Perioperative myocardial infarction or cardiac arrest is associated with significant morbidity and mortality. The Revised Cardiac Risk Index is currently the most commonly used cardiac risk ...stratification tool; however, it has several limitations, one of which is its relatively low discriminative ability. The objective of the present study was to develop and validate a predictive cardiac risk calculator.
Patients who underwent surgery were identified from the American College of Surgeons' 2007 National Surgical Quality Improvement Program database, a multicenter (>250 hospitals) prospective database. Of the 211 410 patients, 1371 (0.65%) developed perioperative myocardial infarction or cardiac arrest. On multivariate logistic regression analysis, 5 predictors of perioperative myocardial infarction or cardiac arrest were identified: type of surgery, dependent functional status, abnormal creatinine, American Society of Anesthesiologists' class, and increasing age. The risk model based on the 2007 data set was subsequently validated on the 2008 data set (n=257 385). The model performance was very similar between the 2007 and 2008 data sets, with C statistics (also known as area under the receiver operating characteristic curve) of 0.884 and 0.874, respectively. Application of the Revised Cardiac Risk Index to the 2008 National Surgical Quality Improvement Program data set yielded a relatively lower C statistic (0.747). The risk model was used to develop an interactive risk calculator.
The cardiac risk calculator provides a risk estimate of perioperative myocardial infarction or cardiac arrest and is anticipated to simplify the informed consent process. Its predictive performance surpasses that of the Revised Cardiac Risk Index.
Abstract Objective To identify preoperative factors associated with an increased risk of postoperative pneumonia and subsequently develop and validate a risk calculator. Patients and Methods The ...American College of Surgeons’ National Surgical Quality Improvement Program, a multicenter, prospective data set (2007-2008) was used. Univariate and multivariate logistic regression analyses were performed. The 2007 data set (N=211,410) served as the training set, and the 2008 data set (N=257,385) served as the validation set. Results In the training set, 3825 patients (1.8%) experienced postoperative pneumonia. Patients who experienced postoperative pneumonia had a significantly higher 30-day mortality (17.0% vs 1.5%; P <.001). On multivariate logistic regression analysis, 7 preoperative predictors of postoperative pneumonia were identified: age, American Society of Anesthesiologists class, chronic obstructive pulmonary disease, dependent functional status, preoperative sepsis, smoking before operation, and type of operation. The risk model based on the training data set was subsequently validated on the validation data set, with model performance being very similar (C statistic: 0.860 and 0.855, respectively). The high C statistic indicates excellent predictive performance. The risk model was used to develop an interactive risk calculator. Conclusion Preoperative variables associated with an increased risk of postoperative pneumonia include age, American Society of Anesthesiologists class, chronic obstructive pulmonary disease, dependent functional status, preoperative sepsis, smoking before operation, and type of operation. The validated risk calculator provides a risk estimate for postoperative pneumonia and is anticipated to aid in surgical decision making and informed patient consent.
Background
Development of autologous and recombinant growth factor/matrix combination products represent a new emerging trend in regenerative therapeutics and have gained increasing attention as a ...strategy to optimize tissue regeneration. The aim of the present study was to evaluate the levels of platelet derived growth factor‐BB (PDGF‐BB) in gingival crevicular fluid (GCF) during early healing period after the regenerative treatment of intrabony defects using beta tricalcium phosphate (β‐TCP) as a bone regeneration material with either platelet rich fibrin (PRF) membrane or collagen membrane (CM) treated with recombinant human PDGF‐BB (rhPDGF‐BB).
Methods
Twenty patients (13 males and 7 females) with chronic periodontitis participated in this prospective, randomized clinical and biochemical study. Each patient was randomly assigned to PRF membrane (group A) or CM incorporated with rhPDGF‐BB (group B). GCF samples were obtained on days 3, 7, 14, and 30 for evaluation of PDGF‐BB levels and alkaline phosphatase (ALP) levels.
Results
On days 3 and 7 following surgery, mean levels of PDGF‐BB at sites treated with PRF membrane or CM incorporated with rhPDGF‐BB as a barrier membrane were not significantly different. PDGF‐BB levels decreased significantly in samples collected on days 14 and 30 with significant differences between both the groups. ALP levels significantly increased from day 3 to day 30 but there was no difference between two groups.
Conclusion
Within the limitations of the study, both PRF membrane and CM incorporated with rhPDGF‐BB showed comparable GCF levels of PDGF‐BB initially with PRF showing more sustained levels throughout the study period.
Background Patients presenting with acute mesenteric ischemia (AMI) sufficiently advanced to require bowel resection have a high morbidity and mortality. The objective of this study was to analyze ...these patients to determine if certain pre- or intraoperative variables are predictive of death or complications which could then be used to develop a predictive model to aid in surgical decision-making. Methods Patients undergoing bowel resection for AMI were identified from the American College of Surgeons’ National Surgical Quality Improvement Program database (2007–2008). Multiple logistic regression analysis was performed. Results The 861 patients identified had a median age of 69 years. Thirty-day postoperative morbidity and mortality were 56.6% and 27.9%, respectively. Pre- and intraoperative variables significantly associated with postoperative mortality (C statistic, 0.84) included preoperative do not resuscitate order, open wound, low albumin, dirty vs clean-contaminated case, and poor functional status. Pre- and intraoperative variables significantly associated with postoperative morbidity (C statistic, 0.79) included admission from chronic care facility, recent myocardial infarction, chronic obstructive pulmonary disease, requiring ventilator support, preoperative renal failure, previous cardiac surgery, and prolonged operative time. A predictive risk calculator was developed using these variables. Conclusion Mortality and morbidity rates after bowel resection for AMI are high. A risk calculator for prediction of postoperative mortality and morbidity has been developed and awaits validation in subsequent studies.
Background Postoperative respiratory failure (PRF) (requiring mechanical ventilation > 48 h after surgery or unplanned intubation within 30 days of surgery) is associated with significant morbidity ...and mortality. The objective of this study was to identify preoperative factors associated with an increased risk of PRF and subsequently develop and validate a risk calculator. Methods The American College of Surgeons National Surgical Quality Improvement Program (NSQIP), a multicenter, prospective data set (2007-2008), was used. The 2007 data set (n = 211,410) served as the training set and the 2008 data set (n = 257,385) as the validation set. Results In the training set, 6,531 patients (3.1%) developed PRF. Patients who developed PRF had a significantly higher 30-day mortality (25.62% vs 0.98%, P < .0001). On multivariate logistic regression analysis, five preoperative predictors of PRF were identified: type of surgery, emergency case, dependent functional status, preoperative sepsis, and higher American Society of Anesthesiologists (ASA) class. The risk model based on the training data set was subsequently validated on the validation data set. The model performance was very similar between the training and the validation data sets (c-statistic, 0.894 and 0.897, respectively). The high c-statistics (area under the receiver operating characteristic curve) indicate excellent predictive performance. The risk model was used to develop an interactive risk calculator. Conclusions Preoperative variables associated with increased risk of PRF include type of surgery, emergency case, dependent functional status, sepsis, and higher ASA class. The validated risk calculator provides a risk estimate of PRF and is anticipated to aid in surgical decision making and informed patient consent.
Background Although a risk score estimating postoperative mortality for patients undergoing gastric bypass exists, there is none predicting postoperative morbidity. Our objective was to develop a ...validated risk calculator for 30-day postoperative morbidity of bariatric surgery patients. Study Design We used the American College of Surgeons' 2007 National Surgical Quality Improvement Program (NSQIP) dataset. Patients undergoing bariatric surgery for morbid obesity were studied. Multiple logistic regression analysis was performed and a risk calculator was created. The 2008 NSQIP dataset was used for its validation. Results In 11,023 patients, mean age was 44.6 years, 20% were male, 77% were Caucasian, and mean body mass index (BMI; calculated as kg/m2 ) was 48.9. Thirty-day morbidity and mortality were 4.2% and 0.2%, respectively. Risk factors associated with increased risk of postoperative morbidity included recent MI/angina (odds ratio OR = 3.65; 95% CI 1.23 to 10.8), dependent functional status (OR = 3.48; 95% CI 1.78 to −6.80), stroke (OR = 2.89; 95% CI 1.09 to 7.67), bleeding disorder (OR = 2.23; 95% CI 1.47 to 3.38), hypertension (OR = 1.34; 95% CI 1.10 to 1.63), BMI, and type of bariatric surgery. Patients with BMI 35 to <45 and >60 had significantly higher adjusted OR compared with patients with BMI of 45 to 60 (p < 0.05 for all). These factors were used to create the risk calculator and subsequently validate it, with the model performance very similar between the 2007 training dataset and the 2008 validation dataset (c-statistics: 0.69 and 0.66, respectively). Conclusions NSQIP data can be used to develop and validate a risk calculator that predicts postoperative morbidity after various bariatric procedures. The risk calculator is anticipated to aid in surgical decision making, informed patient consent, and risk reduction.
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•Electrolytes with high room temperature conductivity are prepared.•Stable SEI is formed between Li and prepared electrolytes.•Low cost thermal lamination technique is used for cell ...assembly.•Use of mesh type Al foil as current collector exhibits lower capacity fading.
Flexible gel polymer electrolytes based on polymer polyethylene oxide, salt lithium bis(fluorosulfonyl)imide and ionic liquid 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide are synthesized. Prepared samples show high thermal stability, high ionic conductivity at room temperature and an electrochemical stability window of ∼3.51V vs. Li/Li+. Lithium deposition-striping voltage profiles show the formation of a stable solid electrolyte interface. A Li/GPE/LiFePO4 cell was assembled by low cost thermal lamination technique. This cell can deliver 143mAhg−1 capacity at room temperature at C/20 rate with good discharge efficiency. Use of micro grid mesh type Al current collector in cathode exhibits significant improvement in capacity retention.
The objective of this study was to assess the impact of preoperative anemia (hematocrit <39%) on postoperative 30-day mortality and adverse cardiac events in patients 65 years or older undergoing ...elective vascular procedures.
Preoperative anemia is associated with adverse outcomes after cardiac surgery, but its association with postoperative outcomes after open and endovascular procedures is not well established. Elderly patients have a decreased tolerance to anemia and are at high risk for complications after vascular procedures.
Patients (N = 31,857) were identified from the American College of Surgeons' 2007-2009 National Surgical Quality Improvement Program-a prospective, multicenter (>250) database maintained across the United States. The primary and secondary outcomes of interest were 30-day mortality and a composite end point of death or cardiac event (cardiac arrest or myocardial infarction), respectively.
Forty-seven percent of the study population was anemic. Anemic patients had a postoperative mortality and cardiac event rate of 2.4% and 2.3% in contrast to the 1.2% and 1.2%, respectively, in patients with hematocrit within the normal range (P < 0.0001). On multivariate analysis, we found a 4.2% (95% confidence interval, 1.9-6.5) increase in the adjusted risk of 30-day postoperative mortality for every percentage point of hematocrit decrease from the normal range.
The presence and degree of preoperative anemia are independently associated with 30-day death and adverse cardiac events in patients 65 years or older undergoing elective open and endovascular procedures. Identification and treatment of anemia should be important components of preoperative care for patients undergoing vascular operations.
Background While the epidemic of obesity continues to plague America, bariatric surgery is underused due to concerns for surgical risk among patients and referring physicians. A risk score estimating ...postoperative mortality (OS-MRS) exists, however, is limited by consideration of only 12 preoperative variables, failure to separate open and laparoscopic cases, a lack of robust statistical analyses, risk factors not being weighted, and being applicable to only gastric bypass surgery. The objective of this study was to develop a validated risk calculator for 30-day postoperative mortality after bariatric surgery. Study Design The National Surgical Quality Improvement Program (NSQIP) dataset (2006 to 2008) was used. Patients undergoing bariatric surgery for morbid obesity (n = 32,889) were divided into training (n = 21,891) and validation (n = 10,998) datasets. Multiple logistic regression analysis was performed on the training dataset. The model fit from the training dataset was maintained and was used to estimate mortality probabilities for all patients in the validation dataset. Results Thirty-day mortality was 0.14%. Seven independent predictors of mortality were identified: peripheral vascular disease, dyspnea, previous percutaneous coronary intervention, age, body mass index, chronic corticosteroid use, and type of bariatric surgery. This risk model was subsequently validated. The model performance was very similar between the training and the validation datasets (c-statistics, 0.80 and 0.82, respectively). The high c-statistics indicate excellent predictive performance. The risk model was used to develop an interactive risk calculator. Conclusions This risk calculator has excellent predictive ability for mortality after bariatric procedures. It is anticipated that it will aid in surgical decision-making, informed patient consent, and in helping patients and referring physicians to assess the true bariatric surgical risk.
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