Systemic anaphylaxis—separation of cardiac reactions from respiratory and peripheral vascular events

An anaphylactic reaction in the isolated perfused heart is characterized by a drastic coronary constriction, arrhythmias, and an impairment of contractility. In vivo anaphylaxis is associated with respiratory distress and cardiovascular failure. The present investigation was designed to ascertain the electrocardiographic and cardiovascular changes during systemic hypersensitivity reactions. In addition, an attempt was made to differentiate cardiac from respiratory events. In guinea pigs, sensitization was produced by s.c. administration of ovalbumin together with Freund's adjuvant solution. Fourteen days after sensitization, the effects of an i.v. infusion of ovalbumin were tested in the anesthetized guinea pigs, which were ventilated with room air or 100% oxygen. A second administration of the antigen induced the development of cardiovascular collapse, leading to death within 12 min. Within 3 min, cardiac output decreased by 90% and end-diastolic left ventricular pressure increased significantly, indicating left ventricular pump failure. In the same time range, ECG recordings uniformly showed signs of acute myocardial ischemia. In addition, arrhythmias occurred in the form of atrioventricular block. Left ventricular contractility declined continuously within the first 4 min. Finally, after 4 min, blood pressure steadily decreased. During ventilation with room air, severe hypoxia developed, with arterial PO₂ decreasing from 94 mm Hg to 14 mmHg after 3 min. However, under ventilation with 100% oxygen, a dissociation between cardiac damage and respiratory distress occurred. Myocardial ischemia and signs of cardiac failure preceded the development of hypoxia by a significant time interval. It is to be concluded that cardiac damage is a primary event in anaphylactic shock. Furthermore, the electrocardiographic signs of ischemia are interpreted as a result of coronary artery spasm.     

Peripheral vascular disease

This article discusses peripheral vascular disease and its associated risk factors. It outlines clinical patient assessment, medical interventions and the role of the nurse in secondary prevention.     

Peripheral vascular pain

Peripheral vascular pain consists of complex factors, and may be divided into three types, i.e., arterial pain, microvessel pain and venous pain. Among these, arterial pain requires intensive pain control because of severe ischemic pain due to arterial obstruction. Under ischemic condition, adenosine is generated, and activates unmyelinated afferents to produce pain. In addition to adenosine, acidic pH itself produces pain and sensitization to mechanical stimuli. Moreover bradykinin generated by kallikurein in acidic pH can produce pain. Nerve block is indicated to improve tissue circulation and to relieve pain. Endoscopic thoracic sympathectomy is indicated for upper extremities, and high frequency thermocoagulation is applied for lumbar sympathectomy. Spinal cord stimulation and the gene therapy with vascular endothelial growth factor have also been reported effective.     

Peripheral vascular trauma

Trauma is now the third leading cause of death and the number one killer of people younger than 45 years of age. Vascular injuries comprise 3% of all civilian traumas and continue to have significant associated morbidity and mortality in the 21st century. The treatment of vascular trauma has evolved to include endovascular options even in the acute setting. Arteriography remains the gold standard for diagnosis. The prognosis of patients with injured vascular structures remains favorable, provided that treatment is not delayed.     

Peripheral vascular surgery in the high-risk patient

In peripheral vascular surgery a patient not infrequently becomes a high-risk case on account of local causes (morphological, haemodynamic), especially during long operations. Hence, low-risk procedures like partial or palliative operations, including extraanatomical procedures, and appropriate anaesthesiological methods are very important. This report includes several possibilities of peripheral arterial reconstruction, as well as a review of experience gained in 37 axillo(bi)femoral and 54 cross-over bypasses, 41 closed retrograde TEA's of the iliac region, 30 transluminal dilatations, 580 embolectomies, 257 reconstructions of the deep femoral artery and 19 in situ vein bypasses (Hall). The distribution of extraanatomical procedures in a high-risk and a local or angiological-morphological situation showed that after one year only 50% of high-risk patients were still alive compared with 85% of the latter group. Local anaesthesia was very suitable for embolectomies, whilst for other indications we prefer spinal and peridural or combined regional and general anaesthesia, with the proviso that the patient is in the hands of a skilled anaesthesiologist.     

Peripheral vascular cutdown.

Critically ill patients who are not candidates for percutaneously placed arterial and venous lines require surgical cutdown. Although significant complications may arise from inadvertent injury to the vessel or associated structures during arterial and venous cutdown, these complications can be minimized by meticulous technique. With attention to site selection and catheter care, the useful life of these complex catheters approaches that of percutaneously placed devices. Finally, although the sequelae of placement by these techniques--including wound and catheter infection, distal ischemia, and vessel ligation--are increased, the need for appropriate intravascular access in these patients far outweighs the potential risks.     

破伤风抗毒素全身过敏反应3例

破伤风抗毒素是一种免疫血清,对人体是一种异体蛋白,具有抗原性,发生过敏反应多为局部反应,全身反应较少见.2006年4月-2007年8月有2例病人在做破伤风抗毒素过敏试验时出现全身过敏症状,1例病人在做脱敏注射时出现全身过敏症状,均经及时处理,症状缓解.现介绍如下.