NONCONVENTIONAL DRUG ADMINISTRATION IN ANESTHESIA

Comparison of the anesthetic effects of oral transmucosal versus injectable medetomidine in combination with tiletamine-zolazepam for immobilization of chimpanzees (Pan troglodytes)

Seventeen adult chimpanzees (Pan troglodytes) with an average age of 37 yr were immobilized with a combination of tiletamine-zolazepam (TZ) and medetomidine (MED) by one of two modes of delivery. Group A animals received the drug combination intramuscularly at 3 mg/kg and 0.05 mg/kg, respectively. Animals in group B received MED by oral transmucosal administration, meaning oral delivery with presumptive transmucosal absorption. MED at 0.1 mg/kg was mixed with marshmallow crème, and delivery was followed by 3 mg/kg of TZ intramuscularly. Chimpanzees from both groups were recovered after administration of atipamezole at 0.3 mg/kg intramuscularly. All chimpanzees were compliant with oral transmucosal drug administration, although two chimpanzees preferred oral MED mixed with applesauce. All animals exhibited some anxiety and excitatory behavior associated with darting, but this was reduced in group B, which was premedicated with oral transmucosal MED. The mean time from TZ administration to sedation sufficient for human contact was 16.4 and 14.7 min with and without oral transmucosal premedication, respectively. The mean time for recovery for those chimpanzees given oral transmucosal premedication was 13.8 min, which was significantly shorter than the time of recovery for the group not given oral premedication (P = 0.02). Oral transmucosal administration of MED provided light sedation in 16 of 17 chimpanzees to the level of arousable recumbency and a heavier sedation in one chimpanzee with no adverse side effects. TZ combined with MED by either oral transmucosal or injectable administration provided safe, heavy, long sedation with rapid, smooth, uneventful recoveries.

Is intranasal midazolam an effective rescue medication in adolescents and adults with severe epilepsy?

The aim of this study was to determine whether intranasal midazolam is a safe and effective rescue medication in adolescent and adult patients with severe epilepsy. This field trial was designed to test the feasibility of the use of intranasal midazolam as an alternative to rectal diazepam in a cohort of patients with severe epilepsy who require rescue medication as part of their treatment. A dose of intranasal midazolam (5 mg if the patient weighed less than 50 kg and 10 mg if the patient weighed over 50 kilograms) was prescribed for those who had previously responded to other rescue medication. Midazolam was prescribed buccally if excessive head movement accompanied seizures. The protocol reverted to the usual rescue medication if there was no response to midazolam within 10 minutes. Vital signs were monitored for half an hour following the administration of the treatment. Twenty-two patients received 84 treatment episodes and 79 of these were considered clinically effective. Five treatment failures were recorded, three due to poor technique in delivering the midazolam. Two patients were successfully retried on midazolam and a third is awaiting a retrial of this drug. The two other treatment failures received the drug buccally. In the first patient the clinical opinion was that this was possibly a psychogenic non-epileptic seizure. The other patient responded initially, but within an hour had another seizure requiring further rescue treatment. No significant adverse effects were reported. Our study shows that intranasal midazolam, when used appropriately, is an effective treatment in those who require rescue treatment. There are clear advantages in the use of midazolam over diazepam in the treatment of acute seizures. These include the favourable pharmacokinetic and pharmacodynamic properties of midazolam as well as the potential of a more acceptable and dignified administration route.

Sedative and physiologic effects of orally administered alpha 2-adrenoceptor agonists and ketamine in cats

OBJECTIVE

To compare efficacy of 3 regimens of orally administered sedatives and determine physiologic effects of 1 of these regimens in healthy cats.

DESIGN

Prospective randomized study.

ANIMALS

34 cats.

PROCEDURE

Cats were assigned to 1 of 3 groups that were treated by oral administration of detomidine and ketamine, xylazine and ketamine, or medetomidine and ketamine. Cats were monitored for degree of sedation at 5-minute intervals for 60 minutes. Physiologic effects in cats treated with detomidine and ketamine were measured at 5-minute intervals for 30 minutes and compared with effects in cats treated i.m. with detomidine and ketamine or xylazine and ketamine.

RESULTS

All cats treated orally with detomidine and ketamine became laterally recumbent; sedation was more variable in the other 2 groups treated orally. Vomiting and excessive salivation were the only adverse effects. Bradycardia (heart rate < 145 beats/min) was detected at each evaluation time in cats treated orally with detomidine and ketamine and in all cats treated i.m. Minimal differences among groups were detected for heart and respiratory rates, rectal temperature, and hemoglobin oxygen saturation.

CONCLUSIONS AND CLINICAL RELEVANCE

Oral administration of detomidine and ketamine is an effective method of sedating healthy cats and induces minimal physiologic effects that are similar to those resulting from i.m. administration of sedatives.

Midazolam via the intranasal route: an effective rescue medication for severe epilepsy in adults with learning disability

People with a learning disability are often disadvantaged due to the nature of their disability. Up to a third are likely to have concomitant epilepsy which adds to the health loss experienced by this group. It is important to manage their epilepsy in such a way as to limit the debilitating effects of both the illness and the medication. Rectal diazepam remains the gold standard rescue medication for prolonged, recurrent seizures or seizures associated with hypoxia. Some of the drawbacks are highlighted in this paper and we go on to explore a novel means of treating these seizures. Midazolam, via the intranasal route, has been used extensively in children, mostly as a sedative but also in the treatment of epilepsy. We present two cases, both are adults with a learning disability, who have benefited significantly from the use of intranasal midazolam. Ongoing research into the safe use of this form of treatment, training of staff and carers and the impact on the individual is being conducted.

Subcutaneous administration of midazolam: a comparison of the Bioject jet injector with the conventional syringe and needle

PURPOSE

The purpose of this study was to compare jet injection to a syringe and needle in terms of the difference in discomfort and pharmacokinetics after the subcutaneous administration of midazolam.

PATIENTS AND METHODS

Using a prospective, randomized, double-blinded study design, 14 subjects were administered midazolam on two separate occasions (at least 2 weeks apart). The subjects were randomly distributed into two groups: syringe and needle (saline)/jet injector (midazolam) or syringe and needle (midazolam)/jet injector (saline). The subjects were randomly assigned to receive either EMLA (eutectic mixture of local anesthetics) or a placebo at the injection site for the first administration and the other topical agent on the second visit. Each subject received one subcutaneous injection in the deltoid region per arm per day. Each injection contained the same volume of solution. Subjects completed visual analog scale (VAS) questionnaires assessing the discomfort of the injection. Blood samples were taken at specified intervals over 2 hours for determination of midazolam levels.

RESULTS

The discomfort associated with the injection was less with the Biojector 2000 (Bioject Inc, Portland, OR) although this was not statistically significant. However, persistent discomfort was significantly greater at the needle site. The mean peak plasma level of midazolam was achieved more rapidly with the Biojector 2000 than with the syringe and needle (P < .05). However, the peak plasma level after jet injection or injection with a syringe and needle was not statistically different.

CONCLUSION

The results of the study show that the Biojector 2000 is a needle-free injection system that can be used for the administration of a premedicant before induction of anesthesia. It has several advantages, including the potential reduction of anxiety associated with the "fear of needles" and occupational injuries.

Midazolam as a pediatric premedicant in the ambulatory setting

In the preoperative setting, the nurse is responsible for the comprehensive evaluation and preparation of the patient. Among these activities, the administration of various premedications to achieve a physiological (eg, raise gastric fluid pH) or psychological (eg, reduce apprehension) effect is commonplace. Midazolam, a benzodiazepine, is one of the more popular medications used preoperatively for its anxiolytic properties. Several studies have evaluated the variety of routes by which midazolam can effectively be administered to the pediatric patient. A review of midazolam as a premedication specific to the pediatric population in the ambulatory setting is presented.