Risk prediction model for respiratory complications after lung resection: An observational multicentre study.

BACKGROUND: Patients undergoing lung surgery are at risk of postoperative pulmonary complications (PPCs). Identifying those patients is important to optimise individual perioperative management. The Clinical Prediction Rule for Pulmonary Complications (CPRPCs) after thoracic surgery, developed by the Memorial Sloan-Kettering Cancer Center, might be an ideal predictor. The hypothesis was that CPRPC performs well for the prediction of PPCs. OBJECTIVE: The aim of our study was to provide the external validation of the CPRPC after lung resection for primary tumours, before universal acceptance. In case of poor discrimination, we planned, as a second objective, to derive a new predictive index for PPCs. DESIGN: Retrospective, observational multicentre study. PATIENTS: A total of 559 adult consecutive patients who underwent pulmonary resection. Inclusion criteria were adult patients (aged over 17 years). SETTING: Thirteen Spanish hospitals during the first half of 2011. INTERVENTIONS: A record of the PPCs defined, as in the original publication, as the presence of any of the following events: atelectasis; pneumonia; pulmonary embolism; respiratory failure; and need for supplemental oxygen at hospital discharge. MAIN OUTCOME MEASURES: The performance of the CPRPC was determined in order to examine its ability to discriminate and calibrate the presence of PPCs. RESULTS: The study included 559 patients, of whom 75 (11.6%) suffered PPCs. The CPRPC did not show enough discriminatory power for our cohort area under the receiver operating characteristic (ROC) curve 0.47 (95% confidence interval 0.37 to 0.57)]. After a fitting step by stepwise multivariate logistic regression, we identified three main predictors of PPCs: age; smoking status; and predicted postoperative forced expiratory volume in 1 s. Combining them into a simple risk score, we were able to obtain an area under the ROC curve of 0.74 (95% confidence interval 0.68 to 0.79). CONCLUSION: In this external validation, the CPRPC performed poorly despite its simplicity. The CPRPC was not a useful scale in our cohort. In contrast, we used a more accurate score to predict the occurrence of PPCs in our cohort. It is based on age, smoking status and predicted postoperative forced expiratory volume in 1 s. We propose that our formula should be externally validated.

Ephedrine shows synergistic motor blockade when combined with bupivacaine or lidocaine for spinal anesthesia in a rat model.

BACKGROUND: Ephedrine is a direct/indirect vasoactive drug. In addition, it also possesses intrinsic local anesthetic properties, mainly due to its sodium-channel blockage. We investigated whether ephedrine demonstrates a synergistic effect with bupivacaine and lidocaine when injected via a spinal catheter into the spinal space of rats. METHODS: Spinal catheters were surgically placed in 47 rats (n = 8 per group; 7 rats were excluded.) Bupivacaine, lidocaine, and ephedrine in various concentrations and constant volumes (60 µL) were injected into the spinal catheters to determine the equipotency of each drug. Ephedrine in combination with either bupivacaine or lidocaine was then injected into the spinal catheters. RESULTS: Ephedrine demonstrated statistically significant synergistic effects with bupivacaine as well as with lidocaine in fixed combinations. The combination index reflecting a synergistic effect was 0.792 (95% confidence interval: 0.665-0.919) for ephedrine + bupivacaine and 0.663 (95% confidence interval: 0.532-0.794) for ephedrine + lidocaine. CONCLUSION: Ephedrine combined with either bupivacaine or lidocaine acted synergistically to block motor function and has the potential to reduce the amount of local anesthetic needed for spinal block. The synergistic effect of ephedrine in combination with local anesthetics is an interesting pharmacological phenomenon that warrants further clinical evaluation.

Timing of renal replacement therapy after cardiac surgery: a retrospective multicenter Spanish cohort study.

BACKGROUND: The optimal time to initiate renal replacement therapy (RRT) in cardiac surgery-associated acute kidney injury (CSA-AKI) is unknown. Evidence suggests that the early use of RRT in critically ill patients is associated with improved outcomes. We studied the effects of time to initiation of RRT on outcome in patients with CSA-AKI. METHODS: This was a retrospective observational multicenter study (24 Spanish hospitals). We analyzed data on 203 patients who required RRT after cardiac surgery in 2007. The cohort was divided into 2 groups based on the time at which RRT was initiated: in the early RRT group, therapy was initiated within the first 3 days after cardiac surgery; in the late group, RRT was begun after the 3rd day. Multivariate nonconditional logistic and linear regression models were used to adjust for potential confounders. RESULTS: In-hospital mortality was significantly higher in the late RRT group compared with early RRT patients (80.4 vs. 53.2%; p < 0.001; adjusted odds ratio of 4.1, 95% CI: 1.6-10.0). Also, patients in the late RRT group had longer adjusted hospital stays by 11.6 days (95% CI: 1.4-21.9) and higher adjusted percentage increases in creatinine at discharge compared with baseline by 67.7% (95% CI: 28.5-106.4). CONCLUSIONS: Patients who undergo early initiation of RRT after CSA-AKI have improved survival rates and renal function at discharge and decreased lengths of hospital stay.

Cardiac-surgery associated acute kidney injury requiring renal replacement therapy. A Spanish retrospective case-cohort study.

BACKGROUND: Acute kidney injury is among the most serious complications after cardiac surgery and is associated with an impaired outcome. Multiple factors may concur in the development of this disease. Moreover, severe renal failure requiring renal replacement therapy (RRT) presents a high mortality rate. Consequently, we studied a Spanish cohort of patients to assess the risk factors for RRT in cardiac surgery-associated acute kidney injury (CSA-AKI). METHODS: A retrospective case-cohort study in 24 Spanish hospitals. All cases of RRT after cardiac surgery in 2007 were matched in a crude ratio of 1:4 consecutive patients based on age, sex, treated in the same year, at the same hospital and by the same group of surgeons. RESULTS: We analyzed the data from 864 patients enrolled in 2007. In multivariate analysis, severe acute kidney injury requiring postoperative RRT was significantly associated with the following variables: lower glomerular filtration rates, less basal haemoglobin, lower left ventricular ejection fraction, diabetes, prior diuretic treatment, urgent surgery, longer aortic cross clamp times, intraoperative administration of aprotinin, and increased number of packed red blood cells (PRBC) transfused. When we conducted a propensity analysis using best-matched of 137 available pairs of patients, prior diuretic treatment, longer aortic cross clamp times and number of PRBC transfused were significantly associated with CSA-AKI.Patients requiring RRT needed longer hospital stays, and suffered higher mortality rates. CONCLUSION: Cardiac-surgery associated acute kidney injury requiring RRT is associated with worse outcomes. For this reason, modifiable risk factors should be optimised and higher risk patients for acute kidney injury should be identified before undertaking cardiac surgery.

Serum C-reactive protein on the prognosis of oncology patients with acute renal failure: an observational cohort study.

BACKGROUND: We undertook this study to evaluate the significance of the C-reactive protein level (CRP) as a prognostic factor in oncology patients with acute renal failure (ARF) during nephrology consultation. METHODS: The study was comprised of a cohort of 375 consecutive oncology patients who had been admitted to a university-affiliated hospital between March 1998 and April 2006 and had been diagnosed with ARF. One hundred and fifty nine patients with ARF who matched at least one of the RIFLE criteria on increased serum creatinine were included for subsequent analysis. We used a Cox proportional hazard model. RESULTS: Clinical pathological variables were compared among patients with serum CRP levels > or =8 mg/dL (exposed group; cut-off point: median) and patients with serum CRP level <8 mg/dL (control group). In-hospital mortality rates associated with CRP levels were 53.8% for > or =8 mg/dL and 21.5% for <8 mg/dL (p <0.001). After adjusted analysis, the presence of a CRP level > or =8 mg/dL was significantly associated with an increased in-hospital mortality (HR 2.10; 95% CI: 1.17-3.78) than in those patients with similar Liano scoring, the same RIFLE classes, and the same treatment for ARF. In addition, each increment of 1 mg/dL of serum CRP was associated with an adjusted 4% increment of in-hospital mortality (HR 1.04, 95% CI: 1.01-1.06). CONCLUSIONS: CRP levels at nephrology consultation were an independent predictor of death in this cohort of oncology patients with ARF. Patients with levels > or =8 mg/dL may be considered at higher risk of death.

Impact of prealbumin levels on mortality in patients with acute kidney injury: an observational cohort study.

OBJECTIVE: We evaluated the prognostic value of prealbumin (transthyretin) levels in patients with acute kidney injury (AKI). STUDY DESIGN: This was a longitudinal, single-center, observational cohort study. SETTING: The setting was a university-affiliated hospital. PARTICIPANTS: One hundred and sixty-one consecutive patients with AKI matched at least one of the Risk, Injury, Failure, Loss, End Stage (RIFLE) criteria for increased serum creatinine, and had requested a nephrology consultation between April 2000 and March 2006. METHODS: We conducted a computer-assisted review of all cases of AKI seen by a nephrologist between April 2000 and March 2006. We used Cox proportional hazards models to estimate the risk of in-hospital mortality associated with serum prealbumin level at the beginning of the nephrology consultation. RESULTS: Clinicopathologic variables were compared between patients with a serum prealbumin level <11 mg/dL (the exposed group; cutoff point, median) and patients with a serum prealbumin level > or =11 mg/dL (the control group). In-hospital mortality rates associated with prealbumin levels were 45.0% for <11 mg/dL, and 19.8% for > or =11 mg/dL (P = .001). After adjusted analysis, the presence of a serum prealbumin level <11 mg/dL was significantly associated with increased in-hospital mortality (hazard ratio, 2.10; 95% confidence interval, 1.08 to 4.08), compared with patients with the same Liano scoring, the same RIFLE classes, and the same treatment for AKI, but with a serum prealbumin level > or =11 mg/dL. In addition, each increment of 5 mg/dL of serum prealbumin was associated with an adjusted 29% decrease of in-hospital mortality (hazard ratio, 0.71; 95% confidence interval, 0.52 to 0.96). CONCLUSIONS: Serum prealbumin levels <11 mg/dL were strongly associated with a higher risk of death, independent of AKI severity, comorbid illnesses, serum C-reactive protein levels, and other possible confounders. The measurement of serum prealbumin levels may be an inexpensive and useful tool in the evaluation of the risk profiles of AKI patients.

Prognosis and serum creatinine levels in acute renal failure at the time of nephrology consultation: an observational cohort study.

BACKGROUND: The aim of this study is to evaluate the association between acute serum creatinine changes in acute renal failure (ARF), before specialized treatment begins, and in-hospital mortality, recovery of renal function, and overall mortality at 6 months, on an equal degree of ARF severity, using the RIFLE criteria, and comorbid illnesses. METHODS: Prospective cohort study of 1008 consecutive patients who had been diagnosed as having ARF, and had been admitted in an university-affiliated hospital over 10 years. Demographic, clinical information and outcomes were measured. After that, 646 patients who had presented enough increment in serum creatinine to qualify for the RIFLE criteria were included for subsequent analysis. The population was divided into two groups using the median serum creatinine change (101%) as the cut-off value. Multivariate non-conditional logistic and linear regression models were used. RESULTS: A >or= 101% increment of creatinine respect to its baseline before nephrology consultation was associated with significant increase of in-hospital mortality (35.6% vs. 22.6%, p < 0.001), with an adjusted odds ratio of 1.81 (95% CI: 1.08-3.03). Patients who required continuous renal replacement therapy in the >or= 101% increment group presented a higher increase of in-hospital mortality (62.7% vs 46.4%, p = 0.048), with an adjusted odds ratio of 2.66 (95% CI: 1.00-7.21). Patients in the >or= 101% increment group had a higher mean serum creatinine level with respect to their baseline level (114.72% vs. 37.96%) at hospital discharge. This was an adjusted 48.92% (95% CI: 13.05-84.79) more serum creatinine than in the < 101% increment group. CONCLUSION: In this cohort, patients who had presented an increment in serum level of creatinine of >or= 101% with respect to basal values, at the time of nephrology consultation, had increased mortality rates and were discharged from hospital with a more deteriorated renal function than those with similar Liano scoring and the same RIFLE classes, but with a < 101% increment. This finding may provide more information about the factors involved in the prognosis of ARF. Furthermore, the calculation of relative serum creatinine increase could be used as a practical tool to identify those patients at risk, and that would benefit from an intensive therapy.

Risks factors and regression model for risk calculation of anesthesiologic intervention in topical and intracameral cataract surgery.

PURPOSE: To determine risk factors for anesthesiologist intervention during routine cataract surgery performed with topical and intracameral anesthesia and establish a regression model to identify high-risk patients. SETTING: Department of Ophthalmology, Clínica Universidad de Navarra, Pamplona, Spain. DESIGN: Prospective case series. METHODS: After cataract surgery at an ambulatory surgical center, anesthesia personnel completed a questionnaire to determine adverse medical events and risk factors related to anesthesiologist intervention. A Poisson regression model was used to calculate the interventional risks. Bootstrapping was performed for internal model validation. RESULTS: Of the 1010 cases, 50 (4.95%) required anesthesiologist intervention. Univariate analysis identified an association between anesthesiologist intervention and hypertension (P<.001), psychiatric history (P=.002), initial systolic blood pressure (P<.001), surgical duration (P=.001), and diabetes (P=.018). Scores were obtained using the following proposed regression model equation: (-8.68 + 0.33 × sex [men, 0; women, 1] + -0.02 × age [years] + 0.68 × hypertensive history [no, 0; yes, 1] + 1.18 × psychiatric background [no, 0; yes, 1] + 0.04 × initial systolic blood pressure [mm Hg]). The area under the receiver-operating curve was 0.803 (95% confidence interval [CI], 0.721-0.886). The area under the curve found in the validation method was 0.813 (95% CI, 0.727-0.887). CONCLUSION: Hypertension was the main risk factor for anesthesiologist intervention. The regression model discriminated between patients at lower and higher risk for intraoperative intervention for monitored anesthesia care. The probability of anesthesiologist intervention was 11.7 times higher when the model obtained a high score. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

External validation and comparison of three scores to predict renal replacement therapy after cardiac surgery: a multicenter cohort.

PURPOSE: Cardiac surgery-associated acute kidney injury requiring renal replacement therapy (RRT) is independently associated with mortality. Several risk scores have been developed to predict the need for RRT after cardiac surgery. We have compared and verified the external validity of the three main available scores for RRT prediction after cardiac surgery: the Thakar score, the Mehta tool, and the Simplified Renal Index. METHODS: The risk scores were calculated in a cohort of 1084 adult patients, 248 of whom required RRT, who underwent open-heart surgery in 24 Spanish hospitals in 2007. The performance of the systems was determined by examining their discrimination (areas under the receiver operating characteristic curves (aROC) and calibration (Lemeshow-Hosmer chi-square goodness-of-fit statistics). RESULTS: The aROCs in the Thakar score, the Mehta tool, and the Simplified Renal Index were 0.82, 0.76 and 0.79, respectively. The three scoring systems were poorly calibrated and tended to underestimate the actual need for RRT. CONCLUSIONS: The Thakar score and the Simplified Renal Index discriminated well between low - and high-risk patients in our cohort, and Thakar outperformed the Mehta tool. These best-performing scores may aid in the selection of optimal therapy, facilitate the planning of hospital resource utilization, improve preoperative counseling, select participants for clinical trials of renal-protective therapies and enable an accurate comparison between different institutions or surgeons.

Karnofsky performance score in acute renal failure as a predictor of short-term survival.

BACKGROUND: Karnofsky Performance Scale Index (KPS) is a measure of functional status that allows patients to be classified according to their functional impairment. We aim to assess if the prior KPS may predict the risk of death among patients with acute renal failure (ARF). METHODS: A cohort of 668 consecutive patients who had been admitted in an university-affiliated hospital between June 2000 and June 2006, and had been diagnosed with ARF, were studied. Three hundred and eighty-six patients with ARF who matched at least one of the RIFLE (Risk, Injury, Failure, Loss and End stage) criteria on increased serum creatinine were included for subsequent analysis. The group was divided into four categories, according to different Karnofsky scores measured by a nephrologist (>or=80, 70, 60 and or=80 Karnofsky group. Adjusted odds ratios were 8.87 (95% confidence interval (CI) 3.03-25.99), 6.78 (95% CI 2.61-17.58) and 2.83 (95% CI 1.04-7.68), for Karnofsky groups of