MRSA: predictor of outcome in critically ill patients

Methicillin resistant Staphylococcus aureus (MRSA) infectionin critically ill patients is associated with considerable morbidity,mortality and cost.^{1 2} In 1994, we studied 29 MRSA positivepatients admitted to the intensive care unit (ICU). Althoughthe size of population studied was too small to be conclusive,there was a suggestion that MRSA did not have a significantimpact on overall mortality (unpublished observation), however,there was an increase in average length of stay. In this retrospective study, microbiology records identifiedMRSA infected/colonised patients admitted to ICU over 36 months(1996–1998). Patient demographics, site of isolation andhospital mortality were recorded. Isolation of MRSA from blood,sterile sites or endotracheal secretions was considered to bea surrogate marker of serious infection. In those patients withMRSA isolated in multiple sites, the most likely site for seriousinfection was selected. One hundred and sixty seven patients were found to be infected/colonizedwith MRSA and of these 59 patients had positive blood or sputumcultures. Hospital mortality of MRSA positive patients was 50.9%compared to 33.8% overall hospital mortality of all ICU patients.Standardized incidence ratio for death was 1.51 (95% confidenceinterval 1.20–1.86) for patients with MRSA. As expectedthe number of deaths rises with age (60 yr was 34.8%, 61–75yr 52.6%, >75 yr 64.4%. Odds ratio 2.74 (95% confidence interval1.09–6.93) for >75 compared with 60 yr old). Diagnosis of MRSA from blood and sputum (group A) had a mortalityof 44.1%, compared to 51.3% in those with MRSA from screeningsites (group B) (P=0.403). Whilst mortality increases with agefor both groups, it rises faster in patients with MRSA in groupB (Table 7). There was no difference in mortality between groups. The poorassociation between mortality and positive blood or sputum culturescorroborates our previous observation that detection of MRSAis more likely to be an indicator of poor prognosis rather thanthe cause of fatal infection.     

Outcome predictors and new score of critically ill cirrhotic patients with acute renal failure.

BACKGROUND: End-stage liver disease is often complicated by renal function disturbances. Cirrhotic patients with acute renal failure admitted to intensive care units (ICUs) have high mortality rates. This work seeks to identify specific predictors of hospital mortality in critically ill cirrhotic patients with acute renal failure. METHODS: A total of 111 patients with cirrhosis and acute renal failure were admitted to ICU from March 2003 to February 2005. Twenty-six demographic, clinical and laboratory variables were prospectively gathered as predictors of survival on the first day of ICU admission. RESULTS: The overall hospital mortality rate was 81.1%. The univariate analysis identified 11 of the 32 variables as prognostically valuable. The multiple logistic regression analysis (excluding five scoring systems) indicates that the mean arterial pressure (MAP), serum bilirubin, respiratory failure and sepsis on the first day in ICU are significantly related to prognosis. The best Youden index (sensitivity + specificity - 1) yields cutoff points of 80 MAP (in mmHg) and 80 serum bilirubin (in micromol/L) (or 4.7 mg/dL) and indicates acute respiratory failure and sepsis. A simple model for mortality is developed on the basis of these four readily available parameters on Day 1 of ICU admission. The new score (MBRS score: MAP + bilirubin + respiratory failure + sepsis) displays an excellent area under the receiver operating characteristic curve (0.898 +/- 0.031, P < 0.001). The mortality rate exceeds 90% when the MBRS (MAP + bilirubin + respiratory failure + sepsis) score is 2 or higher. CONCLUSION: The MBRS score is a straightforward, reproducible and easily adopted evaluative tool with good prognostic abilities, which generates objective data for patient families and physicians and supplements a clinical judgment of prognosis.     

Chlormethiazole sedation for critically ill patients in renal failure

Chlormethiazole infusions were used successfully to provide night sedation for 10-19 nights in three patients with renal failure managed by continuous veno-venous haemofiltration with dialysis. Fluid overload has accompanied the use of this drug previously because of its low concentration. The ability to remove large amounts of fluid during haemofiltration dialysis proved to be effective in preventing this. All three patients had impaired liver function and showed evidence of chlormethiazole accumulation after 4-6 days. The combination of progressive reduction in dose and daily withdrawal of infusions prevented a major problem. Acceptance of this technique by the patients was high. Chlormethiazole may be a useful addition to the drugs available to provide sedation in well defined clinical circumstances.     

Unrecognized renal damage in critically ill patients

INTRODUCTION: The objective of this study was to evaluate the percentage of unrecognized renal damage in patients with normal creatinine and urea in serum and normal creatinine clearance and to evaluate the usefulness of various proteins and enzymes as supplementary procedures for the investigation of renal function. MATERIAL AND METHODS: Forty critically ill male patients (APACHE II-score > 20, injury severity score > 15) were daily screened for a period of five days. In the 1st group there were 30 patients with normal creatinine and urea in serum and with normal creatinine clearances. In the second group there were ten patients with increased values of these parameters. The base-line condition of all patients and any changes in hemodynamic, nutrition and ventilation were noted. Clearances of inulin, para-aminohippuric acid, and creatinine were measured and the Cockcroft-Gault equation was calculated daily for a period of five days. Excretion of alpha-1-microglobulin. Tamm-Horsfall-protein, alanine aminopeptidase, angiotensinase A, albumin and immunoglobulin G were also measured daily. RESULTS: 21 Patients of group 1 and all patients of group 2 showed the expected correlation between the routine parameters of creatinine and urea in serum and the level of protein and enzyme excretion. Nine patients of group 1 (30%) showed normal glomerular filtration rates but pathological excretion fractions of all proteins and enzymes. CONCLUSIONS: Although all routine parameters of renal function (creatinine and urea in serum, creatinine clearance both by 24-h collection period and from the Cockcroft-Gault equation), and additionally inulin and para-aminohippuric acid clearance were measured, no references on tubular and glomerular damage were found in 30% of the investigated patients.     

An assessment of the validity of SOFA score based triage in H1N1 critically ill patients during an influenza pandemic

Sequential Organ Failure Assessment (SOFA) score based triage of influenza A H1N1 critically ill patients has been proposed for surge capacity management as a guide for clinical decision making. We conducted a retrospective records review and SOFA scoring of critically ill patients with influenza A H1N1 in a mixed medical-surgical intensive care unit in an urban hospital. Eight critically ill patients with influenza A H1N1 were admitted to the intensive care unit. Their mean (range) age was 39 (26–52) years with a length of stay of 11 (3–17) days. All patients met SOFA score based triage admission criteria with a modal SOFA score of five. Five patients required invasive ventilation for a mean (range) of 5 (4–11) days. Five patients would have been considered for withdrawal of treatment using SOFA scoring guidelines at 48 h. All patients survived. We conclude that SOFA score based triage could lead to withdrawal of life support in critically ill patients who could survive with an acceptably low length of stay in the intensive care unit.     

A combination of SOFA score and biomarkers gives a better prediction of septic AKI and in-hospital mortality in critically ill surgical patients: a pilot study

Background

Sepsis is a syndrome characterized by a constellation of clinical manifestations and a significantly high mortality rate in the surgical intensive care unit (ICU). It is frequently complicated by acute kidney injury (AKI), which, in turn, increases the risk of mortality. Therefore, it is of paramount importance to identify those septic patients at risk for the development of AKI and mortality. The objective of this pilot study was to evaluate several different biomarkers, including NGAL, calprotectin, KIM-1, cystatin C, and GDF-15, along with SOFA scores, in predicting the development of septic AKI and associated in-hospital mortality in critically ill surgical patients.

Methods

Patients admitted to the surgical ICU were prospectively enrolled, having given signed informed consent. Their blood and urine samples were obtained and subjected to enzyme-linked immunosorbent assay (ELISA) to determine the levels of various novel biomarkers. The clinical data and survival outcome were recorded and analyzed.

Results

A total of 33 patients were enrolled in the study. Most patients received surgery prior to ICU admission, with abdominal surgery being the most common type of procedure (27 patients (81.8%)). In the study, 22 patients had a diagnosis of sepsis with varying degrees of AKI, while the remaining 11 were free of sepsis. Statistical analysis demonstrated that in patients with septic AKI versus those without, the following were significantly higher: serum NGAL (447.5?±?35.7 ng/mL vs. 256.5?±?31.8 ng/mL, P value 0.001), calprotectin (1030.3?±?298.6 pg/mL vs. 248.1?±?210.7 pg/mL, P value 0.049), urinary NGAL (434.2?±?31.5 ng/mL vs. 208.3?±?39.5 ng/mL, P value <?0.001), and SOFA score (11.5?±?1.2 vs. 4.4?±?0.5, P value <?0.001). On the other hand, serum NGAL (428.2?±?32.3 ng/mL vs. 300.4?±?44.3 ng/mL, P value 0.029) and urinary NGAL (422.3?±?33.7 ng/mL vs. 230.8?±?42.2 ng/mL, P value 0.001), together with SOFA scores (10.6?±?1.4 vs. 5.6?±?0.8, P value 0.003), were statistically higher in cases of in-hospital mortality. A combination of serum NGAL, urinary NGAL, and SOFA scores could predict in-hospital mortality with an AUROC of 0.911.

Conclusions

This pilot study demonstrated a promising panel that allows an early diagnosis, high sensitivity, and specificity and a prognostic value for septic AKI and in-hospital mortality in surgical ICU. Further study is warranted to validate our findings.

     

Extrarenal sequential organ failure assessment score as an outcome predictor of critically ill children on continuous renal replacement therapy

Background

The sequential organ failure assessment (SOFA) score is easy to calculate and has been well validated as an outcome predictor in critically ill adult patients. However, its use in children has been limited, mainly because of differences in basal reference levels of serum creatinine.

Methods

Data include 87 patients requiring continuous renal replacement therapy (CRRT) between January 2005 and July 2011. We modified the SOFA score by excluding the renal component to an extrarenal SOFA score, based on the assumption that CRRT may mitigate the renal effect on outcome and investigated the utility in predicting outcome with comparison with pediatric risk of mortality (PRISM) III, pediatric logistic organ dysfunction (PELOD), and SOFA scores.

Results

Results showed that 95.4 % (n?=?83) had multiple organ dysfunction syndrome with an overall mortality of 50.6 %. The extrarenal SOFA score at CRRT initiation and ≥20 % fluid overload were significantly associated with mortality. In comparison with the predictive power of various scoring systems, the extrarenal SOFA score showed the largest area under the receiver operating characteristic curve (extrarenal SOFA 0.774, SOFA 0.770, PRISM III 0.660, and PELOD 0.650).

Conclusions

The extrarenal SOFA score may be a useful prognostic marker in critically ill children treated with CRRT.     

Influence of underlying disease on the outcome of critically ill patients with acute renal failure

BACKGROUND AND OBJECTIVE: The development of acute renal failure (ARF) in critically ill patients is associated with an increase in hospital mortality. Recently, it was shown that starting renal replacement therapy early and using high-filtrate flow rates can improve the outcome, but this could not be confirmed in later investigations. Studying selected patient subgroups could provide a useful basis for patient selection in future trials evaluating the outcome of renal replacement therapies. We, therefore, investigated the impact of the underlying disease on the outcome of patients with ARF. METHODS: We retrospectively analysed 306 patients with ARF who were treated with renal replacement therapy. Patients were classified according to six initial diagnosis groups: haemorrhagic shock, post-cardiac surgery, post-liver transplantation, trauma, severe sepsis and miscellaneous. Univariate and multivariate multiple logistic regression analysis was used to determine which factors influenced the outcome. RESULTS: Underlying disease proved to be the only independent risk factor for mortality that was present at intensive care unit (ICU) admission (P = 0.047). Patients with severe sepsis had a significantly higher mortality rate (68%) than ARF patients as a whole (51%) (P = 0.02). Length of stay in the ICU, the use of catecholamines, the delay before ARF onset, and the correlation between APACHE II score and ICU length of stay proved to be additional independent predictors of outcome. CONCLUSIONS: Patient selection and subgroup definition according to the underlying disease could augment the usefulness of future trials evaluating the outcome of ARF.     

Combining sequential organ failure assessment (SOFA) score with acute physiology and chronic health evaluation (APACHE) II score to predict hospital mortality of critically ill patients

The ability to accurately adjust for the severity of illness in outcome studies of critically ill patients is essential. Previous studies have showed that Sequential Organ Failure Assessment (SOFA) score and Acute Physiology and Chronic Health Evaluation (APACHE) II score can predict hospital mortality of critically ill patients. The effects of combining these two scores to predict hospital mortality of critically ill patients has not been evaluated. This cohort study evaluated the performance of combining the APACHE II score with SOFA score in predicting hospital mortality of critically ill patients. A total of 1311 consecutive adult patients admitted to a tertiary 22-bed multidisciplinary intensive care unit (ICU) in Western Australia were considered. The APACHE II, Admission SOFA, Delta SOFA and maximum SOFA score were all related to hospital survival in the univariate analyses. Combining Max SOFA (area under receiver operating characteristic curve 0.875 vs. 0.858, P = 0.014; Nagelkerke R2: 0.411 vs. 0.371; Brier Score: 0.086 vs. 0.090) or Delta SOFA score (area under receiver operating characteristic curve 0.874 vs. 0.858, P = 0.003; Nagelkerke R2: 0.412 vs. 0.371; Brier Score: 0.086 vs. 0.090) with the APACHE II score improved the discrimination and overall performance of the predictions when compared with using the APACHE II score alone, especially in the emergency ICU admissions. Combining Max SOFA or Delta SOFA score with the APACHE II score may improve the accuracy of risk adjustment in outcome studies of critically ill patients.     

Sustained low-efficiency dialysis for critically ill patients requiring renal replacement therapy

BACKGROUND: The replacement of renal function for critically ill patients is procedurally complex and expensive, and none of the available techniques have proven superiority in terms of benefit to patient mortality. In hemodynamically unstable or severely catabolic patients, however, the continuous therapies have practical and theoretical advantages when compared with conventional intermittent hemodialysis (IHD). METHODS: We present a single center experience accumulated over 18 months since July 1998 with a hybrid technique named sustained low-efficiency dialysis (SLED), in which standard IHD equipment was used with reduced dialysate and blood flow rates. Twelve-hour treatments were performed nocturnally, allowing unrestricted access to the patient for daytime procedures and tests. RESULTS: One hundred forty-five SLED treatments were performed in 37 critically ill patients in whom IHD had failed or been withheld. The overall mean SLED treatment duration was 10.4 hours because 51 SLED treatments were prematurely discontinued. Of these discontinuations, 11 were for intractable hypotension, and the majority of the remainder was for extracorporeal blood circuit clotting. Hemodynamic stability was maintained during most SLED treatments, allowing the achievement of prescribed ultrafiltration goals in most cases with an overall mean shortfall of only 240 mL per treatment. Direct dialysis quantification in nine patients showed a mean delivered double-pool Kt/V of 1.36 per (completed) treatment. Mean phosphate removal was 1.5 g per treatment. Mild hypophosphatemia and/or hypokalemia requiring supplementation were observed in 25 treatments. Observed hospital mortality was 62.2%, which was not significantly different from the expected mortality as determined from the APACHE II illness severity scoring system. CONCLUSIONS: SLED is a viable alternative to traditional continuous renal replacement therapies for critically ill patients in whom IHD has failed or been withheld, although prospective studies directly comparing two modalities are required to define the exact role for SLED in this setting.     

Prospective comparison of clinical judgment and APACHE II score in predicting the outcome in critically ill surgical patients.

Prospective identification of patients who will not survive has been proposed as a means of limiting utilization of medical resources including critical care. This study prospectively compared prediction of outcome for surgical ICU patients by clinical assessment and the APACHE II score. Five hundred seventy-eight patients were assessed within 24 hours of admission by the ICU attending physician and predicted to live or die. An APACHE II score was calculated in that same time period. All data were stored in a data base and compared with actual SICU outcome. There were 40 deaths in 578 patients (6.9%). The clinical assessment had an overall accuracy of 95.2% vs. 90.9% for APACHE II. The Pearson correlation coefficients for the two methods of prediction were 0.59 for clinical assessment and 0.44 for APACHE II. Predictive power was not greatly improved by combining both prediction methods. Over 40% of patients predicted to die by both methods actually survived. This study demonstrates that clinical assessment is superior to APACHE II in predicting outcome in this group of surgical patients, although the difference is small. In addition, this study suggests that neither clinical assessment nor the APACHE II score, when obtained within 24 hours of admission, is very reliable at predicting which surgical ICU patients will die.     

Rhabdomyolysis and secondary renal failure in critically ill surgical patients

Background

Rhabdomyolysis accounts for up to 28% of the causes of posttraumatic acute renal failure requiring dialysis. Clinically significant rhabdomyolysis is poorly characterized biochemically and difficult to diagnose.

Methods

A retrospective review of all surgical, trauma, burn, and pediatric surgical patients admitted to Grady Memorial Hospital in Atlanta, GA, from January 1995, through April 2002 was performed. Patients were screened for serum creatinine, base deficit, serum creatine kinase (CK) ≥1,000, presence of myoglobinuria, or if they had a clinical diagnosis of rhabdomyolysis by an attending surgeon.

Results

The sequential addition of admission laboratory values for serum creatinine ≥1.5 mg/dL (positive predictive value [PPV] = 33%), base deficit ≤−4 (PPV = 52%), serum CK level ≥5,000 U/L (PPV = 80%), and myoglobinuria increases the ability to predict which patients will develop dialysis-requiring acute renal failure after an episode of rhabdomyolysis. Patients with maximum CK ≥5,000 are also at increased risk for persistent renal insufficiency (Cr ≥2.0 mg/dL).

Conclusions

An algorithm for testing at-risk surgical patients was developed and may aid in the early diagnosis of clinically significant rhabdomyolysis.     

Late-onset cytomegalovirus reactivation in critically ill renal transplant patients

BACKGROUND: Cytomegalovirus (CMV) reactivation occurs frequently in the first months after renal transplantation. However, reports concerning long-term kidney transplant recipients are rare and have always pertained to symptomatic CMV disease. METHODS: We report four cases of late-onset asymptomatic CMV reactivation in critically ill renal transplant patients who suffered from severe bacterial infections and in whom CMV antigenemia was observed. RESULTS AND CONCLUSION: CMV reactivation in these patients might indicate an additional disturbance in the patients' immune defenses at the time of critical illness, possibly even necessitating a temporary reduction in immunosuppressive therapy. Prospective, controlled trials are needed to define the role of CMV antigenemia in critically ill patients, including the role of antiviral therapy for asymptomatic reactivations.     

Nosocomial infections and outcome of critically ill elderly patients after surgery

BACKGROUND: The relation between older age and nosocomial infection and mortality in the intensive care unit (ICU) is still a controversial issue. METHODS: The authors prospectively studied 406 patients admitted to a surgical ICU, 106 of whom were more than 75 yr old. Information concerning ICU-acquired nosocomial infections, severity of illness, therapeutic activity, and hospital outcome was collected. A Cox proportional hazard analysis was used to evaluate potential risk factors for ICU-acquired nosocomial infections, ICU, and hospital death. RESULTS: During their ICU stay, 23 elderly patients experienced 40 nosocomial infections, 28 "young" patients (< 60 yr) experienced 54 nosocomial infections, and 52 "intermediate age" patients (60-75 yr) experienced 98 nosocomial infections. Incidence density of nosocomial infections was 4.9% patient days for elderly patients, 4.7% for young patients, and 6.0% for intermediate age patients (no significance). The frequency distribution of the various microorganisms isolated was similar between the three groups. Compared with younger patients, elderly patients had a higher Acute Physiology and Chronic Health Evaluation II score and a higher ICU and hospital mortality rate. Despite a higher level of severity of illness, elderly patients had a reduction of therapeutic activity. However, Cox proportional hazard analysis showed that age more than 75 yr was not a risk factor for ICU-acquired nosocomial infection, ICU, or hospital death. CONCLUSIONS: In patients referred to a surgical ICU after a surgical procedure, age more than 75 yr by itself does not appear to be a significant predictor of ICU-acquired nosocomial infection or mortality rate during the ICU stay. However, it appears that patients more than 60 yr have a higher incidence of nosocomial infection in ICU.     

Indices of nitric oxide synthesis and outcome in critically ill patients

We measured the concentrations of serum nitrates/nitrites and plasma cyclic guanosine monophosphate as markers of nitric oxide synthesis in patients with or without septic shock for 5 days following admission to intensive care. We found that nitrate/nitrite concentrations, when corrected for the effect of renal failure, were significantly higher in patients with septic shock, both on admission and in the final samples drawn. In a logistic regression analysis, the rate of change of nitrate/nitrite concentration was associated with survival to day 28 (falling in survivors). The concentration of cyclic guanosine monophosphate when corrected for the confounding effects of renal function and platelet count, was only associated with the septic shock group on admission.