46

Epidemiology, etiology, and diagnosis of hospital-acquired pneumonia and ventilator-associated pneumonia in Asian countries

<sec><title>BACKGROUND</title>Pulmonary TB (PTB) is a common cause of intensive care unit (ICU) admission. However, there is limited evidence on the factors associated with ICU care for patients initially admitted to the general ward.</sec><sec><title>METHODS</title>The study included 32 PTB patients without HIV infection admitted to the ICU from the general ward, while 55 controls were selected from 623 patients with PTB who had been admitted to the hospital after matching for age, sex, and radiological findings of the extent of TB. The odds ratio for ICU admission was tested using conditional logistic regression.</sec><sec><title>RESULTS</title>Age, sex, and extent of radiological involvement were similar between the two groups. The most common cause of ICU referral was respiratory failure, and the mean duration of ICU stays was 22.5 days. No differences were identified between the epidemiological characteristics and clinical features of patients with TB between the two groups. The ICU group showed lower serum albumin and haemoglobin levels and a higher C-reactive protein level than controls. Patients with lower albumin levels showed an increased risk of ICU admission than those with normal albumin levels.</sec><sec><title>CONCLUSION</title>This study showed that the albumin level at admission was crucial in predicting ICU admission in PTB patients without HIV infection.</sec>.

Respiratory failure in acquired immunodeficiency syndrome (AIDS) patients was the leading cause of intensive care unit (ICU) admission in our center. We aimed to describe the pulmonary infections and outcomes for respiratory failure in AIDS patients. A retrospective study was conducted on AIDS adult patients with respiratory failure who were admitted to the ICU in Beijing Ditan hospital, China, from January 2012 to December 2021. We investigated pulmonary infections complicated by respiratory failure in AIDS patients. The primary outcome was ICU mortality, and a comparison between survivors and nonsurvivors was performed. Multiple logistic regression analysis was used to identify predictors of ICU mortality. The Kaplan-Meier curve and Log rank test were used for survival analysis. A total of 231 AIDS patients were admitted to ICU with respiratory failure over a 10-year period with a male predominance (95.7%). Pneumocystis jirovecii pneumonia was the main etiology of pulmonary infections (80.1%). The ICU mortality was 32.9%. In multivariate analysis, ICU mortality was independently associated with invasive mechanical ventilation (IMV) [odds ratio (OR), 27.910; 95% confidence interval (CI, 8.392-92.818; p = 0.000) and the time before ICU admission (OR, 0.959; 95% CI, 0.920-0.999; p = 0.046). In the survival analysis, patients with IMV and later admission to ICU had a higher probability of mortality. Pneumocystis jirovecii pneumonia was the primary etiology for respiratory failure in AIDS patients admitted to the ICU. Respiratory failure remains a severe illness with high mortality, and ICU mortality was negatively associated with IMV and later admission to ICU.

To the Editor—Viral respiratory infections represent a frequent cause of intensive care unit (ICU) admissions in children and impose a considerable burden worldwide [1]. The main pathogens are respiratory syncytial virus (RSV) and seasonal influenza. Human metapneumovirus (hMPV) is an emerging pathogen of the Paramyxoviridae family causing acute bronchiolitis-like respiratory illness in children [2]. Williams et al [2] have recently reported an annual rate of hMPV-associated hospitalizations of 1.2 per 1000 hospitalized children <5 years of age in the United States, confirming that hMPV contributes significantly to respiratory morbidity with a similar impact as influenza. In their study, most hMPV-infected children had a relatively mild course, with only 1 participant (3%) requiring ICU admission. We would like to comment on severe hMPV infections and to present the case of a child with fatal acute respiratory distress syndrome (ARDS) due to infection with hMPV. The 20-month-old boy initially presented with a bronchiolitis-like pattern, with rhinitis, cough, and increasing respiratory distress. The child's history was unremarkable except for moderate neurodevelopmental delay of unknown etiology. Because of impending respiratory failure (capillary pH, 7.17; partial carbon dioxide pressure, 86 mm Hg; saturation 83% with 100% oxygen), he was intubated. The oxygenation index was 0.32 and the PaO2/FiO2 ratio resulted 68 (55 mm Hg/0.8). On the basis of radiological findings of bilateral diffuse pulmonary infiltrates, the diagnosis of ARDS was made. Echocardiography demonstrated good biventricular function and no evidence for pulmonary hypertension. The patient was placed on high-frequency oscillatory ventilation (Sensormedics 3100A), with a mean airway pressure of up to 30 cm water. Tests for RSV and H1N1 influenza virus were negative. Results of repeated bacterial blood and tracheal fluid cultures were negative. Therefore, an expanded panel of respiratory viruses (adenovirus, picornaviruses, influenzavirus A/B, parainfluenzaviruses 1–3, RSV, and hMPV) was assessed using direct immunofluorescence. The patient tested positive for hMPV. Viral testing was repeated several times and confirmed only infection with hMPV. Because of the high risk of bacterial superinfection, empirical treatment with cefuroxime and vancomycin was initiated. The patient subsequently developed multi-organ failure, with catecholamine-dependent arterial hypotension, renal failure requiring continuous renal replacement, coagulopathy, thrombocytopenia, leukopenia, and hepatitis. Because oxygenation further deteriorated (oxygenation index, .45), venoarterial extracorporal membrane oxygenation (ECMO) was initiated. After repeated failed attempts to wean from ECMO, the decision to limit treatment was made on day 18 after admission. The patient died after cessation of ECMO. The parents declined an autopsy. To date, lethal hMPV infections have been primarily described in immunosuppressed adults [3]. hMPV was first reported in the Netherlands in 2001, and several studies have shown that the clinical course of hMPV closely resembles RSV infection with bronchiolitis, pneumonia, and asthma exacerbation as the main manifestations [2]. In contrast, the proportion of children with severe hMPV infection requiring ICU admission or respiratory support is small [2, 4]. However, infants with RSV and hMPV coinfection had a 10-fold increased risk of requiring mechanical ventilation when compared with infants with isolated RSV infection [4]. Although ARDS is known to occur in patients with RSV bronchiolitis [5], hMPV-associated pediatric ARDS is very rare. An extensive literature search resulted in only 4 pediatric patients with isolated hMPV infection who developed severe ARDS: a 17-month-old girl receiving chemotherapy for acute leukemia died after a prolonged period of mechanical ventilation [6]. Two other children, both with underlying diseases (prematurity with chronic lung disease in one, transplant-related immunosuppression in the other), required ECMO but ultimately recovered [7, 8]. The fourth reported case concerns a 2 year-old, previously healthy girl without any known immunodeficiency who died of pulmonary hemorrhage soon after admission [9]. It has been suggested that deficiencies in innate immunity pathways, such as Toll-like receptor 4, lead to an increased risk of severe RSV infection [10], but the role of innate immunity in hMPV infections has not been studied thus far. The underlying neurodevelopmental delay may represent a clinical risk factor for severe respiratory disease in the presented case [2]. In conclusion, the summarized cases illustrate that hMPV infection may cause severe ARDS in susceptible children. Considering that testing for hMPV is not routinely performed, it is likely that hMPV-related ARDS is underreported. The mortality of pediatric ARDS remains high and early identification of the causative agent is crucial. We, therefore, suggest early testing for hMPV in patients with presumptive viral ARDS where no other agent can be identified. Additional studies investigating the role of hMPV in severe respiratory infections are needed to improve early and appropriate treatment of high-risk patients.

연구배경: 원내 폐렴의 적절한 항균제 치료를 위해서는 원발 병소에서의 원인균 규명과 항균제에 대한 내성 유무 확인이 필수적이다. 본 연구는 원내 폐렴이 의심되는 경우 기관지내시경을 통한 정량적 기관지폐포 세척술(bronchoalveolar lavage, BAL) 배양검사를 시행하여 빈번하게 분리되는 균주와 이들의 항균제 내성 현황을 알아보고자 하였다. 방법: 2004년 1월부터 2006년 6월까지 한림의대 한강성심병원 화상 중환자실과 비화상 중환자실에서 폐 침윤의 원인규명 위해 BAL 검사를 시행하였다. 104 CFU/mL 이상의 균주가 분리되면 양성으로 판정하였다. 결과: BAL 검사 결과 화상중환자실 27예(77.1%), 비화상중환자실 22예(59.4%)에서 배양 양성이었다. 분리되는 주요 균주는 S. aureus, Acinetobacter species 및 P. aeruginosa였다. 화상중환자실에서 분리된 S. aureus의 경우 전부 MRSA(100%)였으며, 비화상중환자실에서는 71.4%가 MRSA로 보고되었다. P. aeruginosa의 경우 화상중환자실 및 비화상중환자실에서 amikacin 54.6% vs. 50.0%, ciprofloaxacin 100% vs. 50%, cefepime 90.9% vs. 50%, imipenem 72.7% vs. 50%, ceftazidime 45.5% vs. 25% 및 piperacillin/tazobactam 90.9% vs. 50%의 내성률을, Acinetobacter species의 경우는 amikacin 90.9% vs. 100%, ciprofloxacin 100% vs. 87.5%, cefepime 90.9% vs. 100%, imipenem 100% vs. 62.5%, ceftazidime 90.9% vs. 100% 및 piperacillin/tazobactam 81.8% vs. 62.5%의 내성률을 보여주었다. 결론: 화상중환자실과 비화상중환자실에서 원내 폐렴이 의심되는 환자의 원인균 분포와 약제 내성 현황을 알 수 있었으며 향후 항균제 치료 전략에 도움을 줄 것으로 사료된다.

Background Respiratory tract infections (RTI) are amongst the five leading causes of death in children in Canada. After relaxation of public health interventions for COVID-19, there was a significant increase in hospital admissions in children with RTI. The epidemiology of these cases, causative viral pathogens, severity of illness, and type of complications are poorly described. Objectives To describe the epidemiology and outcomes of children under 18 years with RTI between July 2022 and June 2023. Design/Methods A retrospective observational cohort study in hospitalized children at two tertiary Canadian centers with an acute RTI. The primary outcome was intensive care unit (ICU) admission. Characteristics of the cohort are described. Regression analyses for risk factors for ICU admission will be performed (data not presented in abstract) Results The median age of 2603 patients was 2.6 (IQR: 0.9-5.1) and 59% were males. Neurologic/genetic diagnoses were the most common comorbidity. Children presented after a median of 4 (IQR: 2-6) days of symptoms with a median of 5 (IQR: 4-6) symptoms. Common symptoms included cough (n=2157, 83%), fever (n=1814, 70%), and increased work of breathing (n=1780, 68%). Most patients had viral testing performed (88%); with one virus identified in 1451 children (63%), two in 288 patients (13%), and three or more in 48 children (2%). In those tested, positive tests for RSV (n=692, 30%) and Rhinovirus/Enterovirus (n=582, 25%) were most common. 653 (25%) patients required an ICU admission. RSV (n=223, 34%) and Rhinovirus/Enterovirus (n=156, 24%) were the most common etiologies in patients admitted to ICU. Median duration of PICU admission was 3 (IQR: 1-6) days, with 41% of patients remaining in ICU for 4 or more days. Three quarters (n=481) of the patients admitted to PICU required non-invasive/invasive mechanical ventilation. Acute respiratory distress syndrome and cardiac complications developed in 40 (2%) and 76 (3%) patients, respectively. Positive blood culture for bacteria implicated in pneumonias were detected in 58 (2%) children. Median length of hospital stay was 3 (IQR: 1-6) days. Only 7% of patients had an emergency department visit within 30 days after discharge. 39 patients (1%) died. Conclusion After the relaxation of public health interventions, RTI related hospital admissions were in young children and over half of patients were positive for RSV and Rhinovirus/Enterovirus. While most admissions were short, one-quarter of children were admitted to PICU.

Objective: Fluctuations in sodium levels (SLs) may increase mortality, severity, and prolonged length of stay (LOS) in critically ill patients. We aim to study the effect of SL on various clinical outcomes in patients with severe traumatic brain injury (TBI). Methods: This is a single-center, retrospective study of patients with severe TBI from 1 January 2020 to 31 December 2023, inclusive. Patients were identified using Abbreviated Injury Severity (AIS) scores and International Classification of Diseases (ICD) injury descriptions. Result: Variations in hospital (H) admission SLs were statistically significant across four age ranges (pediatric, young adult, older adults, and elderly). Intensive care unit (ICU) admission, H discharge, and death also showed significance. A statistical difference was noted in ICU discharge levels while comparing blunt versus penetrating injury. We found statistically significant differences in SLs at H admission, ICU admission, and ICU discharge when compared to the Injury Severity Score (ISS) and the Glasgow Coma Scale (GCS) at admission. A linear regression analysis revealed a statistically significant positive correlation between ICU admission SLs and ISS. We discovered statistically significant differences when comparing ICU admission levels to H LOS, ventilator days, and mortality. Conclusions: SL upon ICU admission is correlated with ISS, GCS, and mortality rates. The elevated admission SL was linked to adverse hospital outcomes, including prolonged LOS at the H, ICU, and mechanical ventilation. Moreover, variability in serum SLs is independently associated with mortality throughout the hospital stay, irrespective of the absolute serum sodium concentration.

This study examined records of 2566 consecutive COVID-19 patients at five Massachusetts hospitals and sought to predict level-of-care requirements based on clinical and laboratory data. Several classification methods were applied and compared against standard pneumonia severity scores. The need for hospitalization, ICU care, and mechanical ventilation were predicted with a validation accuracy of 88%, 87%, and 86%, respectively. Pneumonia severity scores achieve respective accuracies of 73% and 74% for ICU care and ventilation. When predictions are limited to patients with more complex disease, the accuracy of the ICU and ventilation prediction models achieved accuracy of 83% and 82%, respectively. Vital signs, age, BMI, dyspnea, and comorbidities were the most important predictors of hospitalization. Opacities on chest imaging, age, admission vital signs and symptoms, male gender, admission laboratory results, and diabetes were the most important risk factors for ICU admission and mechanical ventilation. The factors identified collectively form a signature of the novel COVID-19 disease.

BackgroundVentilator-associated pneumonia (VAP) is a common nosocomial infection in critically ill patients in intensive care units (ICUs) worldwide. Despite the huge healthcare economic burden and the significant negative morbidity and mortality impact of VAP, its incidence and outcomes in the trauma ICU (TICU) population were poorly documented in South Africa (SA).ObjectivesTo determine the incidence of VAP in a level I trauma centre at Inkosi Albert Luthuli Central Hospital in Durban, SA, compared with international benchmarks. Determining mortality rates, the average length and cost of ICU stay, ventilator days and antibiotic consumption was a secondary objective.MethodsThis retrospective chart review of the trauma registry at the centre examined the incidence of VAP and secondary outcomes over the period January 2017 - December 2019. A data pro forma was used with VAP diagnoses as per the 2015 Centers for Disease Control and Prevention definitions. The comparator was international literature-based benchmark VAP rates in TICUs.ResultsThe study included 395 patients, of whom 143 (36.2%) were diagnosed with VAP. The VAP rate was calculated to be 35.6 per 1 000 ventilator days. Thirty-one patients with VAP (21.7%) died in the ICU, a similar figure to that for the non-VAP group (22.6%). There were no statistically significant differences in age, sex, mechanism of injury or Injury Severity Score between the VAP and non-VAP groups (p>0.05). There were statistically significant differences between the two groups in number of days on mechanical ventilation, ICU length of stay and ICU cost. The VAP group had a median of 12 ventilation days v. 5 days for the non-VAP group (p<0.001), and spent a median of 7 days longer in the ICU (p<0.001). The median cost of ICU stay for VAP patients was almost double that for non-VAP patients (p<0.001).ConclusionVAP rates in this local TICU were similar to international rates. Trauma patients, especially those with traumatic brain injury, are at higher risk of VAP than general ICU patients, so strict adherence to evidence-based VAP prevention bundles is necessary among TICU staff.Contribution of the studyThis study is the first to assess ventilator-associated pneumonia rates in a South African trauma-specific intensive care unit compared with national and international benchmarks, and sets the standard for local morbidity and mortality norms.

Critical Care Medicine

Unplanned Extubation in Adult Critical Care

A multidisciplinary group was formed to develop strategies to reduce ventilator-associated lower respiratory tract infections (LRI) in an intensive care unit (ICU) of a 540-bed acute care teaching medical center. The group process was facilitated by the Infection Director and the quality management specialist. The group was made of medical, nursing, and respiratory therapy staff. Quality improvement techniques were used to define the process of care for ventilated patients in the ICU. "State of the art" care was defined after a literature review and brainstorming sessions. Current practice and new concepts were then forged into a realistic protocol for the ICU. The resulting protocol was introduced into the ICU in May 1992. The information was communicated to Respiratory Therapy and ICU staff in writing and at department meetings. After a 4-month introductory period and learning curve process, a decrease in the endemic rate of ventilator-associated LRI was reduced in the fourth quarter of 1992. The mean 1993 LRI rate was 21 LRI/1000 ventilator days versus 26 LRI/1000 ventilator days in 1992 before protocol implementation. This equates to 18 LRI prevented in 1993. This represents a savings of $126,000. There was a significant decrease in the process variation of the monthly mean LRI/1000 ventilator days in 1993 from 1992. To date, there continues to be improvement with a mean of 16 LRI/1000 ventilator days reported in 1994. The ICU staff developed a multidisciplinary process evaluation and monitored staff implementation of the protocol over time. The results of the evaluation were used as feedback to measure protocol implementation. This was found to improve compliance with the protocol. Both the process (care of ventilated patients) and the outcome (number of LRI) have been improved through use of continuous quality improvement concepts and transdisciplinary interventions.

To assess the impact of delay in emergency department (ED) on outcome of critically ill patients admitted to the medical intensive care unit (MICU). Outcome was defined as hospital mortality and as health-related quality of life (HRQoL) at 6 months after intensive care assessed by the 15D measure. The 15D is a generic, 15-dimensional, standardized measure of HRQoL. We hypothesized that prolonged stay in the ED is related to worse outcome. A prospective follow-up cohort study in university hospital. All consecutive 1675 patients admitted to the MICU between July 2002 and June 2004. The 15D questionnaire was mailed to all patients alive at 6 months after admission. Of all MICU patients, 64% were admitted from ED. The mean length of stay in the ED was 6.2 h (95%CI 5.9-6.5 h). The hospital mortality rate was 24.4% (20.0% in the ED vs. 33.0% in the non-ED cohort, P < 0.001) and it was associated with higher age and degree of physiological derangement at admission. Neither the length of ED stay was associated with hospital mortality (P = 0.82) nor with HRQoL at 6 months after MICU admission (P = 0.34). Altogether, HRQoL at 6 months was significantly lower compared with the age- and sex-matched general population (P < 0.001). In a university hospital, the length of ED stay was not associated with the outcome of critically ill medical patients. However, we feel that the effect of ED treatment and delay on outcome and outcome prediction in the critically ill patients deserves further evaluation.

Health Care–Associated Infection in Elderly Patients With Cerebrovascular Disease in Intensive Care Units: A Retrospective Cohort Study in Taizhou, China

BackgroundRespiratory tract infections are common in intensive care units (ICU), with incidences reported from 10 to 65%, and case fatality rates over 20% in pneumonia. This study was designed to identify risk factors for the development of an early onset respiratory tract infection (ERI) and to review the microbiological profile and the effectiveness of first intention antibiotic therapy.MethodsCase-control, retrospective clinical study of the patients admitted to the Intensive Care Unit (ICU) of our hospital, a teaching and tertiary care facility, from January to September 2000 who had a respiratory tract infection diagnosed in the first 5 days of hospital stay.ResultsOf the 385 patients admitted to our unit: 129 (33,5%) had a diagnosis of ERI and 86 patients were admitted to the control group. Documented aspiration (adjusted OR = 5,265; 95% CI = 1,155 – 24,007) and fractured ribs (adjusted OR = 12,150; 95% CI = 1,571 – 93,941) were found to be independent risk factors for the development of ERI (multiple logistic regression model performed with the diagnostic group as dependent variable and adjusted for age, sex, SAPS II, documented aspiration, non-elective oro-tracheal intubation (OTI), fractured ribs, pneumothorax and pleural effusion).A total of 78 organisms were isolated in 61 patients (47%). The normal flora of the upper airway (Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenza and Moraxella catharralis) accounted for 72% of all isolations achieved, polimicrobian infections were responsible for 25% of all microbiological documented infections. First intention treatment was, in 62% of the patients, the association amoxacillin+clavulanate, being effective in 75% of the patients to whom it was administered.The patients with ERI needed more days of OTI (6 vs 2, p < 0,001) and mechanical ventilation (6 vs 2, p < 0,001) and had a longer ICU (7 vs 2, p < 0,001) and hospital length of stay (17 vs 11, p = 0,018), when compared with controls.ConclusionIn this study documented tracheobronchial aspiration and fractured ribs were identified as independent risk factors for ERI. Microbiological profile was dominated by sensitive micro-organisms. The choice amoxacilin+clavulanate revealed to be a good option with an effectiveness rate of 77% in the patients in whom it was used.