Stanić Mirjana, Sindjelić Radomir, Nesković Vojislava, Davidović Lazar, Lotina Slovodan
Institute of Cardiovascular Diseases, Clinical Centre of Serbia, Belgrade.
Srp Arh Celok Lek. 2002 May-Jun;130(5-6):168-72. doi: 10.2298/sarh0206168s.
Despite the progress in surgical and anaesthetic management, decreased renal function is still observed after abdominal infrarenal aortic surgery and remains an important problem in postoperative period. Although data regarding the efficacy of perioperative renal protection are conflicting, it is widely believed that renal protection before aortic cross-clamping is beneficial and therefore is commonly used. The aim of this study was to evaluate the impact of renal protection in patients undergoing elective infrarenal aortic surgery (1ARS).
We have prospectively studied 80 patients undergoing elective infrarenal aortic surgery from October 1996 to May 1998 in the Clinical Centre of Serbia, because of aorto-occlusive disease or aortic aneurysm. Patients were excluded from the study for three reasons: prior renal dysfunction, suprarenal aortic cross-clamping and ruptured aortic aneurysm. We have randomized the patients in two groups: without renal protection--group A (n = 40) and with renal protection--group B (n = 40). Preanaesthetic medication consisted of midazolam (5 mg i.m.). Anaesthesia was induced with etomidat 0.3 mg/kg, fentanyl 0.05-0.1 mg and succinil-holin Img/kg. Ventilation was controlled using 50% of nitrous oxyde and oxygen. Supplemental anaesthesia consisted of isoflurane and fentanyl, in order to maintain the mean arterial pressure and heart rate +/- 20% regarding preoperative values. In all patients two peripheral vein and radial artery catheters were cannulated before anaesthesia. Central venous catheter and Foley urinary bladder catheter were inserted after the induction of anaesthesia. Two-lead electrocardiograms were recorded. All patients in group B were given intravenously mannitol (0.3 g/kg) before aortic cross-clamping (ACC). After aortic cross-clamping, these patients received furosemide (20-40 mg) or dopamine (1-3 micrograms/kg/min) to the end of surgery (Table 1). In 8 time points (preoperatively, after induction, during ACC, 2 and 8 hours after ACC, on day 1, 2 and 3 postoperatively) haemodynamic parameters (mean arterial and central venous pressure), volume load, urinary output, creatinine and free-water clearance, serum electrolytes, BUN, creatinine, plasma and urine osmolality and ACC time were analyzed in each patient. Renal complications were classified as transient or persistent. Transient renal dysfunction was defined as a greater rise than 20% rise in peak serum creatinine level over baseline serum creatinine level, with a peak of at least 168 mumol/L. Persistent renal insufficiency was defined as a greater rise than 20% rise in discharge serum creatinine level over baseline serum creatinine level, with a peak of at least 168 mumol/L. Moreover, renal insufficiency was defined as a free-water clearance greater than -15 ml/h. Aortic cross-clamping time was defined as a period in which the proximal inflow was occluded. The results were expressed as means +/- SD. Statistical difference detected with Student's t-test, with p < 0.05 being considered significant.
Patients in groups A and B were similar regarding the age (64.32 vs. 62.00), sex (males 35, females vs. males 34, females 6) and preoperative diseases. (Tab. 2) No difference was found between groups regarding any of the parameters (BUN, serum creatinine, electrolytes, volume load, creatinine and free-water clearance, haemodynamic parameters, plasma and urine osmolality). Urinary output was higher in group B during and 2 hours after ACC. (Graph 1.) ACC time was similar in two groups (24.1 min vs 24.5 min). (Graph. 2) Only one patient in group B revealed transitory renal insufficiency, not requiring special treatment. These data indicate that renal protection did not influence renal function. Short ACC time may have impact on the obtained results. Our results suggest that renal protection should not be considered as mandatory for elective infrarenal aortic surgery. Because of the short ACC time observed in this study (in comparison to other studies), further studies of renal protection in patients with longer ACC time are needed.
尽管在外科手术和麻醉管理方面取得了进展，但在腹主动脉肾下段手术后仍观察到肾功能下降，这在术后仍然是一个重要问题。虽然关于围手术期肾脏保护效果的数据存在冲突，但人们普遍认为在主动脉交叉钳夹前进行肾脏保护是有益的，因此被广泛应用。本研究的目的是评估肾脏保护对接受择期肾下段主动脉手术（1ARS）患者的影响。
1996年10月至1998年5月，我们在塞尔维亚临床中心对80例因主动脉闭塞性疾病或主动脉瘤接受择期肾下段主动脉手术的患者进行了前瞻性研究。患者因以下三个原因被排除在研究之外：既往肾功能不全、肾上段主动脉交叉钳夹和主动脉瘤破裂。我们将患者随机分为两组：无肾脏保护组——A组（n = 40）和有肾脏保护组——B组（n = 40）。麻醉前用药包括咪达唑仑（5 mg肌肉注射）。用依托咪酯0.3 mg/kg、芬太尼0.05 - 0.1 mg和琥珀胆碱1 mg/kg诱导麻醉。使用50%氧化亚氮和氧气进行控制通气。补充麻醉包括异氟烷和芬太尼，以维持平均动脉压和心率相对于术前值±20%。所有患者在麻醉前均插入两根外周静脉和桡动脉导管。麻醉诱导后插入中心静脉导管和Foley膀胱导管。记录双导联心电图。B组所有患者在主动脉交叉钳夹（ACC）前静脉注射甘露醇（0.3 g/kg）。主动脉交叉钳夹后，这些患者在手术结束前接受呋塞米（20 - 40 mg）或多巴胺（1 - 3微克/千克/分钟）（表一）。在8个时间点（术前、诱导后、ACC期间、ACC后2小时和8小时、术后第1天、第2天和第3天）分析每位患者的血流动力学参数（平均动脉压和中心静脉压）、容量负荷、尿量、肌酐和自由水清除率、血清电解质、血尿素氮、肌酐、血浆和尿液渗透压以及ACC时间。肾脏并发症分为短暂性或持续性。短暂性肾功能不全定义为血清肌酐峰值水平比基线血清肌酐水平升高超过20%，且峰值至少为168 μmol/L。持续性肾功能不全定义为出院时血清肌酐水平比基线血清肌酐水平升高超过20%，且峰值至少为168 μmol/L。此外，肾功能不全定义为自由水清除率大于-15 ml/h。主动脉交叉钳夹时间定义为近端血流被阻断的时间段。结果以平均值±标准差表示。采用Student's t检验检测统计学差异，p < 0.05被认为具有显著性。
A组和B组患者在年龄（64.32对62.00）、性别（男性35例，女性对男性34例，女性6例）和术前疾病方面相似。（表2）两组在任何参数（血尿素氮、血清肌酐、电解质、容量负荷、肌酐和自由水清除率、血流动力学参数、血浆和尿液渗透压）方面均未发现差异。B组在ACC期间和ACC后2小时尿量较高。（图1）两组ACC时间相似（24.1分钟对vs 24.5分钟）。（图2）B组仅1例患者出现短暂性肾功能不全，无需特殊治疗。这些数据表明肾脏保护并未影响肾功能。较短的ACC时间可能对所得结果有影响。我们的结果表明，对于择期肾下段主动脉手术，不应将肾脏保护视为必需。由于本研究中观察到的ACC时间较短（与其他研究相比），需要对ACC时间较长的患者进行进一步的肾脏保护研究。
