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N McDonnell

Publications and source records attributed to N McDonnell.

8 recordsLinked to original sources

Malignant hyperthermia and day stay surgery.

Patients who are malignant hyperthermia susceptible are often admitted overnight for observation, even after minor surgery. They may be declined care in a stand-alone day stay unit. This prospective audit set out to investigate whether patients susceptible to malignant hyperthermia can be safely treated as day stay patients. The audit was conducted for four years from late 2000. All patients who were known to be susceptible to malignant hyperthermia, and their untested relatives, who received day stay anaesthesia were included in the audit. Malignant hyperthermia status, age, duration of anaesthesia, anaesthetic technique, type of procedure, intraoperative and postanaesthesia care unit observations and complications were recorded. All patients received a trigger-free anaesthetic technique. Detailed postanaesthesia care unit monitoring was undertaken and patients were observed for two and a half hours postoperatively. Seventy-two patients were included in the audit. General anaesthesia was administered to 85% and regional to 15%. Only minor complications arose in the postoperative period, and none suggested a malignant hyperthermia reaction. Postanaesthesia care unit nursing staff contacted 49 (68%) of the patients the following day, and there was no evidence of malignant hyperthermia reactions. This audit suggests that malignant hyperthermia susceptible patients can be safely managed as day stay patients in appropriate facilities, with appropriate postoperative care.

Adolescent↗

Safe duration of postoperative monitoring for malignant hyperthermia susceptible patients.

Postoperative management of malignant hyperthermia (MH) susceptible patients has changed substantially over the last 20 years, with many patients now managed as day cases. Our previous policy was to monitor known MH susceptible patients (and relatives of known MH susceptible individuals not yet investigated by muscle biopsy) for four hours in the Post Anaesthetic Care Unit. However, anaesthetic literature reports suggest that MH reactions usually commence within one hour of anaesthesia. For this reason we conducted a retrospective review of Post Anaesthetic Care Unit data in 254 MH susceptible/related patients treated between 1991 and late 2000. On the basis of this review we instituted a policy change and reduced our monitoring time to one hour in the Post Anaesthetic Care Unit with a further 1.5h in a step-down unit if indicated. A prospective study in a further 68 MH susceptible/related patients showed that no MH reactions were missed due to the shorter monitoring period.

Adolescent↗

Doublecortin is a developmentally regulated, microtubule-associated protein expressed in migrating and differentiating neurons.

Recently, we and others reported that the doublecortin gene is responsible for X-linked lissencephaly and subcortical laminar heterotopia. Here, we show that Doublecortin is expressed in the brain throughout the period of corticogenesis in migrating and differentiating neurons. Immunohistochemical studies show its localization in the soma and leading processes of tangentially migrating neurons, and a strong axonal labeling is observed in differentiating neurons. In cultured neurons, Doublecortin expression is highest in the distal parts of developing processes. We demonstrate by sedimentation and microscopy studies that Doublecortin is associated with microtubules (MTs) and postulate that it is a novel MAP. Our data suggest that the cortical dysgeneses associated with the loss of Doublecortin function might result from abnormal cytoskeletal dynamics in neuronal cell development.

Animals↗

The effect of ionised magnesium on coagulation using thromboelastography.

Magnesium is an ionised mineral with therapeutic uses. There is laboratory evidence that it may have an anticoagulant activity although recent research has been to the contrary. The clinical implications of the effect of a therapeutic dose of magnesium on coagulation have yet to be resolved conclusively. In our study, 10 healthy volunteers were given 4 g of magnesium sulphate intravenously. Thromboelastographs were recorded and blood analysed for haematological indices, before and after the infusion. All variables associated with coagulation remained unchanged except the alpha angle on the thromboelastograph which increased significantly. We conclude that in our in vivo study, the effect of magnesium sulphate on coagulation is not clinically significant.

Blood Coagulation↗

Single and multiple doses of oral cimetidine do not change liver blood flow in humans.

Liver blood flow was measured in 10 healthy men for 6 hours after single (300 mg) and multiple (300 mg every 6 hours for 5 days) oral doses of cimetidine. Blood flow measurements were determined in the superior mesenteric and hepatic arteries and in the intrahepatic branches of the portal and hepatic veins by use of a duplex Doppler ultrasound technique. Compared with baseline measurements obtained before drug administration, cimetidine treatment did not change blood flow in any of the four blood vessels. Cimetidine serum concentrations and pharmacokinetic parameters were similar to those reported in other studies conducted in healthy adults. The findings of this study indicate that single and multiple 300 mg doses of oral cimetidine do not change liver blood flow.

Administration, Oral↗

Safety of GM-CSF in patients with AIDS: a review of the literature.

We performed a literature search for all clinical studies reporting outcomes in patients with the acquired immunodeficiency syndrome (AIDS) receiving granulocyte-macrophage colony-stimulating factor (GM-CSF) for any indication. Safety outcomes included human immunodeficiency virus replication, immune status, and frequency of opportunistic infections and neoplasms. Data were synthesized qualitatively. We identified 22 studies (274 patients): 12 addressed AIDS neutropenia, 8 AIDS cancer therapy, and 2 opportunistic infections. Viral burden was assessed by serum p24Ag in 15 studies. Nine reported no change in levels, three net decreases, and three net increases. All studies showing net increases involved patients receiving GM-CSF without a concurrent antiretroviral. The CD4 counts were unchanged in 5 studies, increased in 3, and not reported in 14. The incidence of neoplasms or new opportunistic infections was low. The literature suggests no increased risk of viral replication or clinical deterioration in patients with AIDS who take GM-CSF concurrently with zidovudine.

Acquired Immunodeficiency Syndrome↗