Valerie A. Lawrence

Preoperative Pulmonary Risk Stratification for Noncardiothoracic Surgery: Systematic Review for the American College of Physicians

Postoperative pulmonary complications contribute importantly to the risk for surgery and anesthesia. The most important and morbid postoperative pulmonary complications are atelectasis, pneumonia, respiratory failure, and exacerbation of underlying chronic lung disease. Since the publication of the first cardiac risk index in 1977 (1), clinicians have been aware of the importance of, and the risk factors for, cardiac complications. Clinicians who care for patients in the perioperative period may be surprised to learn that postoperative pulmonary complications are equally prevalent and contribute similarly to morbidity, mortality, and length of stay. For example, in a large retrospective cohort study of 8930 patients undergoing hip fracture repair, 1737 (19%) patients had postoperative medical complications (2). Serious pulmonary complications occurred in 229 (2.6%) patients and serious cardiac complications occurred in 178 (2.0%) patients. Similarly, in a study of 2964 patients undergoing elective noncardiac surgery, postoperative pulmonary and cardiac complications occurred in 53 patients and 64 patients, respectively (3). Rates of postoperative cardiac and pulmonary complications are similar in other large cohort studies of patients undergoing noncardiac surgery (4-6). Pulmonary complications may also be more likely than cardiac complications to predict long-term mortality after surgery. For example, among postoperative complications in a recent study of patients older than 70 years of age who were undergoing noncardiac surgery, only pulmonary and renal complications predicted long-term mortality (7). In another report of patients undergoing esophagectomy for cancer, postoperative pneumonia was second only to tumor stage in predicting long-term survival after surgery and predicted long-term mortality to a greater degree than postoperative cardiac, renal, or hepatic complications (8). Office and hospital consultation for patients preparing for surgery is an important activity for internists. While guidelines and consensus statements for perioperative cardiac evaluation have been published (9, 10), no similar guideline is available to assist in perioperative pulmonary evaluation. The quality and number of studies that estimate perioperative pulmonary risk have increased in the past 2 decades, and this is no longer a neglected area of inquiry. We prepared this 2-part systematic review 1) to guide clinicians on clinical and laboratory predictors of perioperative pulmonary risk before noncardiothoracic surgery and 2) to evaluate the efficacy of strategies to reduce the risk for postoperative pulmonary complications (11). Risk factors for postoperative venous thromboembolism differ substantially from those for postoperative pulmonary complications, and they are not the subject of our review. Methods Literature Search and Selection Criteria The Appendix contains a detailed description of our methodology. We performed a MEDLINE search to identify relevant publications from 1 January 1980 through 30 June 2005. We used the following Medical Subject Heading (MeSH) terms and specified that they be the articles primary focus: intraoperative complications, postoperative complications, preoperative care, intraoperative care, and postoperative care, plus the text term perioperative complications in the title or abstract. We identified additional MeSH and text terms by a review of the MEDLINE indexing for the retrieved articles. These included terms for pulmonary, respiratory, or cardiopulmonary diseases, conditions, or complications and terms for oxygenation and chest roentgenography. We performed additional searches specific to preoperative chest radiography and preoperative spirometry. We identified additional references by reviewing bibliographies of retrieved studies. We included only English-language publications and excluded publication types without primary data (that is, letters, editorials, case reports, conference proceedings, and narrative reviews). We excluded 1) studies with fewer than 25 participants per study group; 2) studies that used only administrative data (for example, International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes) or lacked explicit criteria or definitions for pulmonary complications; 3) studies from developing countries (because of potential differences in respiratory and intensive care technology); 4) studies of ambulatory surgery; 5) studies of physiologic (for example, lung volumes and flow, oximetry) rather than clinical outcomes; 6) studies of gastric pH manipulation; 7) studies of complications unique to a particular type of surgery (for example, upper airway obstruction after uvulectomy); 8) studies of cardiopulmonary or pediatric surgery; and 9) studies of organ transplantation surgery (because of profoundly immunosuppressive drugs). Of 16959 citations identified by the search, 1223 citations were duplicates and 14793 citations were not relevant by title and abstract review (Figure). Of the remaining 943 potentially relevant citations, we excluded 626 citations after review of the full publication and abstracted 145 citations in detail. Figure 1. Flow chart for article selection process. Assessing Study Quality We used the U.S. Preventive Services Task Force (USPSTF) criteria for assigning hierarchy of research design, grading a studys internal validity as our basis for assessing study quality, and assigning summary strength of recommendations for each risk factor and laboratory test (12). Statistical Analysis Our literature search yielded primarily unadjusted estimates for most laboratory factors of interest. Limited multivariable, adjusted studies were available for serum albumin level less than 30 g/L and elevated blood urea nitrogen level. However, rather than attempt to compute potentially biased summary estimates, we provided narrative descriptions of the pattern of results for these potential risk factors. The eligible multivariable risk factor studies varied considerably in the number and type of competing risks and confounders included in the analyses. Extensive use of prescreening methods and variable selection algorithms often limited reporting to the subset of risk factors that were determined to be statistically significant in a given sample. The result is a subtle form of publication bias, which we verified by examination of the funnel plots and trim-and-fill estimates for each risk factor. We extracted odds ratios from each study, along with their respective SEs, 95% confidence limits, or both. We used the I 2 statistic (13) and the Cochran Q statistic (14) to assess study heterogeneity. We also recomputed pooled estimates with and without studies that produced extreme results. An I 2 statistic of 50% or more indicates substantial heterogeneity among study estimates. We used the DerSimonianLaird method to compute random-effects estimates when the set of studies was heterogeneous (15). In cases where 3 or more studies contributed estimates for a risk factor, we used the trim-and-fill method to adjust pooled estimates of a risk factors effect on postoperative pulmonary complications for publication bias (16). Trim-and-fill estimates check the sensitivity of pooled estimates to potential publication bias (17). We used meta-analysis procedures available in Stata software, version 8 (Stata Corp., College Station, Texas), to conduct these analyses (18). Role of the Funding Source The Veterans Evidence-based Research, Dissemination, and Implementation Center (VERDICT) (Veterans Affairs Health Services Research and Development, HFP 98-002) provided the research librarian and administrative support for the study. The funding source had no role in the design, conduct, or reporting of the study or in the decision to submit the manuscript for publication. Results Eighty-three publications provided univariate data on clinical predictors of postoperative pulmonary complications. Appendix Table 1 summarizes the characteristics of these studies (2, 3, 19-99). Seventy-three (88.0%) publications were cohort studies; 3 (3.6%) were randomized, controlled trials; 2 (2.4%) were casecontrol studies; and the remaining 5 (6.0%) were case-series studies. Slightly less than half (45.8%) of the cohort studies used a prospective design. Ten studies were of good quality, 18 studies were of fair quality, and 55 studies were of poor quality. Eligible studies included 11851 postoperative pulmonary complication events among 173500 patients. Appendix Table 1. Study Characteristics of Univariate Studies of Clinical Risk Factors Twenty-seven studies reporting multivariable analyses (10960 postoperative pulmonary complication events among 324648 patients) met our inclusion criteria (Appendix Table 2) (100-126). These studies form the principal basis of our review. Most studies (96%) were prospective cohort studies, and only 1 report was a casecontrol study. The 3 largest studies (118, 120, 123) used subsets of patients from the Veterans Affairs National Surgical Quality Improvement Project (NSQIP) (127). These 3 studies accounted for 89.8% of all patients included in the multivariable studies and 82.3% of the observed postoperative pulmonary complications. The crude postoperative pulmonary complication rate among the cohort studies was 3.4%. Appendix Table 2. Study Characteristics of Multivariate Studies of Clinical Predictors The studies were heterogeneous with respect to study objectives, study samples, and criteria for defining a postoperative pulmonary complication. Seventeen of the 27 (63.0%) studies aimed to identify potential risk factors for postoperative pulmonary complications. The objective in 3 studies was to develop a risk index for postoperative pulmonary complications (113, 118, 120). The remaining studies focused on high-risk subgroups, such as patients undergoing aortic surgery (104, 125), patients with smoking histories (114), elderly patients

Risk Assessment for and Strategies To Reduce Perioperative Pulmonary Complications for Patients Undergoing Noncardiothoracic Surgery: A Guideline from the American College of Physicians

Recommendations Recommendation 1: All patients undergoing noncardiothoracic surgery should be evaluated for the presence of the following significant risk factors for postoperative pulmonary complications in order to receive pre- and postoperative interventions to reduce pulmonary risk: chronic obstructive pulmonary disease, age older than 60 years, American Society of Anesthesiologists (ASA) class of II or greater, functionally dependent, and congestive heart failure. The following are not significant risk factors for postoperative pulmonary complications: obesity and mild or moderate asthma. Recommendation 2: Patients undergoing the following procedures are at higher risk for postoperative pulmonary complications and should be evaluated for other concomitant risk factors and receive pre- and postoperative interventions to reduce pulmonary complications: prolonged surgery (>3 hours), abdominal surgery, thoracic surgery, neurosurgery, head and neck surgery, vascular surgery, aortic aneurysm repair, emergency surgery, and general anesthesia. Recommendation 3: A low serum albumin level (<35 g/L) is a powerful marker of increased risk for postoperative pulmonary complications and should be measured in all patients who are clinically suspected of having hypoalbuminemia; measurement should be considered in patients with 1 or more risk factors for perioperative pulmonary complications. Recommendation 4: All patients who after preoperative evaluation are found to be at higher risk for postoperative pulmonary complications should receive the following postoperative procedures in order to reduce postoperative pulmonary complications: 1) deep breathing exercises or incentive spirometry and 2) selective use of a nasogastric tube (as needed for postoperative nausea or vomiting, inability to tolerate oral intake, or symptomatic abdominal distention). Recommendation 5: Preoperative spirometry and chest radiography should not be used routinely for predicting risk for postoperative pulmonary complications. Preoperative pulmonary function testing or chest radiography may be appropriate in patients with a previous diagnosis of chronic obstructive pulmonary disease or asthma. Recommendation 6: The following procedures should not be used solely for reducing postoperative pulmonary complication risk: 1) right-heart catheterization and 2) total parenteral nutrition or total enteral nutrition (for patients who are malnourished or have low serum albumin levels). Introduction Postoperative pulmonary complications play a significant role in the risk for surgery and anesthesia. The most important and morbid postoperative pulmonary complications are atelectasis, pneumonia, respiratory failure, and exacerbation of underlying chronic lung disease. While clinicians are very conscious of the importance of, and risk factors for, cardiac complications, clinicians who care for patients in the perioperative period may be surprised to learn that postoperative pulmonary complications are equally prevalent and contribute similarly to morbidity, mortality, and length of stay (1-5). Pulmonary complications may also be more likely than cardiac complications to predict long-term mortality after surgery, particularly among older patients (6). This guideline is based on a 2-part systematic review prepared by Smetana and colleagues (7) and Lawrence and colleagues (8). The American College of Physicians (ACP) developed these guidelines to 1) guide clinicians on clinical and laboratory predictors of perioperative pulmonary risk before noncardiothoracic surgery and 2) evaluate the efficacy of strategies to reduce the risk for postoperative pulmonary complications. Studies of immunosuppressive states other than HIV infection (for example, organ transplantation) and of risk factors for postoperative venous thromboembolism were excluded from the review. The target audience is general internists or other clinicians involved in perioperative management of surgical patients. This guideline applies to adult patients undergoing noncardiopulmonary surgery. The perioperative period as defined in the studies ranged from 2 to 3 months before surgery and up to 3 months after surgery. A more in-depth discussion of the methods and the inclusion and exclusion criteria is available in the accompanying background papers in this issue (7, 8). In this paper, patient- and procedure-related risk factors are discussed separately. Patient-Related Risk Factors Potential patient-related risk factors fell into the following general categories: age; chronic lung disease; cigarette use; congestive heart failure; functional dependence; American Society of Anesthesiologists (ASA) classification; obesity; asthma; obstructive sleep apnea; impaired sensorium, abnormal findings on chest examination, alcohol use, and weight loss; and exercise capacity, diabetes, and HIV infection. Age The evidence review found that advanced age is an important predictor of postoperative pulmonary complications, even after adjustment for comorbid conditions. Ten multivariable studies showed that age was a significant risk predictor and was the second most commonly identified risk factor. The odds ratio was 2.09 (95% CI, 1.70 to 2.58) for patients 60 to 69 years of age and 3.04 (CI, 2.11 to 4.39) for those 70 to 79 years of age compared with younger patients (those <60 years of age). Chronic Lung Disease Among studies reporting multivariable analyses, chronic obstructive pulmonary disease was the most commonly identified risk factor for postoperative pulmonary complications (odds ratio, 1.79 [CI, 1.44 to 2.22]). No eligible study determined the incremental risk for postoperative pulmonary complications in patients with chronic restrictive lung disease or restrictive physiologic characteristics due to neuromuscular disease or chest wall deformity, such as kyphoscoliosis. While clinicians may consider such patients with severe limitations to have an increased risk for postoperative pulmonary complications, the literature did not support an estimate of the magnitude of this risk in this group. Cigarette Use The available data are mixed but suggest a modest increase in risk for postoperative pulmonary complications among current smokers. The odds ratio for cigarette use was 1.26 (CI, 1.01 to 1.56). It is important to assess history of current smoking status and support for smoking cessation intervention very early in the preparation for nonemergency surgery. Congestive Heart Failure Good-quality evidence identified congestive heart failure as a significant risk factor for postoperative pulmonary complications (odds ratio, 2.93 [CI, 1.02 to 8.43]). Functional Dependence The evidence review showed that functional dependence is an important predictor of postoperative pulmonary complications. Total dependence was the inability to perform any activities of daily living, and partial dependence was the need for equipment or devices and assistance from another person for some activities of daily living. The odds ratio was 2.51 (CI, 1.99 to 3.15) for total dependence and 1.65 (CI, 1.36 to 2.01) for partial dependence. ASA Classification Several integrated measures of comorbidity have been evaluated as potential predictors of postoperative pulmonary complications. The ASA classification (Table) aims to predict perioperative mortality rates but has since been proven to predict both postoperative pulmonary and cardiac complications (9). Higher ASA class was associated with a substantial increase in risk when an ASA class of II or greater was compared with an ASA class of less than II (odds ratio, 4.87 [CI, 3.34 to 7.10]) and when an ASA class of III or greater was compared with an ASA class of less than III (odds ratio, 2.25 [CI, 1.73 to 3.76]). Table. American Society of Anesthesiologists Classification Obesity Studies evaluating clinically meaningful pulmonary complications after surgery have generally found no increased risk attributable to obesity, even for patients with morbid obesity (10, 11). Definitions of obesity varied from a body mass index of more than 25 kg/m2 to morbid obesity. Postoperative pulmonary complication rates were 6.3% and 7.0% for obese and nonobese patients, respectively, in studies that reported only univariate data. Asthma Good evidence suggested that asthma is not a risk factor for postoperative pulmonary complications. Only 1 of 4 studies that examined the rate of postoperative pulmonary complications among patients with asthma included a control group; the rate in this study was 3%. Obstructive Sleep Apnea Obstructive sleep apnea increases the risk for airway management difficulties in the immediate postoperative period, but its influence on postoperative pulmonary complications has not been well studied. The evidence review identified a single univariate study that evaluated the risk due to obstructive sleep apnea among patients undergoing hip or knee replacement (12). In this casecontrol study, nonsignificant trends were seen toward higher rates of reintubation, hypercapnia, and hypoxemia for patients with obstructive sleep apnea. This finding suggests that postoperative pulmonary complication rates may have been higher among patients with obstructive sleep apnea, but this needs to be confirmed by more studies. Impaired Sensorium, Abnormal Findings on Chest Examination, Alcohol Use, and Weight Loss Fair evidence shows that impaired sensorium, abnormal findings on chest examination, alcohol use, and weight loss modestly increase the risk for postoperative pulmonary complications. Impaired sensorium is defined as 1) an acutely confused or delirious patient who is able to respond to verbal stimulation, mild tactile stimulation, or both, or 2) a patient with mental status changes, delirium, or both in the context of current illness. This definition excludes patients with stable chronic mental illness or dementia. Exercise Capacity, Diabetes, and HIV Infection Evidence was insufficient to support w

Strategies to reduce postoperative pulmonary complications after noncardiothoracic surgery: Systematic review for the American College of Physicians

Postoperative pulmonary complications are as common as cardiac complications for patients undergoing noncardiothoracic surgery (1-6). Further, these complications have similar mortality rates and length of stay after elective abdominal surgery or hip fracture repair (1, 2). In an accompanying systematic review (7), we identify patient, procedure, and laboratory risk factors for postoperative pulmonary complications. Our current systematic review synthesizes the evidence on preventive strategies and focuses on atelectasis, pneumonia, and respiratory failure. While we have written the review primarily for internists, this field crosses specialty disciplines. Methods Literature Search and Selection Criteria We performed a systematic MEDLINE English-language literature search from 1 January 1980 to 30 June 2005. The search strategy and inclusion and exclusion criteria are described in the accompanying review of risk factors and in further detail in its Appendix (7). The search strategy used 1) the Medical Subject Heading (MeSH) terms preoperative care, intraoperative care, postoperative care, intraoperative complications, and postoperative complications as a focus of the article; 2) the MeSH text term perioperative complications as a text term in the title or abstract; and 3) additional MeSH and text terms for pulmonary, respiratory, or cardiopulmonary conditions, complications, or care. In addition, we performed additional focused searches for preoperative chest radiography and spirometry, laparoscopic versus open major abdominal operations, general versus spinal or epidural anesthesia, intraoperative neuromuscular blockade, postoperative pain management, and postoperative lung expansion techniques. Eligible studies were randomized, controlled trials; systematic reviews; or meta-analyses. We excluded studies with less than 25 participants per group; studies from developing countries (because of potential differences in respiratory and intensive care technology); studies that used physiologic (for example, lung volumes and flow, oximetry) rather than clinical outcome measures; studies of gastric pH manipulation; studies of complications that are unique to the surgery (for example, upper airway obstruction after uvulectomy); studies of cardiopulmonary, pediatric, or organ transplantation surgery (because of profoundly immunosuppressive drugs); and studies that used only administrative data to identify postoperative complications (for example, International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM], codes) because of recent evidence that administrative data have poor validity for postoperative complications (8, 9). Assessment of Study Quality We used the Quality of Reporting of Meta-analyses (QUOROM) statement for reporting meta-analyses and the U.S. Preventive Services Task Force criteria for hierarchy of research design to assess internal validity and study quality (good, fair, or poor) and to make conclusions about strength of the evidence (10, 11). Statistical Analysis We used simple means and chi-square tests to calculate CIs and P values when they were not provided in publications. We did not perform quantitative pooling because multiple meta-analyses were beyond the scope of a broad review of multiple potential interventions. We report pooled results from previous meta-analyses when applicable. Role of the Funding Source The Veterans Evidence-based Research, Dissemination, and Implementation Center (VERDICT) (Veterans Affairs Health Services Research and Development, HFP 98-002) provided the research librarian and administrative support for the study. The funding source had no role in the design, conduct, or reporting of the study or in the decision to submit the manuscript for publication. Results The search and inclusion criteria identified 20 randomized clinical trials and 11 systematic reviews or meta-analyses (12-42). Figure 1 in the accompanying review (7) of risk factors for postoperative pulmonary complications details the search results. Appendix Tables 1, 2, 3, 4, 5, 6, and 7 provide detailed characteristics of the eligible randomized trials and systematic reviews. Appendix Table 1. Abstracted Data for Eligible Randomized Trials Appendix Table 2. Abstracted Data for Eligible Randomized Trials, Continued Appendix Table 3. Abstracted Data for Eligible Randomized Trials, Continued Appendix Table 4. Abstracted Data for Eligible Randomized Trials, Continued Appendix Table 5. Abstracted Data for Eligible Randomized Trials, Continued Appendix Table 6. Abstracted Data for Eligible Systematic Reviews and Meta-Analyses Appendix Table 7. Abstracted Data for Eligible Systematic Reviews and Meta-Analyses, Continued Preoperative Smoking Cessation In the only trial of preoperative smoking cessation (12), 108 older, relatively healthy men undergoing hip or knee replacement were randomly assigned to usual care or weekly meetings with a nurse for advice about smoking cessation and nicotine withdrawal plus individualized nicotine replacement for 6 to 8 weeks before surgery until 10 days after surgery. The mean age of the men was 65 years, and 95% were American Society of Anesthesiologists (ASA) physical status class I or II. Of 56 patients in the intervention group, 36 stopped smoking and 14 reduced smoking before surgery. Overall complications rates were lower in the intervention group (18% vs. 52%; P< 0.001), primarily due to fewer wound complications and urinary tract infections. The only pulmonary outcome, postoperative ventilator support, occurred in 1 patient in each group. Nonstatistically significant trends favored shorter mean hospital stay (11 days vs. 13 days; P= 0.41) and fewer cardiac complications (0% vs. 10%; P= 0.08) in the intervention group. Although the trial was of good quality, several factors limit its ability to demonstrate decreased risk for postoperative pulmonary complications. Pulmonary risk is inherently low with hip and knee replacement. Furthermore, the timing of smoking cessation seems important. A previous cohort study showed paradoxically higher postoperative pulmonary complication rates for smokers who stopped or reduced smoking within 2 months before noncardiothoracic surgery (43). Smoking cessation may increase short-term risk because of transiently increased mucus production due to improved mucociliary activity and reduced coughing due to less bronchial irritation. Anesthetic and Analgesic Techniques Anesthetics disrupt central regulation of breathing and result in uncoordinated neural messaging. Due to resulting hypoventilation plus positional dependence, regional atelectasis occurs shortly after induction. It persists postoperatively and is compounded by ongoing disruption of respiratory muscles, limited respiratory excursion due to pain, and disruption of neurally mediated diaphragmatic functions after manipulation of abdominal viscera (43). Neuromuscular Blockade One good-quality trial found no difference in rates of postoperative pulmonary complications between intermediate-acting (atracurium, vecuronium) and long-acting (pancuronium) neuromuscular blocking agents among 691 patients undergoing elective abdominal, gynecologic, or orthopedic surgery (13). However, the incidence of residual neuromuscular block was higher among patients receiving pancuronium (26% vs. 5%; P< 0.001). Patients with residual blockade after pancuronium were 3 times more likely to develop postoperative pulmonary complications than those without residual block (17% vs. 5%; P< 0.02). In contrast, among patients receiving intermediate-acting agents, postoperative pulmonary complication rates did not differ between those with (4%) and without (5%) prolonged blockade. Therefore, pancuronium may directly lead to higher rates of prolonged neuromuscular blockade and indirectly to increased pulmonary risk compared with shorter-acting agents. Anesthesia and Analgesia Neuraxial blockade (either spinal or epidural anesthesia) blocks a constellation of stress responses to surgery (neuroendocrine, cytokine, and pain threshold) and may improve recovery and prevent complications (44). Postoperative epidural analgesia may reduce respiratory muscle dysfunction and pain-related hypoventilation. The epidural approach involves either a single injection or an infusion and can be used for both intraoperative anesthesia and postoperative analgesia. Spinal anesthesia has a faster onset (5 to 10 minutes vs. 15 to 20 minutes), produces denser sensory and motor block, and is technically easier than epidural anesthesia. However, spinal anesthesia is administered only as a single injection because of practical constraints of indwelling intrathecal catheters. The possible benefit of neuraxial blockade has generated studies of general versus neuraxial blockade anesthesia, followed by trials comparing epidural analgesia to other modes of analgesic delivery (for example, oral, intramuscular, intravenous, patient-controlled analgesia) and, more recently, trials of combined epidural intraoperative anesthesia and epidural postoperative analgesia. Intraoperative General Anesthesia versus Neuraxial Blockade A recent good-quality meta-analysis combined 141 trials (n= 9559) comparing general anesthesia and neuraxial blockade in patients undergoing a variety of operations (32). The authors compared patients receiving neuraxial blockade (with or without concomitant general anesthesia) with those receiving only general anesthesia. Neuraxial blockade reduced overall mortality (2% vs. 3%; odds ratio, 0.70 [95% CI, 0.54 to 0.90]), pneumonia (3% vs. 5%; odds ratio, 0.61 [CI, 0.48 to 0.76]), and respiratory failure (0.5% vs. 0.8%; odds ratio, 0.41 [CI, 0.23 to 0.73]). In a subgroup analysis of trials of neuraxial blockade alone versus general anesthesia alone, results were similar (odds ratio, 0.63 [CI, 0.46 to 0.87] for pneumonia; odds ratio, 0.37 [CI, 0.11 to 1.21] for respiratory failure). Potential sources of bi

Incidence and hospital stay for cardiac and pulmonary complications after abdominal surgery.

OBJECTIVE: Internists frequently evaluate preoperative cardiopulmonary risk and comanage cardiac and pulmonary complications, but the comparative incidence and clinical importance of these complications are not clearly delineated. This study evaluated incidence and length of stay for both cardiac and pulmonary complications after elective laparotomy.DESIGN: Nested case-control.SETTING: University-affiliated Department of Veterans Affairs Hospital.PATIENTS: Computerized registry of all 2,291 patients undergoing elective abdominal operations from 1982 to 1991.MEASUREMENT AND MAIN RESULTS: Strategy for ascertainment and verification of complications was systematic and explicit. The charts of all 116 patients identified by the registry as having complications and 412 (19%) randomly selected from 2,175 remaining patients were reviewed to verify presence or absence of cardiac or pulmonary complications, using explicit criteria and independent abstraction of pre- and postoperative components of charts. From these 528 validated cases and controls (23% of the cohort), 96 cases and 96 controls were matched by operation type and age within ten years. Hospital and intensive care unit stays were significantly longer (p<0.0001) for the cases than for the controls (24.1 vs 10.3 and 5.8 vs 1.5 days, respectively). All 19 deaths occurred among the cases. Among the cases, pulmonary complications occurred significantly more often than cardiac complications (p<0.00001) and were associated with significantly longer hospital stays (22.7 vs 10.4 days, p=0.001). Combined cardiopulmonary complications occurred among 26% of the cases. Misclassification-corrected incidence rates for the entire cohort were 9.6% (95% CI 7.2–12.0) for pulmonary and 5.7% (95% CI 3.8–7.7) for cardiac complications.CONCLUSIONS: For noncardiac surgery, previous research has focused on cardiac risk. In this study, pulmonary complications were more frequent, were associated with longer hospital stay, and occurred in combination with cardiac complications in a substantial proportion of cases. These results suggest that further research is needed to fully characterize the clinical epidemiology of postoperative cardiac and pulmonary complications and better guide preoperative risk assessment.

Higher Hb level is associated with better early functional recovery after hip fracture repair

BACKGROUND: The benefits and indications for blood transfusion are controversial. One possible reason to transfuse is to improve functional recovery after major surgery. However, the data linking improved function with higher Hb concentration are limited.

Clinical studyMilk thistle for the treatment of liver disease: A systematic review and meta-analysis☆

PURPOSE Milk thistle, an herbal compound, is the dietary supplement taken most frequently by patients with chronic liver disease. We performed a systematic review of the literature to determine the efficacy and safety of this herb for the treatment of liver disease. METHODS We searched English and non-English reports through July 1999 using thirteen databases and reference lists, and contacting manufacturers and technical experts. Reviewers independently screened all reports to identify randomized placebo-controlled trials that evaluated milk thistle for the treatment of liver disease. Outcomes of primary interest included mortality, histological findings on liver biopsy specimens, serum aminotransferase and albumin levels, and prothrombin times. RESULTS Fourteen trials met inclusion criteria. Four trials reported outcomes for mortality among 433 participants. The overall summary odds ratio for mortality in the milk thistle group compared with placebo was 0.8 (95% confidence interval [CI]: 0.5 to 1.5; P = 0.6). Three trials assessed histology on liver biopsy; study quality was inversely associated with the likelihood of histological benefit for milk thistle compared with placebo. There were no differences in serum alanine aminotransferase, aspartate aminotransferase, or albumin levels, or prothrombin times, among participants assigned to milk thistle compared with those assigned to placebo. The only statistically significant difference was a greater reduction in alanine aminotransferase levels among patients with chronic liver disease assigned to milk thistle (-9 IU/L, 95% CI: -18 to -1 IU/L; P = 0.05), but this reduction was of negligible clinical importance and no longer statistically significant after limiting analyses to studies of longer duration or of higher quality. The frequency of adverse effects was low and, in clinical trials, indistinguishable from placebo. CONCLUSION Treatment with milk thistle appears to be safe and well tolerated. We found no reduction in mortality, in improvements in histology at liver biopsy, or in biochemical markers of liver function among patients with chronic liver disease. Data are too limited to exclude a substantial benefit or harm of milk thistle on mortality, and also to support recommending this herbal compound for the treatment of liver disease.

Preoperative evaluation for postoperative pulmonary complications.

Preoperative risk assessment for postoperative pulmonary complications is essential when counseling patients about the risks of surgery because of their significant associated morbidity and mortality. There are many patient-related, operation-related, and anesthesia-related risk factors for the development of PPCs. Though many of these risk factors are not modifiable, they can be useful in evaluating preoperative risk, especially when combined into formal risk indices. Preoperative risk assessment enables clinicians to target preoperative testing and perioperative risk reduction strategies to high-risk patients. Reducing PPC risk at the patient level will require a greater understanding of the impact of modifying risk factors through interventional trials. Reducing hospital PPC rates will require future research into the processes of care associated with PPCs through controlled observational and interventional trials.

Patterns of primary care and mortality among patients with schizophrenia or diabetes: a cluster analysis approach to the retrospective study of healthcare utilization

BackgroundPatients with schizophrenia have difficulty managing their medical healthcare needs, possibly resulting in delayed treatment and poor outcomes. We analyzed whether patients reduced primary care use over time, differentially by diagnosis with schizophrenia, diabetes, or both schizophrenia and diabetes. We also assessed whether such patterns of primary care use were a significant predictor of mortality over a 4-year period.MethodsThe Veterans Healthcare Administration (VA) is the largest integrated healthcare system in the United States. Administrative extracts of the VAs all-electronic medical records were studied. Patients over age 50 and diagnosed with schizophrenia in 2002 were age-matched 1:4 to diabetes patients. All patients were followed through 2005. Cluster analysis explored trajectories of primary care use. Proportional hazards regression modelled the impact of these primary care utilization trajectories on survival, controlling for demographic and clinical covariates.ResultsPatients comprised three diagnostic groups: diabetes only (n = 188,332), schizophrenia only (n = 40,109), and schizophrenia with diabetes (Scz-DM, n = 13,025). Cluster analysis revealed four distinct trajectories of primary care use: consistent over time, increasing over time, high and decreasing, low and decreasing. Patients with schizophrenia only were likely to have low-decreasing use (73% schizophrenia-only vs 54% Scz-DM vs 52% diabetes). Increasing use was least common among schizophrenia patients (4% vs 8% Scz-DM vs 7% diabetes) and was associated with improved survival. Low-decreasing primary care, compared to consistent use, was associated with shorter survival controlling for demographics and case-mix. The observational study was limited by reliance on administrative data.ConclusionRegular primary care and high levels of primary care were associated with better survival for patients with chronic illness, whether psychiatric or medical. For schizophrenia patients, with or without comorbid diabetes, primary care offers a survival benefit, suggesting that innovations in treatment retention targeting at-risk groups can offer significant promise of improving outcomes.

Postoperative complications in the seriously mentally ill: A systematic review of the literature

Objective:To determine the knowledge base on clinical outcomes of surgery among persons diagnosed with serious mental illness. Background:Despite a burgeoning literature during the last 20 years regarding perioperative risk management, little is known about intraoperative and postoperative complications among patients with schizophrenia and other serious mental illnesses. Methods:A systematic literature search of Medline (1966–August 2007) and review of studies was conducted. Eligible studies were of any design with at least 10 patients diagnosed with serious mental illness, reporting perioperative medical, surgical, or psychiatric complications. Results:The search identified 1367 potentially relevant publications; only 12 met eligibility criteria. Of 10 studies of patients with schizophrenia, 9 had fewer than 100 patients, whereas one large retrospective study reported higher rates of postoperative complications among 466 schizophrenia patients compared with 338,257 controls. These studies suggest that patients with schizophrenia, compared with those without mental illness, may have higher pain thresholds, higher rates of death and postoperative complications, and differential outcomes (eg, confusion, ileus) by anesthetic technique. Two studies evaluated outcomes in patients with major depressive disorder and found higher rates of postoperative delirium and postoperative confusion. Both schizophrenia and depression patients experienced more postoperative confusion or delirium when psychiatric medications were discontinued preoperatively. We identified no studies of perioperative outcomes in patients with bipolar or posttraumatic stress disorder. Conclusions:There are few studies of perioperative outcomes in patients with serious mental illness. Future research should assess surgical risks among patients with serious psychiatric conditions using rigorous methods and well-defined clinical outcomes.

Definition, Incidence, Risk Factors, and Prevention of Paralytic Ileus Following Radical Cystectomy: A Systematic Review

CONTEXT Postoperative paralytic ileus (POI) has profound clinical consequences because it represents a substantial burden on both patients and health care resources. OBJECTIVE To determine the knowledge base regarding POI in the radical cystectomy (RC) population with an emphasis on preventive measures and risk factors. EVIDENCE ACQUISITION A systematic literature search of Medline (1966 to February 2011) and a study review were conducted. Eligible studies explicitly reported the incidence of POI and/or at least two quantitative measures of gastrointestinal recovery. EVIDENCE SYNTHESIS The search identified 727 relevant articles; 77 met eligibility criteria, comprising 13 793 patients. Of these, 21 used explicit definitions of POI, and they varied widely. Across studies, the incidence of POI ranged from 1.58% to 23.5%. Possible risk factors for POI included increasing age and body mass index. Seventeen studies reported effects of an intervention on POI: 3 randomized controlled studies, 11 observational cohort studies with concurrent comparison, and 3 observational cohort studies with nonconcurrent comparison. Gum chewing was associated with shortened times to flatus (2.4 vs 2.9 d; p<0.0001) and bowel movement (BM) (3.2 vs 3.9 d; p<0.001) in one observational cohort study (n=102); omission of a postoperative nasogastric tube (NGT) was associated with shorter time to flatus (4.21 vs 5.33 d; p=0.0001) and shorter length of stay (14.4 vs 19.1 d; p=0.001) in one observational cohort study (n=430); and the routine use of bowel preparation was associated with an increased incidence of POI (5% vs 19%) in another series (n=86). Additionally, readaptation of the dorsolateral peritoneal layer was shown to shorten times to flatus (p=0.016) and times to BM (p=0.011) in one randomized controlled study (n=200). CONCLUSIONS The incidence/definition of POI after RC is highly variable. An improved reporting strategy is needed to identify true incidence and risk factors, and to guide future research for both potential preventive and therapeutic interventions.