Provision of paediatric intensive care services.

Paediatric intensive care has developed into a highly specialized and labour-intensive clinical activity. The provision of adequate numbers of properly staffed children's intensive care beds within the UK, and the lack of national planning and coordination are both problematic. This article examines these problems and discusses current thinking on the provision of paediatric intensive care services.

The minilink breathing system: resistance and suitability for spontaneous ventilation.

The Portex infant breathing/ventilation systems with 8.5 mm and 15 mm internal diameter connectors were compared with a standard T-piece which had a 15 mm connector and 22 mm internal diameter tubing. The differential pressures across each system were measured at constant fresh gas flows up to 30 l.min-1 dry air. Resistance was calculated at flows compatible with quiet respiration and peak inspiratory flow. Flow resistance of the 3.0 mm internal diameter tracheal tube in conjunction with the minilink breathing systems were similar to those previously reported for tracheal tubes alone. However, the minilink breathing system assumed a greater influence on resistance when tracheal tubes of larger internal diameter were used. It added considerably more resistance than the standard tubing. This may have a deleterious effect during spontaneous ventilation in older children.

Anthropomorphic radiological phantoms for mammography.

Anthropomorphic radiological phantoms are useful in evaluating image quality in mammography by providing realistic detection tasks to the observer. Methods for creating such phantoms, based on original patient mammograms, are described. Photochemical enhancement techniques and application of fractal interpolation methods for improving the fine detail information contained in such phantoms are discussed. Approaches to incorporating additional calibrated test targets within the phantom are also described.

Management of tracheomalacia in association with congenital tracheo-oesophageal fistula.

Tracheomalacia is commonly associated with oesophageal atresia and tracheo-oesophageal fistula. Severe cases may present with life threatening cyanotic and apnoeic attacks following surgical repair of the oesophageal atresia. The anaesthetic, and surgical management (by tracheopexy), of such a case are described.

Day-case herniotomy in children. A comparison of ilio-inguinal nerve block and wound infiltration for postoperative analgesia.

Forty-nine boys scheduled for day-case inguinal herniotomy were studied to compare ilio-inguinal nerve block and wound infiltration for postoperative analgesia. Both techniques were simple to perform and produced no complications. In the ilio-inguinal block group, 100% had either no pain or very mild discomfort when assessed 60 minutes after return to the day unit, compared to 95% in the infiltration group. Some children did appear to have pain following discharge but in all cases this responded well to simple analgesics. We conclude that both techniques provide satisfactory analgesia whilst the complications of narcotics are avoided, and suggest that simple infiltration of the wound with local anaesthetic solution should be encouraged in paediatric anaesthesia.

I.v. flunitrazepam and i.v. diazepam in conservative dentistry. A cross-over trial.

In a randomized cross-over trial in 82 outpatients aged 15-45 yr undergoing conservative dentistry, a solution of flunitrazepam 0.25 mg ml-1 i.v. (average dose 0.014 mg kg-1) was compared with a solution of diazepam 5 mg ml-1 i.v. (0.29 mg kg-1). Cardiovascular changes, operating conditions and side-effects were similar. Forty minutes after the start of injection, about 85% of all patients could not remember the local anaesthetic injection. Thirty minutes after the end of treatment, only 25% of all patients had recovered. One week later, most patients receiving each drug had only vague memories of their treatment; they had felt more relaxed immediately after the i.v. injection than before. Drowsiness was equally common after flunitrazepam and diazepam. Ataxia was more prolonged with flunitrazepam but arm pain and venous thrombophlebitis were less frequent.

In vitro interaction of propanidid and suxamethonium with pooled human plasma cholinesterase. A kinetic study.

Human plasma cholinesterase (E.C. 3.1.1.8) was shown to be inhibited by physiological concentrations of propanidid and suxamethonium using a colourimetric assay at 25 degrees C and pH 7.2 unit with butyrylthiocholine as substrate. Propanidid inhibited the enzyme in a non-competitive manner (I50 = 2.0 mmol litre-1; apparent Km = 6.6 X 10(-4) mol litre-1) as did suxamethonium (I50 = 4.4 mmol litre-1; apparent Km = 1.6 X 10(-4) mol litre-1). Combined inhibition produced Km 3.0 X 10(-3) mol litre-1. The binding of these drugs to specific anionic sites in the vicinity of the active centre is thought to result in stereochemical changes in the enzyme. This mechanism and its relevance to the augmentation of the neuromuscular blockade produced by suxamethonium in the presence of propanidid is discussed.

The use of sodium nitroprusside in children.

The hypotensive response to sodium nitroprusside was investigated in 30 children, age range 5-15 years, weight range 14-60 kg, who were undergoing spinal surgery for kyphoscoliosis. It was possible to achieve a constant level of satisfactory hypotension within the range 70-80 mmHg systolic arterial pressure using sodium nitroprusside infused at a rate of 10 microng/kg/minute and no serious side effects were experienced at this dose rate.