氨基酸溶液和重组人生长激素对肝硬化大鼠生长激素-胰岛素样生长因子1轴的影响

目的探讨氨基酸溶液和重组人生长激素(rhGH)对肝硬化大鼠生长激素(GH)-胰岛素样生长因子1(IGF—1)轴的影响。方法肝硬化大鼠随机分为术前组、肝部分切除后1d组、术后肠外营养用复方氨基酸注射液(Novamin)5d组、用10％复方氨基酸注射液(Hepa)5d组、用rhGH Hepa 5d组,各组均为6只大鼠,对照组为正常大鼠。分别测大鼠肝功能、血糖及血清GH、IGF-1、胰岛素样生长因子结合蛋白3(IGFBP-3)水平,用逆转录聚合酶链反应检测肝白蛋白(ALB) mRNA、IGF-1 mRNA、IGFBP-3m RNA的表达,肝组织行Ki67免疫组化染色。结果用Hepa的肠外营养组5d后与用Novamin组比较,GH水平明显降低,肝ALB mRNA、IGF-1m RNA、IGFBP-3 mRNA表达水平明显升高,肝Ki67指数无差别;而rhGH Hepa组肠外营养5d后比Hepa组血糖、GH、IGF-1、IGFBP-3水平明显升高,肝ALB mRNA、IGF-1 mRNA表达水平及肝Ki67指数也明显升高。结论氨基酸溶液和重组人生长激素均可影响肝硬化大鼠生长激素．胰岛素样生长因子1轴,检测血清IGF-1、IGFBP-3水平有助于营养素的选择和评估。     

Protective effect of nisoldipine on myocardial ischemia during coronary bypass surgery.

BACKGROUND: Nisoldipine, a calcium antagonist, was assessed for myocardial protection and the prevention of reperfusion injury in patients undergoing CABG. METHODS: Of the 34 subjects undergoing CABG in this study, 20 were given nisoldipine orally at 10 mg/day for 2 weeks before surgery (N group) and the other 14 untreated controls (C group). Myocardial protection was conducted via ante-grade cold blood cardioplegia at 20-minute intervals. RESULTS: Myocardial blood flow was significantly higher in the N group (67.8 +/- 21.8 ml/100 g vs. 47.2 +/- 14.4 ml/100 g, p < 0.05) after cardiopulmonary bypass. Serum interleukin-6 levels were significantly lower in the N group 1 hour after reperfusion (116 +/- 58 vs. 409 +/- 362 pg/ml, p < 0.05), as were serum lactate dehydrogenase levels immediately after surgery (888 +/- 268 vs. 1350 +/- 486 IU/L, p < 0.05). The N Group showed a better left ventricle stroke work index 6 hours after surgery (43 +/- 8 vs. 36 +/- 9 g.m/m2). Dopamine dosage in the N group on postoperative day 1 was lower than in controls (5.3 +/- 1.9 vs. 3.0 +/- 2.4 micrograms/kg/min). CONCLUSIONS: Preoperative nisoldipine treatment increased blood flow in the postischemic myocardium and prevented myocardial damage and reperfusion injury to some extent.     

Renal function after cardiac surgery: adverse effect of furosemide

Renal failure is a frequent event after cardiopulmonary by-pass. Hemodynamic alterations that occur during surgery, as well as factors depending on the host, are the main risk factors for renal dysfunction. To evaluate the frequency and risk factors for renal dysfunction in this setting, a cohort of fifty patients with preoperative serum creatinine under 1.5 mg/dL, submitted to cardiac surgery with cardiopulmonary by-pass was analyzed. Variables related to preoperative patient condition, intraoperative and postoperative periods were recorded. Renal function was assessed by clearances of creatinine, urea and free water, also by fractional excretion of sodium (FENa), at baseline, at anesthetic induction and during postoperative period. Patients were arbitrarily divided in two groups, according to the serum creatinine (S(Cr)) value at the end of the postoperative period: Group 1: S(Cr) < 2 mg/dL (n = 44 patients (88.5%)) and Group II: S(Cr) > 2 mg/dL (n = 6 patients (11.5%)). A decrease of renal function was observed in all patients: creatinemia raised from 1.04 +/- 0.2 to 1.55 +/- 0.4 mg/dL (33%), associated with a rise in FENa. Differences between group I and group II using univariate analysis were: baseline serum creatinine (1.01 +/- 0.23 mg/dL vs. 1.26 +/- 0.19 mg/dL, p = 0.03), FENa (0.99 +/- 0.8 vs. 2.2 +/- 2.1, p = 0.04), furosemide dose during surgery normalized to body surface area (93.2 +/- 23 mg/1.73 m2 BSA vs. 135 +/- 38 mg/1.73 m2 BSA, p < 0.001), and hemodilution index (17.3 +/- 4.3% vs. 22.8 +/- 3.2%, p < 0.01). In the multiple regression model, baseline creatinemia and furosemide dose were associated to renal dysfunction.     

Ischemic preconditioning versus intermittent vascular occlusion in liver resections performed under selective vascular exclusion: a prospective randomized study

BACKGROUND: The aim of this study was to compare ischemic preconditioning with the intermittent vascular occlusion technique in liver resections performed under inflow and outflow occlusion. METHODS: Fifty-four patients with resectable liver tumors assigned were randomly to undergo surgery with either ischemic preconditioning (IP group, n = 27) or with intermittent vascular occlusion (IVO group, n = 27). Both groups were compared regarding surgical parameters, aspartate transaminase levels, and apoptosis. RESULTS: For warm ischemic time less than 40 minutes, no significant difference was noticed between the 2 groups apart from caspase-3 activity, which was higher in the IVO group than in the IP group (17.2 +/- 3.4 vs. 10.3 +/- 5.2, P < .05). When warm ischemia exceeded 40 minutes, the IP group showed higher levels in blood aspartate transaminase levels on day 3 (442 +/- 178 IU/L vs. 305 +/- 104 IU/L, P < .05) and higher caspase-3 levels (26.5 +/- 5.7 count/high-power field [hpf] vs. 20.7 +/- 3.6 count/hpf, P < .05) and apoptotic activity (28.5 +/- 7.5 count/hpf vs. 20.2 +/- 4.1 count/hpf, P < .05), as compared with the IVO group. CONCLUSIONS: Although both techniques showed comparable efficacy for short ischemic times, intermittent vascular occlusion provided better cytoprotection when ischemia exceeded 40 minutes.     

Aspartate and glutamate-enriched cardioplegia in left ventricular dysfunction

BACKGROUND: The effects of exogenous L-aspartate and L-glutamate-enriched cardioplegia on postoperative left ventricular functions after coronary artery bypass surgery in patients with moderate left ventricular dysfunction (left ventricular ejection fraction [LVEF]= 30-40%) were studied. METHODS: In this prospective randomized study, 22 patients with moderate left ventricular dysfunction (mean LVEF = 37.27%+/- 3.43%), who underwent elective coronary artery bypass surgery, were examined. Isothermic substrate-enriched [L-aspartate and L-glutamate (13 mmol/L)] blood cardioplegia was used in 11 patients (Group AG), and cardioplegia including only potassium and sodium bicarbonate was used in 11 patients (Group C). All hemodynamic parameters for left and right heart were studied in both groups. Total perfusion time was 126.63 +/- 44.91 minutes versus 114.81 +/- 43.66 minutes (p = 0.54). The aortic cross-clamp time was 77.09 +/- 28.02 minutes versus 67.81 +/- 22.77 minutes (p = 0.4), respectively. The amount of cardioplegic solutions were 7218.2 +/- 3043.6 mL versus 5454.5 +/- 3048.1 mL (p = 0.167). Mean number of distal anastomosis were 3 +/- 0.89 versus 2.9 +/- 0.7 (p = 0.793). RESULTS: There was no difference between both groups in intra- and postoperative periods. In coronary sinus blood gas measures, myocardial acidosis caused by the aortic cross-clamp was found to be more severe in the Group C, but delta pH (0.12 +/- 0.14 vs. 0.092 +/- 0.058; p = 0.613) and delta lactate (1.39 +/- 1.03 vs. 1.62 +/- 0.85; p = 0.579) were similar in both groups. Free oxygen radical production caused by aortic cross-clamp was significant in the Group C. Not all myocardial enzymes, but Troponin-T levels were found higher in control group than the study group (0.6 +/- 0.36 vs. 0.36 +/- 0.25; p = 0.1). CONCLUSIONS: Although L-aspartate and L-glutamate favor myocardial metabolic functions, they do not have any affect on myocardial functional recovery in patients with moderate left ventricular dysfunction.     

Off-pump multivessel coronary artery surgery in high-risk patients

BACKGROUND: Coronary artery bypass surgery on cardiopulmonary bypass is associated with significant morbidity and mortality, which may be more marked in high-risk patients. We evaluated our results of off-pump coronary artery bypass (OPCAB) in high-risk patients with multivessel coronary artery disease and compared them with results in similar patients who underwent operation on cardiopulmonary bypass. METHODS: A total of 1,075 patients who underwent OPCAB between October 1996 and June 2001 and who had one or more of the following risk factors were included in the study: poor left ventricular function (EF < or = 30%), advanced age (> 70 years), left main stenosis, acute myocardial infarction, and redo coronary artery surgery. These patients were compared with 2,312 similar patients who underwent coronary artery bypass grafting on cardiopulmonary bypass during the same period. Preoperative risk factors, intraoperative variables, and postoperative results were analyzed and compared between two groups. RESULTS: The average number of grafts was 3.0 +/- 0.4 and 3.2 +/- 0.3 in the off-pump (OPCAB) and on-pump (CCAB) groups, respectively. Hospital mortality was 3.2% and 4.5% in OPCAB and CCAB groups respectively (p = 0.109). Perioperative myocardial infarction, requirement of inotropic agents, stroke, and renal dysfunction were comparable in two groups. Intubation time (19 +/- 5 vs 24 +/- 6 hours, p < 0.001), mean blood loss (362 +/- 53 vs 580 +/- 66 mL, p < 0.001), atrial fibrillation (14.3 vs 19.7%, p < 0.001), and prolonged ventilation (4.6 vs 7.6%, p = 0.002) were less in OPCAB group. Intensive care unit stay (20 +/- 8 hours) and hospital stay (6 +/- 3 days) were significantly less in the OPCAB group (p < 0.001). CONCLUSIONS: Off-pump coronary artery surgery can be safely performed in high-risk patients with multivessel coronary artery disease. Operative mortality is comparable to that associated with on-pump surgery, and avoidance of cardiopulmonary bypass is associated with reduced postoperative morbidity in these patients.     

Thoracic epidural analgesia improves pulmonary function in patients undergoing cardiac surgery

PURPOSE: Pulmonary dysfunction commonly occurs following coronary artery bypass graft (CABG) surgery, increasing morbidity and mortality. We hypothesized that thoracic epidural anesthesia (TEA) would improve pulmonary function and would decrease complications in patients undergoing CABG surgery. METHODS: This prospective, randomized, controlled trial was conducted with Ethics Board approval. Fifty patients, undergoing CABG surgery, were randomized to the epidural group or to the patient-controlled analgesia morphine group. Patients in the epidural group received a high, thoracic epidural, preoperatively. Intraoperatively, 0.75% ropivacaine was infused, followed postoperatively, by 0.2% ropivacaine for 48 hr. Outcome measurements included: visual analogue pain scores; spirometry; atelectasis scores on chest radiographs; and the incidence of atrial fibrillation. RESULTS: Twenty-five patients were enrolled in each group. Patients in the epidural group had significantly less pain on the operative day, and for the subsequent two days. Compared to baseline, the forced expiratory volume in one second was significantly higher in the epidural group, on the first and second postoperative days (43.7 +/- 12.2% vs 36.4 +/- 12.0%, p < 0.002, and 43.3 +/- 12.5% vs 38.4 +/- 11.0%, p <0.05). There was significantly more atelectasis in the control group, four hours postoperatively (p < 0.04); however, on the third, postoperative day, the groups were similar with regards to this outcome. The incidence of atrial fibrillation was similar in both groups, and there were no complications related to the epidural. CONCLUSIONS: High TEA decreases postoperative pain and atelectasis and improves pulmonary function in patients undergoing CABG surgery. Our results support the use of TEA in this group of patients.     

Effects of ischemic preconditioning in human heart

BACKGROUND: The aim of this study is to investigate the effects of ischemic preconditioning (IP) on myocardium and the level of nitric oxide (NO) in patients undergoing aorta-coronary bypass surgery. METHODS: Twenty consecutive patients with coronary artery disease were subjected into two equal groups; the IP group and the control group. Following the onset of cardiopulmonary bypass in the study group, hearts were preconditioned with two 3-minute periods of cross-clamping separated by 2 minutes of reperfusion. In the control group, cardiopulmonary bypass was continued for 10 minutes without using cross-clamp. Arterial and coronary sinus blood samples were used to determine serum NO, malondialdehyde (MDA), creatine phosphokinase-MB (CKMB), and lactate dehydrogenase (LDH) levels. Need for defibrillation after cross-clamp removal, ECG changes, postoperative arrhythmias, ejection fraction, and fractional shortening rates were recorded as hemodynamic data. RESULTS: Serum NO level was higher in the study group 5 minutes after aortic clamp removal (199.3 +/- 92.7 vs. 112.2 +/- 35.8 micromol; p = 001). Serum MDA (2.55 +/- 0.4 vs. 4.06 +/- 0.5; etamol/ml; 5 minutes after the aortic clamp removal; p = 0.0002); CK-MB (22.8 +/- 2.5 vs. 37.4 +/- 4.1; U/L 12 hours after the operation, p < 0.0001), and LDH (501.8 +/- 46.7 vs. 611.4 +/- 128.3; IU/L 48 hours after the operation, p = 0.02) levels were significantly lower in the preconditioned group when compared with the control group. Also, need for electrical defibrillation was significantly lower in the study group; Ejection fraction (64.3 +/- 6.3 vs. 57.6 +/- 7.6; p = 0.04) and fractional shortening (31.7 +/- 3.9 vs. 26.2 +/- 4.0; p = 0.04) rates were better in the study group postoperatively. CONCLUSIONS: These data may suggest that cardioprotection by ischemic preconditioning offers higher NO production, a lower myocardial ischemia, and better functional recovery of the hearts in coronary artery surgery patients.     

Effects of combined conventional and modified ultrafiltration in adult patients

BACKGROUND: Modified ultrafiltration (MUF) improves hemodynamics and postoperative recovery in children. Ultrafiltration (UF) may have similar benefits in adults. The purpose of this study was to investigate the effects of UF in adult patients. METHODS: A total of 40 adult patients undergoing cardiac surgery were randomized into a study group of conventional UF during bypass + venovenous MUF after bypass and a control group with no UF. Perioperative clinical variables, cytokines, and endothelin-1 levels were compared between groups. RESULTS: There was no mortality in either group. The patients in the study group had a greater rise in hematocrit (5.7% +/- 2.4% vs 1.2% +/- 1.9%, p < 0.001), hemoglobin (1.7 +/- 0.8 mg/mL vs 0.5 +/- 0.6 mg/mL, p < 0.0005), and platelet levels (27,800 +/- 29,200 vs -9,000 +/- 30,970, p < 0.001). Mean arterial blood pressure and CI increased after MUF (from 64.2 +/- 16.9 mm Hg to 72.3 +/- 14.1 mm Hg, p = 0.05, and from 2.4 +/- 0.7 to 2.8 +/- 0.6, p < 0.03, respectively). Postoperative oxygenation was better in the study group (alveolo-arterial PO2 tension gradient 74.6 +/- 43.9 mm Hg vs 107.2 +/- 27.8 mm Hg, p = 0.03). Ultrafiltration reduced postoperative bleeding (522.2 +/- 233.4 mL vs 740 +/- 198.4 mL, p < 0.003). CONCLUSIONS: A combination of conventional and modified UF is effective and safe in adult patients undergoing cardiac surgery. Ultrafiltration improved hemodynamics, hemostatic, and pulmonary functions. We recommend the use of combined UF in high-risk adult patients.     

Postoperative white blood cell count predicts atrial fibrillation after cardiac surgery

BACKGROUND: Postoperative atrial fibrillation (AF) occurs in as many as 50% of cardiac surgery patients and represents the most common postoperative rhythm complication. The cause of AF after cardiac surgery is incompletely understood, and its prevention remains suboptimal. Currently the role of inflammation and oxidative stress on electrical remodeling is under investigation, and recent studies have demonstrated that C-reactive protein levels are elevated in AF. The purpose of the present study was to investigate the correlation between the postoperative white blood cell (WBC) count as a marker of inflammation and the development of postoperative AF after cardiac surgery. METHODS AND RESULTS: Patients undergoing elective cardiac surgery in the absence of significant left ventricular dysfunction (n = 253; average age, 65 +/- 11 years) were recruited to the present prospective study. Atrial fibrillation developed during the postoperative period in 99 patients (39.1%) of the total study population. The WBC count was prospectively assessed in all patients to determine the predictive value of baseline and postoperative WBC count on development of postoperative AF. Baseline WBC count was 6.8 +/- 1.9 x 10(9)/L and 6.8 +/- 2.2 x 10(9)/L (p = 0.95), respectively, in patients with and without postoperative AF; and postoperative peak WBC count was 16.3 +/- 6.5 x 10(9)/L and 15 +/- 4.2 x 10(9)/L (p = 0.048), respectively, in patients without postoperative AF. However, neither baseline nor peak monocyte count differed significantly among patients with and without postoperative AF: 0.43 +/- 0.15 x 10(9)/L and 0.46 +/- 0.46 x 10(9)/L (p = 0.5), and 0.91 +/- 0.3 x 10(9)/L and 0.93 +/- 0.4 x 10(9)/L (p = 0.8), respectively. In addition to a more pronounced increase in peak WBC count (above v below median; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1-2.7; p < 0.05), increasing age (above v below median; OR, 2.6; CI, 1.2-3.9; p < 0.01), surgery for valvular heart disease versus coronary artery bypass grafting (OR, 2.8; CI, 1.1-3.5; p < 0.01), development of postoperative complications, such as stroke, infections, or unstable hemodynamics (OR, 1.9; CI, 1.0-7.5; p < 0.05), and perioperative nonuse of beta-adrenergic blockers (OR, 1.7; CI, 1.1-4.9; p < 0.05) were identified as independent predictors of postoperative AF by multivariate logistic regression analysis. CONCLUSIONS: Cardiac surgery is associated with an elevated postoperative WBC count that represents a common marker of inflammation. A more pronounced increase in postoperative WBC count independently predicts development of postoperative AF. These data provide additional evidence to support the association between the inflammatory response and postoperative AF.     

Titration of isoflurane using BIS index improves early recovery of elderly patients undergoing orthopedic surgeries

PURPOSE: This study was designed to investigate the effect of bispectral index (BIS) monitoring on the recovery profiles, level of postoperative cognitive dysfunction, and anesthetic drug requirements of elderly patients undergoing elective orthopedic surgery with general anesthesia. METHODS: Sixty-eight patients over the age of 60 were randomized into one of two groups. In the standard practice (SP) group, the anesthesiologists were blinded to the BIS value, and isoflurane was titrated according to standard clinical practice. In the BIS group, isoflurane was titrated to maintain a BIS value between 50-60. RESULTS: The total isoflurane usage was 30% lower in the BIS group compared to the SP group (5.6 +/- 3 vs 7.7 +/- 3 mL, P <0.05). The time to orientation was faster in the BIS group compared to the SP group (9.5 +/- 3 vs 13.1 +/- 4 min, P <0.001). There were no differences in the postoperative psychometric tests between the two groups. CONCLUSIONS: There was no difference in the level of postoperative cognitive dysfunction between the two groups. However, titration of isoflurane using the BIS index decreased utilization of isoflurane and contributed to faster emergence of elderly patients undergoing elective knee or hip replacement surgery.     

Serum IFN-inducible protein-10: a new clinical prognostic predictor of hepatocyte death in biliary atresia

PURPOSE: The aim of this study was to determine whether chemokines such as serum IP-10 levels in patients with biliary atresia (BA) correlate with liver function and histology and assess its value as a medium to long-term prediction of prognosis in postoperative BA patients. METHODS: Thirty postoperative BA patients (mean age, 10.8+/-3.5 years) and eight normal controls (mean age, 10.3+/-3.3 years) were studied. The BA patients were divided into three groups according to liver function. Group I (n = 8) was jaundice free, had normal liver function and no evidence of severe cholangitis or portal hypertension. Group II (n = 12) had moderate liver dysfunction. Group III (n = 10), had severe liver dysfunction. Hepatic histology was assessed using conventional needle biopsy. Serum IP-10 levels were determined using a specific enzyme-linked immunosorbent assay (ELISA). RESULTS: Serum levels of IP-10 in group III (458.0+/-240.0 pg/mL) were significantly higher than those in group II (233.6+/-126.9 pg/mL; P < .0001). Levels in group II were also significantly higher than those in group I (144.8+/-23.4 pg/mL; P < .05), but there was no significant difference between group I and controls (107.9+/-34.0 pg/mL). Liver biopsy findings showed a progression of fibrosis and mononuclear cell infiltration from group I to group III. There was intimal hyperplasia and swelling of endothelial cells of branches of the hepatic artery in the portal area in group III. CONCLUSION: Because IP-10 levels correlate closely with histological findings in postoperative BA patients, it would appear to play a specific role in hepatocyte death and hepatic artery changes, thus providing important information about progressive fibrosis in BA patients that facilitates treatment decision making and prediction of prognosis.     

Should We Give Prophylactic “Renal‐Dose” Dopamine After Coronary Artery Bypass Surgery?

OBJECTIVE: A prospective double-blind randomized study undertaken to assess the effect of postoperative prophylactic "renal-dose" dopamine on post-coronary artery bypass grafting surgery's clinical outcome. METHODS: Eighty-five consecutive patients undergoing CABG operation were randomized to receive either 3-5 microg/kg/min dopamine (group D, n = 41) or saline as placebo (group P, n = 45) for 48 postoperative hours. Clinical outcome parameters were collected for four postoperative days. RESULTS: Preoperative and operative parameters were similar in both groups. Four patients from group P and none from group D reached an end-point of the study (oliguria, renal dysfunction) and received dopamine. Two patients from group P and none from group D needed an additional inotropic support. Mean arterial pressure values were similar during the first 24 hours after operation, but left atrial pressure values tended to be higher in group P (10 +/- 4 vs 7 +/- 3 mmH2O, p = 0.18). The mean pH was higher in group D at 8 hours after operation (7.38 +/- 0.2 vs 7.36 +/- 0.3, p = NS), due to higher bicarbonate levels (23 +/- 2 mmol/l vs 21 +/- 2, p = 0.49). The incidence of lung congestion in chest X-rays and CT scans was significantly higher in group P (50% vs 29%, p = 0.073 at 48 hours postoperatively). Room air blood O2 saturation and maximal expiratory volume tended to be higher in group D (at 72 hours after operation- 92 +/- 4 vs 90%+/- 5, p = 0.29 and 646 +/- 276 vs 485 ml +/- 206, p = 0.16, respectively). There was no statistical difference in urine output but the amount of furosemide given to patients in group P was significantly higher (during the first 8 hours 2.5 +/- 0.5 vs. 0.3 mg +/- 1.6, p = 0.07). Plasma creatinine levels were significantly lower in group D (at 24 hours 0.93 +/- 0.02 vs 1.05 mg/dL +/- 0.02, p = 0.02). Mobilization after surgery was faster in group D. CONCLUSIONS: Prophylactic dopamine administration after coronary artery bypass grafting surgery improves patient hemodynamic and renal status, reduces the need for additional medical support (inotropes and furosemide) and thus, provides stable postoperative course.     

The efficacy of microendoscopic discectomy in reducing iatrogenic muscle injury

OBJECT: The objective of this study was to evaluate the invasiveness of microendoscopic discectomy (MED) in comparison with microscopic discectomy (MD) by measuring serum levels of creatine phosphokinase (CPK)-MM and lactate dehydrogenase (LDH)-5, and by comparing visual analog scale (VAS) scores of postoperative pain. METHODS: This study included a group of 15 patients who underwent surgery using MED and 15 patients who underwent surgery using MD, both for single-level unilateral herniated nucleus pulposus. The CPK-MM and LDH-5 levels were measured at admission and after 1, 3, and 5 days postoperatively. Pain assessment was recorded using scores raging from 0 to 10 on a subjective VAS at admission and at 1, 3, and 5 days postoperatively. RESULTS: The mean CPK-MM levels were lower for the MED group than for the MD group at both 3 (576.1 +/- 286.3 IU/L compared with 968.1 +/- 377.8 IU/L) and 5 days (348.1 +/- 231.0 IU/L compared with 721.7 +/- 463.2) postoperatively (p < 0.05). The mean VAS scores for postoperative back pain were lower in the MED group than in the MD group, both at 1 (3.3 +/- 2.3 compared with 5.8 +/- 1.5) and 5 days (1.9 +/- 1.1 compared with 3.6 +/- 1.1) postoperatively (p < 0.01). CONCLUSIONS: The MED procedure is less invasive than MD, and causes less muscle damage and less back pain.     

Continuous infusion of remifentanil and target-controlled infusion of propofol for coronary surgery in elderly patients: comparison with continuous infusion of remifentanil and propofol

OBJECTIVES: Comparison of the length of mechanical ventilation and postoperative complications after coronary surgery in elderly patients anaesthetised with propofol associated with either alfentanil or remifentanil. STUDY DESIGN: Retrospective study with an historic control group. PATIENTS: Three hundred thirty-eight consecutive patients (75-year-old or more) undergoing isolated coronary surgery. One hundred and fifty seven patients operated between January 1998 and June 2000 received alfentanil (1 microg/kg/minute) with a manually control infusion of propofol, 181 operated between July 2000 and 2002, remifentanil 0.25 microg/kg/minute with target controlled infusion of propofol (target blood concentration: 1.5 to 2 microg/ml). METHODS: The two groups were compared for preoperative and surgical data. The length of mechanical ventilation, stay in ICU and the main postoperative complications were compared between the two groups. RESULTS: Length of mechanical ventilation was significantly reduced in the remifentanil group (6 +/- 9 h vs. 13 +/- 63 h ; p <0.0001), 70% of the patients were extubated before the 6th postoperative hours against 53% in the alfentanil group (p =0.0023). This was not associated with a reduction of stay in ICU or postoperative complications. During surgery, an increased used of vasopressor was observed in the remifentanil group (40.2% vs 2.4% ; p <0.0001) with a postoperative elevation of blood concentration of CKMb (35.7 +/- 38.2 microg/l, vs. 27.7 +/- 31.9 microg/l, p =0.02). CONCLUSION: Elderly patients undergoing coronary surgery were extubated earlier with remifentanil. However, this had no effect on duration of ICU stay but was associated with an increased used of vasopressor.     

Effects of lung metastasectomy on respiratory function

OBJECTIVE: The effects of lung metastasectomy on respiration were evaluated. SUBJECTS: From 1961 to 1999, 203 patients underwent lung metastasectomy. Of these, 102 patients who had undergone only partial lung resection, had undergone sufficient respiratory function testing, and had not suffered from other lung disease were included. RESULTS: Unilateral thoracoscopic surgery caused less decrease in percent vital capacity than surgery through a posterolateral thoracotomy, in both the early (rate of decrease: 16.2 +/- 9.1 vs. 33.0 +/- 12.0%, p < 0.01), and the late postoperative period (2.0 +/- 4.5 vs. 17.8 +/- 6.0%, p < 0.0001). Two thoracoscopic operations caused less decrease in percent vital capacity than 2 operations through a posterolateral thoracotomy (21.3 +/- 13.8 vs. 61.1 +/- 8.1%, p = 0.02). Bilateral metastasectomy through a median sternotomy caused less decrease in percent vital capacity than that through posterolateral thoracotomies (45.5 +/- 13.7 vs. 60.8 +/- 8.8%, p < 0.05). Four (36%) of 11 patients who had undergone 3 or more metastasectomies exhibited dyspnea of degree 3 or higher on the Hugh-Jones classification. CONCLUSIONS: Thoracoscopic metastasectomy and metastasectomy through a median sternotomy caused less restrictive respiratory dysfunction than metastasectomy through a posterolateral thoracotomy. Since metastatic lung disease often necessitates repeated metastasectomy, and repeated metastasectomy often causes severe restrictive respiratory dysfunction, metastasectomy should be performed with a less invasive procedure.     

Postoperative changes in paraspinal muscle thickness after various lumbar back surgery procedures

Damage to the paraspinal muscle after various lumbar back surgery procedures was evaluated by measuring the paraspinal muscle thickness preoperatively and postoperatively in 89 patients, 61 males and 28 females. There were 42 single interlaminar level procedures (SL group), 13 multiple interlaminar level procedures (ML group), and 34 posterolateral fusion procedures (PLF group). Changes in paraspinal muscle thickness were evaluated at more than 10 months after surgery, because muscle swelling continued as long as 10 months after surgery, and then reduced as the edema subsided. Postoperative serum creatine phosphokinase (CPK) level on postoperative day 2 was also measured. The decrease of paraspinal muscle thickness was significantly larger in the PLF group than in the SL group (-12.9% and -2.7%, respectively, p < 0.02). There was no significant correlation between postoperative serum CPK level and decrease of paraspinal muscle thickness. However, the postoperative elevation of serum CPK level was significantly higher in the PLF group than in the SL and ML groups (979 +/- 114 vs. 292 +/- 45 and 410 +/- 44 IU/l, respectively, p < 0.001). In conclusion, posterolateral fusion is the most invasive procedure of the paraspinal muscles in various lumbar back surgery procedures. Paraspinal muscle damage during lumbar back surgery may be one of the most important factors that causes atrophy of the muscles.     

Heparin influences human platelet behavior in cardiac surgery with or without cardiopulmonary bypass

The objective was to investigate whether the platelet dysfunction in cardiac surgery is caused by hemodilution or by shear stress due to cardiopulmonary bypass (CPB). Platelet count and function were prospectively analyzed in two groups of patients undergoing cardiac surgery either with or without CPB (n = 40). In the first study (n = 20; 10 patients with and 10 without CPB), platelet counts were assessed at seven time points. In the second study (n = 20; 10 patients with and 10 without CPB), platelet function was studied with platelet aggregometry at different points during surgery: (a) after induction of anesthesia; (b) after sternotomy; and (c) 1 h after heparin. In the first study, the CPB group showed a significant decrease in platelet count starting after sternotomy (230 +/- 34 vs. 182 +/- 25, P < 0.05) and a maximum decrease at day 1 postoperative (96 +/- 34, P < 0.05). A similar observation was made in the non-CBP group. In the second study, a significant decrease of ADP (54 +/- 13% vs. 38 +/- 9%, P < 0.05), AA (76 +/- 16% vs. 22 +/- 14%, P < 0.05), and Collagen (66 +/- 13% vs. 37 +/- 11%, P < 0.05) induced platelet aggregation was observed at MOMENT d compared to the beginning of surgery in the CPB group. In the non-CBP group a significant decrease was observed in AA-induced platelet aggregation at MOMENT d (83% +/- 4 vs. 44% +/- 14, P < 0.05). The reduction in platelet count is similar with or without cardiopulmonary bypass and is due to pure hemodilution. Platelet function reduces significantly after heparin administration. Hemodilution and predominantly heparin are the causes of platelet dysfunction after cardiac surgery.     

Administration of pamidronate helps prevent immediate postparathyroidectomy hungry bone syndrome

BACKGROUND: Despite the use of vitamin D analogues and oral calcium supplements, hypocalcaemia following surgical parathyroidectomy is a common problem, because of the so-called hungry bone syndrome. METHODS: The aim of this audit was to determine whether the change in clinical practice by the administration of pamidronate before parathyroidectomy, in addition to standard perioperative management, could prevent severe postoperative hypocalcaemia. RESULTS: The postoperative course of 37 end-stage renal failure patients on regular dialysis referred for total parathyroidectomy were reviewed. Twenty-seven patients had been given pamidronate 24-48 h before surgery. Pamidronate reduced corrected serum calcium from 2.54 +/- 0.18 mmol/L (mean +/- SD) to 2.36 +/- 0.18 before surgery (P < 0.05). Following surgery, serum calcium in the 10 patients given standard therapy alone fell to a nadir of 2.08 mmol/L (1.75-2.19) (median (interquartile range) by the first postoperative day, and all 10 patients required additional support with multiple boluses of intravenous calcium. In the pamidronate group, the lowest median postoperative calcium was 2.3 mmol/L (2.2-2.46), P < 0.05, and only two patients required additional support with intravenous calcium, chi(2) = 27, P < 0.001). However, in the longer term the annual percentage increase in bone mineral density following parathyroidectomy was non-statistically lower in the pamidronate group compared with the controls (lumbar spine (L1-L4), 0.041 +/- 0.04 vs 0.058 +/- 0.41, P = 0.23 and femoral neck, 0.03 +/- 0.03 vs 0.107 +/- 0.1, P = 0.15, respectively). CONCLUSION: Preoperative pamidronate in combination with high doses of oral alfacalcidol and calcium supplements can prevent symptomatic postoperative hypocalcaemia, reduce the requirement for intensive monitoring of calcium, reduce patient morbidity, and reduce hospital stay from 9.2 +/- 1.9 to 5.7 +/- 2.9 days, P < 0.05. However, in the longer term pamidronate may potentially delay bone remodelling.     

Ischemic preconditioning for major liver resection under vascular exclusion of the liver preserving the caval flow: a randomized prospective study

BACKGROUND: Two randomized prospective studies suggested that ischemic preconditioning (IP) protects the human liver against ischemia-reperfusion injury after hepatectomy performed under continuous clamping of the portal triad. The primary goal of this study was to determine whether IP protects the human liver against ischemia-reperfusion injury after hepatectomy under continuous vascular exclusion with preservation of the caval flow. STUDY DESIGN: Sixty patients were randomly divided into two groups: with (n=30; preconditioning group) and without (n=30; control group) IP (10 minutes of portal triad clamping and 10 minutes of reperfusion) before major hepatectomy under vascular exclusion of the liver preserving the caval flow. Serum concentrations of aspartate transferase, alanine transferase, glutathione-S-transferase, and bilirubin and prothrombin time were regularly determined until discharge and at 1 month. Morbidity and mortality were determined in both groups. RESULTS: Peak postoperative concentrations of aspartate transferase were similar in the groups with and without IP (851 +/- 1,733 IU/L and 427 +/- 166 IU/L respectively, p=0.2). A similar trend toward a higher peak concentration of alanine transferase and glutathione-S-transferase was indeed observed in the preconditioning group compared with the control group. Morbidity and mortality rates and lengths of ICU and hospitalization stays were similar in both groups. CONCLUSIONS: IP does not improve liver tolerance to ischemia-reperfusion after hepatectomy under vascular exclusion of the liver with preservation of the caval flow. This maneuver does not improve postoperative liver function and does not affect morbidity or mortality rates. The clinical use of IP through 10 minutes of warm ischemia in this technique of hepatectomy is not currently recommended.