Protective effects of beta blockade on pulmonary function when intracranial pressure is elevated

Intracranial pressure (ICP) was increased by hyperosmolar intracerebral infusion in dogs and the cardiopulmonary and catecholamine (CA) responses followed for 4 h. Increased ICP evoked persistent increases in endogenous CAs, pulmonary vascular pressures, pulmonary blood volume, and venous admixture. Other dogs similarly monitored were treated with a beta-blocking dose of propranolol 25 min after the onset of increased ICP. Although catecholamines were increased, elevated pulmonary pressures and venous admixture returned to control levels. CO and heart rate (HR) were reduced after beta blockade but systemic vascular resistance increased. It was concluded that increased ICP induces sustained increases in CAs which adversely affect pulmonary pressures and shunting. Selective beta blockade reverses these effects and may be useful in patients with evidence of sympathetic overactivity and progressive hypoxemia after head injury.     

阿替普酶治疗急性肺栓塞的初步研究

目的:评价在急性肺血栓栓塞症(PTE)治疗中使用阿替普酶(rt-PA)的方法、安全性和有效性。方法:按照实验设计,于2010-07-2012-06间将20例中重度急性期肺血栓栓塞症患者,随机分成导管接触溶栓组(10例,留置导管于肺动脉血栓处,2h内持续导管泵入阿替普酶50mg)、外周静脉溶栓组(10例,15mg静脉推注,其余35mg滴注2h)。分析治疗前后患者血气分析、超声心动图、肺动脉CTA等检查结果的变化情况。结果:20例患者溶栓1d及5d后,其呼吸困难症状均有所改善,但两组间部分检查指标比较差异有统计学意义。结论:阿替普酶治疗急性期肺血栓栓塞症,在相同剂量、相同使用时间的情况下对比导管接触溶栓与外周静脉溶栓,临床治疗短期表现前者优于后者。所以我们认为在临床上采用阿替普酶导管接触溶栓治疗是安全的、效果优于传统的外周静脉用法。     

Management of sympathetic overactivity in tetanus with epidural bupivacaine and sufentanil: experience with 11 patients.

OBJECTIVE: To determine the efficacy and safety of epidural bupivacaine and sufentanil for the management of sympathetic overactivity in tetanus. DESIGN: Retrospective case review. SETTING: Sixteen-bed surgical intensive care unit in a tertiary care centre. PATIENTS: All patients referred to the unit during a 63-month period with the diagnosis of tetanus were included in the study. MEASUREMENTS AND MAIN RESULTS: All patients (n = 11) had severe tetanus and developed sympathetic overactivity, which was managed by epidural blockade. Three patients died, but there were no fatalities directly attributable to sympathetic overactivity. Before epidural blockade, the average difference between the mean maximum and mean minimum systolic blood pressures was 78 +/- 28 (so) mm Hg. After blockade, this difference was reduced to 38 +/- 15 (so) mm Hg (p < .0001). Similar significant reductions in diastolic blood pressure and heart rate were observed. The mean hourly infusion doses of bupivacaine and sufentanil were 17 mg and 21 microg, respectively. Midazolam was the principal adjunctive sedative agent and was used in all patients (mean dose, 9 mg/hr). Additional pharmacologic agents were necessary in two patients in whom epidural blockade alone was insufficient to control sympathetic overactivity. One patient developed renal failure and there were no instances of pneumothorax. One patient developed an epidural abscess of probable hematogenous origin, which was successfully treated without neurologic sequelae. CONCLUSIONS: Epidural blockade is effective in controlling sympathetic overactivity and the associated complications (renal failure, cardiac injury, and sudden death). Although a serious complication occurred in one patient, the efficacy of the technique deserves further validation.     

Sympathetic reflex control of subcutaneous blood flow in patients with congestive heart failure

Central and local regulation of forearm subcutaneous vascular resistance (FSVR) during postural changes were studied in congestive heart failure (CHF). Blood flow was measured by the local 133Xe-washout technique. Nine patients with severe CHF (baseline angiographic ejection fraction, 23 +/- 2%, mean +/- SEM; cardiac index, 2.2 +/- 0.2 litres min-1 m-2; increased left ventricular pressures and dimensions) were compared with seven control subjects who had normal cardiac performance. Baseline FSVR and plasma concentrations of noradrenaline and adrenaline were substantially higher in patients with CHF than control subjects. However, the patients, like control subjects, increased FSVR by 46 +/- 3% in response to increase in local venous transmural pressure and disclosed a normal response to decrease in forearm perfusion pressure. Both responses to changes in vascular transmural pressure were preserved after either proximal nervous blockade or local beta-receptor blockade. Central sympathetic stimulation was induced with use of 45 degrees upright tilt. Control subjects developed vasoconstriction (FSVR increased by 59 +/- 5%), which was completely abolished after proximal nerve blockade. Patients with CHF developed vasodilatation (FSVR decreased by 24 +/- 8%), which was not only abolished but reversed after proximal nerve blockade (FSVR increased by 22 +/- 7%), probably owing to the increased humoral vasoconstrictor activity. The paradoxical vasodilator response to central sympathetic stimulation in these patients was reversed after local beta-receptor blockade (FSVR increased by 19 +/- 9%). The local vasoconstrictor reflex responsiveness and intrinsic vascular reactivity were not affected by the augmented baseline sympathetic vasoconstrictor activity in patients with CHF.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) in 13 children: a case series

Since thromboembolic events (TE) are rare among children there is only limited information on the optimal choice of antithrombotic agents, dose and duration of antithrombotic therapy. Recombinant tissue plasminogen activator (rt-PA) is increasingly used for thrombolytic therapy of organ- and limb threatening thrombosis in children. We investigated retrospectively the efficacy and safety of rt-PA in 13 children treated consecutively between 1996-1999, following the same protocol. The median age was 3.9 years (3 days to 16 years). All children suffered from underlying diseases. In addition, 7 children had cardiac catheters and central venous catheters and two children suffered from Factor V Leiden mutation. Seven children presented with a TE in the arterial system, 6 with one in the venous system. All children were treated with continuous infusion of rt-PA (median dose 0.05; 0.0125-0.2 mg/kg/h) together with low-dose standard heparin (median dose 8; 5-15 IU/kg/h). Thrombolysis was performed for a median time period of 102 hours (6 hours to 16 days). Treatment effects on the thrombus were regularly confirmed by ultrasound. Plasma levels of fibrinogen and haemoglobin decreased moderately during treatment. No cumulative effect or increased dose requirement of rt-PA was detected during extended treatment. Patency of obstructed vessels was achieved in all children. One child developed severe gastrointestinal bleeding. Six children (46%) developed minor bleeding at the site of catheter puncture. One child developed rethrombosis at the site of the previous thrombus 2 weeks after completion of rt-PA treatment. Under rigorous laboratory and ultrasound control, our protocol using low dose rt-PA over a prolonged period of time was effective and safe.     

小剂量尿激酶溶解透析患者深静脉导管内血栓的临床应用

目的回顾分析小剂量尿激酶溶解深静脉导管内血栓形成的安全性及疗效。方法23例深静脉置管的血液净化患者并发29例次深静脉导管内血栓形成,给予尿激酶(12 500~25 000 kU/L)1.0~2.0 ml导管内浸注,观察溶栓效果,尿激酶浸注30分钟后导管未通畅重复治疗1次,其中19例患者监测了血小板(Plt)、凝血酶原时间(PT)、活化的部分凝血活酶时间(APTT)和纤维蛋白原浓度(FG)等凝血指标,观察不良反应发生情况。结果20例患者进行26例次导管内浸注尿激酶,30分钟内血栓溶解24例次,2例重复1次溶栓成功,1例溶栓失败,尿激酶用量20 000~850 000 U,19例患者监测PT、APTT延长,但Plt和FG浓度无明显变化,所有患者未出现出血等副作用。结论深静脉导管血栓形成应用小剂量尿激酶导管内浸注溶栓有效安全。     

Enhanced sympathetic nervous activity after intravenous propranolol in ischaemic heart disease: plasma noradrenaline splanchnic blood flow and mixed venous oxygen saturation at rest and during exercise

To study the mechanisms by which acute beta-adrenergic blockade may change the activity of the sympathetic nervous system we have measured haemodynamic responses including splanchnic blood flow in twenty-three patients with ischaemic heart disease at rest and during supine exercise before and after i.v. injection of 0.039 mmol (10 mg) dl-propranolol. After propranolol both at rest and on exercise blood pressure, cardiac output and heart rate decreased, while splanchnic vascular resistance increased; mixed venous oxygen saturation decreased whilst arterial oxygen saturation and oxygen uptake were unchanged. Plasma noradrenaline increased after propranolol, values correlating with mixed venous oxygen saturation and splanchnic vascular resistance, both at rest and during exercise before and after propranolol, only at rest was there any correlation with arterial blood pressure. The increase in sympathetic nervous activity after propranolol may be due to a reduction in cardiac output and thereby alteration of the metabolic state (oxygen or related factors) in tissues. Afferent neural signals from the tissues may play a significant role in the regulation of sympathetic nervous activity.     

Pathophysiologic and pharmacokinetic determinants of the antihypertensive response to propranolol.

The tendency for patients with essential hypertension to differ markedly in antihypertensive response to propranolol could arise from pathophysiologic or pharmacokinetic differences between them. This possibility was investigated in 23 men with mild to moderately severe essential hypertension. At each of three propranolol doses, 40 mg, 80 mg, and 320 mg daily, approximately a 20-fold range in steady-state plasma propranolol concentrations was observed. Clinical response however was unrelated to plasma propranolol: oral dose ratio, since patients with higher plasma levels were less sensitive to the existing plasma drug concentration. When falls in blood pressure and plasma propranolol concentration were compared overall, a biphasic dose-response relationship was noted, with a first component at plasma propranolol concentrations of 3 to 30 ng/ml and a second at concentrations above 30 ng/ml. Only patients with increased sympathetic nervous system activity and high plasma renin activity (PRA) had substantial falls in pressure at propranolol levels of 3 to 30 ng/ml. Cardiac beta adrenergic receptor blockade, not suppression of PRA, seemed to be the antihypertensive mechanism. This relation of pretreatment sympathetic nervous activity and PRA to antihypertensive response existed only at lower plasma propranolol concentrations. With a propranolol dose of 320 mg daily, both plasma norepinephrine concentration and PRA were unrelated to the clinical response.     

Effect of histamine H3 receptor blockade on venous return and splanchnic hemodynamics in experimental bacteremia

OBJECTIVE: In the heart, histamine H3 receptors may function as inhibitory presynaptic receptors that decrease adrenergic neural norepinephrine release in conditions of enhanced sympathetic tone. In a previous study, we found that H3 receptor blockade improved cardiac contractility and systemic hemodynamics in experimental bacteremia in dogs. Because histamine H3 receptors have been found in the splanchnic circulation in other animal models, it was not clear the extent to which H3 receptor blockade may have altered splanchnic hemodynamics, and variables of venous return, that in turn contributed to the overall improvement in systemic hemodynamics observed in the previous experiment. In the present study, we examined splanchnic hemodynamics in the presence of H3 receptor blockade in a canine model of Escherichia coli bacteremia. DESIGN: Bacteremia was produced by intravenous infusion of live E. coli administered throughout the experiment. Variables of venous return included mean systemic pressure, resistance to venous return, and mean right atrial pressure. Splanchnic measurements included hepatic and portal pressures and flows. Measurements were obtained before and after H3 receptor blockade with thioperamide maleate. The animals were studied while ventilated and anesthetized. RESULTS: H3 receptor blockade caused a decrease in mean right atrial pressure from 5.9 mm Hg pretreatment to 3.5 mm Hg posttreatment (p < .05), although it did not affect mean systemic pressure or resistance to venous return. There were no changes in portal or hepatic flows after H3 receptor blockade. The cardiac function curve after H3 receptor blockade was shifted upward and to the left compared with the pretreatment curve. CONCLUSIONS: The results showed that the primary effect of H3 receptor blockade in experimental bacteremia was attributable to an increase in inotropy. There was no evidence to indicate that H3 receptor activation contributed to altered splanchnic hemodynamics in this model.     

静脉输液拔针后两种按压法的效果观察

对静脉输注脑活素、蝮蛇抗栓酶的病人，在输注结束拔针后，采用大面积按压法按压穿刺部位，并与传统的按压法进行了比较。输注脑活素的２２８例次中，１０８例次采用传统按压法，皮下出血率为３７．９６％；１２０例次采用大面积按压法，皮下出血率为３．３３％，二者比较有显著性差异（Ｐ＜０．００５）；输注蝮蛇抗栓酶的２３０例次中，１１０例次采用传统按压法，皮下出血率为４５．４５％，１２０例次采用大面积按压法，皮下出血率为５．００％，二者比较有显著性差异（Ｐ＜０．００５）。本结果提示静脉输注抗凝、溶栓类药物拔针后，大面积按压法优于传统按压法。     

超声在诊断肺栓塞及溶栓疗效评价中的价值

目的 探讨超声诊断肺栓塞（PTE）及评价溶栓抗凝疗效的价值。方法 临床疑似PTE患者130例接受超声心动图和下肢深静脉超声检查，经临床表现、心电图、超声、核素、螺旋CT综合检查确诊的61例为病例组。其中临床确诊为大面积或次大面积的35例接受溶栓抗凝治疗，比较溶栓前、溶栓后24h、2周、3个月、6个月心脏及下肢深静脉血栓的变化情况。结果 超声心动图诊断PTE29例，PTE可能性大17例，可疑PTE8例，7例仅表现为右心室轻度扩大和（或）肺动脉高压。下肢深静脉检查发现54例286条血管内血栓。溶栓抗凝后32例有效，3例无效；右心系统血栓27例减小或消失，2例无明显变化。PTE患者右心明显缩小，右室壁运动幅度增强，肺动脉内径回缩，肺动脉压力降低；溶栓后24h各指标好转，2周继续好转，3个月除右室轻度扩大外，各测值与正常对照组比较差异无统计学意义，溶栓后6个月各测值与正常对照组间无差异。溶栓治疗后下肢深静脉急性和亚急性血栓明显减少，管腔大部分再通，陈旧性血栓变化不明显。结论 超声诊断PTE安全、无创、价值高，可用于评价疗效和长期随诊。     

Intradermal injection of norepinephrine evokes pain in patients with sympathetically maintained pain

Tissue injuries, with or without involvement of nerves, may lead to ongoing pain and hyperalgesia to external stimuli. In a subset of patients, the pain is maintained by sympathetic efferent activity (SMP). We investigated if the peripheral administration of the alpha-adrenergic agonist, norepinephrine (NE), in physiologically relevant doses resulted in pain in patients with SMP. To establish the dose of intradermal NE required to induce cutaneous vasoconstriction, NE (1 nM-10 microM, 30 microl) was injected under a laser Doppler probe on the volar forearm of seven normal subjects. A decrease in blood flow was evident at a dose of 10 microM. Twelve patients (five male, seven female) diagnosed to have SMP based on the decrease in pain by a local anesthetic sympathetic blockade (70+/-6%) were enrolled in the study. Pain ratings were obtained continuously for 5 min after intradermal injections of saline and NE (0.1-10 microM) into their hyperalgesic zone and the mirror-image contralateral side. Injections were done during the period of pain relief following a local anesthetic sympathetic blockade. Similar injections were made in eight control subjects. On the affected side of the patients, the two highest concentrations of NE (1 and 10 microM) caused significantly more pain than saline (P<0.05, ANOVA). In contrast, there was no significant pain induced by the NE injections in the unaffected side and in control subjects. Six of nine patients tested reported a marked decrease in pain and hyperalgesia following infusion of phentolamine (1 mg/kg over 10 min). Two of the three patients who did not receive pain relief following phentolamine infusion also did not report pain to the NE injections. We conclude that NE injections produce pain in SMP patients at doses that are at the threshold for producing vasoconstriction. These studies support a role for cutaneous adrenoceptors in the mechanisms of sympathetically maintained pain.     

Regional sympathetic blockade in primary fibromyalgia

Twenty-eight patients with primary fibromyalgia participated in the study. Eight patients received a stellate ganglion blockade with bupivacaine, and 14 days later an intravenous regional sympathetic blockade with guanethidine. The remaining patients served as controls and were randomly allocated to receive either a sham (placebo) injection with physiologic saline superficial to the stellate ganglion (n = 10) or bupivacaine intramuscularly (n = 10). The efficiency of the stellate ganglion blockade was evaluated by measuring skin blood flow (using a laser Doppler flowmeter), skin temperature, and skin conductance responses ('sympathogalvanic reflex'). Trigger and tender points (TePs) were counted, and rest pain in the arm, shoulder and neck evaluated at intervals up to 4 h after the injection. The guanethidine blockade was evaluated 24 h after the injection by counting TePs and by assessment of rest pain in the hand and forearm. The results indicate that a complete sympathetic blockade, produced by a stellate ganglion blockade, markedly reduced the number of TePs and produced a marked decrease in rest pain. The guanethidine blockade reduced the number of TePs, but had no effect on rest pain. The reduction in pain and TePs produced by a sympathetic blockade may be due to an improvement in microcirculation. Sympathetic activity may, in some patients, contribute to the pathogenesis of primary fibromyalgia.     

下腔静脉滤器植入后中西医结合介入治疗急性下肢深静脉血栓的临床应用

目的 探讨下腔静脉滤器植入后中西医结合介入治疗急性下肢深静脉血栓形成的应用价值.方法 收集有明确临床症状、体征,并经彩色多普勒超声或造影证实的下肢深静脉血栓形成患者56例,随机分为治疗组(28例)和对照组(28例),所有急性下肢深静脉血栓患者均在植入下腔静脉滤器后抗凝治疗,治疗组经插管溶栓或经患肢足背静脉溶栓治疗并联合应用中药内服外敷,对照组经插管溶栓或经患肢足背静脉溶栓治疗.结果 按血管通畅度评价,治疗组血管通畅度高于对照组.随访结果显示治疗组治疗的疗效优于对照组治疗(P＜0.01).溶栓治疗过程中未出现肺动脉栓塞症状及出血现象.结论 中西医结合介入治疗方法对急性下肢深静脉血栓形成有良效,结合中医辨证论治综合治疗,可以增强疗效.     

Vasopressin inhibits sympathetic ganglionic transmission but potentiates sympathetic neuroeffector responses in hindlimb vasculature of rabbits

To determine whether vasopressin (AVP) affects vasoconstrictor responses to electrical stimulation of sympathetic nerves or i.a. norepinephrine (NE), changes in perfusion pressure were measured during lumbar sympathetic nerve stimulation (LSNS, 1-8 Hz), or administration of NE (50-200 ng), in the isolated constant-flow perfused hind limb of chloralose-anesthetized rabbits (n = 7), before and after i.a. infusion of AVP (0.65 mU/kg/min). AVP significantly potentiated responses to LSNS (relative potency (RP) = 1.59) and to NE (RP = 5.17). The potentiation of LSNS and NE by AVP infusion was abolished by the AVP V1 antagonist, d(CH2)5[Tyr(Me)2]AVP, 400 ng, total dose (n = 6). Because there was a significant difference between the RP of LSNS (stimulation of both preganglionic and postganglionic nerves) and NE (direct effect on the vascular smooth muscle), we verified whether this difference might represent disparate actions of AVP on the ganglia and/or sympathetic neuroeffector sites. To evaluate responses to stimulating only the postganglionic sympathetic nerves, we repeated the above study in animals pretreated with a supramaximal dose of the ganglionic blocking agent hexamethonium (25 mg/kg i.v.). After ganglionic blockade the responses to LSNS were reduced to 22% of control. In the presence of ganglionic blockade, AVP potentiated responses to LSNS (RP = 4.09) (n = 6).(ABSTRACT TRUNCATED AT 250 WORDS)     

The efficacy and safety of reteplase for thrombolysis of hemodialysis catheters at a community and academic regional medical center

In occluded hemodialysis catheters, thrombolytic agents are used to dissolve fibrin clots, reestablish blood flow and allow the patient to continue with hemodialysis treatment. Prior to 2001, urokinase was the indicated fibrinolytic for hemodialysis catheter thrombolysis. However, when urokinase became unavailable in the United States, New Hanover Regional Medical Center developed and implemented a protocol for the use of another fibrinolytic, reteplase, to lyse catheter occlusions. The purpose of this retrospective analysis was to assess the safety and efficacy of reteplase in opening occluded catheters in a series of patients receiving hemodialysis. Between January 1 and June 30, 2002, 59 patients could not complete dialysis, because of either poor arterial blood flow or elevated venous resistance. Reteplase, 0.4 U, was administered to the lumen of occluded catheters. After 30 min dwell times, the lumens were aspirated. If flow could not be sufficiently reestablished, a second reteplase dose was administered. Efficacy endpoints were defined as the ability to complete hemodialysis and achieve flow rates of > or =250 ml/min. Safety endpoints were defined as the occurrence of allergic reactions or bleeding. Eighty-five percent (50/59) of the patients were able to complete their hemodialysis session following reteplase administration, with 70% (41/59) able to sustain blood flow rates of > or =250 ml/min. Of the 50 patients who successfully completed dialysis, 66% (33/50) required only one 0.4-unit dose of reteplase per lumen while 34% (17/50) required a second dose. No instances of bleeding or allergic reactions were noted.     

Defining the therapeutic role of local anesthetic sympathetic blockade in complex regional pain syndrome: a narrative and systematic review

OBJECTIVE: There is growing controversy on the value of blocking the sympathetic nervous system for the treatment of complex regional pain syndromes (CRPS). The authors sought to evaluate the efficacy of sympathetic blockade with local anesthetic in these syndromes. In addition, they performed a comprehensive review of the pathophysiology and other treatments for CRPS. DESIGN: Systematic review of the literature was performed. MEDLINE was searched from 1966 through 1999. The authors identified only three randomized controlled trials (RCTs) that evaluated sympathetic blockade with local anesthetic, but because of differences in study design they were unable to pool the study data. The authors therefore included nonrandomized studies and case series. INTERVENTIONS: Studies were included if local anesthetic sympathetic blockade was used in at least 10 patients. Studies were excluded if continuous infusion techniques, somatic nerve blocks, or combined sympatholytic therapies were evaluated. OUTCOME MEASURES: Pain relief was classified as full, partial, or absent. The lack of a comparison group in the studies allowed only the calculation of distribution of the response categories, and the sum of the pooled rates does not equal 100%. RESULTS: Twenty-nine studies were included that evaluated 1,144 patients. Nineteen studies were retrospective, 5 prospective case series, 3 RCTs, and 2 nonrandomized controlled studies. The quality of the publications was generally poor. Twenty-nine percent of patients had full response, 41% had partial response, and 32% had absent response. It was not possible to estimate the duration of pain relief. CONCLUSIONS: This review raises questions as to the efficacy of local anesthetic sympathetic blockade as treatment of CRPS. Its efficacy is based mainly on case series. Less than one third of patients obtained full pain relief. The absence of control groups in case series leads to an overestimation of the treatment response that can explain the findings.     

Clinical and physiologic evaluation of stellate ganglion blockade for complex regional pain syndrome type I

OBJECTIVE: The efficacy of peripheral sympathetic interruption after stellate ganglion blockade was assessed by a sympathetic function test. Results were compared with clinical signs such as temperature changes, pain reduction, and the development of Horner syndrome to evaluate the correlation with clinical investigations. DESIGN: Stellate ganglion blockade with local anesthetics was carried out via an anterior paratracheal approach in 33 patients suffering from complex regional pain syndrome type I. Patients were examined before and after the procedure. For assessment of sympathetic nervous function, the vasoconstrictor response to sympathetic stimuli was assessed using laser Doppler flowmetry. Clinical parameters like surface temperature changes (thermography), pain relief (visual analogue scale), and Horner syndrome were monitored. RESULTS: Twenty-three (70%) of 33 patients developed an increase in temperature difference between the treated hand and the contralateral hand of more than 1.5 degreesC after the procedure, which is a clinical sign of sympathicolysis. In 48% (n = 11) of these patients, the sympathetic function test showed an undisturbed sympathetic nervous function. In 10 patients, no significant increase in temperature difference was observed. Although these patients presented with a normal sympathetic vasoconstrictor response, 4 felt pain relief of more than 50%, suggesting a placebo effect. Only 7 patients with pain relief revealed both clinical sympathicolysis and extinguished sympathetic nervous function and qualified for sympathetically maintained pain. CONCLUSIONS: Clinical investigation is not reliable in the assessment of stellate ganglion blockade. Proof of sympathetically maintained pain based on pain relief after stellate ganglion blockade is not conclusive.     

Laser Doppler measurements of skin blood flow before,during, and after lumbar sympathetic blockade in children and young adults with reflex sympathetic dystrophy syndrome

Changes in the skin capillary blood flow (SBF) and temperature before, during, and 1 hour after unilateral lumbar paravertebral sympathetic blockade (LSB) were studied simultaneously with laser Doppler flowmetry and thermometry in patients with reflex sympathetic dystrophy syndrome. The baseline flow measurements in the toes on the affected limb were significantly lower than in the contralateral limb (p<0.01). During LSB, a 10-fold increase in SBF was detected within 4 minutes after injection of a local anesthetic agent when the sympathetic blockade was effective; an increase of more than 1°C in the skin temperature occurred within 11 minutes. Measurements 1 hour after blockade showed an 18-fold (mean) increase in SBF in the toes (p<0.0001) and a 2-fold (mean) increase in SBF in the thighs (p<0.001). There was a significant decrease in the skin blood flow in the contralateral toes after the sympathetic blockade (p<0.01). We conclude that laser Doppler flow measurements can be used to detect immediate onset of sympathetic blockade in patients under general anesthetic or conscious sedation.     

彩色多普勒血流显像对PICC术后上肢静脉血栓溶栓疗效的评估作用

目的：探讨彩色多普勒血流显像对经外周静脉穿刺中心静脉置管（Peripherally inserted central cather,PICC）术后,上肢静脉血栓形成溶栓治疗中评估疗效及预后的价值.方法：利用彩色多普勒超声对2012年3月-2013年5月的12例PICC术后,上肢静脉血栓形成溶栓治疗的患者,进行随访观察并总结分析.结果：12例患者,7例导管位于右上肢,5例位于左上肢.男8例,女4例.胃肠道恶性肿瘤4例,肺部恶性肿瘤3例,乳腺恶性肿瘤3例,均为女性患者,腹部恶性肿瘤2例.11例患者上肢静脉血栓经溶栓治疗均消失,1例患者出现双上肢静脉广泛栓塞,临床上怀疑合并肺血栓栓塞.彩色多普勒超声能短时间内准确的判断上肢静脉血栓溶栓治疗过程中,血栓大小、形态及范围的变化,反应血流再通的情况,清楚的显示导管的位置以及状态,很大程度帮助临床判定溶栓治疗的效果及指导治疗方案.结论：彩色多普勒超声能对PICC术后,上肢静脉血栓形成溶栓治疗过程中血栓范围、大小、导管的位置以及状态及其作出准确的判断,对临床PICC术后血栓形成溶栓效果评估及治疗方案选择具有重要作用.