Factors predicting ventilator dependence in patients with ventilator-associated pneumonia

Mortality and ventilator dependence in critically ill patients with ventilator-associated pneumonia caused by carbapenem-resistant Acinetobacter baumannii

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a key pathogen associated with ventilator-associated pneumonia (VAP). Research on treatment outcomes, especially ventilator dependence, in patients with VAP caused by CRAB remains limited.

METHODS

This retrospective multicenter study included ICU-admitted patients with VAP caused by CRAB. The original cohort was included as the mortality evaluation cohort. The ventilator dependence evaluation cohort included cases that survived more than 21 days after VAP and without prolonged ventilation before VAP onset. The mortality rate, ventilator dependence rate, clinical factors associated with treatment outcomes, and treatment outcome differences with various VAP onset times were investigated.

RESULTS

In total, 401 patients with VAP caused by CRAB were analyzed. The 21-day all-cause mortality rate was 25.2%, and the 21-day ventilator dependence rate was 48.8%. Clinical factors associated with 21-day mortality included lower body mass index, higher sequential organ failure assessment score, vasopressors usage, CRAB persistence, and VAP onset time > seven days. Clinical factors associated with 21-day ventilator dependence included older age, vasopressors usage, and VAP onset time > seven days.

CONCLUSIONS

ICU-admitted patients with CRAB-related VAP had high mortality and ventilator dependence rates. Older age, vasopressor usage, and longer VAP onset time were independent factors associated with ventilator dependence.

The Use of Antibiotics for Ventilator-Associated Pneumonia in the MIMIC-IV Database

Purpose: By analyzing the clinical characteristics, etiological characteristics and commonly used antibiotics of patients with ventilator-associated pneumonia (VAP) in intensive care units (ICUs) in the intensive care database. This study aims to provide guidance information for the clinical rational use of drugs for patients with VAP. Method: Patients with VAP information were collected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, including their sociodemographic characteristics, vital signs, laboratory measurements, complications, microbiology, and antibiotic use. After data processing, the characteristics of the medications used by patients with VAP in ICUs were described using statistical graphs and tables, and experiences were summarized and the reasons were analyzed. Results: This study included 2,068 patients with VAP. Forty-eight patient characteristics, including demographic indicators, vital signs, biochemical indicators, scores, and comorbidities, were compared between the survival and death groups of VAP patients. Cephalosporins and vancomycin were the most commonly used. Among them, fourth-generation cephalosporin (ForGC) combined with vancomycin was used the most, by 540 patients. First-generati49n cephalosporin (FirGC) combined with vancomycin was associated with the highest survival rate (86.7%). More than 55% of patients were infected with Gram-negative bacteria. However, patients with VAP had fewer resistant strains (<25%). FirGC or ForGC combined with vancomycin had many inflammation-related features that differed significantly from those in patients who did not receive medication. Conclusion: Understanding antibiotic use, pathogenic bacteria compositions, and the drug resistance rates of patients with VAP can help prevent the occurrence of diseases, contain infections as soon as possible, and promote the recovery of patients.

Cost-Effective Home Mechanical Ventilation in Neurosurgery Patients: Case Series of Three Patients

Background  Neurological patients who are ventilator-dependent occupy scarce beds in the hospitals for prolonged periods of time. Most, if not all, can be discharged on home mechanical ventilation (HMV). However, due to lack of insurance and state support, it remains prohibitively expensive for the vast majority of those who require it most.

Materials and Methods  The authors discuss three patients admitted in the Department of Neurosurgery between January and August 2019, who were discharged on HMV after remaining on ventilator support for prolonged period in the hospital. Each patient was discharged with two units (one as standby) of AgVa home ventilator (AgVa Healthcare; New Delhi, India), one Ambu-bag, one pulse oximeter, and one backup power supply unit capable of supplying power to ventilator for a minimum of 24 hours. All the equipment were given free-of-cost through donations by hospital staffs and other donors. All patients were followed up telephonically from their homes and the incidence of complications, ventilator malfunction, and additional cost of HMV on the families were ascertained.

Observation and Results  Of the three patients, two were male and one female. Age ranged from 12 to 17 years. The duration of in-hospital ventilator support prior to discharge on HMV varied from 1 to 5 years. There was no insurance cover available for any of the patients with all expenses being “out of pocket.” The equipment cost Indian Rupees (INR) 115,700 (USD 1,615: two units of AgVa home ventilator costing INR 100,000 [USD 1,396], one Ambu-bag costing INR 1,100 [USD 15], one pulse oximeter costing INR 1,600 [USD 22], and one backup power supply unit costing INR 13,000 [USD 182]). Discharge on HMV was planned on specific request from patients’ families and informed consent was taken from all. All patients had tracheostomies. Mode of HMV was pressure support ventilation in all. Telephonic follow-up ranged from 1 to 7 months. The cost of disposables was INR 100 per month (USD 0.7) for all the patients. No complications occurred in any patient. There was no incidence of ventilator-associated pneumonia (VAP) or ventilator malfunction.

Conclusions  Availability of cost-effective indigenous ventilator like AgVa home has made HMV possible, even for poor patients with neurological diseases, and has the potential to improve quality of life, decrease VAP rates, and free up scarce ventilator beds in hospitals. Longer-term follow-up in larger number of patients will improve the data on safety and feasibility in developing countries like India.

Factors Associated With Prolonged Mechanical Ventilation and Reventilation in Acute Cervical Spinal Cord Injury Patients

MINI: In this study, respiratory function at the time of extubation can be useful optimal clinical guidelines for weaning and extubation attempts in patients with acute cervical spinal cord injury. Serum thiobarbituric acid-reactive substances level at admission can be a useful predictor for severity in acute cervical patients with spinal cord injury.

STUDY DESIGN

Patients who had suffered from acute blunt cervical spinal cord injury (SCI) and admitted our hospital within 24 hours after injury were included in the study.

OBJECTIVE

We compared the respiratory function and serum reactive oxidative stress (ROS) after acute cervical SCI, and tried to find out the valuable predictors of weaning in patients with acute cervical SCI.

SUMMARY OF BACKGROUND DATA

Ventilation impairment is a major complication of acute cervical SCI. Evidence of oxygen radical formation in secondary injury from animal SCI models demonstrates an immediate postinjury increase in ROS production after SCI. We hypothesize that the serum ROS is associated with the severity of patients with acute cervical SCI.

METHODS

Thirty-eight adult patients who had acute cervical SCI and 58 healthy volunteers were enrolled. Respiratory function at admission, at the time of extubation and at 48 hours after extubation, serum oxidative stress, Injury Severity Score and Japanese Orthopaedic Association score at admission were compared.

RESULTS

The most notable predictor of mechanical ventilation more than 48 hours was serum thiobarbituric acid-reactive substances (TBARS) level at admission (P = 0.027), and the cut-off value of serum TBARS level was 731.7 μmol/L (sensitivity 87.5% and specificity 78.9%). For the reventilation ≤5 days, the notable predictors were respiratory function at the time of extubation (maximal inspiratory pressure, P = 0.040; maximal expiratory pressure, P = 0.020; and tidal volume, P = 0.036) and serum TBARS level at admission (P = 0.013), the cut-off value of serum TBARS level at admission was 762.3 μmol/L (sensitivity 100% and specificity 90.0%).

CONCLUSION

In this study, respiratory function (maximal inspiratory pressure, maximal expiratory pressure, and tidal volume) at the time of extubation can be useful optimal clinical guidelines for weaning and extubation attempts in patients with acute cervical SCI. Serum TBARS level at admission can be a useful predictor for severity in acute cervical SCI patients.

LEVEL OF EVIDENCE

3.

Description of Clinical Characteristics of VAP Patients in MIMIC Database

Background: Ventilator-associated pneumonia (VAP) is a common and serious nosocomial infection of intensive-care units (ICUs). Accurate, timely diagnosis enables early VAP patients to receive appropriate therapies and reduce the occurrence of complication. However, so far clinical datas regarding the epidemiology and mortality of VAP are still limited. Medical Information Mart for Intensive Care (MIMIC) database is a free, open and public resource about ICU research database. MIMIC database is a free, open, public database that collects information on more than 40,000 ICU patients who are predominantly white people. Therefore, the purpose of the present study is to observe and describe the clinical characteristics of VAP patients in ICU from the MIMIC database. Method: A total of 418 patients were enrolled in the study. General information, ventilator use information, microbiology information, antibiotic use information, and some nursing-related information were extracted to describe and analyze the clinical features of VAP patients. Results: The results of the study showed that patients with one or three pathogens were the most. The main pathogens were YEAST (16.71%), STAPH AUREUS COAG+ (11.63%), Staphylococcus, COAGULASE NEGATIVE (8.68%), GRAM NEGATIVE ROD (S) (6.14%), and Pseudomonas aeruginosa (5.73%). Patients using 4 antibiotics were the most. The top five antibiotics in the largest proportion were synthetic antibacterials (24.66%), peptides (20.13%), cephalosporins (19.60%), penicillins (13.54%), and aminoglycosides (5.27%). Conclusion: This study summarizes the common pathogens of VAP and the antibiotics commonly used in the treatment of VAP by describing the clinical information of 418 patients with VAP in the MIMIC database. In clinical treatment, we should pay attention to aseptic operation, develop appropriate antibacterial measures, closely monitor the pathogens of VAP infection, and use antibiotics in a timely manner to control the occurrence and development of VAP.

Ventilator Dependence Risk Score for the Prediction of Prolonged Mechanical Ventilation in Patients Who Survive Sepsis/Septic Shock with Respiratory Failure

We intended to develop a scoring system to predict mechanical ventilator dependence in patients who survive sepsis/septic shock with respiratory failure. This study evaluated 251 adult patients in medical intensive care units (ICUs) between August 2013 to October 2015, who had survived for over 21 days and received aggressive treatment. The risk factors for ventilator dependence were determined. We then constructed a ventilator dependence (VD) risk score using the identified risk factors. The ventilator dependence risk score was calculated as the sum of the following four variables after being adjusted by proportion to the beta coefficient. We assigned a history of previous stroke, a score of one point, platelet count less than 150,000/μL a score of one point, pH value less than 7.35 a score of two points, and the fraction of inspired oxygen on admission day 7 over 39% as two points. The area under the curve in the derivation group was 0.725 (p < 0.001). We then applied the VD risk score for validation on 175 patients. The area under the curve in the validation group was 0.658 (p = 0.001). VD risk score could be applied to predict prolonged mechanical ventilation in patients who survive sepsis/septic shock.

Clinical factors associated with weaning failure in patients requiring prolonged mechanical ventilation

BACKGROUND

For patients requiring prolonged mechanical ventilation (PMV), weaning is difficult and mortality is very high. PMV has been defined recently, by consensus, as constituting ≥21 consecutive days of mechanical ventilation (MV) for ≥6 hours per day. This study aimed to evaluate the clinical factors predicting weaning failure in patients undergoing PMV in medical intensive care unit (ICU).

METHODS

We retrospectively reviewed the clinical and laboratory characteristics of 127 patients who received MV for more than 21 days in the medical ICU at Chonnam National University Hospital in South Korea between January 2005 and December 2014. Patients who underwent surgery or experienced trauma were excluded from this study.

RESULTS

Among the 127 patients requiring PMV, 41 (32.3%) were successfully weaned from MV. The median age of the weaning failure group was higher than that of the weaning success group (74.0 vs. 70.0 years; P=0.003). The proportion of male patients was 58.5% in the weaning success group and 72.1% in the weaning failure group, respectively. The most common reasons for ICU admission were respiratory causes (66.1%) followed by cardiovascular causes (16.5%) in both groups. ICU mortality and in-hospital mortality rates were 55.1% and 55.9%, respectively. In the multivariate analysis, respiratory causes of ICU admission [odds ratio (OR), 3.98; 95% confidence interval (CI), 1.29-12.30; P=0.016] and a high sequential organ failure assessment (SOFA) score on day 21 of MV (OR, 1.47; 95% CI, 1.17-1.85; P=0.001) were significantly associated with weaning failure in patients requiring PMV. The area under the receiver operating characteristic (ROC) curve of the SOFA score on day 21 of MV for predicting weaning failure was 0.77 (95% CI, 0.67-0.87; P=0.000).

CONCLUSIONS

Respiratory causes of ICU admission and a high SOFA score on day 21 of MV could be predictive of weaning failure in patients requiring PMV.

An Overview of the Predictor Standard Tools for Patient Weaning from Mechanical Ventilation

Most patients staying in the intensive care unit (ICU) require respiratory support through a ventilator. Since prolonged mechanical ventilation and weaning from the ventilator without criteria or at the inappropriate time can result in many complications, it is required that patients be weaned off the ventilator as soon as possible. This study was conducted to investigate a few standard tools that predict successful and timely weaning of patients from the ventilator. In the literature, SOFA and APACHE II scores, along with various tools, including Burn, Morganroth, and Corgian, have been used in weaning patients from the ventilator. In most of these studies, the increase or decrease in the APACHE II score was correlated with the patient’s weaning time, and this score could be used as a criterion for weaning. Several authors have expressed their belief that the SOFA score in the ICU is a good indicator of the prognosis of patient’s weaning from the ventilator, length of stay, mortality, and rate of recovery. Several studies have compared SOFA and APACHE II scores and have shown that there is a positive correlation between the SOFA and APACHE II scores and that both mortality and dependence on the ventilator are related to these two scores. Another tool is Burn’s weaning program. A higher Burn score indicates successful weaning off of the ventilator, successful extubation, lower length of mechanical ventilation, and shorter stay in the hospital. However, the capabilities of the Morganroth scale and the Gluck and Corgian scoring systems were evaluated only for successful weaning off of the ventilator, and a decrease in the Morganroth and Gluck scores indicated successful weaning.

Predictive Factors of Ventilator Dependency after Colon and Rectal Surgery

There is limited data analyzing ventilator dependency by operative diagnoses and types of the procedures performed in colorectal surgery. We sought to identify predictive factors of ventilator dependency in colorectal surgery and investigate complication rates across various colorectal procedures. The National Surgical Quality Improvement Program database was used to examine the clinical data of patients with ventilator dependency for more than 48 hours after colorectal resection during 2005–2013. Multivariate regression analysis was performed to identify predictors of ventilator dependency. A total of 219,716 patients who underwent colorectal resection were identified. The rate of ventilator dependency was 3.9 per cent. The rate varied significantly based on patient diagnosis; with the highest rate seen in patients with acute mesenteric ischemia (25.9%). The highest risk of ventilator dependency according to the patients indication of surgery, type of the procedure, and preoperative factors exist in lower gastrointestinal bleeding [adjusted odds ratio (AOR): 77.44, P < 0.01], total colectomy (AOR: 1.58, P = 0.04), and American Society of Anesthesiologists classification of three or greater (AOR: 2.52, P < 0.01). Also, serum albumin level (AOR: 0.67, P < 0.01) seems to be associated with ventilator dependency. The overall rate of ventilator dependency is 3.9 per cent in colorectal surgery. However, depending on the indication for surgery, rates can be as high as 25.9 per cent. American Society of Anesthesiologist score can predict the risk of postoperative ventilator dependency in patients undergoing colorectal surgery. Serum albumin level is reversely associated with postoperative ventilator dependency.

Sequential oxygenation index and organ dysfunction assessment within the first 3 days of mechanical ventilation predict the outcome of adult patients with severe acute respiratory failure

OBJECTIVE

To determine early predictors of outcomes of adult patients with severe acute respiratory failure.

METHOD

100 consecutive adult patients with severe acute respiratory failure were evaluated in this retrospective study. Data including comorbidities, Sequential Organ Failure Assessment (SOFA) score, Acute Physiological Assessment and Chronic Health Evaluation II (APACHE II) score, PaO2, FiO2, PaO2/FiO2, PEEP, mean airway pressure (mPaw), and oxygenation index (OI) on the 1st and the 3rd day of mechanical ventilation, and change in OI within 3 days were recorded. Primary outcome was hospital mortality; secondary outcome measure was ventilator weaning failure.

RESULTS

38 out of 100 (38%) patients died within the study period. 48 patients (48%) failed to wean from ventilator. Multivariate analysis showed day 3 OI (P=0.004) and SOFA (P=0.02) score were independent predictors of hospital mortality. Preexisting cerebrovascular accident (CVA) (P=0.002) was the predictor of weaning failure. Results from Kaplan-Meier method demonstrated that higher day 3 OI was associated with shorter survival time (log-Rank test, P<0.001).

CONCLUSION

Early OI (within 3 days) and SOFA score were predictors of mortality in severe acute respiratory failure. In the future, prospective studies measuring serial OIs in a larger scale of study cohort is required to further consolidate our findings.