Fibrinolytic responses of human peritoneal fluid in laparoscopic cholecystectomy: a prospective clinical study

Background The reduction in peritoneal fibrinolysis is believed to be the pathogenetic mechanism of adhesion formation. The general conclusion based on previous clinical and experimental studies is that laparoscopic procedures produce less adhesion formation. The association between this beneficial effect of laparoscopic cholecystectomy and peritoneal fibrinolytic changes is not clear. Therefore, the authors aimed to compare the effects of open and laparoscopic cholecystectomy on peritoneal fibrinolysis. For this purpose, fibrinolytic parameters in peritoneal fluid were investigated 24 h after laparoscopic and open cholecystectomies. Methods In a prospective clinical study, peritoneal fluid was sampled via a drain 24 h after laparoscopic (n = 10) and open (n = 9) cholecystectomies. Activities and concentrations of tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), and tPA/PAI-1 complex were determined by enzyme-linked immunosorbent assay (ELISA) kits. Results In peritoneal fluids, tPA and tPA/PAI-1 complex concentrations were higher in the open cholecystectomy group (p = 0.009 and p < 0.001, respectively), but tPA activity and PAI-1 concentrations did not differ between the groups (p = 0.514 and p = 0.716, respectively). Conclusions Fibrinolytic changes in peritoneal fluid have several similarities in open and laparoscopic cholecystectomies with regard to tPA activity and PAI-1 levels. However, higher tPA levels after the open procedure probably are secondary to more intense tissue handling leading to mesothelial release of tPA.     

Heating of carbon dioxide during insufflation alters the peritoneal fibrinolytic response to laparoscopic surgery

Background Laparoscopic surgery is evolving rapidly. It involves the creation of a pneumoperitoneum, mostly using carbon dioxide. Cooling of the peritoneum, due to insufflation, might traumatize the peritoneum and disturb peritoneal fibrinolysis, important in peritoneal healing processes. The current study was performed to elucidate the effects of the temperature of insufflation gas on the peritoneal fibrinolytic response to laparoscopic surgery. Methods Thirty patients scheduled for laparoscopic cholecystectomy were randomized in two groups: one group in which the pneumoperitoneum was created with carbon dioxide at room temperature, and one wherein carbon dioxide at body temperature was used. Peritoneal biopsies were taken at the start and at the end of surgery. Tissue concentrations of tPA antigen, tPA activity, uPA antigen, and PAI-1 antigen were measured using ELISA techniques. Results Peritoneal PAI-1 antigen levels were significantly higher at the end of the procedure in patients operated with carbon dioxide at room temperature (p < .05). A slight, but not significant, decrease in tPA antigen and activity was observed in both groups during the procedure. Peritoneal concentrations of uPa antigen did not change during the procedure. Conclusions The temperature of carbon dioxide used for insufflation of the abdominal cavity affects peritoneal biology. Cooling of the peritoneum by unheated carbon dioxide causes increased peritoneal PAI-1 levels, important in peritoneal healing processes.     

CO2部分重吸入法测心排血量在冠脉搭桥术中的应用

目的 观察CO2部分重吸入法测心排血量在冠脉搭桥术中的应用。方法 选择冠脉搭桥术26例,于诱导后、切皮、体外循环转流前、停转流后60min、停转流90min、术毕及术后监护室各时点采用CO2部分重吸入法测心排血量（RBco),并与温度稀释法（TDco)作比较。结果 于诱导后、切皮、停转流90min、术毕、术后监护室RBco和TDco测量数值均无显著性差异（P＞0．05）,于转流前、转流后60min测量值有显著性差异（P＜0．05）。各时点RBco和TDco相关系数均P＜0．01,其中术后监护室中的相关系数最高,r＝0．8511。结论 CO2部分重吸入法测心排血量在冠脉搭桥术术后监测中有良好的准确度,术中监测也有一定的临床价值。     

翻转大翼软骨瓣辅助硅胶假体置入隆鼻术

目的 探讨一种在应用硅胶假体进行隆鼻术时防止假体外露,同时有利于鼻尖与鼻翼成形,并有效增加鼻长的手术方法.方法 在16例临床隆鼻手术中,应用翻转大翼软骨瓣辅助硅胶鼻假体置入的方法,术中离断大翼软骨外侧脚,保留内侧脚完整,单端游离大翼软骨至鼻尖,充分松解大翼软骨对鼻尖的牵拉,以便在增高鼻背的同时增加鼻长,并满足个性化鼻尖与鼻翼成形.结果 16例受术者全部Ⅰ期愈合,无感染及假体外露等并发症发生.术后1个月回访,鼻尖高度及鼻长明显增加,鼻形自然,鼻翼立体感不仅未受影响,反而不同程度地得到优化,鼻尖与鼻翼轮廓清晰.结论 应用翻转大翼软骨瓣辅助硅胶鼻假体置入的隆鼻方法,可有效防止要求较高隆起鼻梁、鼻尖时造成的假体外露风险,同时有助于实现个性化鼻尖与鼻翼成形.由于软骨瓣取材方便、无需第2术区,软骨瓣血运有保障,不易发生变形和吸收,是提高隆鼻术美容效果的可行方法.     

Cerebral hypoperfusion in immediate postoperative period following coronary artery bypass grafting, heart valve, and abdominal aortic surgery

Perioperative levels of jugular bulb oxyhaemoglobin saturation(Sj_O2) and lactate concentration (Lj), and postoperative durationof Sj_O2<50% were compared between patients undergoing coronaryartery bypass grafting (CABG) (n=86), heart valve (n=14) andabdominal aortic (n=16) surgery. Radial artery and jugular bulbblood samples were aspirated after induction of anaesthesia,during re-warming on cardiopulmonary bypass (CPB) (36°C),on arrival in the intensive care unit (ICU) and, subsequently,at 1, 2 and 6 h after ICU admission. Most patients having heartsurgery were hypocapnic at 36°C on CPB. Following CABG andheart valve surgery, many patients were hypocapnic whereas afterabdominal aortic surgery, most were hypercapnic. During CPBand postoperatively, Sj_O2 and Lj were significantly correlatedto Pa_CO2 and the arterial concentration of lactate (La) respectively(P<0.05). After correction for arterial carbon dioxide tension(Pa_CO2) and La, there were no significant changes in Sj_O2 orLj on CPB. Postoperatively, having corrected for Pa_CO2, therewere significant effects on Sj_O2 over all groups as a resultof time from surgery (P<0.001) and its interaction with operationtype (P<0.001). Following correction for La, there were nopostoperative effects on Lj. No significant differences (P=0.2)in duration of Sj_O2<50% existed between patients undergoingCABG (1054 (82) min), abdominal aortic (893 (113) min) and heartvalve (1073 (91) min) surgery. The lack of significant reciprocaleffects on Lj combined with the frequency of hypocapnia andstrong influence of Pa_CO2on Sj_O2, suggest that Sj_O2<50% duringCPB and after cardiac surgery represents hypoperfusion as aconsequence of hypocapnia rather than cerebral ischaemia. Br J Anaesth 2001; 87: 229–36     

Dynamic skin cooling with an environmentally compatible alternative cryogen during laser surgery

BACKGROUND AND OBJECTIVES: Cryogen spray cooling with tetrafluoroethane (R134a) has been used to enhance epidermal protection during dermatologic laser surgery. However, R134a has a very high global warming potential (GWP = 1300). Our objective was to evaluate the cooling effectiveness of an alternative cryogen with a much lower GWP, namely liquid carbon dioxide (CO(2), GWP = 1). STUDY DESIGN/MATERIALS AND METHODS: A thin-film thermocouple deposited on an epoxy skin phantom was used to measure surface temperature (T(s)) variations induced by R134a or CO(2) sprays. The temperature distribution in the skin phantom was estimated using T(s) and Duhamel's method. Impact pressure and noise level of both cryogen sprays were measured with a dynamic sensor and sound meter, respectively. Consumption of both cryogens was also evaluated. RESULTS: For R134a sprays, T(s) was kept almost constant after 15 milliseconds. For CO(2) sprays, T(s) decreased continuously during the entire spurt of 50 milliseconds. The minimum T(s) induced by the CO(2) sprays was lower than that induced by R134a when the spurt duration was longer than 35 milliseconds. Numerical simulation shows that CO(2) sprays were able to induce very similar temperature reductions in the skin phantom as compared to R134a sprays when the spurt duration and delay time were selected appropriately. R134a sprays induced an impact pressure of 3.6 kPa, as compared to 43.1 kPa for CO(2) sprays. The maximum noise level for R134a sprays was 109 dBA as compared to 135 dBA for the CO(2) sprays. The R134a consumption for a 50 milliseconds spurt is 67 mg as compared to 225 mg for a CO(2) spurt of the same duration. CONCLUSIONS: CO(2) sprays are expected to have similar skin cooling efficacy as R134a sprays. Although the CO(2) consumption is higher than R134a, its contribution to global warming is still much less than R134a. The effects of varying spurt durations on in vivo human skin and the impact on cutaneous blood flow require further investigation.     

Technical Indicators to Evaluate the Degree of Large Clot Formation Inside the Membrane Fiber Bundle of an Oxygenator in an In Vitro Setup

The most common technical complication during ECMO is clot formation. A large clot inside a membrane oxygenator reduces effective membrane surface area and therefore gas transfer capabilities, and restricts blood flow through the device, resulting in an increased membrane oxygenator pressure drop (dpMO). The reasons for thrombotic events are manifold and highly patient specific. Thrombus formation inside the oxygenator during ECMO is usually unpredictable and remains an unsolved problem. Clot sizes and positions are well documented in literature for the Maquet Quadrox‐i Adult oxygenator based on CT data extracted from devices after patient treatment. Based on this data, the present study was designed to investigate the effects of large clots on purely technical parameters, for example, dpMO and gas transfer. Therefore, medical grade silicone was injected into the fiber bundle of the devices to replicate large clot positions and sizes. A total of six devices were tested in vitro with silicone clot volumes of 0, 30, 40, 50, 65, and 85 mL in accordance with ISO 7199. Gas transfer was measured by sampling blood pre and post device, as well as by sampling the exhaust gas at the devices’ outlet at blood flow rates of 0.5, 2.5, and 5.0 L/min. Pre and post device pressure was monitored to calculate the dpMO at the different blood flow rates. The dpMO was found to be a reliable parameter to indicate a large clot only in already advanced “clotting stages.” The CO₂ concentration in the exhaust gas, however, was found to be sensitive to even small clot sizes and at low blood flows. Exhaust gas CO₂ concentration can be monitored continuously and without any risks for the patient during ECMO therapy to provide additional information on the endurance of the oxygenator. This may help detect a clot formation and growth inside a membrane oxygenator during ECMO even if the increase in dpMO remains moderate.     

10% 5-氨基酮戊酸光动力疗法联合卡介菌多糖核酸注射液治疗面部扁平疣临床观察

目的探讨10%5-氨基酮戊酸光动力疗法(ALA-PDT)联合卡介菌多糖核酸注射液治疗面部扁平疣的临床疗效。方法将70例面部扁平疣患者按治疗方法不同随机分为观察组和对照组,各35例。观察组采用10%ALA-PDT联合卡介菌多糖核酸注射液治疗,对照组采用二氧化碳(CO_2)激光联合卡介菌多糖核酸注射液治疗。若第1次治疗皮损未完全消退,需进行第2次或第3次治疗,每次治疗间隔2周,观察第2周、第4周、第6周及治疗结束后3个月时的疗效和不良反应。结果两组患者治疗后与治疗前比较,皮损均明显消退及改善;治疗后6周,观察组总有效率为88.57%(31/35),对照组为68.57%(24/35),差异有统计学意义(P0.05)。随访3个月,观察组复发率为2.86%(1/35),对照组复发率为17.14%(6/35),差异有统计学意义(P0.05)。结论 10%ALA-PDT联合卡介菌多糖核酸注射液治疗面部扁平疣安全有效,并降低其复发率。     

Preoperative glucocorticoids decrease pulmonary hypertension in piglets after cardiopulmonary bypass and circulatory arrest

BACKGROUND: Glucocorticoids during cardiopulmonary bypass benefit pediatric patients undergoing repair of congenital heart defects and are routine therapy, but underlying mechanisms have not been fully examined. The hypothesis was that glucocorticoids could improve cardiopulmonary recovery after cardiopulmonary bypass and deep hypothermic circulatory arrest. METHODS: Crossbred piglets (5 to 7 kg) were cooled with cardiopulmonary bypass, followed by 120-min deep hypothermic circulatory arrest. Animals were then warmed to 38 degrees C, removed from bypass, and maintained for 120 min. Methylprednisolone (60 mg/kg) was administered in the cardiopulmonary bypass pump prime (intraoperative glucocorticoids) or 6 hours before bypass (30 mg/kg) in addition to the intraoperative dose (30 mg/kg; preoperative and intraoperative glucocorticoids). Controls (no glucocorticoids) received saline. RESULTS: Pulmonary vascular resistance in controls increased from a baseline of 152 +/- 40 to 364 +/- 29 dynes. s/cm(5) at 2 hours of recovery (p < 0.001). Intraoperative glucocorticoids did not alleviate the increase in pulmonary vascular resistance (301 +/- 55 dynes. s/cm(5) at 2 hours of recovery, p < 0.001). However, animals receiving pre and intraoperative glucocorticoids had no increase in pulmonary vascular resistance (155 +/- 54 dynes. s/cm(5)). Plasma endothelin-1 in controls increased from 1.3 +/- 0.2 at baseline to 9.9 +/- 2.0 pg/mL at 2 hours recovery (p < 0.01), whereas glucocorticoid-treated animals had lower endothelin-1 levels (4.5 +/- 2.1 pg/ml, preoperative and intraoperative glucocorticoids; 4.9 +/- 1.7 pg/mL, intraoperative glucocorticoids) at the end of recovery (p < 0.05). Intracellular adhesion molecule-1 in lung tissue was lower in animals receiving pre and intraoperative glucocorticoids (p < 0.05). Myeloperoxidase activity was elevated in control lungs at 2 hours of recovery compared with glucocorticoid-treated groups (p < 0.05). Inhibitor kappaBalpha, the inhibitor of nuclear factor-kappaB, was higher in lungs of animals receiving glucocorticoids compared with controls (p < 0.05). CONCLUSIONS: Glucocorticoids prevented pulmonary hypertension after cardiopulmonary bypass and deep hypothermic circulatory arrest, which was associated with reduced plasma endothelin-1. Glucocorticoids also reduced pulmonary intercellular adhesion molecule-1 and myeloperoxidase activity. Inhibition of nuclear factor-kappaB, along with reduced neutrophil activation, contributed to glucocorticoid alleviation of pulmonary hypertension after cardiopulmonary bypass and deep hypothermic circulatory arrest.