Preoperative pulse pressure and major perioperative adverse cardiovascular outcomes after lower extremity vascular bypass surgery.

BACKGROUND: Preoperative increased pulse pressure (PP) has been found to be a predictor of major adverse cardiovascular events (MACEs) after coronary artery bypass graft surgery. In this study, we evaluated the predictive ability of increased preoperative PP to identify MACEs in patients with peripheral vascular disease undergoing lower extremity vascular bypass surgery. METHODS: We used the prospectively collected vascular surgery database at our institution to identify 412 consecutive patients who had lower extremity bypass surgery between January 2003 and December 2004. Preoperative demographics including comorbidities, medications, intraoperative characteristics, and postoperative MACE outcomes (myocardial infarction, congestive heart failure, stroke, and in-hospital mortality) were recorded. PP data as a continuous and categorical variable (PP <80 or ≥80 mm Hg) were tested for the ability to predict postoperative MACEs. A final parsimonious logistic regression was built to evaluate the predictive ability of PP. RESULTS: MACEs occurred in 5.7% of patients in the PP <80 mm Hg group compared with 8.8% in the PP ≥80 mm Hg group (P = 0.229). Patients with MACEs were older (76 ± 10 years vs 68 ± 12 years; P = 0.001), had a history of myocardial infarction (9% vs 4%; P = 0.049), and had a preoperative PP of 75 ± 19 mm Hg vs 71 ± 21 mm Hg (P = 0.306). In the final logistic regression model, only age in years was a predictor of MACEs (odds ratio, 1.062; 95% confidence interval, 1.02-1.10; P = 0.02). There was no relationship between PP ≥80 mm Hg and risk for MACEs (odds ratio, 1.36; 95% confidence interval, 0.62-2.90; P = 0.44). CONCLUSIONS: Preoperative increase in PP is not a predictor of adverse cardiovascular outcomes in patients having lower extremity revascularization surgery.

Monitoring the variation in myocardial function with the Doppler-derived myocardial performance index during aortic cross-clamping.

OBJECTIVES: To investigate the effects of acute elevation in afterload on global (systolic and diastolic) myocardial function by performing serial intraoperative transesophageal echocardiograms during and after cross-clamp application on patients undergoing elective abdominal aortic aneurysm (AAA) surgery. DESIGN: A prospective observational study. SETTING: A tertiary care university hospital. PARTICIPANTS: Patients undergoing elective AAA repair under general anesthesia (GA). INTERVENTION: The use of perioperative transesophageal echocardiography to calculate a tissue Doppler-derived myocardial performance index (MPI) during different stages of the surgery. MEASUREMENT AND RESULTS: Twenty consecutive patients scheduled for suprarenal AAA repair under GA were included in the study. Perioperative transesophageal echocardiography was performed after the induction of GA. MPI was calculated with Doppler tissue imaging as the sum of isovolumetric contraction and relaxation times divided by the ejection time before cross-clamping of the aorta and then 2, 10, and 20 minutes after cross-clamp application. A final MPI was measured after unclamping of the aorta. As compared with baseline, cross-clamp application initially worsened MPI within 2 minutes and then MPI improved to baseline after 10 minutes of cross-clamp application. The MPI improved significantly after unclamping of the aorta. CONCLUSIONS: The authors observed a temporal variation in global myocardial function after the application of a cross-clamp in the suprarenal position. There was transient deterioration of global myocardial function (the prolongation of MPI) 2 minutes after cross-clamp application, which improved within 10 minutes. Myocardial function returned to baseline after unclamping the aorta.

Systematic review of radiofrequency ablation and pulsed radiofrequency for management of cervicogenic headache.

BACKGROUND: Cervicogenic headache is a secondary headache that has a source in the upper cervical spine. There is a small but growing body of evidence to establish effectiveness of radiofrequency (RF) neurotomy, and the pulsed RF (PRF) procedure for management of cervicogenic headache. OBJECTIVE: To investigate the clinical utility of RF neurotomy, and PRF ablation for the management of cervicogenic headache. STUDY DESIGN: Systematic review. METHODS: The review included relevant literature identified through searches of PubMed, Cochrane, Clinical trials, U.S. National Guideline Clearinghouse and EMBASE from 1960 to January 2014.The quality assessment and clinical relevance criteria utilized were the Cochrane Musculoskeletal Review Group criteria for randomized control trials and the Newcastle-Ottawa Scale criteria for observational studies. The level of evidence was classified as good, fair, and poor based on the quality of evidence. OUTCOMES MEASURED: The primary outcome measures were reduction in pain scores and improvement in quality of life. RESULTS: The primary outcome measures were headache relief and improved quality of life. Twenty five studies were identified for full text review of these, 9 studies met inclusion criteria. There were 5 non-randomized, among them 4/5 were of moderate quality, 3/5 showed RF ablation and 1/5 showed PRF as an effective intervention for cervicogenic headache. There were 4 randomized trials among them 2/4 were of high quality, 3/4 investigated RF ablation as an intervention for CHA, 1/4 investigated PRF ablation as an intervention for CHA and none of the randomized studies showed strong evidence for RF and PRF ablation as an effective intervention for CHA. LIMITATIONS: In the selected studies there were inconsistencies between randomized trials, flaws in trial design, and gaps in the chain of evidence. CONCLUSION: There is limited evidence to support RF ablation for management of CHA as there are no high quality RCTs and/ or multiple consistent non-RCTs without methodological flaws. There is poor evidence to support PRF for CHA as there are no high quality RCTs or Non-RCTs.