Sciatic nerve block for children. Sciatic nerve block by the anterior approach for postoperative pain relief.

This study aimed to establish whether it was practical to perform sciatic nerve block by the anterior approach in a group of children of different ages and weights. A total of 82 blocks were performed of which 78 (95.2%) were judged to have been successful. The technique of the block differed slightly from that used in adult practice, in that great reliance was placed on the loss of resistance felt as the needle point passed through the thigh muscles into the sciatic neurovascular compartment. There were no immediate or late complications associated with this block in any of the patients. It is concluded that the block is easy to perform and can produce reliable postoperative analgesia for most common operations on the foot and ankle in paediatric practice.

Lower limb blocks for children. Lateral cutaneous and femoral nerve blocks for postoperative pain relief in paediatric practice.

Femoral and lateral cutaneous nerve of the thigh blocks have been performed in a group of 50 children; the method has not previously been described in paediatric practice. The technique was judged to have been successful in 48 (96%) of the children. There were no early or late complications. It is concluded that these blocks are easy to perform, even in small children and infants, and that they can produce reliable postoperative analgesia for a variety of orthopaedic and plastic procedures.

Hypoxaemia during induction of anaesthesia--an audit of children who underwent general anaesthesia for routine elective surgery.

Arterial oxygen saturation was measured using pulse oximetry during induction of anaesthesia in 108 children aged 10 days--14 years. No restriction was placed on the method of induction. Oxygen saturation decreased to less than 90% in 29 children (26.8%) and less than 80% in seven children (6.4%). There was a significantly increased incidence of desaturation (to less than 90%) in children under one year of age, in those who had no premedication, in those who received only atropine as a premidicant and in children who were anxious or crying before intravenous induction. Oxygen saturation did not decrease below 90% in any child who received inhalational induction.

Hypoxaemia during recovery from anaesthesia--an audit of children after general anaesthesia for routine elective surgery.

Arterial oxygen saturation was measured by pulse oximetry in 105 children (aged 2 weeks-14 years) during recovery from general anaesthesia. Oxygen saturation was monitored continuously from the time that anaesthesia ended in the operating theatre until the children were fit to leave the recovery ward. All children breathed room air during transfer to the recovery area; 81 children continued to breathe room air in the recovery ward while the remainder received supplementary oxygen. Fifty-six children became significantly hypoxaemic (oxygen saturation less than 90%) at some stage. Hypoxaemia occurred most frequently after termination of anaesthesia (immediate postoperative period) and then later in the recovery ward when the children began to wake up (post-waking period). The administration of 100% oxygen at the end of anaesthesia had no effect on the incidence of early hypoxaemia which was greatest in children whose trachea had been intubated. Late hypoxaemia was associated most commonly with crying and breath-holding and was reduced significantly by supplemental oxygen. The oxygen saturation of children on return to the ward was significantly lower than the pre-operative value (p less than 0.001).

Anaesthesia and septo-optic dysplasia. Implications of missed diagnosis in the peri-operative period.

Septo-optic dysplasia (De Morsier's syndrome) is a common cause of congenital optic nerve hypoplasia. Associated abnormalities such as hypothalamic/pituitary dysfunction, hypotonia or spasticity, may result in affected children presenting for surgical procedures under general anaesthesia. A 3.5-year-old boy with the undiagnosed condition had his Achilles tendons elongated under an uncomplicated general anaesthetic. The postoperative period was complicated by coma and a major convulsive seizure which responded to glucose and steroids. The importance of awareness of this condition in short children with poor visual acuity who require general anaesthesia is stressed, and the presenting features of seven other cases are demonstrated.

Anaphylactoid reaction complicating neonatal anaesthesia.

A three-week-old girl presented for surgery for congenital pyloric stenosis. The anaesthetic technique included intravenous induction with thiopentone and neuromuscular blockade with atracurium. The administration of these drugs was followed within 2-3 minutes by oedema of the eyelids and epiglottis, reduced peripheral circulation and central cyanosis. There was no previous exposure to either drug and no definite family history of allergy. Analysis of subsequent sequential blood samples indicated that the reaction mechanism was non-immune and was presumed to be due to pharmacological release of histamine.

Plasma bupivacaine levels after fascia iliaca compartment block with and without adrenaline.

Twenty children undergoing unilateral surgery on the thigh received a fascia iliaca compartment block using 2 mg.kg-1 of bupivacaine with (Group A) or without (Group P) adrenaline 1/200,000. Venous blood samples were taken as 5, 10, 15, 20, 25, 30, 40, 50 and 60 min after injection and assayed for concentrations of bupivacaine. In all subjects an adequate block was produced. Plasma concentrations of bupivacaine in Group P were significantly higher than those in Group A (P < 0.05). The median maximum plasma concentration (Cmax) was 1.1 micrograms.ml-1 (range 0.54-1.29 micrograms.ml-1) in Group P and 0.35 microgram.ml-1 (range 0.17-0.96 microgram.ml-1) in Group A. The median time taken to attain Cmax (Tmax) was 20 min (range 10-25 min) in Group P and 45 min (range 5-50 min) in Group A. The median time to first analgesia was 9.75 h (range 3-15 h) in Group P and 10.5 h (range 2.5-21 h) in Group A. The study confirmed the efficacy of the fascia iliaca compartment block in children and showed that when performed with 2 mg.kg-1 of bupivacaine it is associated with plasma concentrations of bupivacaine well within acceptable limits. The addition of adrenaline 1/200,000 to the local anaesthetic solution reduces the maximum plasma concentration reached.

Comparison of patient-controlled analgesia in children by i.v. and s.c. routes of administration.

Sixty children undergoing appendicectomy were allocated randomly to receive one of two PCA regimens with morphine. Group IV received standard i.v. PCA with a bolus dose of morphine 20 micrograms kg-1 and a background infusion of 4 micrograms kg-1 h-1 while group SC received PCA by the s.c. route with a bolus dose of morphine 20 micrograms kg-1 and a background infusion of 5 micrograms kg-1 h-1. In both groups there was a lockout interval of 5 min. Group SC self-administered significantly less morphine (P < 0.05) and had a significantly (P < 0.01) greater percentage of valid demands for analgesia than group IV. There were no differences in pain scores between the groups at rest or during movement. Group IV suffered significantly (P < 0.01) more hypoxic episodes than group SC. There were no differences between groups in the incidence of postoperative nausea and vomiting or oversedation. S.c. PCA appears to be as effective and safe as i.v. PCA. By giving patients feedback on the occurrence of valid demands for analgesia, s.c. PCA may produce more appropriate and effective use of PCA.

Diclofenac vs oxybuprocaine eyedrops for analgesia in paediatric strabismus surgery.

Forty children undergoing strabismus surgery as day patients were randomly allocated to receive oxybuprocaine 0.4% eyedrops or 0.1% diclofenac eyedrops for perioperative analgesia. A non-invasive anaesthetic technique using the reinforced laryngeal mask airway was used. The study demonstrated that both topical analgesics provided good to excellent analgesia and the anaesthetic technique was associated with a relatively low incidence of nausea and vomiting. Complications were limited to two children who were admitted with persistent postoperative nausea and vomiting.

Prevention of postoperative nausea and vomiting with transdermal hyoscine in children using patient-controlled analgesia.

We have studied 40 children aged 6-14 yr undergoing abdominal surgery under general anaesthesia with extradural block; they were allocated randomly to receive transdermal hyoscine (loading dose 140 micrograms, followed by 5 micrograms h-1) or placebo for the duration of postoperative analgesia with PCA morphine. There was a significant (P < 0.001) reduction in the incidence of postoperative nausea and vomiting in the treated group compared with the placebo group during the first 48 h after operation. The treated group also had a significantly increased incidence of sedation (P < 0.02) and dry mouth (P < 0.01).

Ketamine disposition in children and adults.

The pharmacokinetics of ketamine 2 mg kg-1 i.v. and 6 mg kg-1 i.m. were investigated in nine children undergoing minor surgery. After either route of administration plasma ketamine concentrations were similar to those found in adult patients receiving the same dose, except at later times after i.v. injection, when concentrations were smaller in children. Also, absorption after i.m. injection appeared to be more rapid in children. Substantially larger concentrations of the metabolite norketamine were found in children than in adults after the injection of ketamine. Concentrations of ketamine upon awakening in a further group of nine children receiving ketamine as the sole anaesthetic showed large inter-individual variation. The concentrations were greater than those previously reported for adults. The greater dose requirements in children, compared with adults, are probably attributable to pharmacodynamic rather than pharmacokinetic factors.

Adrenocortical hormone concentrations in children during cardiopulmonary bypass with and without pulsatile flow.

Plasma cortisol and ACTH concentrations were measured in two groups of children (aged 1-16 yr). Ten children underwent routine (non-pulsatile) cardiopulmonary bypass and 10 underwent pulsatile bypass under moderate hypothermia (28-32 degrees C). Comparable increases in cortisol and ACTH concentrations were demonstrated at the onset of bypass and the concentrations of both hormones increased during bypass. In the post-bypass period plasma cortisol concentration increased sharply; there was no further increase in the plasma ACTH concentration. By 24 h the concentrations of both hormones had declined towards baseline values. There were no significant differences between the groups.