INTERNATIONAL ABSTRACTS
spontaneous movements and pain on injection, as well as decreases in arterial pressure, are greater when using propofol than with thiopentone. The researchers concluded that thiopentone was a better induction agent than propofol.--R.J. Fitzgerald Pharmacokinetics of Alfentanil in Children Undergoing Surgery. P.
Roure, N. Jean, A.C. Leclerc, et al. Br J Anaesth 59:1437-1440, (November), 1987. Alfentanil (short acting analgesic) pharmacokinetics and protein binding were determined in 20 children aged 10 months to 6.5 years, and the data compared with those from 10 adult patients. There was a significantly shorter elimination half-life of alfentanil and plasma clearance in children when compared with adults. With a rapid transfer of alfentanil across the blood-brain barrier, it is expected that a close relationship exists between the plasma concentration and the effect of alfentanil. The results of this study suggest that alfentanil will have a short duration of action in paediatric patients.--R.J. Fitzgerald Continuous Extradural Anaesthesia in Childron: Clinical and Haemodynamic Implicaitons. L Murat, M.M. Delleur, C. Esteve, et al.
Br J Anaesth 59:1441-1450, (November), 1987. This study reports the experience of 234 continuous extradural anaesthetics in 229 children. A catheter was placed under general anaesthetic, and bupivacaine introduced with or without adrenaline. In 74 of the children heamodynamic studies were undertaken. After extradural anaesthesia with 0.25% bupivacaine with adrenaline 1:200,000, minimal changes in heart rate (HR) or systolic arterial pressure (SAP) occured in children <8 years of age, while in those >8 years of age, there was a significant decrease in both HR and SAP. It is concluded that extradural anesthesia is a valuable technique in children in order to produce analgesia for surgical procedures of long duration. Avoiding the use of opiates, it allows a rapid recovery and facilitates postoperative care. It is stressed that this technique requires trained medical staff as well as special equipment to ensure safety. Furthermore, its long-term consequences have yet to be assessed.--R.J. Fitzgerald.
873 Tracheal and Bronchial Injury in High-Frequency Oscillatory Ventilation Compared With Conventional Positive Pressure Ventilation,
R.H. Clark, T.E. Wiswetl, D.M. Null, et al. J Pediatr 111:114-118, (July), 1987. The airway histopathologic findings in premature baboons given standard positive pressure ventilation was compared with those seen after high-frequency oscillatory ventilation. Six animals received standard-frequency conventional ventilation for a mean of 9.2 days; seven received high-frequency oscillatory ventilation at 10 Hz using a piston oscillator for a mean of 10.2 days; five baboons served as controls, and were killed immediately after birth. A semiquantitative histopathologic scoring system was used to grade tissue changes in the trachea, carina, and both mainstem bronchi. Compared with the nonventilated control animals, injury was produced with both forms of mechanical ventilation (P < .01 for both instruments). However, the degree of damage was mild, with no significant difference in the extent of injury between the two treatment groups. High-frequency oscillatory ventilation appears to result in no greater degree of airway damage than does conventional positive pressure ventilation.--George Holcomb, Jr The Role of Cryoanalgesia in the Control of Pain After Thoracotom y . J.C. Roxburgh, C.G. Mark/and, B.A. Ross, et al. Thorax 42:292-295, (April), 1987.
A prospective randomized blind trial of direct cryotherapy to at least five intercostal nerves related to a thoracotomy incision showed no benefit in the control of post-thoracotomy pain.--J.M. Beck
THORAX Mediastinal Hemangiomas. A.J. Cohen, R.J. Sbaschnig, L. Hoch-
holzer, et al. Ann Thorac Surg 43:656-659, (June), 1987.
The percutaneous absorption of eight local anaesthetics in a standard formulation was compared in vitro using a lipophilic barrier membrane, and in vivo using a volunteer trial. Although amethocaine and lignocaine obtained the greater permeability coefficients in vivo, amethocaine was significantly better at producing full-depth anaesthesia of the skin to the challenge of insertion of a sterile needle. Further work is required to produce an optimum amethocaine formulation that will most closely meet the requirements for an ideal skin-absorbed local anaesthetic.--R.J. Fitzgerald.
Fifteen cases of mediastinal hemangiomas are reported. Eight were located in the anterior mediastinum, and of these, four were symptomatic. Seven hemangiomas were located in the posterior mediastinum, producing symptoms in four. The majority of symptoms were produced by invasion of the surrounding structures by the hemangioma. The patients ranged in age from newborn to 68 years. Four patients were <2 years of age. Preoperative studies were numerous and varied. Computed tomography did not aid in a preoperative diagnosis in any patient. Total excision was possible in six patients, and subtotal excision in five patients, Involvement with vital structures prevented total excision. The other four patients were diagnosed by biopsy or upon autopsy. Follow-up ranged from 21/2to 15 years. Recurrence developed in one patient treated with subtotal excision. The recurrence was re-excised and the patient has been stable for 10 years. One patient treated with total excision had a suspected recurrence found on chest roentgenogram 9 years following the original excision. The researchers conclude that mediastinal hemangiomas are slow-growing benign lesions. Total excision is recommended if possible, but subtotal excision is advised if important adjacent structures are threatened. Subtotal excision yields similar long-term results.--Marleta Reynolds
Management of Trachaomalacia in Association With Congenital Tracheo-Oesophageal Fistula. P.T. Conroy and N.R. Bennett. Br J
Congenital Bronchopulmonary Vascular Malformations: Clinical Application of a Single Anatomical Approach in 25 Cases. B.S.
Anaesth 59:1313-1317, (October), 1987.
Clements, J. Warner, and E.A. Shinebourne. Thorax 42:409-416, (June), 1987.
Comparative In Vivo and In Vitro Assessment of the Percutaneous Absorption of Local Anaesthetics. D.F. McCafferty, A.D. Woo~f-
son, K.H. McClelland,.et al. Br J Anaesth 60:64-69, (January), 1988.
The detailed management, particularly anaesthetic, of a patient with severe tracheomalacia associated with esophageal atresia and distal tracheoesophageal fistula is outlined. The surgery of tracheopexy, which was carried out on this patient, is supported and compared wtih other types of management advocated in the literature.--Ray J. Fitzgerald
Congenital malformations of the tracheobronchial tree and related arterial supply are a complex group of lesions where associated anomalies of venous drainage and lung parenchyma may exist. The role of ligation or occlusion of an aberrant systemic artery is discussed in patients with and without haemodynamic distur-