appropriately had significantly lower mortality rates than those who did not (28-day mortality: 25% vs. 40%, P = 0.032; 60-day mortality: 41% vs. 55%, P = 0.032, respectively). Administration of appropriate empirical antibiotics (odds ratio [OR], 0.282; confidence interval [CI], 0.092-0.859; P = 0.026), Day 7 treatment failure (OR, 4.515; CI, 1.545-13.192; P = 0.006), and APACHE II score on day 1 (OR, 1.326; CI, 0.988-1.779; P = 0.012) were the factors that determined the 28-day mortality in patients with HAP who had identified bacteria as pathogens.

CONCLUSION

In HAP/VAP patients, there was a large burden of MDR pathogens, and their associated mortality rate was high. Proper selection of empirical antibiotics was significantly associated with the patient's prognosis; however, there was a discrepancy between major pathogens and empirical antibiotic therapy.

Outcomes of critically ill patients according to the perception of intensivists on the appropriateness of intensive care unit admission

Background

It is important for intensivists to determine which patient may benefit from intensive care unit (ICU) admission. We aimed to assess the outcomes of patients perceived as non-beneficially or beneficially admitted to the ICU and evaluate whether their prognosis was consistent with the intensivists’ perception.

Methods

A prospective observational study was conducted on patients admitted to the medical ICU of a tertiary referral center between February and April 2014. The perceptions of four intensivists at admission (day 1) and on day 3 were investigated as non-beneficial admission, beneficial admission, or indeterminate state.

Results

A total of 210 patients were enrolled. On days 1 and 3, 22 (10%) and 23 (11%) patients were judged as having non-beneficial admission; 166 (79%) and 159 (79%), beneficial admission; and 22 (10%) and 21 (10%), indeterminate state, respectively. The ICU mortality rates of each group on day 1 were 59%, 23%, and 59%, respectively; their 6-month mortality rates were 100%, 48%, and 82%, respectively. The perceptions of non-beneficial admission or indeterminate state were the significant predictors of ICU mortality (day 3; odds ratio [OR], 4.049; 95% confidence interval [CI], 1.892–8.664; P<0.001) and 6-month mortality (day 1: OR, 4.983; 95% CI, 1.260–19.703; P=0.022; day 3: OR, 4.459; 95% CI, 1.162–17.121; P=0.029).

Conclusions

The outcomes of patients perceived as having non-beneficial admission were extremely poor. The intensivists’ perception was important in predicting patients’ outcomes and was more consistent with long-term prognosis than with immediate outcomes. The intensivists’ role can be reflected in limited ICU resource utilization.

Rapid Response System Improves Sepsis Bundle Compliances and Survival in Hospital Wards for 10 Years

BACKGROUND

Hospitalized patients can develop septic shock at any time. Therefore, it is important to identify septic patients in hospital wards and rapidly perform the optimal treatment. Although the sepsis bundle has already been reported to improve survival rates, the controversy over evidence of the effect of in-hospital sepsis continues to exist. We aimed to estimate the outcomes and bundle compliance of patients with septic shock in hospital wards managed through the rapid response system (RRS).

METHODS

A retrospective cohort study of 976 patients with septic shock managed through the RRS at an academic, tertiary care hospital in Korea from 2008 to 2017.

RESULTS

Of the 976 enrolled patients, the compliance of each sepsis bundle was high (80.8-100.0%), but the overall success rate of the bundle was low (58.3%). The compliance rate for achieving the overall sepsis bundle increased from 26.5% to 70.0%, and the 28-day mortality continuously decreased from 50% to 32.1% over 10 years. We analyzed the two groups according to whether they completed the overall sepsis bundle or not. Of the 976 enrolled patients, 569 (58.3%) sepsis bundles were completed, whereas 407 (41.7%) were incomplete. The complete bundle group showed lower 28-day mortality than the incomplete bundle group (37.1% vs. 53.6%, p < 0.001). In the multivariate multiple logistic regression model, the 28-day mortality was significantly associated with the complete bundle (adjusted odds ratio (OR), 0.61; 95% confidence intervals (CI), 0.40-0.91; p = 0.017). The obtaining of blood cultures (adjusted OR, 0.45; 95% CI, 0.33-0.63; p < 0.001) and lactate re-measurement (adjusted OR, 0.69; 95% CI, 0.50-0.95; p = 0.024) in each component of the sepsis bundle were associated with the 28-day mortality.

CONCLUSIONS

The rapid response system provides improving sepsis bundle compliances and survival in patients with septic shock in hospital wards.

Relationship between the presence of dedicated doctors in rapid response systems and patient outcome: a multicenter retrospective cohort study

BACKGROUND

Rapid response systems (RRSs) improve patients' safety, but the role of dedicated doctors within these systems remains controversial. We aimed to evaluate patient survival rates and differences in types of interventions performed depending on the presence of dedicated doctors in the RRS.

METHODS

Patients managed by the RRSs of 9 centers in South Korea from January 1, 2016, through December 31, 2017, were included retrospectively. We used propensity score-matched analysis to balance patients according to the presence of dedicated doctors in the RRS. The primary outcome was in-hospital survival. The secondary outcomes were the incidence of interventions performed. A sensitivity analysis was performed with the subgroup of patients diagnosed with sepsis or septic shock.

RESULTS

After propensity score matching, 2981 patients were included per group according to the presence of dedicated doctors in the RRS. The presence of the dedicated doctors was not associated with patients' overall likelihood of survival (hazard ratio for death 1.05, 95% confidence interval [CI] 0.93‒1.20). Interventions, such as arterial line insertion (odds ratio [OR] 25.33, 95% CI 15.12‒42.44) and kidney replacement therapy (OR 10.77, 95% CI 6.10‒19.01), were more commonly performed for patients detected using RRS with dedicated doctors. The presence of dedicated doctors in the RRS was associated with better survival of patients with sepsis or septic shock (hazard ratio for death 0.62, 95% CI 0.39‒0.98) and lower intensive care unit admission rates (OR 0.53, 95% CI 0.37‒0.75).

CONCLUSIONS

The presence of dedicated doctors within the RRS was not associated with better survival in the overall population but with better survival and lower intensive care unit admission rates for patients with sepsis or septic shock.

Failure of High-Flow Nasal Cannula Therapy in Pneumonia and Non-Pneumonia Sepsis Patients: A Prospective Cohort Study

Despite the increasing use of high-flow nasal cannulas (HFNCs) to treat critically ill patients, data on their effectiveness for sepsis patients remains very limited. We studied a prospective cohort of sepsis patients from the Korean Sepsis Registry (18 intensive care units (ICUs)). Patients started on HFNC therapy for hypoxemia within the first three ICU days were enrolled. HFNC failure was defined as intubation or ICU death, and the primary outcome was early HFNC failure occurring within 72 h of HFNC initiation. Of 901 patients with sepsis admitted to the ICU, 206 who received HFNC therapy were finally included (117 with pneumonia vs. 89 with non-pneumonia sepsis; median age, 71.0 (63.0–78.0) years; P_aO₂/F_iO₂ ratio, 160.2 (107.9–228.2) mm Hg; septic shock, n = 81 (39.3%)). During HFNC therapy, 72 (35.0%) patients were intubated and 51 (24.8%) died. HFNC failure developed in 95 (46.1%) patients, and among them, early failure rate was 85.3% (81/95). On multivariate analysis, an immunocompromised state (odds ratio (OR) = 2.730), use of a combination of antibiotics (OR = 0.219), and the P_aO₂/F_iO₂ ratio (OR = 0.308) were significantly associated with early HFNC failure in pneumonia sepsis patients. However, in non-pneumonia sepsis patients, lactate levels (OR = 1.532) were significantly associated with early HFNC failure. In conclusion, a high proportion of sepsis patients experience HFNC failure, usually within 72 h after therapy initiation, which emphasizes the importance of close monitoring. Furthermore, unlike in pneumonia sepsis, organ failure (i.e., lactate) might serve as a prognostic marker in non-pneumonia sepsis (i.e., type IV respiratory failure).

Long-Term Outcomes After In-Hospital Cardiac Arrest: Does Pre-arrest Skeletal Muscle Depletion Matter?

Background: Skeletal muscle depletion is prevalent in elderly patients and is associated with unfavorable outcomes in patients with chronic diseases. However, the relationship between skeletal muscle mass and neurological outcomes following in-hospital cardiac arrest (IHCA) has not been evaluated. The aim of this study was to investigate whether skeletal muscle status before cardiac arrest is an independent factor affecting neurological outcomes in patients with IHCA. Methods: We reviewed a prospectively enrolled registry of IHCA patients. Consecutive adult patients (>18 years) admitted to a tertiary care hospital from 2013 to 2019 were included in the study. Of these, 421 patients who underwent abdominopelvic computed tomography within 3 months of cardiac arrest were included. Skeletal muscle index (SMI) was measured at the third lumbar vertebra, and skeletal muscle depletion was defined using sex- and body mass index-specific cutoffs of SMI. The primary outcome was a Cerebral Performance Category score of 1 or 2 at 6 months after cardiac arrest, which was considered a good neurological outcome. Results: Of the 421 patients, 248 (58.9%) had skeletal muscle depletion before IHCA. The patients without skeletal muscle depletion showed significantly better neurological outcomes at 6 months after cardiac arrest than those with pre-arrest muscle depletion (20.8 vs. 10.9%, p = 0.004). The absence of skeletal muscle depletion was significantly associated with good neurological outcomes in a multivariable logistic analysis (OR = 3.49, 95% confidence intervals: 1.83-6.65, p < 0.001), along with the absence of diabetes, presence of active cancer, shockable rhythm, and short resuscitation duration. Conclusion: Pre-arrest skeletal muscle depletion was associated with long-term mortality and poor neurological outcomes after IHCA. Skeletal muscle depletion may be used as a tool to identify at-risk patients who may benefit from aggressive treatments.

Effects of high-flow nasal cannula in patients with mild to moderate hypercapnia: a prospective observational study

Background

Evidence for using high-flow nasal cannula (HFNC) in hypercapnia is still limited. Most of the clinical studies had been conducted retrospectively, and there had been conflicting reports for the effects of HFNC on hypercapnia correction in prospective studies. Therefore, more evidence is needed to understand the effect of the HFNC in hypercapnia.

Methods

We conducted a multicenter prospective observational study after applying HFNC to 45 hospitalized subjects who had moderate hypercapnia (arterial partial pressure of carbon dioxide [PaCO₂], 43–70 mm Hg) without severe respiratory acidosis (pH <7.30). The primary outcome was a change in PaCO₂ level in the first 24 hours of HFNC use. The secondary outcomes were changes in other parameters of arterial blood gas analysis, changes in respiration rates, and clinical outcomes.

Results

There was a significant decrease in PaCO₂ in the first hour of HFNC application (-3.80 mm Hg; 95% confidence interval, -6.35 to -1.24; P<0.001). Reduction of PaCO₂ was more prominent in subjects who did not have underlying obstructive lung disease. There was a correction in pH, but no significant changes in respiratory rate, bicarbonate, and arterial partial pressure of oxygen/fraction of inspired oxygen ratio. Mechanical ventilation was not required for 93.3% (42/45) of our study population.

Conclusions

We suggest that HFNC could be a safe alternative for oxygen delivery in hypercapnia patients who do not need immediate mechanical ventilation. With HFNC oxygenation, correction of hypercapnia could be expected, especially in patients who do not have obstructive lung diseases.

Right Ventricular Assist Device With Extracorporeal Membrane Oxygenation for Bridging Right Ventricular Heart Failure to Lung Transplantation: A Single-Center Case Series and Literature Review

OBJECTIVE

Right ventricular heart failure (RVHF) is a critical complication in patients with respiratory failure, particularly among those who transitioned to lung transplantation using venovenous (VV) extracorporeal membrane oxygenation (ECMO). In these patients, both cardiac and respiratory functions are supported using venoarterial or venoarterial-venous ECMO. However, these modalities increase the risk of device-related complications, such as thromboembolism, bleeding, and limb ischemia, and they may disturb early rehabilitation. Due to these limitations, a right ventricular assist device with an oxygenator (Oxy-RVAD) using ECMO may be considered for patients with RVHF with VV ECMO.

DESIGN

A retrospective case series and literature review.

SETTING

A single tertiary care university hospital.

PARTICIPANTS

The study comprised lung transplantation candidates on ECMO bridging who developed right-sided heart failure.

INTERVENTIONS

An RVAD with ECMO.

MEASUREMENTS AND MAIN RESULTS

Of eight patients who underwent the study protocol, seven were bridged successfully to lung transplantation (BTT), and all patients with BTT were discharged, with a 30-day survival rate of 100% (7/7 patients). The 180-day survival rate was 85% (6/7 patients).

CONCLUSIONS

The study suggested that Oxy-RVAD using ECMO may be a viable option for bridging patients with RVHF to lung transplantation.

TRIAL REGISTRATION

Retrospectively registered.

Effects of the duration of bridge to lung transplantation with extracorporeal membrane oxygenation

Background

Although bridge to lung transplantation (BTT) with extracorporeal membrane oxygenation (ECMO) is increasingly performed, the impact of BTT and its duration on post-transplant outcomes are unclear.

Methods

We retrospectively reviewed medical records of adult patients who underwent lung or heart-lung transplantation in our institution between January 2008 and December 2018. Data were compared in patients who did (n = 41; BTT) and did not (n = 36; non-BTT) require pre-transplant ECMO support. Data were also compared in patients who underwent short-term (<14 days; n = 21; ST-BTT) and long-term (≥14 days; n = 20; LT-BTT) BTTs.

Results

Among 77 patients included, 51 (66.2%) were male and median age was 53 years. The median bridging time in the BTT group was 13 days (interquartile range [IQR], 7–19 days). Although simplified acute physiologic score II was significantly higher in the BTT group (median, 35; IQR, 31–49 in BTT group vs. median, 12; IQR, 7–19 in non-BTT group; p<0.001), 1-year (73.2% vs. 80.6%; p = 0.361) and 5-year (61.5% vs. 61.5%; p = 0.765) post-transplant survival rates were comparable in both groups. Comparison of ST- and LT-BTT subgroups showed that 1-year (90.5% vs. 55.0%; p = 0.009) and 5-year (73.0% vs. 48.1%; p = 0.030) post-transplant survival rates were significantly higher in ST-BTT group. In age and sex adjusted model, the LT-BTT was an independent risk factor for 1-year post-transplant mortality (hazard ratio, 3.019; 95% confidence interval, 1.119–8.146; p = 0.029), whereas the ST-BTT was not.

Conclusions

Despite the severe illness, the BTT group showed favorable post-transplantation outcomes, particularly those bridged for less than 14 days.

Dynamic inhomogeneity of aeration along the vertical axis of the lung may predict weaning failure regardless of diaphragm dysfunction

PURPOSE

This study aimed to investigate dynamic changes of lung aeration during a spontaneous breathing trial (SBT) in patients with diaphragm dysfunction (DD) and to predict weaning failure using electrical impedance tomography (EIT).

MATERIALS AND METHODS

We enrolled 40 adult patients who received mechanical ventilation over 48 h and were eligible for SBT with a T-piece. All patients were screened for DD using ultrasonography before SBT. EIT data, including global inhomogeneity index (an off-site parameter), and temporal skew of aeration (TSA) (an on-site parameter) were collected.

RESULTS

Sixteen (40%) patients had DD. During SBT, the tidal impedance variation decreased by 32% from baseline in patients with DD and by 14% in those without DD (p = 0.001). The global inhomogeneity index in the SBT failure group (n = 9) was 0.92 (median), and that of the SBT success group was 0.65 (p = 0.004). The TSA along the vertical axis of the lung was 12.0% and 2.0%, respectively (p = 0.001). With a vertical TSA cutoff of ≥4.35%, SBT failure was predicted with a sensitivity of 88.9% and specificity of 96.9% (area under the curve: 0.955).

CONCLUSION

Dynamic inhomogeneity of aeration along the vertical axis of the lung as assessed using TSA predicts SBT failure regardless of DD.

TRIAL REGISTRATION

This trial was retrospectively registered at cris.nih.go.kr (identifier: KCT003567; release date February 27, 2019).

Clinical outcomes of immunocompromised patients on extracorporeal membrane oxygenation support for severe acute respiratory failure

OBJECTIVES

There are limited data regarding extracorporeal membrane oxygenation (ECMO) support in immunocompromised patients, despite an increase in ECMO use in patients with respiratory failure. The aim of this study was to investigate the clinical characteristics and outcomes of immunocompromised patients requiring ECMO support for severe acute respiratory failure.

METHODS

Between January 2012 and December 2015, all consecutive adult patients with severe acute respiratory failure who underwent ECMO for respiratory support at 16 tertiary or university-affiliated hospitals in South Korea were enrolled retrospectively. The patients were divided into 2 groups based on the immunocompromised status at the time of ECMO initiation. In-hospital and 6-month mortalities were compared between the 2 groups. In addition, association of immunocompromised status with 6-month mortality was evaluated with logistic regression analysis.

RESULTS

Among 461 patients, 118 (25.6%) were immunocompromised. Immunocompromised patients were younger and had lower haemoglobin and platelet counts than immunocompetent patients. Ventilatory parameters and the use of adjunctive/rescue therapies were similar between the 2 groups, but prone positioning was more commonly used in immunocompetent patients. Successful weaning rates from ECMO (46.6% vs 58.9%; P = 0.021) was lower and hospital mortality (66.1% vs 59.8%; P = 0.22) was higher in immunocompromised patients. In addition, immunocompromised status was associated with higher 6-month mortality (74.6% vs 64.7%, adjusted odds ratio 2.10, 95% confidence interval 1.02-4.35; P = 0.045).

CONCLUSIONS

Immunocompromised patients treated with ECMO support for severe acute respiratory failure had poorer short- and long-term prognoses than did immunocompetent patients.