Intravenous sedation for retrobulbar injection and eye surgery: Diazepam and/or propofol?

Principle goals of sedation for eye surgery are to provide patient comfort and to allow the patient to stay calm during both retrobulbar injection and surgery. Insufficient sedation may not prevent the patient from moving during retrobulbar injection, whereas very deep sedation may result in respiratory complications during surgery. The aim of the present study was to evaluates the effectiveness and suitability of a combination of diazepam and propofol for sedation for both application of retrobulbar block and subsequent elective eye surgery.
One-hundred and fifty patients were randomly allocated to receive either diazepam, propofol or a combination of both drugs before retrobulbar injection. Tolerance of retrobulbar injection and comfort during the surgical procedure were assessed by comfort scores using a nominal analogue scale between 1 (worst possible condition) and 6 (best conceivable condition). Side effects related to sedation were recorded.
The combination of diazepam and propofol resulted in the highest comfort scores for both retrobulbar block (5.3±0.3) and the surgical procedure (5.4±0.4). Diazepam alone did not produce adequate sedation for retrobulbar block (3.1±0.3), whereas comfort scores during surgery were significantly higher (5.3±0.3) compared to propofol alone (3.6±0.4). No severe side effects induced by sedation were noted in any of the study groups.
The combination of diazepam and propofol proved able to provide a reliable degree of sedation with minimal side effects for both retrobulbar block and surgery. The combination was clearly superior to the sedation induced by propofol or diazepam alone.     

Action of benzodiazepines on the immune response

Laboratory of Mechanisms of Neurochemical Modulation, Institute of Physiology, Siberian Branch, Academy of Medical Sciences of the USSR, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR A. V. Val'dman.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, vol. 105, No. 4, pp. 440–442, April, 1988.     

Prepulse inhibition as a screening test for potential antipsychotics

Startle response amplitude is greatly reduced by a low intensity pulse presented 100 msec prior to the startle stimulus. The magnitude of this prepulse inhibition (PPI) is reduced in schizophrenic patients. In rats, apomorphine disrupts PPI; haloperidol antagonizes apomorphine's effects. We tested the antipsychotic drugs haloperidol, chlorpromazine, clozapine, and risperidone, and the non-antipsychotic psychopharmacological agents diazepam, buspirone, and imipramine for their ability to antagonize apomorphine's effects on PPI of the acoustic startle reflex. Haloperidol, chlorpromazine, and risperidone antagonized apomorphine's blockade of PPI. Clozapine antagonized apomorphine's effect only at a dose that decreased startle amplitude by 82%. Imipramine and diazepam did not antagonize apomorphine's effect at behaviorally relevant doses. Buspirone weakly antagonized apomorphine blockade of PPI, but, like apomorphine, disrupted PPI when given alone. These results suggest that this PPI test may provide a useful screening procedure for compounds wtih antipsychotic activity. However, the lack of a robust clozapine effect needs to be investigated.     

Interaction of cholecystokinin and diazepam: effects on brain monoamines

An antagonism between cholecystokinin (CCK) peptides and benzodiazepines (BZD) has been described in various paradigms. We sought to determine whether CCK and BZD are also antagonistic in their effects on brain neurotransmitter levels in the rat. No effect on the noradrenergic system was induced in any brain area by CCK 8 S and diazepam alone or in combination. Administered alone, sulfated CCK octapeptide (CCK 8 S) (5 micrograms/kg ip) and diazepam (5 mg/kg ip) were found to decrease DOPAC levels in the cortex and to induce 5-hydroxy-tryptamine accumulation in the hippocampus. When administered together, these variations were no longer observed. However, a slight tendency by each substance to decrease 3-methoxy-tyramine levels in the striatum, became significant when given in association. The differences in CCK-BZD interactions observed in the striatum, cortex and hippocampus suggest that different mechanisms of action are involved. The addition of the effects occurring in the striatum might involve a GABA-ergic mechanism.     

Hemodynamic effects of vecuronium in patients with coronary artery disease

The hemodynamic effects of vecuronium 0.2 mg/kg were investigated in 11 patients with coronary artery disease. Vecuronium, at a dose double the ED90, produced 90% neuromuscular block in a mean time of 163 +/- 7 s, and was not associated with any significant hemodynamic changes. The results suggest that vecuronium can safely be used in cardiac patients.     

Comparison of the serum levels in primary non-agitated depressed out-patients treated with imipramine in combination with placebo, diazepam or dixyrazine

Sixty-three non-agitated depressed out-patients were selected according to the Feighner-Robins-Guze criteria for primary depressions for a double-blind, between-patient randomized study for an 8 week duration. All the patients were treated with imipramine following a fixed dose schedule for the first 2 weeks and thereafter according to clinical response (100-200 mg/day). This treatment was combined with either placebo, diazepam (10 mg/day) or dixyrazine (50 mg/day). The serum concentration of imipramine both at 2 weeks and later was significantly higher (P less than 0.05) in the group treated with dixyrazine than in the other two groups. In the group treated with diazepam, the serum levels of imipramine and desipramine were significantly lower than in the placebo group. The serum concentrations of diazepam, desmethyldiazepam and dixyrazine were almost unchanged during the study. No significant correlation was found between the dosage and the serum concentration of imipramine or desipramine. The change in mean CPRS-score correlated neither with the imipramine nor with the desipramine serum levels, it did correlate but negatively with the degree of side effects. The degree of side effects correlated positively with the serum concentration of desipramine.     

Skin-sniffing/ion mobility spectrometric analysis: A potential screening method in clinical toxicology

This paper deals with the detection of drug residues on the hands of subjects who simulated overdose situations. The results demonstrate that detectable amounts of particulate matter are transferred to the hands when certain types of drugs are handled in the manner of a person taking them. The residues are recovered from the hands by means of a suction probe and thermally desorbed directly into an ion mobility spectrometer (IMS). The IMS was shown to respond selectively to the drugs investigated, and thus ion mobility peaks can be used as markers for the presence of these drugs. Mass characterization of ions giving particular mobility peaks was achieved by coupling the IMS to a quadrupole mass spectrometer (IMS/MS). The major drugs detected were codeine, benzodiazepines, acetaminophen, dimenhydrinate, and some tricyclic antidepressants. The method was tested in a hospital environment. It has the potential as a preliminary screening test for drugs in emergency patients suspected of drug overdose.