A simple tissue-handling technique performed in the endoscopy suite improves histologic section quality and diagnostic accuracy for serrated polyps.

BACKGROUND AND STUDY AIMS: Surveillance intervals after colonoscopic resection of serrated polyps are partially predicated on the histology of the polyp(s) removed during the index exam. Histologic discrimination between sessile serrated adenomas/polyps (SSA/P) and hyperplastic polyps is challenging. We devised and tested a simple tool--an envelope--that gastroenterologists can integrate into routine colonoscopy practice to address this problem. METHODS: In the "modified protocol," immediately after polypectomy each serrated polyp was flattened and enclosed in a paper envelope before being placed in formalin. In the pathology laboratory, each polyp was sectioned after processing. A two-site, prospective, randomized, single-blinded trial was performed to compare this modified protocol with the conventional protocol. Serrated polyps located proximal to the splenic flexure and 5-20 mm in diameter were included. A novel orientation score that measured the number of well-oriented crypts per unit area of polyp (higher orientation score = better orientation) was validated. Orientation score, SSA/P diagnosis rate, and inter-pathologist agreement were measured. RESULTS: A total of 375 polyps were enrolled, of which 264 were identified for analysis. The mean orientation scores in the modified and conventional protocol groups were 3.11 and 1.13, respectively (P < 0.0001). SSA/Ps were diagnosed in 103/135 cases (76.3%) in the modified protocol group vs. 54/129 (41.9%) in the conventional protocol group (P < 0.0001). Inter-pathologist agreement was higher with the modified than the conventional protocol (77.0% vs. 62.8%; P = 0.015). CONCLUSION: Standard polyp handling techniques may be sub-optimal for interpretation of serrated polyps resected at colonoscopy, and may lead to inadvertent histologic "under-grading" of many lesions. Our intervention improved histopathologic interpretation and increased the SSA/P diagnosis rate.

Vocal cord paralysis after aortic surgery.

OBJECTIVE: The purpose of this study was to investigate variables associated with vocal cord paralysis during complex aortic procedures. DESIGN: A retrospective review. SETTING: A tertiary care center. PARTICIPANTS: Four hundred ninety-eight patients who underwent aortic surgery between 2002 and 2007. METHODS: Two groups were studied. Group A patients had procedures only involving their aortic root and/or ascending aorta. Group B patients had procedures only involving their aortic arch and/or descending aorta. RESULTS: The incidence of vocal cord paralysis was higher (7.26% v 0.8%) in group B patients (p < 0.0001). Increasing the duration of cardiopulmonary bypass time was associated with an increased risk of vocal cord paralysis and death in both groups A and B (p = 0.0002 and 0.002, respectively). Additionally, within group B, descending aneurysms emerged as an independent risk factor associated with vocal cord paralysis (p = 0.03). Length of stay was statistically significantly longer among group A patients who suffered vocal cord paralysis (p = 0.017) and trended toward significance in group B patients who suffered vocal cord paralysis (p = 0.059). The association between tracheostomy and vocal cord paralysis among group A patients reached statistical significance (p = 0.007) and trended toward significance in group B patients (p = 0.057). CONCLUSIONS: Increasing duration of cardiopulmonary bypass time was associated with a higher risk of vocal cord paralysis in patients undergoing aortic surgery. Additionally, within group B patients, descending aortic aneurysm was an independent risk factor associated with vocal cord paralysis. Most importantly, vocal cord paralysis appeared to have an association between an increased length of stay and tracheostomy among a select group of patients undergoing aortic surgery.

Is production pressure jeopardizing the quality of colonoscopy? A survey of U.S. endoscopists' practices and perceptions.

BACKGROUND: Fatigue is an underestimated cause of underperformance among physicians. There is evidence that fatigue or other byproducts of production pressure may negatively influence the quality of colonoscopy. OBJECTIVE: To investigate the practices and perceptions of U.S. endoscopists regarding the effect of production pressure on the performance of colonoscopy. DESIGN: We conducted a 40-question online survey to assess endoscopists' practices and perceptions concerning production pressure. SETTING: A total of 5030 U.S. American Society for Gastrointestinal Endoscopy members. MAIN OUTCOME MEASUREMENTS: The proportion of endoscopists responding positively to questions pertaining to the impact of production pressure on colonoscopy practice. RESULTS: Ninety-two percent of respondents indicated that production pressure influenced one or more aspects of their endoscopic practices. Examples of production pressure included (1) postponing polypectomy for a subsequent session (2.8%), (2) reducing the length of time spent inspecting the colon (7.2%), and (3) proceeding with colonoscopy in a patient with an unfavorable risk/benefit ratio (69.2%). Forty-eight percent of respondents reported witnessing the effects of production pressure on a colleague. Respondents working fee-for-service and those with >10 years since completion of fellowship were more likely to describe their weekly workloads as excessive compared with those who were salaried (81.3% vs 71.3%; P = .01) and <10 years out of training (81% vs 72.7%; P = .01). LIMITATIONS: Nonresponse bias due to low response rate (22.3%). CONCLUSION: Production pressure influences the conduct of colonoscopy for many endoscopists and could have an adverse effect on the outcome of colorectal cancer screening. ( CLINICAL TRIAL REGISTRATION NUMBER: RE:GIE D 11-01288R1.) The study was an Internet study and did not involve human subjects.

Methohexital and succinylcholine dosing for electroconvulsive therapy (ECT): actual versus ideal.

This report compares the actual doses of methohexital and succinylcholine used for optimal anesthesia and muscle relaxation in electroconvulsive therapy with written guidelines for dosing. The initial doses of methohexital and succinylcholine in milligrams per kilogram were reviewed and compared with subsequent doses of each agent after adjustments were made for individual patient responses during treatment. The dose of methohexital required to induce general anesthesia for most patients is 1.0 mg/kg. The dose of succinylcholine required to provide adequate muscle relaxation during electroconvulsive therapy is 0.9 mg/kg, although there is considerable variability in patient response to this drug.

The detection of premalignant colon polyps during colonoscopy is stable throughout the workday.

BACKGROUND: Recent studies have shown that colonoscopic polyp detection decreases as the workday progresses. This may reflect time-dependent factors such as colonoscopist fatigue and decreased colon cleanliness, which can be addressed through adaptations in colonoscopy practice. OBJECTIVE: To test for time-of-day differences in adenomatous polyp (AP) and sessile serrated polyp (SSP) detection in a practice that uses split-dose bowel preparation and moderated daily colonoscopist procedure loads. DESIGN: Retrospective chart review. SETTING: Community-based, group gastroenterology practice. PATIENTS: This study involved 2439 patients undergoing surveillance or screening colonoscopy. INTERVENTION: Colonoscopy. MAIN OUTCOME MEASUREMENTS: Detection rate of all premalignant polyps (PMPs), and of APs and SSPs, individually. RESULTS: A total of 1183 PMPs were identified in 1486 eligible patients (mean PMP/colonoscopy = 0.80; PMP detection rate = 47%). In univariate and multivariate analyses, PMP detection as well as detection of APs or SSPs individually did not vary significantly in relation to the hour of the day. In a binary comparison of morning (am) versus afternoon (pm) procedures, the total polyp detection rate was 67% and 66%, respectively. For PMPs, APs, SSPs, and hyperplastic polyps (HPs), the am and pm detection rates were 46% and 47%, 41% and 44%, 8% and 8%, and 27% and 24%, respectively. Bowel preparation quality was independent of time of day and was rated excellent or good in 86% to 87% of cases. LIMITATIONS: Retrospective, nonrandomized study. CONCLUSION: Stable PMP, AP, SSP, and HP detection rates throughout the workday occur under certain practice conditions, including the use of split-dose bowel preparation and/or moderated daily colonoscopist procedure loads.

A morphologic analysis of sessile serrated polyps observed during routine colonoscopy (with video).

BACKGROUND: Proximal colorectal cancer may arise from sessile serrated polyps (SSPs), which are often inconspicuous during colonoscopy. The gross morphologic characteristics of SSPs have not been systematically described, and this omission may contribute to colonoscopists overlooking them. OBJECTIVES: To analyze the gross morphologic characteristics of SSPs detected during routine colonoscopy. DESIGN: Retrospective analysis of high-resolution endoscopic video clips depicting SSPs in situ. SETTING: Outpatient gastroenterology practice. PATIENTS: A total of 124 subjects undergoing surveillance or screening colonoscopy after split-dose bowel preparation. INTERVENTIONS: Analysis of 158 SSPs performed by using validated descriptors. MAIN OUTCOME MEASUREMENTS: The prevalence of morphologic characteristics related to polyp shape, color, and texture. RESULTS: A total of 158 SSPs were studied. For 7 visual descriptors, a κ coefficient of ≥ 0.7 was achieved, indicating good to excellent intraobserver agreement. The most prevalent visual descriptors were the presence of a mucous cap (63.9%), rim of debris or bubbles (51.9%), alteration of the contour of a fold (37.3%), and interruption of the underlying mucosal vascular pattern (32.3%). The most common "sentinel signs" were the presence of a mucous cap and alteration of the contour of a mucosal fold (each 24.6%), rim of debris or bubbles (21.7%), and a dome-shaped protuberance (20.3%). When comparing SSPs with adenomatous polyps, the frequencies of 5 of 7 morphologic characteristics and the distribution of sentinel signs differed (P < .01). LIMITATIONS: Single-site, retrospective analysis. CONCLUSIONS: SSPs exhibit distinct, variable morphologic characteristics. Many do not display classic features such as a mucous cap. Enhanced appreciation of these morphologic characteristics may improve SSP detection and thereby colorectal cancer prevention.

Is gastroduodenal biopsy safe in patients receiving aspirin and clopidogrel?: a prospective, randomized study involving 630 biopsies.

GOALS: To assess prospectively the bleeding risk attributable to gastroduodenal biopsy in subjects taking antiplatelet medications. BACKGROUND: No prospective data exist regarding the bleeding risk attributable to endoscopic biopsy in patients taking antiplatelet agents. A majority of Western endoscopists withdraw antiplatelet agents before upper endoscopy, despite expert guidelines to the contrary. STUDY: We performed a prospective, single-blind, randomized study in healthy volunteers participating in a larger study regarding the effect of antiplatelet agents on gastroduodenal mucosal healing. Multiple gastroduodenal biopsies were performed during 2 esophagogastroduodenoscopy in subjects dosed with aspirin enteric-coated 81 mg once daily or clopidogrel 75 mg once daily. Data for endoscopic bleeding, clinical bleeding, blood vessel size, and depth of biopsy in histology specimens were collected. RESULTS: Four hundred and five antral biopsies and 225 duodenal biopsies were performed during 90 esophagogastroduodenoscopy in 45 subjects receiving aspirin or clopidogrel. Median maximum blood vessel diameter per biopsy was 31.9 µ (range: 9.2 to 133.8). About 50.8% of biopsy specimens breached the muscularis mucosa. In the clopidogrel group, no bleeding events were noted after 350 biopsies [upper confidence limit (UCL) for probability of bleeding=0.0085]. In the aspirin group, there were no clinical events (UCL=0.0106) and one minor endoscopic bleeding event (UCL=0.0169). CONCLUSIONS: Consistent with expert guidelines, the absolute risk attributable to gastroduodenal biopsy in adults taking antiplatelet agents seems to be low. Half of routine biopsies enter submucosa. The largest blood vessels avulsed during biopsy correspond to midsized and large arterioles and venules.

Labor pain at the time of epidural analgesia and mode of delivery in nulliparous women presenting for an induction of labor.

OBJECTIVE: To assess whether the degree of labor pain at the initiation of neuraxial analgesia is associated with mode of delivery. METHODS: Nulliparous women who presented to the labor department for an induction of labor, who were between 37 and 41 weeks of gestation, and who requested labor epidural analgesia with a pain score of 0-3 (low pain) and a cervical dilatation less than 4 cm were assessed retrospectively. Maternal and neonatal outcome including mode of delivery and duration of labor were compared with a similar group of women with pain scores of 4-6 (moderate pain), and 7-10 (severe pain). Assessing whether there was an association between pain level at the time of epidural and operative delivery rates was analyzed using a chi test for trend and by logistic regression to include potentially relevant covariates. RESULTS: We found 185 nulliparous women with low pain and compared them with a randomly selected equal number of women in each of the other pain groups. There was no significant association between pain groups in terms of duration of the first or second stage of labor or mode of delivery. Women with low pain had an operative delivery rate (instrumental assisted vaginal delivery plus cesarean delivery) of 49%, compared with 45% and 45% in those with moderate and severe pain, respectively (P=.40). CONCLUSION: We did not find an association between the degree of labor pain at initiation of epidural analgesia and mode of delivery or duration of labor. LEVEL OF EVIDENCE: II.

A mission-based productivity compensation model for an academic anesthesiology department.

INTRODUCTION: We replaced a nearly fixed-salary academic physician compensation model with a mission-based productivity model with the goal of improving attending anesthesiologist productivity. METHODS: The base salary system was stratified according to rank and clinical experience. The supplemental pay structure was linked to electronic patient records and a scheduling database to award points for clinical activity; educational, research, and administrative points systems were constructed in parallel. We analyzed monthly American Society of Anesthesiologist (ASA) unit data for operating room activity and physician compensation from 2000 through mid-2007, excluding the 1-yr implementation period (July 2004-June 2005) for the new model. RESULTS: Comparing 2005-2006 with 2000-2004, quarterly ASA units increased by 14% (P = 0.0001) and quarterly ASA units per full-time equivalent increased by 31% (P < 0.0001), while quarterly ASA units per anesthetizing location decreased by 10% (P = 0.046). Compared with a baseline year (2001), Instructor and Assistant Professor faculty compensation increased more than Associate Professor and Professor faculty (P < 0.001) in both pre- and postimplementation periods. There were larger compensation increases for the postimplementation period compared with preimplementation across faculty rank groupings (P < 0.0001). Academic and educational output was stable. DISCUSSION: Implementing a productivity-based faculty compensation model in an academic department was associated with increased mean supplemental pay with relatively fewer faculty. ASA units per month and ASA units per operating room full-time equivalent increased, and these metrics are the most likely drivers of the increased compensation. This occurred despite a slight decrease in clinical productivity as measured by ASA units per anesthetizing location. Academic and educational output was stable.

B-type natriuretic peptide (BNP) in patients undergoing mitral valve surgery.

BACKGROUND AND AIM: Plasma B-type natriuretic peptide (BNP) level may be increased in patients with valvular disease. Recent studies have suggested that in patients undergoing aortic valve replacement, an increased preoperative BNP is associated with a worse operative outcome. Little is known about the perioperative value of BNP in patients undergoing mitral valve (MV) surgery. We measured the preoperative and postoperative BNP levels in this population and analyzed the impact of the increased BNP level on surgical outcome. METHODS: From March 2004 to February 2005, 42 patients (mean age 64 +/- 12 years, 18 [42%] male) were enrolled in a prospective study. All patients underwent surgery for severe mitral regurgitation. The mean ejection fraction was 49 +/- 13%, and 26 (62%) patients presented with atrial fibrillation (AF). RESULTS: The median preoperative and postoperative BNP levels were 108 (9.7 to 995) and 357 (143 to 904) pg/mL, respectively (p = 0.002). Heart failure (p = 0.03), atrial fibrillation (AF) (p = 0.01), and ejection fraction (p = 0.01) were associated with an increased preoperative BNP level. In a multivariate analysis, the only independent predictor of the increased BNP level was AF (p = 0.01). In a univariate analysis, the preoperative BNP level was a significant predictor for inotropic support (p < 0.001), ventilation time (p = 0.003), intensive care unit (ICU; p = 0.01), and hospital length of stay (p = 0.02). In the multivariate analysis, BNP was not a predictor of these variables. CONCLUSIONS: Preoperative plasma BNP level presents with a high individual variability in patients with MV regurgitation. AF was the only independent predictor of an increased preoperative BNP level. The preoperative BNP level was not a predictor of surgical outcome. Further studies are required to confirm these findings and evaluate the potential role of this marker for patient selection.

Impact of body mass index on early outcome and late survival in patients undergoing coronary artery bypass grafting or valve surgery or both.

The influence of body mass on outcome after cardiac surgery remains controversial. The aim of this study was to analyze the impact of body mass index (BMI) on early and late outcomes in a large series of patients who underwent cardiac surgery. We retrospectively analyzed 5,950 consecutive patients who underwent cardiac surgery between January 1998 and September 2006. Patients were divided into 4 groups defined by BMI (weight divided by square of height [kilograms divided by meters squared]): underweight (20 to 25 to 30 kg/m2): 22%, n=1,292. Analysis was further refined by performing subgroup analysis according to the surgical procedure (valve surgery, coronary artery bypass grafting, and combined valve/coronary artery bypass grafting). Main outcome measure was the association between BMI and hospital mortality, postoperative morbidities, and late survival. Hospital mortality was 3.4% (n=203). There was no association between BMI and hospital mortality in the entire patient population. Multivariate analysis revealed obesity as an independent predictor of hospital mortality in patients who underwent valve surgery (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.2 to 4.5, p=0.018). Obesity was associated with an increased risk for sternal infection (OR 1.8, 95% CI 1.1 to 2.9, p=0.013), whereas underweight correlated with postoperative bleeding (OR 2.0, 95% CI 1.1 to 3.6, p=0.017). Underweight was an independent predictor for decreased long-term survival (OR 1.8, 95% CI 1.3 to 2.5, p<0.001). In conclusion, cardiac surgery can be performed safely in both underweight and obese patients but carries a higher postoperative rate of major complications.

Local anesthetics and mode of delivery: bupivacaine versus ropivacaine versus levobupivacaine.

BACKGROUND: The influence of the labor epidural local anesthetic (LA) on mode of delivery has not been adequately studied. In this study, we sought to determine if there is a difference in mode of delivery among parturients who receive epidural bupivacaine, ropivacaine, or levobupivacaine. METHODS: Nulliparous women at term requesting labor analgesia with a cervical dilation <5 cm were randomized to receive epidural bupivacaine, ropivacaine, or levobupivacaine. Analgesia was initiated with a bolus of 15 mL of 0.0625% of the assigned LA with fentanyl 2 microg/mL. Analgesia was maintained with an infusion of the same solution at 10 mL/h. The primary endpoint was the operative delivery rate (instrumental assisted vaginal delivery plus cesarean delivery). RESULTS: Ninety-eight women received bupivacaine, 90 ropivacaine, and 34 levobupivacaine (before it was removed from the US market). There was no significant difference in the operative delivery rate (bupivacaine = 46%, ropivacaine = 39%, and levobupivacaine = 32%, P = 0.35) among groups. There was less motor block in the levobupivacaine group when compared with the ropivacaine and bupivacaine groups, P < 0.05. There was no significant difference in the duration of the first or second stage of labor, the total dose of LA received per hour of labor, or neonatal outcome among groups. CONCLUSIONS: Bupivacaine, ropivacaine, and levobupivacaine all confer adequate labor epidural analgesia, with no significant influence on mode of delivery, duration of labor, or neonatal outcome.

Changing patterns of postoperative nausea and vomiting prophylaxis drug use in an academic anesthesia practice.

STUDY OBJECTIVE: To characterize the evolution of postoperative nausea and vomiting (PONV) prophylactic drug use. DESIGN: Retrospective data extraction and analysis of electronic anesthesia records. SETTING: Anesthesia department of an urban academic medical center. MEASUREMENTS: 144,134 anesthetics given by 57 attending anesthesiologists were studied. Administered doses of droperidol, ondansetron, dexamethasone, and metoclopramide were tabulated for each year for each practitioner. MAIN RESULTS: Ondansetron use in the periods before and after the Food and Drug Administration (FDA) warning concerning droperidol was 8% and 35%, respectively. Use of PONV prophylaxis increased for all included patient and anesthetic factors. Among those who used droperidol before the revised FDA warning, 61% stopped using it altogether. Afterwards, 75% (27-100%) of droperidol use was in combination with another agent. CONCLUSIONS: We found a significant and sustained decrease in droperidol use after the FDA-mandated labeling revision. We also found a significant increase in ondansetron use--an increase that exceeded the amount needed to substitute for the decreased droperidol use. The changes may be related to multiple factors, including the FDA warning, a trend toward more PONV prophylaxis, and the increasing predominance of serotonin antagonists for this indication.

Marked Differences in acute cellular rejection rates between living-donor and deceased-donor liver transplant recipients.

BACKGROUND: : Due to ongoing organ donor shortage, an increasing number of adult live-donor liver transplants (LDLT) are being performed. The aims of this study were to compare the incidence of ACR between recipients of live- and deceased-donor liver transplants, and to note any differences in ACR among related and unrelated living-donor recipients. METHODS: : Sixty-four adults undergoing LDLT between 1998-2001 were closely matched with a deceased recipient. Statistical comparisons in ACR between the live- and deceased-donor groups were based on the differences between the ACR rates of each LDLT patient and the corresponding matched deceased recipient. Analyses were performed separately for pairs in which the living donor was not related to the recipient, was a nonsibling relative, or was a sibling. RESULTS: : Live- and deceased-donor recipients underwent a similar number of liver biopsies. In all, 16/50 (32%) of the biopsied LDLT patients had ACR compared to 36/49 (73%) of the deceased-donor recipients. ACR rates of living donors and their deceased-donor matches did not differ significantly for the unrelated living donors, but did differ for the nonsibling related (P=0.03) and the sibling LDLT (P=0.03). The results were similar when comparing rates of high-degree ACR for unrelated, nonsibling related, and sibling pairs. High-degree ACR differences in the sibling LDLT group were significantly greater than in the nonsibling group (P=0.05). CONCLUSIONS: : Rates of ACR and high-degree ACR are decreased in living-related liver transplant recipients. This difference is likely genetically related as ACR rates are lower in recipient-donor pairs of increasing genetic similarity.

Optimal temperature for selective cerebral perfusion.

OBJECTIVE: Although combinations of hypothermic circulatory arrest and antegrade selective cerebral perfusion are used for cerebral protection during arch surgery, there is no consensus regarding the optimal temperature during selective cerebral perfusion. This study explored the effect of different temperatures during selective cerebral perfusion on cerebral metabolism and neurologic outcome. METHODS: In this blinded study, 40 pigs (19-21 kg) were randomized into 4 groups after 30 minutes of hypothermic circulatory arrest at 20 degrees C. During a 60-minute interval of selective cerebral perfusion, with flow regulated to maintain a perfusion pressure of 50 mm Hg, pigs were perfused at 10 degrees C, 15 degrees C, 20 degrees C, and 25 degrees C. Fluorescent microspheres enabled calculation of cerebral blood flow during perfusion and recovery. Hemodynamics, intracranial pressure, cerebrovascular resistance, and oxygen consumption were also monitored. Behavioral scores were obtained for 7 days after surgery. RESULTS: Cerebral blood flow decreased significantly ( P < .002) during cooling in all groups: it was significantly higher throughout selective cerebral perfusion in the 20 degrees C to 25 degrees C versus the 10 degrees C to 15 degrees C group ( P = .0001) and remained higher during recovery ( P = .0001). Oxygen consumption decreased significantly with cooling ( P = .0001), remained low during perfusion, and rebounded with rewarming but was significantly lower at 10 degrees C to 15 degrees C than at 20 degrees C to 25 degrees C throughout selective cerebral perfusion ( P = .003) and after CPB was discontinued ( P = .001). Postoperative behavioral scores were significantly better after selective cerebral perfusion at 10 degrees C to 15 degrees C than at 20 degrees C to 25 degrees C ( P = .001). CONCLUSIONS: This study suggests that selective cerebral perfusion at 10 degrees C to 15 degrees C provides better cerebral protection than selective cerebral perfusion at 20 degrees C to 25 degrees C, even though oxygen consumption remains low for hours after selective cerebral perfusion at 10 degrees C to 15 degrees C. Prompt return of metabolism to baseline levels after hypothermic circulatory arrest/selective cerebral perfusion does not necessarily predict superior behavioral outcome.

Cooling to 10 degrees C and treatment with Cyclosporine A improve cerebral recovery following prolonged hypothermic circulatory arrest in a chronic porcine model.

OBJECTIVE: This study was undertaken to assess whether cooling to 10 degrees C and/or treatment with Cyclosporine A (CsA) can reduce neurological injury during prolonged hypothermic circulatory arrest (HCA) in a chronic animal model. METHODS: In this blinded study, 24 pigs (20-23 kg) were randomized to HCA for 90 min at 20 degrees C (n=8), at 10 degrees C (n=8), or at 10 degrees C with 5 mg/kg CsA (n=8). CsA (or placebo) were given intravenously before and for 3 days after HCA. Hemodynamics and neurophysiological data were monitored periodically throughout the experiment and for 3 h after HCA, as well as intracranial pressure (ICP), which has been shown to correlate with outcome. Daily neurological/behavioral evaluation (mental status, coordination and appetite; 12=normal and 0=coma or death) was carried out until sacrifice on postoperative day (POD) 3. RESULTS: Overall survival rate was 83.3%: one 20 degrees C control, two 10 degrees C controls, and one 10 degrees C/CsA pig died and were replaced. Basic hemodynamic data revealed no significant differences between groups. ICP differed significantly among the groups during the first 3 h postoperatively (P=0.003 by repeated measures ANOVA); it was higher in the 20 degrees C group than in the 10 degrees C/CsA or 10 degrees C control groups. Recovery of visual evoked potentials was significantly better in the 10 degrees C/CsA group than in the 10 degrees C control group; no recovery was seen by 3 h in the 20 degrees C control group. Postoperative behavioral scores also differed significantly between the groups, P=0.03: a good behavioral outcome--a score >9 on POD3--was more prevalent among CsA-treated pigs (75%) than among 10 degrees C controls (50%), or 20 degrees C controls (12.5%, P=0.06). CONCLUSIONS: The data suggest that cooling to 10 degrees C and CsA treatment are both of benefit in improving cerebral recovery after HCA when compared with untreated 20 degrees C controls, and may be synergistic.

Outcome analysis of cirrhotic patients undergoing chest tube placement.

OBJECTIVES: Patients with cirrhosis can acquire pulmonary conditions that may or may not be related to their illness. Although posing a greater risk for complications, chest tubes are sometimes placed as treatment for hepatic hydrothorax and other pulmonary conditions. The aim of this study was to analyze the outcomes of chest tube placement in cirrhotic patients. METHODS: A retrospective analysis was performed of 59 adults with cirrhosis undergoing chest tube placement. Variables that were investigated included reason for chest tube placement, complications developing while having the tube in place, and outcome. RESULTS: The 59 subjects were classified as having Child-Turcotte-Pugh (CTP) class A cirrhosis (n = 3), CTP class B cirrhosis (n = 31), and CTP class C cirrhosis (n = 25). Indications for having a chest tube placed were hepatic hydrothorax (n = 24), pneumothorax (n = 9), empyema (n = 8), video-assisted thoracoscopy (VAT) [n = 7], non-VAT (n = 5), and hemothorax (n = 3). The CTP class A subjects had their chest tubes removed without further complications early in the course, and were excluded from further statistical analysis. Twenty-five subjects (42%) had significant pleural effusions requiring chest tube placement. Among the CTP class B and class C subjects, the median duration with chest tube in place was 5.0 days (range, 1 to 53 days). Serum total bilirubin levels, presence of portosystemic encephalopathy, and CTP C classification were predictors of mortality. Mortalities were seen in 5 of 31 CTP class B subjects (16%), and 10 of 25 CTP class C subjects (40%). The tubes were successfully removed in a total of 39 subjects (66%) with no further procedure. Forty-seven subjects (80%) acquired one or more of the following complications: renal dysfunction, electrolyte imbalances, and infection. CONCLUSIONS: When placed for all indications, chest tubes may be successfully removed in the majority of cirrhotic patients. However, a third of all patients still die with the chest tube still in place. Failure to remove the chest tube increases mortality in patients with increasing severity of liver disease.

Cerebral physiology and outcome after hypothermic circulatory arrest followed by selective cerebral perfusion.

BACKGROUND: This study explored the impact of an interval of hypothermic circulatory arrest (HCA) preceding selective cerebral perfusion (SCP) on cerebral physiology and outcome. This protocol allows use of SCP during aortic surgery without the threat of embolization inherent in balloon catheterization of often severely atherosclerotic cerebral vessels. METHODS: In this blinded study, 30 pigs (20 to 22 kg) were randomized after cooling to 20 degrees C. Pigs in the HCA-CPB group (n = 10) underwent 30 minutes of HCA followed by 60 minutes of total body perfusion (CPB); HCA-SCP pigs (n = 10) underwent 30 minutes of HCA followed by 60 minutes of SCP, and SCP pigs (n = 10) had 90 minutes of SCP without prior HCA. Fluorescent microspheres enabled calculation of cerebral blood flow during perfusion and recovery. Hemodynamics, intracranial pressure, cerebrovascular resistance, and cerebral oxygen consumption were also monitored. Daily behavioral scores were obtained for 7 days postoperatively. RESULTS: In all groups, cerebral oxygen consumption fell significantly with cooling (p < 0.0001), remained low during perfusion, and rebounded promptly with rewarming; cerebral oxygen consumption was significantly (p = 0.027) greater during SCP than during HCA-CPB. Cerebral blood flow was significantly higher throughout SCP in the HCA-SCP group (p < 0.0001) than with CPB. Cerebrovascular resistance during SCP and HCA-SCP was significantly lower (p = 0.036) than during CPB. Behavioral scores were significantly better with SCP than with HCA-CPB throughout recovery, but did not differ between SCP and HCA-SCP. CONCLUSIONS: This study suggests that a short period of HCA preceding SCP provides global cerebral protection comparable to continuous SCP, implying that in clinical practice, a short period of HCA to reduce risk of embolization will not compromise the superior cerebral protection provided by SCP.

Effect of hypothermia on cerebral blood flow and metabolism in the pig.

BACKGROUND: The pig has become an increasingly popular model for the study of cerebral protection during cardiothoracic surgery in recent years, but little information is available concerning hypothermic porcine physiology. Because the efficacy of cerebral protection depends largely upon metabolic suppression, we studied cerebral oxygen metabolism at various temperatures using two different methods to assess cerebral blood flow (CBF). MATERIAL AND METHODS: Twelve pigs (7 to 13 kg) underwent cooling on cardiopulmonary bypass to 8 degrees C as recorded by an electrode placed deep in the parenchyma of the brain. CBF was measured in 6 animals using radioactive microspheres and in the other 6 using fluorescent microspheres. CBF, cerebral oxygen consumption, and cerebral vascular resistance were determined at 37 degrees C, 28 degrees C, 18 degrees C, and 8 degrees C. RESULTS: Both methods produced very similar data. CBF fell steadily with decrease in temperature to 18 degrees C but failed to drop further with more profound hypothermia. With both groups combined, mean cerebral oxygen metabolism was 2.63 mL/100 g per minute at 37 degrees C. Metabolic activity was 50% of base line values at 28 degrees C, 19% at 18 degrees C, and 11% at 8 degrees C. The Q10 value in the pig--the degree of metabolic suppression achieved by a 10 degrees C drop in temperature--is 2.46 (95% confidence interval 2.1 to 2.9); this value is consistent with similar studies in humans. CONCLUSIONS: The presence of significant residual metabolic activity at 18 degrees C suggests that this degree of hypothermia may provide incomplete cerebral protection during prolonged interruption of CBF. This study demonstrates that cooling to temperatures below 18 degrees C in the pig can achieve greater metabolic suppression although it may be associated with loss of cerebral autoregulation.

Bioprosthetic valved conduit aortic root reconstruction: the Mount Sinai experience.

BACKGROUND: Patients requiring aortic root reconstruction who are deemed unable to take anticoagulants offer unique challenges to the surgeon. For these patients, we have been manufacturing composite conduits intraoperatively using stented bioprostheses. METHODS: During the 10-year period from April 1992 until May 2002, 141 patients (105 male, 36 female) from 34 to 88 years of age underwent aortic root reconstruction with biological valved conduits. Diagnoses included dissection (n = 28, 9 acute type A), degenerative (64), atherosclerotic (32), anuloaortic ectasia (9), endocarditis (5), and other causes (3). Preoperative risk factors included hypertension (90), smoking (63), coronary artery disease (48), and diabetes (6). Valved conduits were mainly constructed from pericardial valves and impregnated Dacron grafts. Distal anastomosis was performed open in all cases except 6; the ascending aorta only was replaced in 63 patients, a hemiarch reconstruction was used in 71, and more extensive arch reconstruction in 7. Additional cardiac procedures were performed in 59 patients. RESULTS: Two deaths occurred in the operating room (biventricular failure). Late hospital mortality was 11 of 141 (7.8%) of which 6 (55%) were cardiac, 2 (18.2%) were infectious, 2 (18.2%) were of other complications and 1 (9.1%) was unknown. Three patients (2.1%) sustained permanent and 3 transient strokes. No structural deterioration of the valve and an approximately 86% freedom from thromboembolic events was observed during 5 years. CONCLUSIONS: For patients for whom anticoagulation is contraindicated or undesirable, reconstruction of the aortic root with a stented bioprosthetic valved conduit offers an acceptable alternative to mechanical prostheses.