Plasma concentrations of bupivacaine after combined spinal epidural anaesthesia in infants and neonates

The unbound and bound plasma concentration of bupivacaine in 50 infants less than 55 weeks postconceptual age was determined following combined spinal and epidural anaesthesia (csea). Plasma concentrations were determined at 15-min intervals up to 60 min postspinal anaesthesia. Maximum plasma bupivacaine levels were recorded between 45 and 60 min post CseA. Total plasma concentrations above a toxic threshold level of 4 microg.ml(-1) were recorded in 4% of patients and above 2.5 microg.ml(-1) in 10% of patients. Unbound bupivacaine levels were greater than a presumed toxic level of 0.25 microg.ml(-1) in 16% of cases and above 0.3 microg. ml(-1) in 14% of cases. A wide range of protein binding was measured (varying from 53.8-98.2%) and could not be correlated with standard indicators of local anaesthetic binding. Two neonates had brief apnoeas in the immediate perioperative phase but no adverse cardiac or central nervous system events attributable to the performance of Csea were demonstrated.     

Urethral meatal stenosis in boys easily overlooked

Three boys aged 8, 5, 3 and 9 years, respectively, appeared to have urethral meatal stenosis. In the first patient this appeared during a check-up following treatment for balanitis. Patient history revealed that his micturition duration was longer than before. In the second patient, who underwent surgical correction for hypospadia, it was discovered because he took longer to urinate than his brother. In the third patient stenosis was observed during an appointment for a retracted testicle; he had been circumcised earlier for cultural reasons. Meatomy was performed under anaesthesia in all 3 patients, after which the micturition duration and stream velocity were normal. The third patient continued to have an extremely large bladder capacity and residual volume. Meatal stenosis may lead to obstructive uropathy, urinary tract infection and eventually damage to renal parenchyma. Symptomatic presentation can be late. Diagnostic tests include urine analysis and culture, and uroflowmetry. Visual inspection by spreading the meatal dimple to visualise a pinhole urethra cannot be overemphasised.