General Surgical Intensive Care Unit Research Articles

Microbiology, resistance patterns, and risk factors of mortality in ventilator-associated bacterial pneumonia in a Northern Thai tertiary-care university based general surgical intensive care unit.

BackgroundVentilator-associated pneumonia (VAP) occurrence, causative pathogens, and resistance patterns in surgical intensive care units (SICU) are different between Western and developing Asian countries. In Thailand, resistant organisms have progressively increased in the last decade. However, the evidence describing causes of VAP and its outcomes, especially secondary to resistant pathogens, in Asian developing countries’ SICUs is very limited. Therefore, the objective of this study was to describe the incidence, pathogen characteristics, and risk factors that impact mortality and patient survival following VAP in a tertiary Northern Thai SICU.MethodsBetween 2008 and 2012, VAP occurred in a total of 150 patients in Chiang Mai University’s general SICUs (6.3±2.8 cases per 1,000 mechanical ventilator days). The following clinical data were collected from 46 patients who died and 104 patients who survived: microbiologic results, susceptible patterns, and survival status at hospital discharge. Antimicrobial susceptibility patterns were classified as susceptible, multidrug resistant (MDR), extensively drug resistant (XDR), and pan-drug resistant (PDR). The hazard ratio (HR) was calculated for risk factor analysis.ResultsRegarding the microbiology, gram negative organisms were the major pathogens (n=142, 94.7%). The first three most common organisms were Acinetobacter baumannii (38.7% of all organisms, mortality 41.4%), Klebsiella pneumoniae (17.3%, mortality 30.8%), and Pseudomonas aeruginosa (16.7%, mortality 16%) respectively. The most common gram positive organism was Staphylococcus aureus (4.0%, mortality 50%). The median day of VAP occurrence were significantly different between the three groups (P<0.01): susceptible (day 4), MDR (day 5), and XDR (day 6.5). Only half of all VAP cases were caused by susceptible organisms. Antibiotic resistance was demonstrated by 49.3% of the gram negative organisms and 62.5% of the gram positive organisms. Extensive drug resistance was evident only in Acinetobacter baumannii (30.6%) and Pseudomonas aeruginosa (1.3%). No pan-drug resistance was found during surveillance. The significant HR risk factors were age (P=0.03), resistant organisms (P=0.04), XDR (P=0.02), and acute physiology and chronic health evaluation II score (<0.01). Acinetobacter baumannii (P=0.06) and intubation due to severe sepsis (P=0.08) demonstrated a trend toward a significant increase in the HR. On the other hand, there were significantly decreased HRs in trauma patients (P=0.01). Initial administration of appropriate antibiotic therapy had a tendency toward a significant decrease in the HR (P=0.08).ConclusionGram negative organisms were the primary cause of bacterial VAP in Chiang Mai University’s general SICU. Resistant strains were present in half of all VAP cases and were associated with the day of VAP onset. Regarding risk factors, age, acute physiology, chronic health evaluation II score, resistant organisms (especially XDR), and being a non-trauma patient increased the risk of mortality.

Effect of nasal high flow for postoperative respiratory failure: a prospective observational study

We studied the effect of nasal high flow (NHF) for postoperative respiratory failure after extubation in our general surgical ICU. Recently some studies have reported that NHF improves oxygenation and reduces respiratory rate. However, the usefulness of NHF in the general surgical ICU has not been fully determined.

Early acute kidney injury in nonsepsis, noncardiac surgical patients admitted to a general surgical ICU

Perioperative AKI is a significant factor determining morbidity/mortality in surgical patients. We sought to determine the prevalence and risk factors of early AKI (within 72 hours of ICU admission) in nonsepsis, noncardiac surgical patients admitted to the general surgical ICU.

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Introduction: Heparin Induced Thrombocytopenia (HIT) in critically ill patients remains associated with increased morbidity and mortality. Yet, the burden of this disease in the intensive care unit (ICU) remains poorly understood. We sought to clarify the incidence of HIT in ICU patients. Hypothesis: HIT occurs infrequently in non-cardiac surgery ICU patients. Methods: We performed a prospective observational study in consecutive ICU patients who underwent HIT antibody testing (August 2009 – March 2012). The decision to pursue HIT diagnostically was left to the primary team. The enzyme immunoassay served as the initial screening test for HIT and by convention an optical density > 0.4 defined a positive test. The final diagnosis of HIT was confirmed by a serotonin release assay (SRA) which was performed in a central lab in all subjects. The incidence of HIT represented our primary endpoint. We then compared rates of HIT in various patient populations. Results: The cohort consisted of 218 subjects (mean age: 62.5 +/- 17.1; male gender: 56.0%). An SRA was positive and the diagnosis of HIT confirmed in 3.2% of patients tested. Physicians were more likely to order HIT in the surgical (SICU) compared to the medical service (67.5% vs 32.5%). HIT was diagnosed in 1.1% of the medical ICU patients tested vs 4.7% of the surgical ICU patients (p=0.17). Among the surgical population diagnosed with HIT, 83.3% had undergone cardiovascular surgery prior to the development of HIT. Coronary artery bypass grafting (CABG) was the most common cardiovascular surgery that predisposed to HIT (49.6%). In all non-cardiac surgery ICU patients, HIT occurred in 0.00%. Conclusions: HIT remains rare in the ICU, particularly in the general medical-surgical ICU patient population. The highest burden of this disease in the ICU is associated with those who undergo cardiovascular surgery. More importantly, patients who undergo CABG have higher risk than other general surgical ICU patients. Given the low prevalence of HIT in the non-cardiac ICU patient population, testing for HIT should only be pursued if the pre-test probability for HIT is high.

ICU scoring systems: which one to use in patients with sepsis?

Disease-severity scoring systems have been developed for stratification of ICU patients. These systems have been tested and validated in various general medical and surgical ICU patients. However, the validity and efficacy of these systems, especially the newer generation, has not been assessed in patients with sepsis, which is the commonest indication for admission to a medical ICU. Hence, we conducted this study to assess the performance of various ICU scoring systems - Acute Physiology and Chronic Health Evaluation (APACHE) II, III, IV; Simplified Acute Physiology Score (SAPS) II, III; Mortality Prediction Model (MPM) II0, III0; and Sequential Organ Failure Assessment (SOFA) scores - in septic patients admitted to a medical ICU.

Factors influencing enoxaparin anti-Xa activity in surgical critically ill patients

Study ObjectiveThe objectives of the present study were to describe the incidence of low anti-Xa levels defined as below 0.1 IU/mL in a general surgical intensive care unit population and to evaluate factors independently influencing anti-Xa activity. DesignA prospective study was undertaken. SettingThirty-six patients admitted to a general intensive care unit and receiving subcutaneous (SC) enoxaparin 30 mg twice daily for thromboprophylaxis between November 2003 and August 2005 were included in the study. Measurements and Main ResultsAfter reaching steady state, anti-Xa activity was determined by chromogenic assay at 0, 3, 6, and 9 hours after injection. Anti-Xa levels below 0.1 IU/mL at any time were considered subtherapeutic. Areas under the curve (AUCs) for a 12-hour dosing interval were estimated. Factors influencing anti-Xa AUC were evaluated using linear regression. Two patients (5.6%) did not attain therapeutic levels defined as anti-Xa more than 0.1 IU/mL at 3 hours post dose. Median AUC was 1.84 IU·h/mL (interquartile range, 1.47 IU·h/mL). In the linear regression analysis, sex and creatinine clearance were significant predictors of anti-Xa AUC0-12h levels. ConclusionIn the study, prophylactic SC enoxaparin in critically ill patients at the current 30 mg SC twice daily dosage attained an anti-Xa level more than 0.1 U/mL in nearly all patients. In addition, low creatinine clearances and female sex are associated with higher anti-Xa activity AUC0-12h.

Fever in the Critically Ill

Fever is common among patients admitted to intensive care units (ICUs). In spite of the frequency of its occurrence, the biological mechanisms regulating the initiation and progression of fever are poorly understood. In addition, there are few large studies reporting on the epidemiology and etiology of fever in general medical and surgical ICU patients. Current evidence suggests that the development of high fever by patients admitted to ICUs with a medical admission diagnosis is associated with an increased risk of death. The decision to treat fever should therefore be obvious, but several lines of evidence argue against temperature-lowering strategies. Furthermore, the use of different temperature control strategies in febrile patients without acute brain injury or acute myocardial infarction is guided by a paucity of randomized clinical trials and by a lack of understanding of the biology of the induction and control of fever. As such, a review of the epidemiology, molecular mechanisms, and immunology of fever as well as the evidence behind management of fever in the critically ill is pertinent to all critical care practitioners.

Mixed fibers diet in surgical ICU septic patients.

Diarrhea commonly occurs in surgical critically ill patients, especially septic patients and fiber formulas have been reported to improve diarrhea. Most reports have used soluble or insoluble fiber exclusively, while the effects of a mixed fiber diet remain unclear. This study compares diarrhea scores between mixed-fiber and non-fiber diets in surgical septic patients receiving broad spectrum antibiotics. We conducted a prospective randomized control double blind study in a general surgical ICU. Patients who received broad spectrum antibiotics and no contraindication to enteral feeding were randomly allocated to a fiber or non-fiber diet for up to 14 days. Nutritional delivery and diarrhea scores were recorded daily. Intention to treat analysis was performed. Thirty-four patients were enrolled in the study, 17 in the fiber group and 17 in non-fiber group. These two patients groups were similar in demographics, disease severity, nutritional status, cause of sepsis and total feeding per day. The proportion of patients with diarrhea score ≥12 was higher in the non-fiber group than in the fiber group, but the difference was not statistically significant [8/17 (47.06%) vs. 4/17(23.53%); p=0.15]. However, the fiber group had a lower mean diarrhea score (fiber vs. non-fiber = 3.6 ± 2.3 vs. 6.3 ± 3.6; p=0.005), as well as a lower global diarrhea score from the generalized estimation equation model for repeated measurement [Coefficient -3.03 (95%CI= -5.03 to -0.92); p=0.005]. In summary, a mixed fiber diet formula can reduce the diarrhea score in surgical critically ill septic patients who received broad spectrum antibiotics.

Decolonization therapy in infection control

Hospital acquired infections (HAIs) are costly and are a leading cause of hospital death. Many HAIs originate from patients' own flora. Decolonization strategies aim to prevent infection from these endogenous sources. This review focuses on data published from 2008 to the present on effectiveness and safety of patient decolonization strategies for preventing HAIs. Surgical site infections (SSIs): recent literature confirms that Staphylococcus aureus decolonization to prevent SSIs is effective in cardiac and likely certain orthopedic surgery patients. The benefit to general surgery patients is not clear. Ventilator-associated pneumonia (VAP): although past studies have found that decolonization benefits cardiac surgery patients, recent studies have not found the same benefit in general medical and surgical ICU patients. Blood stream infection (BSI): mupirocin on hemodialysis catheter exit sites is protective against BSI. Chlorhexidine and selective decontamination of the digestive tract have been studied as ways to decrease ICU BSI, but their roles are still being clarified. Methicillin-resistant Staphylococcus aureus (MRSA)-specific decolonization: evidence of benefit to MRSA-colonized nonsurgical patients is lacking. Decolonization is likely an effective infection-control strategy for hemodialysis catheter-associated infections and in cardiac and orthopedic surgery patients. More research is needed on its role in other settings.

Prognostic accuracy of severity score for prolonged ICU length of stay &gt;72 hours in general surgical ICU: a prospective study

Prolonged ICU stay is associated with high morbidity, mortality and costs [1,2]. Prediction of this prolonged stay will provide information for physician and family and help with resource allocation. Even though, available severity scoring system ie. APACHE II, APACHE III, MPM, SAPS II, MODS scores are widely accepted for evaluating outcomes in the ICU population. But these models might be inaccurate when apply to subpopulation and might not predict prolonged length of stay. The objective of this study was to refine ASA physical status and five severity scores (APACHE II, APACHE III, SOFA, SAPS, MOFS) in order to predict prolonged length of stay in the adults patients admitted to the general surgical ICU.

Factors associated with longer stay on a surgical intensive care unit

The advance in medical care for surgical patients results in older patients, increasing medical problems, and complexities of operations in surgical patients. Therefore, these patients may require a longer stay in the surgical ICU (SICU). The aim of the present study was to evaluate the occurrence, clinical outcome, and predictive risk factors for the longer SICU length of stay in critically ill surgical patients in our general SICU.

Effects of a closed ICU model on a general surgical ICU

A closed model of ICU care is associated with improved outcomes and less resource utilization in mixed medical and surgical ICUs as well as traumatic ICUs. However, most of our country ICUs use an open model, especially in surgical ICUs due to lack of specialized physicians. The aims of this study are to compare the effects of closed and open models on ICU mortality and length of ICU stay.

Evaluation of SOFA-based models for predicting mortality in the ICU: A systematic review

IntroductionTo systematically review studies evaluating the performance of Sequential Organ Failure Assessment (SOFA)-based models for predicting mortality in patients in the intensive care unit (ICU).MethodsMedline, EMBASE and other databases were searched for English-language articles with the major objective of evaluating the prognostic performance of SOFA-based models in predicting mortality in surgical and/or medical ICU admissions. The quality of each study was assessed based on a quality framework for prognostic models.ResultsEighteen articles met all inclusion criteria. The studies differed widely in the SOFA derivatives used and in their methods of evaluation. Ten studies reported about developing a probabilistic prognostic model, only five of which used an independent validation data set. The other studies used the SOFA-based score directly to discriminate between survivors and non-survivors without fitting a probabilistic model. In five of the six studies, admission-based models (Acute Physiology and Chronic Health Evaluation (APACHE) II/III) were reported to have a slightly better discrimination ability than SOFA-based models at admission (the receiver operating characteristic curve (AUC) of SOFA-based models ranged between 0.61 and 0.88), and in one study a SOFA model had higher AUC than the Simplified Acute Physiology Score (SAPS) II model. Four of these studies used the Hosmer-Lemeshow tests for calibration, none of which reported a lack of fit for the SOFA models. Models based on sequential SOFA scores were described in 11 studies including maximum SOFA scores and maximum sum of individual components of the SOFA score (AUC range: 0.69 to 0.92) and delta SOFA (AUC range: 0.51 to 0.83). Studies comparing SOFA with other organ failure scores did not consistently show superiority of one scoring system to another. Four studies combined SOFA-based derivatives with admission severity of illness scores, and they all reported on improved predictions for the combination. Quality of studies ranged from 11.5 to 19.5 points on a 20-point scale.ConclusionsModels based on SOFA scores at admission had only slightly worse performance than APACHE II/III and were competitive with SAPS II models in predicting mortality in patients in the general medical and/or surgical ICU. Models with sequential SOFA scores seem to have a comparable performance with other organ failure scores. The combination of sequential SOFA derivatives with APACHE II/III and SAPS II models clearly improved prognostic performance of either model alone. Due to the heterogeneity of the studies, it is impossible to draw general conclusions on the optimal mathematical model and optimal derivatives of SOFA scores. Future studies should use a standard evaluation methodology with a standard set of outcome measures covering discrimination, calibration and accuracy.

1-Microgram-cosyntropin test for the evaluation of adrenal insufficiency in critically ill surgical patients

1-Microgram-cosyntropin test for the evaluation of adrenal insufficiency in critically ill surgical patients

Effectiveness of a spontaneous breathing trial with a low-pressure support protocol for liberation from the mechanical ventilator in a general surgical ICU

Discontinuing patients from mechanical ventilation is an important problem in ICUs. The aim of this study is to compare the effectiveness between a spontaneous breathing trial with a low-pressure support protocol and a liberal or nonprotocol-directed method.

152: Glucose control in a surgical intensive care unit after orthotopic liver transplantation

Introduction: End-stage liver disease and the process of orthotopic liver transplantation (OLT) is associated with insulin resistance and hyperglycemia. Maintenance of euglycemia has been established as the standard of care in the non-transplant critical care population. The efficacy and safety of euglycemia protocols in OLT patients has not been established. We hypothesized that a computerized euglycemia protocol is safe and effective in the post-OLT population. Methods: All critically ill, ventilated patients were prospectively placed on a euglycemic protocol that uses an automated, computerized tool. Blood glucose (BG) samples and insulin infusion rates were recorded in a protocol database every two hours. After obtaining IRB approval, all patients undergoing OLT were compared to the non-OLT surgical intensive care unit (SICU) patients. Efficacy was defined as number BG values between 80-110 (in mg/dL). Safety was defined as prevention of hypoglycemia (BG<60). Differences between groups were assessed using Fisher’s exact test for categorical variables, and Wilcoxon’s rank-sum test for continuous variables. Statistical significance was defined as p<0.05. Results: Clinical data was available for a total of 560 patients who were divided into two groups: post-OLT (group 1, n=100) and non-OLT SICU patients (group 2, n=460). There were a total of 5899 data points for group 1, 26,644 for group 2. There were no differences between the groups with regard hospital length of stay (LOS), SICU LOS, and APACHE II scores. There were a greater number of males in group 1 (72% vs 58.3%, p<0.05). Mortality was higher in group 2 (4% vs 14.6%, p<0.05). Predicted mortality on the basis of APACHE II scores was 25% for both groups. Group 2 had more BG values in range in the first 24 hours (33.2% vs 22.4%, p<0.05). By 48 and 72 hours, number of BG values in range were similar. Hypoglycemic events (defined by BG<60) and severe hypoglycemic events (BG<40) were similar between the groups. Hyperglycemic events (defined by BG>150 and BG>200) were higher in group 1 over the entire study period (p<0.05). Glucose control is shown in the Table below. Conclusions: Maintenance of euglycemia is as safe following orthotopic liver transplantation as it is in the general SICU patient population, with no increase in the number of hypoglycemic events. Maintenance of euglycemic control was less efficacious for the first 24 hours in post-OLT patients, but was statistically equivocal at 48 and 72 hours. While safe, the benefit of maintaining euglycemia in liver transplant patients requires further study. Tabled 1Glucose control in critically ill surgical population Measurement Group 1 Group 2 p Total% BG 80-110 34.69 39.84 0.0083 % BG 80-110 1st 24 hours 22.40 33.19 <0.0001 % BG 80-110 1st 48 hours 32.86 37.21 0.082 % BG 80-110 1st 72 hours 33.94 38.24 0.0738 % BG <40 0.06 0.15 02144 % BG <60 0.71 1.31 0.4167 % BG >/= 150 21.55 14.91 <0.0001 % BG >= 200 12.38 5.55 <0.0001 BG=Blood Glucose BG values in mg/dL Group 1=OLT Group 2=non-OLT Open table in a new tab

Risk Factors for Mortality of Nosocomial Bacteraemia in Intensive Care Units

Objective: The aim of this study was to follow critically ill patients prospectively in intensive care units (ICUs) to determine risk factors for mortality and outcome associated with nosocomial bacteraemia (NB). Subjects and Methods: A case-control study of 176 patients was conducted to identify the risk factors for mortality of NB in ICU patients. The study was performed in emergency, surgical and general surgical ICUs with 23 beds during a 15-month period. A total of 1,450 patients were admitted to the ICUs during the study period. The USA Center for Disease Control and Prevention definitions were used to diagnose nosocomial infections. Nosocomial bacteraemia was defined as the isolation of one or more organisms from blood cultures taken at least 48 h after admission, which were not related to a problem present on admission. An assessment of whether the isolated organisms represented true bacteraemia rather than contamination was made by clinical or laboratory evidence of infection. Results: A total of 214 bacteraemia episodes were found in the 176 patients (64 female, 112 male; 51.3 ± 21.3 years old), 90 of whom died and 86 survived. The bacteraemia rate was 12.1%. The most common etiological agents of bacteraemia were Klebsiella pneumoniae: 46 (21.5%), methicillin-resistant Staphylococcus aureus: 46 (21.5%), Pseudomonas aeruginosa: 32 (14.9%), and Escherichia coli: 20 (9.3%). Multivariate analysis showed that the requirement of mechanical ventilation for more than 7 days (p < 0.001), total parenteral nutrition (p = 0.034), inotropic drug (p < 0.001), and increased creatinine level (p = 0.034) were independent risk factors for mortality of NB in ICUs. Conclusions: Nosocomial infections caused by Gram-negative bacteria continue to be one of the major sources of morbidity and mortality.

Carnitine Deficiency, Mitochondrial Metabolism, and Abnormal Response to Anesthetics

Jikei University, School of Medicine, Tokyo, Japan. uezono@jikei.ac.jpI appreciate Drs. Weinberg and Baughman for their interest in our Letter to the Editor.1They call attention to an underlying carnitine deficiency associated with an increased risk of unexpected metabolic acidosis and cardiovascular collapse triggered by drugs that may potentially induce mitochondrial dysfunction. Acquired carnitine deficiency may be caused by cirrhosis, chronic renal failure, malabsorption syndrome, renal tubular acidosis, and certain drugs that are conjugated carnitine (e.g. , valproate, zidovudine), which are not uncommon in the intensive care unit setting.2Of particular note, patients receiving valproate may develop low concentrations of free carnitine in plasma, thus rendering them at risk for development of mitochondrial β-oxidation defects when propofol is used for sedation. This may partly explain why many case reports of so-called propofol infusion syndrome have been reported from patients in the neurosurgical intensive care unit but not the general surgical intensive care unit.3If this is the case, I suspect that l-carnitine therapy may reverse clinical manifestations of propofol infusion syndrome.Jikei University, School of Medicine, Tokyo, Japan. uezono@jikei.ac.jp

Identification and characterisation of the high-risk surgical population in the United Kingdom

IntroductionLittle is known about mortality rates following general surgical procedures in the United Kingdom. Deaths are most common in the 'high-risk' surgical population consisting mainly of older patients, with coexisting medical disease, who undergo major surgery. Only limited data are presently available to describe this population. The aim of the present study was to estimate the size of the high-risk general surgical population and to describe the outcome and intensive care unit (ICU) resource use.MethodsData on inpatient general surgical procedures and ICU admissions in 94 National Health Service hospitals between January 1999 and October 2004 were extracted from the Intensive Care National Audit & Research Centre database and the CHKS database. High-risk surgical procedures were defined prospectively as those for which the mortality rate was 5% or greater.ResultsThere were 4,117,727 surgical procedures; 2,893,432 were elective (12,704 deaths; 0.44%) and 1,224,295 were emergencies (65,674 deaths; 5.4%). A high-risk population of 513,924 patients was identified (63,340 deaths; 12.3%), which accounted for 83.8% of deaths but for only 12.5% of procedures. This population had a prolonged hospital stay (median, 16 days; interquartile range, 9–29 days). There were 59,424 ICU admissions (11,398 deaths; 19%). Among admissions directly to the ICU following surgery, there were 31,633 elective admissions with 3,199 deaths (10.1%) and 24,764 emergency admissions with 7,084 deaths (28.6%). The ICU stays were short (median, 1.6 days; interquartile range, 0.8–3.7 days) but hospital admissions for those admitted to the ICU were prolonged (median, 16 days; interquartile range, 10–30 days). Among the ICU population, 40.8% of deaths occurred after the initial discharge from the ICU. The highest mortality rate (39%) occurred in the population admitted to the ICU following initial postoperative care on a standard ward.ConclusionA large high-risk surgical population accounts for 12.5% of surgical procedures but for more than 80% of deaths. Despite high mortality rates, fewer than 15% of these patients are admitted to the ICU.

Diabetic and nondiabetic hyperglycemia in the ICU

Summary Hyperglycemia is a common feature in critically ill patients, whether they are diabetic or not, and it is associated with unfavorable outcome. The more severe the underlying disease, the more important the hyperglycemia appears to be although, we still cannot define whether hyperglycemia is just a marker of the severity of the acute illness or rather an active contributor to poor outcome. The review of the literature on this subject published from 2001 up today conveys a massive amount of information the interpretation of which is equivocal, due to the heterogeneity of patients (nondiabetic vs. diabetic, medical intensive care unit (ICU) pts vs. surgical ICU pts) and of interventions (dose and modality of insulin infusion). The association between high glucose level and mortality is strong in critically ill patients without a previous history of diabetes. Admission hyperglycemia seems to be an independent risk factor of in-hospital mortality in patients both with and without diabetes in cardiac, cardiothoracic and neurosurgical ICUs. No data are still available on general surgical ICU patients. Tight control of blood glucose levels has been demonstrated to improve outcome in both diabetic and nondiabetic critically ill patients. In surgical ICUs, tight glucose control improves mortality and reduces morbidity only among patients admitted in ICU for more than 5 days, while outcome is not improved in patients who stay in ICU for less than 3 days. However, it is not yet understood if such favorable effect is secondary to glucose control itself or if insulin plays a part, by means of its nonglucose, anabolic effects. More randomized controlled trials are needed, addressing specific issues—such as the optimal target glucose concentration and the most effective insulin regimen—especially in the general surgical patient.