Mortality In Surgical Patients Research Articles

Audit of venous thromboembolism prophylaxis administered to general surgical patients undergoing elective and emergency operations at National Hospital, Sri Lanka

Venous thromboembolism (VTE) is a significant global cause for morbidity and mortality of surgical patients. Clinical guidelines written by the National Institute of Clinical Excellence (NICE) in Great Britain is available to manage this problem. The Sri Lanka Health Service currently has no such guidelines. We conducted a retrospective audit of current practice of VTE prophylaxis in general surgical patients having operations at the National Hospital of Sri Lanka (NHSL). Ethical approval was obtained. Clinical records were perused to audit risk assessment and management by clinical teams involved. A data form addressing NICE guidelines was used and statistically analysed. Of 244 cases listed in the theatre register 154 case notes were located. We identified that clinical staff were deficient in obtaining information required to classify patient risk of VTE. Only 13% of cases had a Body Mass Index calculated. Sub optimal records were evident in the surgical, anaesthetic and nursing notes. Majority of cases had one or more risk factors for VTE. Most patients underwent elective surgery under general anaesthesia. 71.4% of patients had an indication for mechanical, pharmacological or both methods for VTE prophylaxis. None of the patients requiring only mechanical or only pharmacological prophylaxis received any. Only 5.9% of patients were correctly administered both forms of prophylaxis when required. Administration of mechanical prophylaxis was not documented in a single case. We suggest changes at an institutional/ individual level. These should aim to improve proper note binding, clinical record keeping, availability of guidelines/ protocols and a multi-disciplinary approach to risk assessment. Hospitals should ensure a minimum standard availability of mechanical prophylaxis. Anaesthetists should cover VTE risk during pre-operative assessment. Mechanical prophylaxis commenced in theatre should be documented in the anaesthetic chart. Post-operative visit should include a risk assessment for ongoing risk of VTE. Measures should be taken to re-audit clinical practice according to set guidelines in future. DOI: http://dx.doi.org/10.4038/slja.v20i1.4272 Sri Lankan Journal of Anaesthesiology 20(1): 23-27 (2012)

Incidence and risk factors for sepsis in surgical patients: A cohort study

PurposeThe aim of the study was to evaluate risk factors for infection and sepsis in surgical patients admitted to the intensive care unit (ICU). Materials and MethodsData were prospectively collected from a cohort of surgical patients from January 2005 to December 2007. We analyzed the incidence of infection and sepsis and certain other variables from the pre-, intra-, and postoperative periods as risk factors for infection and sepsis. ResultsWe studied 625 surgical patients. The mortality rate was 18.2%, and the mean age of the subjects was 53.1 ± 18.8 years. The incidences of severe sepsis and septic shock were 5% and 11.5%, respectively. A multivariate analysis showed that the following variables were associated with sepsis in the postoperative period: urgent surgery (odds ratio, 2.63; 95% confidence interval [CI], 1.50-4.63), fluid resuscitation (odds ratio, 1.90; 95% CI, 1.18-3.05), vasoactive drugs (odds ratio, 2.58; 95% CI, 1.61-4.14), and mechanical ventilation (odds ratio, 5.51; 95% CI, 3.07-9.89). A Sequential Organ Failure Assessment was associated with infection or sepsis upon ICU admission (area under the curve, 0.737 ± 0.019; 95% CI, 0.748-0.825). ConclusionsThis study showed that sepsis has high incidence and mortality in surgical patients admitted to the ICU. Urgent surgeries, mechanical ventilation, fluid resuscitation, and vasoactive drugs in the postoperative period and Sequential Organ Failure Assessment at ICU admission were risk factors for sepsis.

Importance of Pre-Anesthetic Evaluation: Case Report of a Patient with Obstructive Sleep Apnea

The objective of this report was to show the importance of pre-anesthetic assessment in reducing morbidity and mortality of surgical patients and alert to problems and anesthetic care associated with obstructive sleep apnea. This is a 28-year old male patient with class II obesity, sleep apnea, hypertension, referred to the pre-anesthetic outpatient clinic for evaluation of uvuloplasty under general anesthesia. After orientation on sleep apnea, explaining to the patient the risks associated with the procedure, and discussing with the surgeon, we decided to review the surgical indication and postpone the procedure. The pre-anesthetic outpatient clinic is extremely important in reducing morbidity as well as mortality of surgical patients and, especially, in evaluating patients with obstructive sleep apnea, showing to be fundamental for the anesthetic-surgical schedule, orienting conducts to be followed, and interfering positively on patient prognosis.

What is the Optimal Blood Glucose Range to Improve Morbidity and Mortality in Surgical Patients?

What is the Optimal Blood Glucose Range to Improve Morbidity and Mortality in Surgical Patients?

What is the Optimal Blood Glucose Range to Improve Morbidity and Mortality in Surgical Patients?

Ross Tilley Burn Centre, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute and Department of Surgery Division of Plastic SurgeryUniversity of Toronto, Ontario, Canada, [email protected] Disclosure: The author declares there is nothing to disclose.

Perioperative mortality of surgical patients: Record of patients and evaluation of risk factors in the period 2005-9

s and Programme: EUROANAESTHESIA 2011: The European Anaesthesiology Congress: Evidence-based Practice and Quality Improvement

Rationale and study design of PROVHILO - a worldwide multicenter randomized controlled trial on protective ventilation during general anesthesia for open abdominal surgery

BackgroundPost-operative pulmonary complications add to the morbidity and mortality of surgical patients, in particular after general anesthesia >2 hours for abdominal surgery. Whether a protective mechanical ventilation strategy with higher levels of positive end-expiratory pressure (PEEP) and repeated recruitment maneuvers; the "open lung strategy", protects against post-operative pulmonary complications is uncertain. The present study aims at comparing a protective mechanical ventilation strategy with a conventional mechanical ventilation strategy during general anesthesia for abdominal non-laparoscopic surgery.MethodsThe PROtective Ventilation using HIgh versus LOw positive end-expiratory pressure ("PROVHILO") trial is a worldwide investigator-initiated multicenter randomized controlled two-arm study. Nine hundred patients scheduled for non-laparoscopic abdominal surgery at high or intermediate risk for post-operative pulmonary complications are randomized to mechanical ventilation with the level of PEEP at 12 cmH2O with recruitment maneuvers (the lung-protective strategy) or mechanical ventilation with the level of PEEP at maximum 2 cmH2O without recruitment maneuvers (the conventional strategy). The primary endpoint is any post-operative pulmonary complication.DiscussionThe PROVHILO trial is the first randomized controlled trial powered to investigate whether an open lung mechanical ventilation strategy in short-term mechanical ventilation prevents against postoperative pulmonary complications.Trial registrationISRCTN: ISRCTN70332574

High Mortality in Surgical Patients With Do-Not-Resuscitate Orders

To evaluate outcomes of patients who undergo surgery with a do-not-resuscitate (DNR) order. Retrospective cohort study. More than 120 hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program from 2005 to 2008. There were 4128 adult DNR patients and 4128 age-matched and procedure-matched non-DNR patients. Outcomes were occurrence of 1 or more postoperative complications, reoperation, death within 30 days of surgery, total time in the operating room, and length of stay. The χ(2) test was used for categorical variables and t and Wilcoxon tests were used for continuous variables. Multivariate logistic regression was done to determine independent risk factors associated with mortality in DNR patients. Most DNR patients were white (81.5%), female (58.2%), and elderly (mean age, 79 years). Compared with non-DNR patients, DNR patients experienced longer length of stay (36% increase; P<.001) and higher complication (26.4% vs 31%; P<.001) and mortality (8.4% vs 23.1%; P<.001) rates. Nearly 63% of DNR patients underwent nonemergent procedures; they sustained a 16.6% mortality rate. After risk adjustment, DNR status remained an independent predictor of mortality (odds ratio, 2.2; 95% confidence interval, 1.8-2.8). American Society of Anesthesiologists class 3 to 5, age older than 65 years, and preoperative sepsis were among independent risk factors associated with mortality in DNR patients. Surgical patients with DNR orders have significant comorbidities; many sustain postoperative complications, and nearly 1 in 4 die within 30 days of surgery. Do-not-resuscitate status appears to be an independent risk factor for poor surgical outcome.

Incidence and risk factors for sepsis in surgical patients: a cohort study

Purpose: The aim of the study was to evaluate risk factors for infection and sepsis in surgical patients admitted to the intensive care unit (ICU). Materials and Methods: Data were prospectively collected from a cohort of surgical patients from January 2005 to December 2007. We analyzed the incidence of infection and sepsis and certain other variables from the pre-, intra-, and postoperative periods as risk factors for infection and sepsis. Results: We studied 625 surgical patients. The mortality rate was 18.2%, and the mean age of the subjects was 53.1 ± 18.8 years. The incidences of severe sepsis and septic shock were 5% and 11.5%, respectively. A multivariate analysis showed that the following variables were associated with sepsis in the postoperative period: urgent surgery (odds ratio, 2.63; 95% confidence interval [CI], 1.50-4.63), fluid resuscitation (odds ratio, 1.90; 95% CI, 1.18-3.05), vasoactive drugs (odds ratio, 2.58; 95% CI, 1.61-4.14), and mechanical ventilation (odds ratio, 5.51; 95% CI, 3.07-9.89). A Sequential Organ Failure Assessment was associated with infection or sepsis upon ICU admission (area under the curve, 0.737 ± 0.019; 95% CI, 0.748-0.825). Conclusions: This study showed that sepsis has high incidence and mortality in surgical patients admitted to the ICU. Urgent surgeries, mechanical ventilation, fluid resuscitation, and vasoactive drugs in the postoperative period and Sequential Organ Failure Assessment at ICU admission were risk factors for sepsis.

Targeting Hypoxia-induced Inflammation

In the current issue of Anesthesiology, a paper by Kim et al. from the research laboratory of Dr. H. Thomas Lee investigates strategies to dampen ischemia-driven inflammation of the kidneys and subsequent multi-organ failure utilizing experimental models of acute kidney injury (AKI).1 In fact, one of the leading causes of morbidity and mortality in surgical patients is perioperative organ failure, such as occurs in the context of acute kidney injury, liver failure, intestinal or myocardial ischemia, stroke or acute lung injury. A common feature of these perioperative diseases is the presence of hypoxia-induced inflammation.2,3 The relationship between hypoxia and inflammation under these conditions is inter-dependent. For example, exposure to ambient hypoxia - as seen during high-altitude mountaineering - is associated with edema of the lungs or the brain, and systemic inflammatory responses in humans.4,5 Similarly, acute exposure of mice to ambient hypoxia (e.g. 8% of oxygen over 4–8h) leads to increased inflammatory cytokine levels and pulmonary edema.6 Moreover, prolonged donor organ exposure to ischemia during organ transplantation is known to enhance graft inflammation and early graft failure.7,8 For example, the endotoxin-receptor TLR4 is expressed in the donor kidney during kidney transplantation, and TLR4 expression levels increase with prolonged ischemia time. Donor kidneys with a loss-of-function mutation of the TLR4 receptor show attenuated kidney inflammation, and an increased rate of immediate graft function.7 Together, these studies indicate that hypoxia represents an inflammatory stimulus (Figure 1) and suggest that targeting hypoxia-elicited inflammation could represent an important therapeutic approach in perioperative medicine.

Predictors of mortality in surgical patients with Acinetobacter baumannii bacteremia

Acinetobacter baumannii has emerged as an important pathogen of nosocomial infection. The aim of this study was to evaluate the predictors of poor outcome in surgical patients with A baumannii bacteremia. We retrospectively recruited a total of 50 patients who developed A baumannii bacteremia within 2 weeks after surgery during a 113-month period. The primary outcome for this study was all-cause 14-day mortality. Clinical and laboratory data, antimicrobial susceptibility, treatment, and Sequential Organ Failure Assessment (SOFA) score were evaluated as possible predictors of outcome. The 14-day mortality was 20% and there was no association between type of surgery and mortality. The SOFA score was the only independent predictor of 14-day mortality after adjustment for other variables. The calibration was acceptable (Hosmer-Lemeshow χ(2) = 3.65, p = 0.72) and the discrimination was good (area under the receiver operating characteristic curve: 0.80 ± 0.07, 95% confidence interval, 0.67-0.94). We found that a SOFA score ≥ 7 was a significant predictor of 14-day mortality in surgical patients with A baumannii bacteremia. The SOFA score assessed at the onset of bacteremia is a reliable tool for predicting 14-day mortality in surgical patients with A baumannii bacteremia.

Influence of Central Venous Oxygen Saturation on In-hospital Mortality of Surgical Patients

Low central venous oxygen saturation (ScvO₂) indicates an imbalance between cellular oxygen supply and consumption and, consequently, worse prognosis for critical patients. However, it is not clear what the value of this marker in surgical patients. The objective of the present study was to evaluate whether low perioperative ScvO₂ determines a worse prognosis. This is a 6-month observational study carried on in a tertiary hospital. Patients who needed to be in the intensive care unit (ICU) postoperatively, with age ≥ 18 years, who underwent large surgeries, were included. Patients who underwent palliative surgeries and those with severe heart failure were excluded. Levels of ScvO₂ were measured before the surgery, during the procedure, and after the surgery in the ICU. Sixty-six patients were included in this study, but 25.8% of them did not survive. Mean ScvO₂ levels were higher intraoperatively, 84.7 ± 8.3%, than preoperatively and in the ICU, 74.1 ± 7.6% and 76.0 ± 10.5% (p = 0.0001), respectively. However, only preoperative SvcO₂ levels of non-surviving patients were significantly lower than those who survived. By logistic regression, preoperative ScvO₂, OR = 0.85 (95% CI 0.74-0.98) (p = 0.02), was an independent factor of in-hospital mortality. Patients with preoperative ScvO₂ < 70% had greater need of intraoperative blood transfusion (80.0% versus 37.0%, p = 0.001) and volume replacement, 8,000.0 (6,500.0-9,225.0) mL versus 6,000.0 (4,500.0-8,500.0) mL (p = 0.04), with greater chances of postoperative complications (75% versus 45.7%, p = 0.02) and longer time in the ICU, 4.0 (20.0-5.0) days versus 3.0 (1.7-4.0) days (p = 0.02). Intraoperative ScvO₂ levels are higher than those both in the pre- and postoperative period. However, low preoperative ScvO₂ determines worse prognosis.

Malnutrition as a predictor of poor postoperative outcomes in gynecologic cancer patients

Poor nutritional status has been associated with increased postoperative morbidity and mortality in surgical patients. The purpose of this study is to evaluate if decreased nutritional parameters correlate with increased postoperative complications regardless of other risk factors in the gynecologic cancer patient. A retrospective chart review was performed among women who underwent surgical management for gynecologic malignancies from October 2006 to June 2008. Variables included age, race, medical comorbidities, cancer type/stage, preoperative albumin, absolute lymphocyte count (ALC), and body mass index (BMI), estimated blood loss (EBL), intraoperative blood transfusion (BT), intraoperative or postoperative complications, intensive care unit (ICU) admissions, hospital readmissions, reoperations, and cancer recurrence. Three hundred gynecologic oncology patients with preoperative nutritional parameters were included in the study. Decreased albumin was significantly associated with more postoperative complications (p<0.001), hospital readmissions (p=0.01), reoperations (p=0.03), ICU admissions (p<0.001), and cancer recurrence (p<0.001). Decreased ALC and BMI preoperatively was also significantly associated with higher incidence of cancer recurrence (p=0.01, p=0.01). Surgical cases involving increased EBL (p=0.01, p<0.001) and more BT (p<0.001, p<0.001) had significantly more postoperative complications and more ICU admissions. Multivariable logistic regression found preoperative albumin to be an independent predictor of increased postoperative complications. Decreased albumin is significantly associated with more postoperative complications, hospital readmissions, reoperations, ICU admissions, and cancer recurrence. This nutritional parameter is an important predictor of postoperative morbidity and mortality. Thus, it is important to assess nutritional status preoperatively and offer nutritional support or alternate treatment options if necessary.

The impact of nurses on patient morbidity and mortality - the need for a policy change in response to the nursing shortage

Workforce projections indicate that by 2012 there will be a shortfall of 61,000 registered nurses in Australia. There is a growing body of evidence that links registered nurse staffing to better patient outcomes. This article provides a comprehensive review of the research linking nurse staffing to patient outcomes at a time of growing shortages, highlighting that a policy response based on substituting registered nurses with lower skilled workers may have adverse effects on patient outcomes. An electronic search of articles published in English using the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Journals @ OVID and Medline was undertaken. Robust evidence exists nationally and internationally that links nurse staffing to patient outcomes. Recent meta-analyses have found that there was a 3-12% reduction in adverse outcomes and a 16% reduction in the risk of mortality in surgical patients with higher registered nurse staffing. Evidence confirms that improvements in nurse staffing is a cost-effective investment for the health system but this is not fully appreciated by health policy advisors. An appropriate policy response demands that the evidence that patient safety is linked to nurse staffing be recognised. Policy makers must ensure there are sufficient registered nurses to guarantee patient safety.

Intraoperative blood salvage and retransfusion from citrate treated wounds is safe and feasible

Objectives. Allogenic blood transfusions are associated with increased morbidity and mortality in surgical patients. The study objective was to investigate the feasibility and safety of intraoperative autotransfusion of unwashed shed whole blood using a novel method. Design. Twenty pigs were randomised to autotransfusion or crystalloid volume replacement. In two separate surgical wounds, the surfaces and 400 ml of shed blood were treated in situ with citrate, delivered with an equipment transforming suction to positive pressure. Central haemodynamics were monitored with a pulmonary artery catheter. Effects on oxygen-carrying capacity, formed blood elements, haemolysis, inflammation, metabolism, and coagulation were evaluated with biochemical analyses. Results. No clinically relevant adverse effects on haemodynamics were encountered, apart from a decrease in cardiac output and mixed venous saturation similar to that in control animals. Haemoglobin level was better preserved in the autotransfused group (97 vs. 86 g/L, p=0.0007). There were no major differences in biochemical variables and no macroscopic clot formation precluding autotransfusion. Conclusions. The technique was safe and feasible for intraoperative blood salvage and auotransfusion. Haemodynamics and biochemical variables were similar to controls. The technique warrants further studies in humans, as it may contribute towards a reduction of allogenic blood transfusions.

Selecting a Short-term Prognostic Model for Hepatocellular Carcinoma

The model for end-stage liver disease (MELD) and MELD-sodium (MELD-Na) are prognostic models for cirrhotic patients with or without hepatocellular carcinoma (HCC). This study compared the predictive accuracy between the MELD, MELD-Na, TNM (tumor, node, metastasis), Cancer of the Liver Italian Program (CLIP), Barcelona Clinic Liver Cancer (BCLC), Japan Integrated Scoring (JIS), and Tokyo score for 3-month and 6-month mortality in HCC patients. A total of 953 patients were prospectively enrolled. The predictive accuracy was compared between different models using the area under receiver operating characteristic curve (AUC). The CLIP system had the highest AUC (0.875) for predicting 3-month mortality, followed by the Tokyo score (0.874), JIS (0.868), BCLC (0.855), MELD-Na (0.829), MELD (0.803), and finally, TNM (0.795) system. At 6 months, the top 3 models and their AUCs were the CLIP (0.882), Tokyo (0.861), and JIS (0.85). MELD-Na consistently had significantly better predictive accuracy than the MELD at 3 and 6 months. The MELD and MELD-Na were better prognostic models in predicting the mortality for surgical patients (AUC, 0.719 to 0.740), whereas the CLIP and Tokyo systems were the 2 better models in staging nonsurgical (AUC, 0.849 to 0.884) and high-risk patients (AUC, 0.790 to 0.846), defined as having at least 2 independent risk factors of mortality, at 3 and 6 months. The MELD-Na may improve the prognostic ability of the MELD system for patients with HCC. Both the CLIP and Tokyo systems are better short-term prognostic models. These findings are helpful in designing future clinical trials for HCC.

Is the Search for a Single Comprehensive Staging System for Hepatocellular Carcinoma an Elusive One?

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and there are more than 500,000 attributable deaths each year.1,2 Accumulating evidence suggests that the incidence is rising.3,4 Most patients with HCC have cirrhosis from chronic viral hepatitis, either hepatitis B or C. The prognosis of HCC depends on both tumor characteristics and residual liver function. The role of tumor biology may also prove to be an important predictor of outcome. Clinical staging systems should ideally group patients together to define prognosis and thereby allow for selection of appropriate treatment options. HCC was initially classified by the Okuda staging system and tumor, node, metastasis staging. However, the Okuda system does not distinguish between early and late stage HCC and the tumor, node, metastasis staging does not employ variables of liver function. Consequently, several staging systems have been subsequently developed including the Cancer of the Liver Italian Program system, the Barcelona Clinic Liver Cancer system, the Tokyo scoring system, and the Japan Integrated Scoring system. However, the optimal staging system for HCC remains controversial and lacks worldwide consensus. In this issue of the journal, Huo et al5 attempt to evaluate a short-term prognostic model by examining 5 HCC staging systems as well as the applicability of the model for end-stage liver disease (MELD) and the addition of sodium to the model (MELD-Na). The authors suggest that MELD and MELD-Na are better prognostic models in predicting short-term mortality for surgical patients. This is conceivable but the tumor-related factors were already removed from the analysis as the patients were deemed eligible for surgical resection. MELD has been validated as an accurate predictor of survival among different populations of patients with end-stage liver disease.6,7 Its application postresection would be based upon the severity of cirrhosis and would have accurate prognostic implications. The potential for recurrence of tumor after resection is high and in one series, the median disease-free survival postsurgery was only 3 months.8 Therefore, it would be of interest to see if the MELD or MELD-Na could be useful as prognostic indicators, if the study was extended for a longer period of time. In this study, only 27% of the patients underwent surgical resection and a very small percentage, 0.7%, underwent liver transplantation. Consequently, it is difficult to make conclusions from this limited data. Majority of patients in the study (73%) received medical therapy, which combined local regional therapies with best supportive care. Patients who have smaller tumors and receive ablative, potentially curative therapies will certainly have better survival than patients with extensive tumor burden who receive palliative care. Therefore, it may have been more informative to separate local regional therapies from supportive care given the potential disparity in prognosis. The authors conclude that the Cancer of the Liver Italian Program and Tokyo systems are better in predicting short-term mortality in nonsurgical and high-risk patients. It would stand to reason that MELD and MELD-Na would perform poorly in this scenario, as these systems do not take tumor characteristics into account. As the authors point out, the results from this cohort of Taiwanese patients with hepatitis B virus-related HCC may not be applicable to patients in other countries or to patients with other etiologies of cirrhosis, such as hepatitis C or alcohol. In addition, the applicability of staging systems for patients with HCC is most likely dependent on the actual parameters employed in the staging system itself and the availability of different treatment modalities. This underscores the need for better understanding of tumor biology and its incorporation potentially into a simple, well-designed staging system that would have widespread use. The applicability of the staging system will then depend on the surgical and local regional therapies that would be available to the patient.

Systemic inflammatory response syndrome outcome in surgical patients.

The problems of inflammation and infection as a leading cause of organ dysfunction and failure is a major problem after injury or operations. When systemic inflammatory response syndrome (SIRS) progress to multiple organ failure (MOF), the mortality reach up to 30-80% depending on the number of failed organs. Recent discoveries and improvement in patient care, a reasonable question then arises, are the incidence of MOF decreasing? The literature suggests a decrease in mortality of patients with severe organ failure and a decrease in elective surgical mortality in patients. This is prospective study of 50 patients who underwent surgical procedure. They were followed up till date of termination with daily SIRS monitoring, development of MODS and MOF. Risk factors for MOF are addressed. There are total 31 patients who develop SIRS, of whom 7 patients develop severe sepsis and 4 went into MOF. Early detection of SIRS helps us to prevent multiple organ dysfunction syndrome (MODS)/MOF, leading to lesser hospital stay and better outcome.

Does perioperative hemodynamic optimization protect renal function in surgical patients? A meta-analytic study

Postoperative acute deterioration in renal function, producing oliguria and/or increase in serum creatinine, is one of the most serious complication in surgical patients. Most cases are due to renal hypoperfusion as a consequence of systemic hypotension, hypovolemia, and cardiac dysfunction. Although some evidence suggests that perioperative monitoring and manipulation of oxygen delivery by volume expansion and inotropic drugs may decrease mortality in surgical patients, no study analyzed this approach on postoperative renal dysfunction. The objective of this investigation is to perform a meta-analysis on the effects of perioperative hemodynamic optimization on postoperative renal dysfunction. DATA SOURCES, STUDY SELECTION, DATA EXTRACTION: A systematic literature review, using MEDLINE, EMBASE, and The Cochrane Library databases through January 2008 was conducted and 20 studies met the inclusion criteria (4220 participants). Data synthesis was obtained by using odds ratio (OR) with 95% confidence interval (CI) by random-effects model. Postoperative acute renal injury was significantly reduced by perioperative hemodynamic optimization when compared with control group (OR 0.64; CI 0.50-0.83; p = 0.0007). Perioperative optimization was effective in reducing renal injury defined consistently with risk, injury, failure, and loss and end-stage kidney disease and Acute Kidney Injury Network classifications, and in studies defining renal dysfunction by serum creatinine and/or need of renal replacement therapy only (OR 0.66; CI 0.50-0.88; p = 0.004). The occurrence of renal dysfunction was reduced when treatment started both preoperatively and intraoperatively or postoperatively, was performed in high-risk patients, and was obtained by fluids and inotropes. Mortality was significantly reduced in treatment group (OR 0.50; CI 0.31-0.80; p = 0.004), but statistical heterogeneity was observed. Surgical patients receiving perioperative hemodynamic optimization are at decreased risk of renal impairment. Because of the impact of postoperative renal complications on adverse outcome, efforts should be aimed to identify patients and surgery that would most benefit from perioperative optimization.

Soft tissue penetration of cefuroxime determined by clinical microdialysis in morbidly obese patients undergoing abdominal surgery

Antibiotic prophylaxis is intended to prevent postoperative wound infections, a major source of morbidity and mortality in surgical patients. Cefuroxime is a well-established second-generation cephalosporin that is given preoperatively in surgery units at a standard dose of 1.5 g. It is therefore important to determine whether cefuroxime distributes to the interstitial space fluid (ISF) of subcutaneous (s.c.) soft tissues, especially in obese patients who are at a higher risk of surgical site infections. In a single centre, prospective, open-label study, six morbidly obese patients [body mass index (BMI) ≥ 40] undergoing abdominal surgery received a single intravenous dose of 1.5 g cefuroxime within 1 h of incision. Blood and microdialysis samples from the ISF of skeletal muscle and s.c. adipose tissue were collected before, throughout and after surgery for up to 6 h post-dosing. Cefuroxime concentrations were determined by high-performance liquid chromatography–ultraviolet (HPLC-UV). Total peak concentrations in plasma ( C max) (66.8 ± 18.9 μg/mL) were higher than free C max levels in the ISF of muscle (60.1 ± 15.2 μg/mL) and s.c. adipose tissue (39.2 ± 26.4 μg/mL). Mean area under the free concentration–time curve ratios of muscle/total plasma (1.0 ± 0.2) or s.c. adipose tissue/total plasma (0.6 ± 0.5) indicate that cefuroxime distributes into the ISF of these tissues. In conclusion, the findings of this pilot study indicate that cefuroxime distributes into the ISF of muscle and s.c. adipose tissue of morbidly obese patients undergoing abdominal surgery. Concentrations in the ISF of soft tissues following a single 1.5 g dose may be high enough to prevent infections with Gram-positive organisms but may be insufficient to prevent infections with Gram-negative organisms.