Hazards and Intensive Care Unit Economic Burden of Cigarette Smoking on Critically Ill Surgical Patients: Analysis of the THAI-SICU Study.

Objective: Cigarette smoking is not only has detrimental effects on the respiratory system but also contributes to development of atherosclerosis and inflammatory vascular reactions. We hypothesized whether smoking is associated with increased risk of acute respiratory distress syndrome (ARDS), systemic inflammatory response syndrome (SIRS), sepsis, distant organ dysfunctions, and the increase of total cost of surgical intensive care unit (SICU) in critically ill surgical patients. Material and Method: We performed analysis using the THAI-SICU data, a prospective, observational, multicenter study in patients who admitted to SICU in nine university-based hospitals in Thailand. The patients were categorized into 3 groups based on their smoking histories, which were 1) never smoked, 2) former smoker, and 3) current smoker. The primary outcome was probability of ARDS and the secondary outcomes included incidences of SIRS, sepsis, distant organ dysfunction (included acute kidney injury (AKI) and acute myocardial infarction (AMI)), total SICU cost, and 28-day mortality Results: A total of 4,652 patients had complete data of smoking and were analyzed. The smoking status was never smoked (2,947 patients), former smokers (1,148 patients), and current smokers (557 patients). Compared to current smokers and former smokers, patients who had never smoked had significantly lower proportion of patients with chronic obstructive pulmonary disease (p<0.01) and had significantly higher PaO2/FiO2 ratio on SICU admission (p = 0.02). Compared to patients who had never smoked and former smokers, current smokers had significantly higher probability of ARDS (p = 0.003), higher incidence of SIRS (p = 0.006), and AKI (p<0.001), after adjustment for age, gender, APACHE II score, and patients' pre-existing diseases. We found that every 1-pack year of cigarette smoking increased risk of ARDS with a hazard ratio of 1.02 (95% CI 1.01-1.03, p = 0.001). There was no difference in incidence of sepsis, AMI, and 28-day mortality among three groups of patients. Current smokers had significantly higher SICU cost, followed by former smokers, and patients who had never smoked (p = 0.02). Conclusion: In critically ill surgical patients, we found dose-response association between smoking pack year and risk of ARDS. Compared to patients who had never smoked and former smokers, current smokers had significantly higher probability of ARDS, higher incidence of SIRS, AKI, and higher total SICU cost. Our findings demonstrated harm of cigarette smoking in critically ill surgical patients who admitted to SICU.

Prevalence and Impact of Overweight and Obesity in Critically Ill Surgical Patients: Analysis of THAI-SICU Study.

Objective: To investigate the prevalence of overweight and obesity, and their impacts in patients admitted to a surgical intensive care unit (SICU) in Thailand. Material and Method: We conducted an analysis using the THAI-SICU database. All 4,579 patients who had weight and height measured were classified into four groups using body mass index (BMI) based on the World Health Organization criteria, which were 1) underweight (BMI <18.5 kg/m2), 2) normal BMI (BMI 18.5-24.9 kg/m2), 3) overweight (BMI 25-29.9 kg/m2), and 4) obese (BMI >30 kg/m2) groups. Primary outcome was prevalence of overweight and obesity. Secondary outcomes were 28-day survival, and SICU outcomes between four patient groups. Results: There were 768 (16.8%) of underweight, 2,624 (57.3%) of normal BMI, 858 (18.7%) of overweight, and 329 (7.2%) of obese patients. Compared to other three patient groups, obese had the highest 28-day survival (log-rank, p<0.001), lowest incidence of systemic inflammatory response syndrome (SIRS) (underweight 41.1%, normal BMI 35.6%, overweight 34.5%, and obese 29.5%; p = 0.001), and lowest incidence of new infection (underweight 27.3%, normal BMI 23.3%, overweight 24.5%, and obese 20.4%; p = 0.047). After adjustment for related confounding factors, we found that every one unit increasing of BMI associated with lower risk of hospital mortality [odds ratio, OR, 0.97(95% confidence interval, CI, 0.94-0.99); p = 0.04], higher risk of acute respiratory distress syndrome (ARDS) [OR 1.06 (95% CI 1.03-1.08); p<0.001], and higher risk of intra-abdominal hypertension (IAH) [OR 1.06 (95% CI 1.03-1.09); p<0.001]. Conclusion: The prevalence of overweight and obesity in Thai critically ill surgical patients were 18.7% and 7.2%, respectively. Compared to patients with lower BMI, patients with higher BMI had significantly lower mortality but greater risk of ARDS and IAH.

Central Venous Oxygen Saturation Is not a Predictor of Extubation Success after Simple Weaning from Mechanical Ventilation in Post-Cardiac Surgical Patients.

Objective: Central venous oxygen saturation (ScvO2) is a measure of the balance between oxygen delivery and consumption. The purpose of this study was to evaluate whether ScvO2 predict weaning success and extubation in simple weaning postcardiac surgical patients. Material and Method: We prospective observed critically ill post-cardiac surgical patients who were intubated and mechanically ventilated between December 2011 and October 2014. All enrolled patients underwent a spontaneous breathing trial (SBT) before extubation. Arterial and venous blood gas analysis, and hemodynamic and ventilator variables were recorded at the beginning of SBT (T1) and before extubation (T2). Weaning success was defined as successful extubation after SBT without re-intubation within 48 hours. The area under the receiver characteristic curve (ROC) demonstrated the ability to discriminate weaning success. Statistical significance was defined as p<0.05. Results: A total 121 patients were included. Of these, 18 patients (15%) were re-intubation within 48 hours after extubation. There was no statistically significance in age, gender, and type of operations between those who were extubated successfully and those who were re-intubated within 48 hours. Regarding hemodynamic and respiratory parameters, the significant differences were found only in partial arterial oxygen pressure (PaO2; p = 0.048) and PaO2 to oxygen fraction ratio (PF ratio; p=0.048) at T1. There was no difference between the groups in ScvO2 at either T1 or T2. The area under the ROC (95% confidence interval) of ScvO2 was 0.60 (0.47-0.74) and 0.53 (0.39-0.66) at T1 and T2, respectively. Although ScvO2 was combined with rapid shallow breathing index (RSBI), PF ratio and minute volume on the regression model at both T1 and T2, the discrimination ability was not significant increased. Conclusion: ScvO2 or its combination with RSBI, PF ratio and minute volume does not predict successful weaning from mechanical ventilators and extubation in critically ill post-cardiac surgical patients.