Effects of deamino-8-D-arginin vasopressin on blood loss and coagulation factors in scoliosis surgery. A double-blind randomized clinical trial.

STUDY DESIGN: A double-blind, randomized, prospective clinical study was performed to evaluate the efficacy of deamino-8-D-arginin vasopressin in reducing blood loss in major scoliosis surgery. OBJECTIVES: To evaluate whether desmopressin has any effect on reducing blood loss in spinal surgery, to identify the probable mechanisms of effectiveness via blood coagulation factors, and to outline any adverse effect associated with the use of deamino-8-D-arginin vasopressin. SUMMARY OF BACKGROUND DATA: Scoliosis surgery is known to be associated with major blood loss. Because of major drawbacks of homologous blood transfusion, many alternative methods have been used to counter the blood loss. Only a few studies exist, with controversial results, on the use of deamino-8-D-arginin vasopressin. METHODS: The study population included 40 operations on 35 consecutive patients undergoing reconstructive surgery for either idiopathic (n = 26) or congenital (n = 9) scoliosis. Operations were randomized into deamino-8-D-arginin vasopressin (0.3 microgram/kg body weight; maximum, 20 micrograms) (n = 18) or placebo (n = 22) groups and stratified according to the diagnosis and the type of surgery performed (i.e., anterior versus posterior versus anterior and posterior sequential). Parameters of blood loss, serum levels of blood coagulation factors at different time intervals, and urinary output were measured. RESULTS: Findings indicated that blood loss per kilogram of body weight, blood loss per surgically treated spinal level, urinary output per kilogram of body weight and serum levels of fibrinogen, von Willebrand factor (vWF) activity, tissue type plasminogen activator activity, and plasminogen activator inhibitor activity were not sensitive to the administration of deamino-8-D-arginin vasopressin at any time interval during surgery or at 24 hours after surgery (P > 0.05). Only factor VIII:C levels exhibited significant elevations at 30 minutes and at 24 hours (P < 0.05). CONCLUSIONS: This study could not demonstrate any significant effect of deamino-8-D-arginin vasopressin on the amount of blood loss in a group of patients with idiopathic or congenital scoliosis. Findings indicate that for most of the coagulation factors, any changes in serum levels induced by deamino-8-D-arginin vasopressin were much like those expected from surgery itself. This study also failed to demonstrate any significant effects altering the urinary output that may be attributed to the use of deamino-8-D-arginin vasopressin.

A study of adenosine treatment in experimental acute spinal cord injury. Effect on arachidonic acid metabolites.

STUDY DESIGN: A prospective, randomized, blinded experimental trauma study. STUDY OBJECTIVE: The effect of adenosine on arachidonic acid metabolites and lipid peroxidation was investigated in induced spinal cord injury. SUMMARY OF BACKGROUND DATA: Effects of adenosine in ischemia-reperfusion models have been studied, but no studies of adenosine's effect on direct trauma to the spinal cord have been reported. METHODS: Thirty-seven adult Wistar albino rats were randomly divided into four groups and underwent laminectomy. Group 1 underwent a sham operation. Group 2 received an intravenous adenosine infusion of 100 micrograms/kg per minute for 30 minutes. In Group 3, a standard spinal cord trauma of 50 g.cm strength was established at the lower thoracic level with a "weight-drop" technique, and Group 4 received an infusion of adenosine (100 micrograms/kg per minute) for 30 minutes after the trauma. RESULTS: Tissue prostaglandin E2 activity was significantly higher in adenosine-treated trauma groups when compared with that in other groups (P < 0.0001). The difference in tissue leukotriene C4 activity between control and trauma groups was significant (P < 0.05). Adenosine infusion after trauma limited the increases in lipid peroxidation, with the difference approaching significance at P = 0.06. The structure of myelin was well preserved in the adenosine-treated trauma group. However, the changes were irreversible in severely damaged areas. CONCLUSION: After acute spinal cord trauma, intravenous adenosine infusion of 100 micrograms/kg per minute could attenuate progression to secondary injury, but adenosine alone was not effective yet.

The effect of pre-induction clonidine on platelet aggregation during minor surgery.

OBJECTIVE: This paper reports the results of a prospective randomized double-blind trial on the effects of pre-operative clonidine on platelet aggregation. METHODS: Thirty adult (ASA I-II) patients undergoing elective minor orthopaedic surgery were randomly allocated into three groups of ten patients each. In group I clonidine 2 microg x kg(-1), in group II clonidine 4 microg x kg(-1) and in group III saline placebo was administered intravenously before the induction of anaesthesia. Anaesthesia was induced with propofol and vecuronium and maintained with halothane-nitrous oxide. Platelet counts and aggregation tests were performed before (t0) and 1 h (t1) and 24 h (t24) after administration of the study drug. RESULTS: Changes in platelet counts among the groups and values over time were not significant. Both maximum rate and intensity of collagen-induced aggregation in both clonidine groups and maximum intensity of adenosine 5'-diphosphate (ADP)-induced aggregation in the high-dose clonidine group increased significantly at t1. However, all these increases in aggregation were within the normal ranges. CONCLUSION: The effects of both low and high doses of clonidine on platelet aggregation appeared to be minor, and we did not observe any increases above the normal ranges.

Risk factors associated with corrective surgery in congenital scoliosis with tethered cord.

Severe neglected congenital scoliosis with tethered cord presents major difficulties in management. The primary objective of this study was to identify the risk factors associated with corrective scoliosis surgery in neglected cases presenting with severe deformity. Six patients who presented with such problems draw attention to the importance of a staged anterior and posterior approach in order to obtain satisfactory functional results. However, corrective surgery is associated with major neurologic and systemic complications, and every effort should be made to intervene with the progression of the deformity before corrective measures becomes necessary.