Risk of intraoperative hypotension with loop diuretics: a randomized controlled trial.

BACKGROUND: There is growing concern regarding the safety of blood pressure-lowering medications administered during the perioperative period. Whether loop diuretics also induce intraoperative hypotension is uncertain. Our objective was to compare the effects of continuing or withholding furosemide on the day of noncardiac elective surgery on intraoperative hypotension among chronic users of furosemide. METHODS: A double blind, randomized, placebo controlled trial was conducted at 3 North American university centers between September 2000 and December 2006. Participants were randomly assigned in a 1:1 ratio to receive either furosemide or placebo on the day of surgery. The primary outcome was risk of developing intraoperative hypotension. A priori secondary outcomes included risk of heart failure; composite cardiovascular event (myocardial infarction, arrhythmia, stroke or transient ischemic attack, or death); and change in renal function and electrolytes. RESULTS: Of the 212 patients enrolled, 193 patients underwent surgery. There was no significant difference in risk of developing intraoperative hypotension between the furosemide (49%) and placebo (51.9%) groups (relative risk [RR], 0.95; 95% confidence interval [CI], 0.72-1.24; P = .78). The intraoperative administration of vasopressors and fluids were similar between both groups. The risk of developing postoperative cardiovascular events was not significantly different between those randomized to furosemide (4.8%) or placebo (2.8%) (RR, 1.73; 95% CI, 0.42-7.06; P = .49). There was no significant difference in renal function or electrolytes between the 2 groups. CONCLUSION: Among elective, noncardiac surgeries in patients chronically treated with furosemide, the administration of furosemide on the day of surgery did not significantly increase the risk for intraoperative hypotension.

Prospective evaluation of the clinical prediction of electrodiagnostic results in carpal tunnel syndrome.

OBJECTIVE: To develop a unique clinical prediction point-score system for the diagnosis of carpal tunnel syndrome (CTS) and to prospectively evaluate this clinical rule to determine its ability to predict electrodiagnostic results. DESIGN: Retrospective case control to develop the clinical point-score system and then prospective diagnostic study with blind comparison to electrodiagnostic results. SETTING: Community-based electrodiagnostic laboratory. PATIENTS: A total of 348 subjects referred to the electrodiagnostic laboratory with a clinical suspicion of CTS to develop the clinical point-score system and then a different population of 278 subjects referred to the electrodiagnostic laboratory over a 1-year period with a clinical suspicion of CTS to prospectively evaluate the ability of the clinical rule to predict electrodiagnostic results. MAIN OUTCOME MEASURES: Clinical point-score system results were compared with the electrodiagnostic results for CTS, which served as the primary outcome measure. RESULTS: A "weighted" point-score system was developed from 9 clinical variables including: gender, duration of symptoms, presence of wrist pain (negative predictor), presence of neck pain (negative predictor), nocturnal symptoms, presence of thenar atrophy, abductor pollicis brevis weakness, median sensory symptoms, and results of pinprick sensation examination. The prospective evaluation indicated that the clinical point-score rule, overall, performed moderately in predicting electrodiagnostic results (receiver operator characteristic curve = 0.80). The clinical point score was most predictive in a small subset of subjects with very high scores. However, in most subjects, the clinical point score could not accurately predict electrodiagnostic outcome in CTS, particularly in subjects with middle to low clinical point scores. CONCLUSIONS: The developed clinical point-score rule was most predictive in subjects with high point score; however, the majority of the referrals to the electrodiagnostic laboratory indicated that the electrodiagnostic studies provided additional, independent information beyond what could be obtained by the clinical point score.

Delayed transfers of older people from hospital: Causes and policy implications.

Health and social care agencies in the UK. have been under pressure for some time to reduce delayed transfers of older people from hospital because they absorb scarce health service resources and incur a human cost through inappropriate placement. A local study based on an analysis of records and interviews with managers showed that delays reflect the complex needs of older people, and arise from financing and organisational problems at both the planning and implementation stages of a discharge. Family resistance may also be a factor. Budgetary constraints result in delays in confirming public support for some clients. Shortages of professional staff and care assistants limit the provision of domiciliary packages. The contraction of the residential sector has reduced the availability of beds and increased the cost of care home placements. Scope exists for expediting administrative aspects of transfers by coordinating health and social services. More recent legislation that imposes fines on social service departments for delayed transfers does not address underlying causes.

Perioperative cardiac events in patients undergoing noncardiac surgery: a review of the magnitude of the problem, the pathophysiology of the events and methods to estimate and communicate risk.

This is the first of 2 articles evaluating cardiac events in patients undergoing noncardiac surgery. In this article, we review the magnitude of the problem, the pathophysiology of these events, approaches to risk assessment and communication of risk. The number of patients undergoing noncardiac surgery worldwide is growing, and annually 500,000 to 900,000 of these patients experience perioperative cardiac death, nonfatal myocardial infarction (MI) or nonfatal cardiac arrest. Although the evidence is limited, a substantial proportion of fatal perioperative MIs may not share the same pathophysiology as nonoperative MIs. A clearer understanding of the pathophysiology is needed to direct future research evaluating prophylactic, acute and long-term interventions. Researchers have developed tools to facilitate the estimation of perioperative cardiac risk. Studies suggest that the Lee index is the most accurate generic perioperative cardiac risk index. The limitations of the studies evaluating the ability of noninvasive cardiac tests to predict perioperative cardiac risk reveals considerable uncertainty as to the role of these popular tests. Similarly, there is uncertainty as to the predictive accuracy of the American College of Cardiology/American Heart Association algorithm for cardiac risk assessment. Patients are likely to benefit from improved estimation and communication of cardiac risk because the majority of noncardiac surgeries are elective and accurate risk estimation is important to allow informed patient and physician decision-making.

Surveillance and prevention of major perioperative ischemic cardiac events in patients undergoing noncardiac surgery: a review.

This is the second of 2 articles evaluating cardiac events in patients undergoing noncardiac surgery. Unrecognized myocardial infarctions (MIs) are common, and up to 50% of perioperative MIs may go unrecognized if physicians rely only on clinical signs or symptoms. In this article, we summarize the evidence regarding monitoring strategies for perioperative MI in patients undergoing noncardiac surgery. Perioperative troponin measurements and 12-lead electrocardiograms can detect clinically silent MIs and provide independent prognostic information. Currently, there are no standard diagnostic criteria for perioperative MIs in patients undergoing noncardiac surgery. We propose diagnostic criteria that reflect the unique features of perioperative MIs. Finally, we review the evidence for perioperative prophylactic cardiac interventions. There is encouraging evidence that some perioperative interventions (e.g., beta-blockers, alpha2-adrenergic agonists, statins) may prevent major cardiac ischemic events, but firm conclusions await the results of large definitive trials. The best evidence does not support a management strategy of preoperative coronary revascularization before noncardiac surgery.

Community-based referrals for electrodiagnostic studies in patients with possible carpal tunnel syndrome: what is the diagnosis?

OBJECTIVES: To determine what proportion of patients referred with a clinical suspicion of carpal tunnel syndrome (CTS) have negative electrodiagnostic studies and identify their clinical diagnoses and to identify clinical features that predict the outcome of electrodiagnostic testing in patients referred with suspected CTS. DESIGN: Retrospective review of patients consecutively referred to the electrodiagnostic center with suspected CTS over a 1-year period. SETTING: Community-based electrodiagnostic center. PARTICIPANTS: Three hundred forty-eight patients with suspected CTS. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The diagnosis of CTS was based on the electrodiagnostic findings. RESULTS: Of the 348 patients enrolled, 179 (51.4%) had electrodiagnostic studies that were inconsistent with a diagnosis of CTS. Twenty-seven patients (15.1%) had other electrodiagnostic abnormalities (eg, ulnar neuropathy, cervical radiculopathy), whereas the remaining 152 (84.9%) patients had studies within normal limits. Seventy-one patients (46.7%) with normal studies were diagnosed with musculoskeletal disorders, with myofascial pain and musculotendinous strain being most common. By using a multiple logistic regression model, clinical variables that may predict the outcome of electrodiagnostic testing for CTS included gender, duration of symptoms, nocturnal symptoms, sensory symptoms, wrist pain, neck pain, pinprick sensation, abductor pollicis brevis strength, and thenar bulk. CONCLUSIONS: Many patients referred to an electrodiagnostic laboratory with a clinical suspicion of CTS have other diagnoses, most commonly musculoskeletal disorders. Because these various conditions may be mistaken for CTS, the electrodiagnostic evaluation is therefore an important diagnostic tool. Although traditional clinical findings including Tinel and Phalen sign were found to have limited clinical use, further validation of the groups of positive and negative clinical features may potentially enable the referring physician to identify more accurately patients who would benefit most from electrodiagnostic testing.