Warming and Inhibition of Salinization at the Ocean's Surface by Cyanobacteria.

This paper describes high-resolution in situ observations of temperature and, for the first time, of salinity in the uppermost skin layer of the ocean, including the influence of large surface blooms of cyanobacteria on those skin properties. In the presence of the blooms, large anomalies of skin temperature and salinity of 0.95°C and -0.49 practical salinity unit were found, but a substantially cooler (-0.22°C) and saltier skin layer (0.19 practical salinity unit) was found in the absence of surface blooms. The results suggest that biologically controlled warming and inhibition of salinization of the ocean's surface occur. Less saline skin layers form during precipitation, but our observations also show that surface blooms of Trichodesmium sp. inhibit evaporation decreasing the salinity at the ocean's surface. This study has important implications in the assessment of precipitation over the ocean using remotely sensed salinity, but also for a better understanding of heat exchange and the hydrologic cycle on a regional scale.

Anaesthesia for spinal surgery in children.

Spinal surgery is performed in children of all age groups. Some of these children will have significant, other medical problems. For most, surgery will be performed in the prone position. Blood loss may be high for some types of surgery, and patients will benefit from use of a blood-sparing technique. Many patients will require spinal cord monitoring to assess cord function and to prevent neurological deficit.

Managing sedation withdrawal in children who undergo prolonged PICU admission after discharge to the ward.

Children who undergo a prolonged stay within the intensive care unit require adequate sedation and analgesia. During the recovery phase there will need to be a period of sedation withdrawal to prevent occurrence of an abstinence syndrome. We present a strategy developed within our hospital for managing this process which uses the resource of the Pain Service, along with guidelines to help prevent the development of withdrawal, and a plan for managing any signs of abstinence which occur.

A comparison of three methods of analgesia in children having day case circumcision.

Sixty-one children were randomized to receive one of three methods of analgesia for day case circumcision. Group 1 received a penile block, group 2 received a penile block plus diclofenac suppository and group 3 received a diclofenac suppository alone. CHEOPS pain scoring was performed in the recovery area, one h after awakening and two h after awakening. There was no difference between the groups except in the recovery area when group 3 cried more and had a higher pain score than group 2. Parental follow-up questionnaires for the subsequent two days showed no difference in measured parameters between the groups.

Pain assessment and documentation--making a difference.

Pain assessment is essential for effective pain management. Development of structured pain assessment and documentation of the child's pain history is vital. Involving the child and family in pain assessment is crucial for effective pain management. Pain management requires multiprofessional commitment and involvement. The role of the acute pain service is a vital element within a Children's Trust.

Incidence of malignant hyperthermia reactions in 2,214 patients undergoing muscle biopsy.

To determine the incidence of malignant hyperthermia (MH) reactions after trigger-free anaesthesia in a large population of MH-susceptible (MHS) patients, the charts of 2,214 patients who underwent elective muscle biopsy for malignant hyperthermia were reviewed. Either general or regional anaesthesia with non-triggering drugs was used. For general anaesthesia, the trachea was intubated in the absence of muscle relaxants. The halothane/caffeine contracture test was performed on the biopsied muscle. Suspected MH reactions were identified according to their site of occurrence (in the operating room, recovery room or ward). Ninety-seven percent of patients received a general anaesthetic; 3% received a regional anaesthetic or field block. Of the 2214 patients whose muscles were biopsied, 1082 patients were biopsy-positive for MH. Five patients in whom MH reactions were diagnosed in the recovery room were all subsequently proved to be biopsy-positive for MH. Four of the five received intravenous dantrolene as part of their therapy; the fifth received only symptomatic therapy as parenteral dantrolene was not commercially available. All patients recovered completely from their reactions. We conclude that the incidence of MH reactions in biopsy-positive patients who receive a trigger-free anaesthetic for minor surgery is small (0.46%, (0.15-1.07%, 95% CI)). These reactions occur in the immediate postoperative period.

Dose of propofol required to insert the laryngeal mask airway in children.

We have assessed the ease of insertion of the Brain Laryngeal Mask Airway (LMA) after induction of anaesthesia with propofol in 60 healthy unpremedicated children aged between four and nine years. Patients were randomly allocated into three groups: group A = propofol 2.5 mg.kg-1; group B = propofol 3 mg.kg-1 and group C = propofol 3.5 mg.kg-1. Propofol was mixed with lignocaine 0.5 mg.kg-1. Insertion conditions were assessed subjectively as good, acceptable, unacceptable or impossible. Insertion of the LMA was possible in all patients. Good and acceptable conditions were obtained in 35%, 70% and 95% in groups A, B, and C respectively (P < 0.0001). There was no statistically significant inter group variation in systolic and diastolic arterial pressure or in heart rate for five min after induction. All measured cardiovascular changes were considered to be clinically insignificant in healthy children. We conclude it is safe and effective to insert a LMA immediately after induction of anaesthesia with propofol 3.5 mg.kg-1.

Thiopental attenuates dysrhythmias in children: comparison of induction regimens.

Anesthesia was induced in 91 children using one of three induction regimens: (a) thiopental, atropine, and succinylcholine (T group); (b) halothane, atropine, and succinylcholine (H group); and (c) halothane, thiopental, atropine, and succinylcholine (H/T group). The incidence of dysrhythmias was significantly greater in the H group (85%) than in the T group (6%) and H/T group (20%). Fewer dysrhythmias occurred in the H/T group compared to the H group despite similarly prolonged QTc intervals in both groups. We conclude that induction of anesthesia with thiopental is appropriate and reduces the incidence of cardiac rhythm disturbances in children and that administration of thiopental to children during induction of anesthesia with halothane, atropine, and succinylcholine may reduce the incidence of cardiac dysrhythmias.

Truncus arteriosus with interrupted aortic arch: successful correction in a neonate.

Truncus arteriosus (type II) with interrupted aortic arch (type B) was successfully repaired at 11 days of age using anterior translocation of the pulmonary arteries, resection of the ductus arteriosus, and direct anastomosis between the descending aorta and truncus. This technique permitted wide reconstruction of the aortic arch and minimized the number of suture lines. It also positioned the right ventricle-pulmonary artery conduit anteriorly, which may simplify its subsequent replacement.

The boxers' fracture: a prospective study of functional recovery.

The rate of functional recovery following fracture of the fifth metacarpal neck is reported. The recovery of power grip and finger grip strength is complete in most patients by two months. The functional outcome is not significantly related to the degree of angulation at the fracture site.

Neuromuscular blockade for rapid tracheal intubation in children: comparison of succinylcholine and pancuronium.

To compare the effectiveness of succinylcholine and pancuronium for rapid intubation in children, 49 healthy children ages two to eight years were studied. After induction of anaesthesia with thiopentone and atropine, and administration of droperidol, fentanyl, nitrous oxide, and oxygen, each child received one of the following muscle relaxants: succinylcholine 1.5 mg X kg-1 (n = 12), succinylcholine 1.0 mg X kg-1 (n = 13), pancuronium 0.15 mg X kg-1 (n = 11), or pancuronium 0.10 mg X kg-1 (n = 13). The force of thumb adduction was measured by stimulating the ulnar nerve with repetitive supramaximal single twitches (0.15 Hz). The time to 95 per cent twitch depression (mean +/- S.D.) was most rapid with succinylcholine 1.5 mg X kg-1 (40.8 +/- 3.0 seconds) and succinylcholine 1.0 mg X kg-1 (51.8 +/- 14.0 seconds), slowest with pancuronium 0.10 mg X kg-1 (150.9 +/- 38.0 seconds), and intermediate with pancuronium 0.15 mg X kg-1 (80.3 +/- 21.8 seconds) (p less than 0.005). The intubating conditions were excellent in 100% of the children who received succinylcholine 1.5 and 1.0 mg X kg-1, and pancuronium 0.15 mg X kg-1, but were excellent in only 69 per cent of those who received pancuronium 0.10 mg X kg-1. We conclude that succinylcholine 1.5 mg X kg-1 produces the most rapid onset of excellent intubating conditions in children. In children in whom succinylcholine is contra-indicated, pancuronium 0.15 mg X kg-1 provides excellent intubating conditions within 80 seconds.

Anaesthetic implications of nemaline rod myopathy.

Nemaline rod myopathy is an inherited congenital myopathy first described in 1963. Affected patients characteristically present in infancy with a non-progressive hypotonia and symmetrical muscle weakness. The disease affects all skeletal muscles including the diaphragm with sparing of cardiac and other muscle. Facial dysmorphism is common as are skeletal deformities, including kyphosis, scoliosis and pectus excavatum. We present two sisters with nemaline rod myopathy and their anaesthetic management for scoliosis surgery. Facial dysmorphism was a feature of both cases. Preoperatively, both patients demonstrated poor respiratory function on pulmonary function testing. Both cases were successfully managed using controlled ventilation and inhalational anaesthetic agents, avoiding muscle relaxants. Postoperatively, there were no respiratory complications. Although one case report describes the use of succinylcholine and pancuronium in a patient with nemaline rod myopathy, we feel that neuromuscular blocking agents should be avoided where possible and only used with careful monitoring.