手术后早期低钾的临床观察及护理

观察１２３例手术后病人早期血钾浓度，其中低血钾６３例，占５１．２２％。对手术后早期发生低血钾的可能因素进行探讨并提出如何防治，同时还阐述了手术后早期补钾的观察和护理。１２３例病人分别在术后２４ｈ内补钾２．０￣９．０ｇ，无１例出现异常反应，且血钾浓度均能维持在正常范围内。     

腹部手术后钾代谢的临床研究及早期补钾对胃肠功能的影响

目的　观察腹部手术后早期补钾对胃肠功能恢复的影响。方法　测定 6 7例腹部手术前后血钾、钠、氯的变化和尿、胃肠减压液及引流液中电解质丢失量 ,并观察手术后不同时间补钾者的胃肠功能恢复情况。结果手术日和术后钾丢失平均 72 .6mmol/d ,最多达 2 76 .3mmol/d ,尿钾浓度无明显改变 ,尿钾丢失主要为尿量增加所致。术后平均补钾 49.6mmol/d ,但血钾较术前明显降低 (P <0 .0 5 ) ,5例血钾低于 3 .5mmol/L ,无 1例出现高血钾。术后早期补钾者胃肠功能恢复快。结论　只要肾功能正常 ,术后第 1d可开始见尿即补钾 ,除应常规补钾外 ,应根据尿量随时调整钾的补充量     

择期手术患者围手术期体内血钾变化的临床观察

观察围手术期体内血钾的变化规律，探讨血钾发生变化的机制及围手术期补钾的方法。对30例择期手术患者随机分成3组（各n＝10），不补钾组、慢补钾组、快补钾组，观察围手术期血清钾、尿钾、红细胞压积的变化。结果表明：三组麻醉前血清钾比术前降低（P＜0．05），慢补钾组术后24小时血钾恢复至术前水平，另二组仍低于术前水平（P＜0．05）。交感神经兴奋是术前血钾下降的主要原因，术毕血钾降低与血液稀释有关。认为择期手水患者从术中即开始补钾是可取的方法。     

手术前后血钾浓度的动态观察

目的 动态观察病人外科手术前后血钾浓度的变化。方法 分别于手术前及手术后30min,12、24、48h检测209例病人血钾浓度。结果 病人手术后血钾浓度均明显低于手术前(P<0.01),至手术后48h低钾病人数目有逐渐增多的趋势。腹部手术后血钾浓度与甲状腺手术后血钾浓度比较,前者降低更为显著。结论 手术后应早期补钾。     

腹部择期手术前后电解质变化及术后早期补钾对胃肠功能的影响

为观察腹部择期手术前后电解质变化及早期补钾对胃肠功能恢复的影响,对６９例患者术前和术后电解质水平进行了测定,并观察了术后不同时间补钾者的胃肠功能恢复情况。结果：术后血Ｋ＋、Ｎａ＋、Ｃｌ－水平均较术前有明显降低（Ｐ＜０．０５）,但仍在正常值范围,而血Ｃａ２＋及血Ｍｇ２＋手术前后无显著变化;术中输血量与血Ｋ＋变化无明显相关性;术后早期补钾者胃肠功能恢复快。本组资料结果提示：只要肾功能正常,术中输血不会引起高血钾,因此术后第１天可开始见尿补钾     

腹部手术后钾代谢的临床研究

目的 探讨腹部术后是否需立即补钾，血钾与静脉补钾和钾排出的关系，方法 测定４７例腹部手术前后血钾，氯变化和尿，胃肠减压液体及引流液中电解质丢失量。分析酸碱平衡，肌酐清除率对钾代谢的影响。结果 手术日和术后钾丢失平均７２．９ｍｍｏｌ／ｄ，最多达２８９．２ｍｍｏｌ／ｄ尿钾浓度无明显改变，尿钾么失主要为尿量增加所致。术后平均补钾４９．８ｍｍｏｌ／ｄ但血钾较术前明显降低（Ｐ〈０．０１），５例血钾低于３．５     

体外循环与非体外循环冠状动脉旁路移植术补钾影响因素的比较

目的 探讨常规冠状动脉旁路移植术(CCABG)与非体外循环冠状动脉旁路移植术(OPCABG)围术期钾离子变化特点与补钾影响因素.方法 50例接受CABG患者,分为CCABG组和OPCABG组,每组25例.术中根据血气结果补钾,维持血清钾离子浓度在4.0～5.0mmol/L.记录并比较两组术中及术后液体出入量、补钾量、单位时间补钾量(补钾量/手术时间)、尿钾浓度、尿排钾量(总尿量×平均尿钾浓度)以及心肺转流(CPB)指标,分析两组术中补钾量的独立影响因素.结果 CCABG组术中补钾量及单位时间补钾量均高于OPCABG组,但其CPB前后单位时间补钾量低于OPCABG组(P＜0.05);CCABG组桥血管数、手术时间、术中尿量、尿排钾量及术后24 h补钾量均大于OPCABG组,术中平均尿钾浓度和最低体温低于OPCABG组(P＜0.05).多元线性回归分析显示尿量和入室血钾浓度是OPCABG组术中补钾量的独立影响因素;年龄和CPB转机时间是CCABG组术中补钾量的独立影响因素(P＜0.05).结论 CABG围术期需积极补钾.OPCABG中应根据基础血清钾水平结合尿量尽早开始补钾;CCABG中应根据CPB时间合理补钾.     

开胸术后早期血清钾钠氯的变化

对１０６例开胸术后病人按是否行胃肠减压及是否经静脉补钾分组，进行术后１～５天血清钾、钠、氯水平的观察。结果发现：（１）术后早期补钾不一定产生高血钾；（２）术后血钾高峰出现于第２天；（３）禁食可使血钾升高；（４）术后血氯降低。     

门冬氨酸钾镁注射液在胃肠道术后禁食患者电解质补充中对钾镁离子影响的多中心随机对照临床试验

目的评价门冬氨酸钾镁注射液在胃肠道术后禁食患者电解质补充中的疗效和安全性。方法以门冬氨酸钾镁注射液(潘南金)为观察药物,进行多中心随机对照临床观察。将111例患者随机分为试验组(门冬氨酸钾镁注射液和氯化钾注射液联用补钾,56例)和对照组(单纯使用氯化钾注射液补钾,55例),连续补充5 d,并进行临床疗效观察,包括血钾和尿钾的跟踪检测。结果试验组和对照组患者基线水平一致(P>0.05),补钾后2组血钾水平差异无统计学意义(P>0.05),但试验组患者24 h尿钾量在术后1～4 d均明显低于对照组(P<0.05)。试验组术后不同时相血镁离子浓度均高于对照组,差异有统计学意义(P<0.05)。在临床观察过程中,未发现与门冬氨酸钾镁注射液相关的不良事件。结论门冬氨酸钾镁注射液在禁食患者钾缺乏治疗方面疗效显著,特别是对细胞内补钾明显优于氯化钾,安全性高,是临床纠正钾缺乏的合理选择。     

低镁综合征15例诊治分析

１９８３年１月～１９９３年１月，治疗外科手术后低镁综合征１５例，疗效满意。１５例均国外科疾病手术，术后出现顽固性低血钾、低血钙，并伴有水电解质紊乱及酸碱平衡失调，大剂量补钾补钙后症状不见好转，考虑同时存在低血镁。治疗上应在补镁的同时补钾补钙，才能纠正低血镁。本文就其低镁综合征的发病原因、临床表现、诊断与治疗方法进行了分析和讨论     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.