PubMed Health⌕ Search

Biomedical subjects

T Elwood

Publications and source records attributed to T Elwood.

16 recordsLinked to original sources

Oropharyngeal airway diameter during sedation in children with and without developmental delay.

STUDY OBJECTIVE: To determine whether children with developmental delay would have closer apposition of upper airway tissues during sedation, perhaps because of poor coordination of upper airway musculature. DESIGN: Case-control and retrospective chart review. SETTING: Tertiary-care pediatric teaching hospital. PATIENTS: 40 children 3 to 6 years of age, with and without a diagnosis of developmental delay. MEASUREMENTS: Subjects received only pentobarbital sedation by a protocol. Magnetic resonance imaging (MRI) scans of the head were reviewed, and transverse airway diameters at the soft palate and tongue were determined from midline sagittal images. MAIN RESULTS: Age, weight, sedative dose, MRI window level, and window width were not different between patients with and without developmental delay. We found the airway diameter at the level of the soft palate was decreased 40% in children with developmental delay compared with those children without delay, 3 mm (1.4, 5.5 interquartile range) versus 5 mm (3, 8); p = 0.035, power 76%. CONCLUSIONS: The anteroposterior oropharyngeal airway diameter was smaller in children with developmental delay than in those without developmental delay, in static MRI images. It is possible that children with developmental delay are at higher risk for airway obstruction during sedation.

Airway Obstruction↗

Respiratory complications during anaesthesia in Apert syndrome.

BACKGROUND: Clinical experience with anaesthesia for a series of patients with Apert syndrome (craniosynostosis, midface hypoplasia and syndactyly) has not been reported previously. METHODS: In this review, 10 years of experience was examined at our hospital. There were 145 anaesthetics administered to 18 individuals. RESULTS: There were 16 complications (15 were perioperative wheezing) which occurred in seven patients. In four cases, surgery was cancelled due to intractable wheezing. CONCLUSIONS: We could not demonstrate any benefit from preoperative administration of nebulized albuterol. Paediatric anaesthetists should be aware of this high incidence of respiratory complications in Apert syndrome.

Acrocephalosyndactylia↗

Oxygen in nitrogen versus nitrous oxide during pediatric general anesthesia.

BACKGROUND: Induction of anesthesia decreases lung volumes, giving areas of non-ventilated lung. Nitrogen is a slowly-absorbed gas that could prevent resorption of gases from these closed spaces, preventing atelectasis and improving oxygen saturations during recovery. METHODS: We evaluated oxygen saturations during emergence after intra-operative administration of 33% oxygen in nitrogen versus 33% oxygen in nitrous oxide in 62 children having elective urologic surgery. Patients were randomly assigned to either group A (2.5 L/min air with 0.5 L/min oxygen) or group N (2 L/min nitrous oxide and 1 L/min oxygen). Flowmeters were covered to maintain blinding. Anesthetic technique was standardized (laryngeal mask airway, caudal, halothane, and deep extubation). Patients breathed room air during emergence, while a blinded observer recorded duration of desaturations by stopwatch for 15 min. RESULTS: We found similar desaturations in both groups. The difference in desaturations < 94% at an interim 2-min total probably reflects diffusion hypoxia and was not significant at 15 min. The frequency of desaturations < 87% during emergence was significantly greater in children who were crying during induction. CONCLUSIONS: The intra-operative use of air versus nitrous oxide has no substantial effect on oxygen saturations during emergence from anesthesia in children. These results are consistent with a recently published mathematical model.

Anesthesia, General↗

Effects of neurokinin receptor antagonists in virus-infected airways.

We investigated the effects of a neurokinin-1 (NK(1)) receptor antagonist (SR-140333) and a NK(2) receptor antagonist (SR-48968) on airway responsiveness and on the function of neuronal M(2) muscarinic receptors, which normally inhibit vagal acetylcholine release, in guinea pigs infected with parainfluenza virus. Antagonists were given 1 h before infection and daily thereafter. Four days later, bronchoconstriction induced by either intravenous histamine (which is partly vagally mediated) or electrical stimulation of the vagus nerves was increased by viral infection compared with control. In addition, the ability of the muscarinic agonist pilocarpine to inhibit vagally induced bronchoconstriction was lost in virus-infected animals, demonstrating loss of neuronal M(2) receptor function. Macrophage influx into the lungs was inhibited by pretreatment with both antagonists. However, only the NK(1) receptor antagonist prevented M(2) receptor dysfunction and inhibited hyperresponsiveness (measured as an increase in either vagally induced or histamine-induced bronchoconstriction). Thus virus-induced M(2) receptor dysfunction and hyperresponsiveness are prevented by a NK(1) receptor antagonist, but not by a NK(2) receptor antagonist, whereas both antagonists had similar anti-inflammatory effects.

Animals↗

Cancer pain emergencies: a protocol for management.

Cancer is often associated with chronic pain, which can be managed by established algorithms. Cancer is also occasionally associated with sustained episodes of excruciating pain (cancer pain emergencies) that require rapid application of powerful analgesic strategies in a manner that is distinct from chronic pain management techniques. To clarify the utility of rapid opioid dose escalation in this setting, we reviewed the management of ten cancer pain emergencies in nine patients. After initial assessment, all patients were managed according to a protocol whereby intravenous boluses of opioid are administered with rapid upward titration until an effective analgesic dose is found. Using this technique, all patients had relief of their excruciating pain after a mean of 89 min (range, 4-215 min). No patient demonstrated evidence of significant toxicity. We conclude that repeated intravenous boluses of an opioid, doubling the dose every 30 min until analgesia is achieved, is effective and safe management of cancer pain emergencies. Validation of this protocol is required.

Adult↗

Eschew the achoo!

Explore the source record for details and available documents.

Anesthesia, Conduction↗

Laryngeal mask insertion with a laryngoscope in paediatric patients.

PURPOSE: To assess epiglottic position after laryngeal mask airway (LMA) insertion with or without the use of a laryngoscope. METHODS: A double-blind randomized study. In 48 children an LMA (#2 for 6-20 kg, #2.5 for 20-30 kg) was inserted either blindly or with the help of a laryngoscope and its position assessed using fibreoptic endoscopy. RESULTS: An unobstructed view of the glottis, as assessed by fibrescope, was observed in 10 of 25 patients in the laryngoscope group, but only in 1 of 22 patients in the blind insertion group (P = 0.005). CONCLUSION: This technique offers an alternative when the standard technique has failed, or when LMA insertion precedes bronchoscopy or intubation via the laryngeal mask.

Child↗

Midazolam coinduction does not delay discharge after very brief propofol anaesthesia.

Previous reports have demonstrated synergism of midazolam and propofol for induction of anaesthesia in humans. We tested the hypothesis that in the presence of alfentanil, the combination of midazolam with propofol for a very brief operative procedure would not affect the recovery phase. During pre-oxygenation, 64 outpatients scheduled for dilatation and curettage received placebo, or low-dose midazolam (0.03 mg.kg-1), or high-dose midazolam (0.06 mg.kg-1) iv, in a randomized double-blind manner. They then received alfentanil 10 micrograms.kg-1 iv, followed by titrated doses of propofol iv for induction and maintenance of anaesthesia. Ventilation with 70% N2O in O2 by mask was controlled to achieve a PETCO2 30-40 mmHg. Outcome measures were: propofol dose (induction and maintenance), time until eye-opening to command, and time to discharge-readiness. Propofol induction dose was decreased by increasing doses of midazolam (P = 0.00005). Midazolam delayed time to eye-opening (P = 0.02) but not time to discharge-readiness. This study had an 80% power to detect a 39 min difference in time to discharge-readiness. We conclude that midazolam propofol co-induction in the presence of alfentanil delays eye-opening, but does not delay discharge after anaesthesia.

Alfentanil↗

A patient presenting for pharyngeal biopsy.

A 68-yr-old man presented for pharyngeal biopsy under general anaesthesia. Coincidentally he was found to have a large mediastinal mass. The evaluation of this patient is described. The exact risk of catastrophic airway collapse on induction of anaesthesia in patients with mediastinal masses is controversial but probably small. As there is no test to prevent airway collapse, it is suggested that attempts at biopsy be performed with regional anaesthesia after radiotherapy.

Aged↗