前置钢板微创固定治疗肱骨干中下段骨折的可行性研究

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.     

前置钢板微创固定治疗肱骨干中下段骨折的可行性研究

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.     

前置钢板微创固定治疗肱骨干中下段骨折的可行性研究

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.     

前置钢板微创固定治疗肱骨干中下段骨折的可行性研究

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.     

前置钢板微创固定治疗肱骨干中下段骨折的可行性研究

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.     

前置钢板微创固定治疗肱骨干中下段骨折的可行性研究

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.     

前置钢板微创固定治疗肱骨干中下段骨折的可行性研究

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.     

前置钢板微创固定治疗肱骨干中下段骨折的可行性研究

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.     

新型微创前置肱骨中下段解剖锁定钢板的设计及相关解剖研究

目的 探讨应用自行研制的3.5 mm新型前置肱骨中下段解剖锁定钢板微创治疗肱骨干中下段骨折的可行性和安全性.方法 新鲜冷冻成人上肢6具,分别于上臂前侧远近端做3 cm皮肤切口,通过肌下隧道插入钢板,经切口打入螺钉固定.原位解剖重要神经结构,观察其与钢板的关系,测量桡神经在不同位置与钢板外侧缘、钢板最远端内侧与正中神经、螺钉头部与桡神经沟处桡神经的距离.结果 新增前置肱骨中下段解剖锁定钢板远端的绝大部分被肱肌覆盖,其与桡神经、肌皮神经及正中神经之间隔有肱肌肌腹,钢板与桡神经之间分别在穿经外侧肌间隔以及冠状窝水平的距离平均分别为14.53 mm和8.38 mm,桡神经穿经外侧肌间隔至冠状窝上缘连线中点处的平均距离为8.39 mm;屈肘80°和伸肘0°位时钢板最远端内侧与正中神经的距离平均分别为11.89 mm和l0.53mm,由近向远的第3枚螺钉头部与桡神经沟近侧缘的距离平均为5.90 mm.结论 采用自行研制的新型前置解剖锁定钢板微创固定肱骨干中下段骨折理论上是可行且安全的.

Abstract：

Objective To verify the feasibility and safety of a self-designed anatomical anterior locking plate for minimally invasive treatment of mid-distal humeral fractures. Methods Six fresh-frozen cadaveric specimens of upper extremity were used for the present anatomic study.A 3 cm incision was made on the anterior side of the arm between the deltoid muscle and biceps muscle and another 3 cm incision was made along the lateral side of biceps muscle proximal to the cubital crease to expose the anterior cortex.The plate was inserted from the distal incision proximally and positioned on the anterior side of the humeral shaft.The biceps muscle and brachialis were dissected to expose the radial,musculocutaneous and median nerves in situ.Relationships between the plate and nerves were observed.The distances between the lateral border of the plate and the radial nerve were measured where the nerve pierced the lateral intermuscular septum and at the point above the coronoid fossa and at the middle of the above 2 points.The distances between the distal end of the plate and the median nerve were measured when the elbow was in 80° flexion and full extension.The distance between the head of the third proximal screw and the spiral groove was also measured. Results Most part of the plate was covered by the brachial muscle.There was no direct contract between the plate and the radial,musculocutaneous and median nerves,all separated by the muscle belly of the brachialis.The average distances between the lateral border of the plate and the radial nerve where the nerve pierced the lateral intermuscular septum and at the superior edge of the coronoid fossa and at the middle of the 2 points were 14.53 mm (range,13.1 to 17.1 mm),8.38 mm (range,4.2 to 11.3 mm) and 8.39 mm (range,0 to 13.9 mm) respectively.The average minimum distances between the medial border of the distal end of the plate and the median nerve when the elbow was in 80° flexion and full extension was 11.89 mm (range 9.6 to 15.5 mm) and 10.53 mm (range 9.0 to 12.1 mm) respectively.The average distance between the head of the third proximal screw and the spiral groove was 5.90 mm (range,4.2 to 7.1 mm). Conclusions Our novel anatomical anterior locking plate is theoretically safe for the minimally invasive treatment of mid-distal humeral fractures.     

Combined radial and median nerve injury in diaphysea fracture of humerus： a case report

Radial nerve palsy is the most common neurological involvement in humeral shaft fractures.But combined radial and median nerve injury in a closed diaphyseal fracture of the humerus is rare.Combined injury to both radial and median nerve can cause significant disability.A detailed clinical examination is therefore necessary following humeral shaft fractures.We report a patient with closed diaphyseal humeral fracture （AO 12A-2.3） together with radial and median nerve palsy,its management and review of the literature.As the patient had two nerves involved,surgical exploration was planned.Fracture was reduced and fixed with a 4.5 mm narrow dynamic compression pla te.There was no external injury to both radial and median nerves on surgical exploration.Neurological recovery started at 3 weeks＇ follow-up.Complete recovery was seen at 12 weeks.Careful clinical examination is of the utmost importance in early diagnosis of combined nerve injuries,which allows better management and rehabilitation of the patient.     

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 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.     

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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.