Plasma pentobarbitone levels. Influence of the preparation, route and method of administration

Hemodynamic effects of dexmedetomidine sedation for CT imaging studies

BACKGROUND

Dexmedetomidine sedation for radiological imaging studies is a relatively recent application for this drug. Previous studies have demonstrated some haemodynamic effects of dexmedetomidine, however, the effects remain poorly described in children. The aim of this study was to better define the effect of age on heart rate (HR) and blood pressure changes in children sedated for CT imaging with dexmedetomidine.

METHODS/MATERIALS

At our institution dexmedetomidine is given for sedation for CT imaging as a bolus of 2 mcg.kg(-1) over 10 min followed by an infusion of 1 mcg.kg(-1).h(-1) with a second bolus if required. Detailed quality assurance data sheets document patient demographics, sedation outcomes, adverse events, and hemodynamic data are recorded for each patient.

RESULTS

A total of 250 patients (range 0.1-10.6 years) received dexmedetomidine. ANOVA revealed strong evidence for changes in HR and mean arterial blood pressure during bolus and infusion relative to presedation values (P < 0.001). These changes were apparent in each age group and similar between groups. During the first bolus and during infusion, 82% and 93% of patients respectively were within the age-based normal range for HR. For mean arterial blood pressure, 70% of patients were within the normal range during first bolus and 78% during infusion.

CONCLUSION

In the pediatric population studied, intravenous dexmedetomidine sedation was associated with modest fluctuations in HR and blood pressure. Hemodynamic changes were independent of age, required no pharmacologic interventions and did not result in any adverse events. By anticipating these possible hemodynamic effects and avoiding dexmedetomidine in those patients who may not tolerate such fluctuations in HR and blood pressure, dexmedetomidine is an appropriate sedative for children undergoing CT imaging.

Superiority of Pentobarbital versus Chloral Hydrate for Sedation in Infants during Imaging

PURPOSE

To compare the effectiveness and safety of oral pentobarbital and oral chloral hydrate for sedation in infants younger than 1 year during magnetic resonance (MR) imaging and computed tomography (CT).

MATERIALS AND METHODS

A computerized database was used to collect information about all cases in which sedation was used. Outcomes of all infants who received oral pentobarbital or oral chloral hydrate for sedation between 1997 and 2002 were reviewed. Two study groups were compared for sedation and discharge times by using Student t test and for adverse events by using Fisher exact test and multiple logistic regression analysis.

RESULTS

Infants (n = 1,316) received an oral medication for sedation. Mean doses were 50 mg/kg chloral hydrate and 4 mg/kg pentobarbital. Student t test demonstrated no difference in mean time to sedation and in time to discharge between groups. Overall adverse event rate during sedation was lower with pentobarbital (0.5%) than with chloral hydrate (2.7%) (P <.001). There were fewer episodes of oxygen desaturation with pentobarbital (0.2%) than with chloral hydrate (1.6%) (P <.01). Both medications were equally effective in providing successful sedation.

CONCLUSION

Although oral pentobarbital and oral chloral hydrate are equally effective, the incidence of adverse events with pentobarbital was significantly reduced.

Comparison of oral pentobarbital sodium (nembutal) and oral chloral hydrate for sedation of infants during radiologic imaging: preliminary results

OBJECTIVE

The purpose of this study was to compare the safety and efficacy of oral cherry-flavored pentobarbital sodium (Nembutal) and oral chloral hydrate to sedate infants undergoing radiologic imaging.

SUBJECTS AND METHODS

We prospectively recorded data for all infants sedated with oral cherry-flavored pentobarbital sodium and oral chloral hydrate for imaging examinations between January 1997 and August 1999. The parameters recorded were each patient's age, weight, and American Society of Anesthesiologists classification; the time required to sedate; the total length of sedation time; the time required to discharge from the recovery room; and adverse events. The two-sample Student's t test and Fisher's exact test were used for statistical analysis.

RESULTS

Oral pentobarbital sodium was administered to 317 infants. These infants had a mean age +/- SD of 6.9 +/- 3.1 months and a mean weight of 7.8 +/- 4.8 kg; they received a median dose of 4 mg/kg of body weight. Oral chloral hydrate was administered to 358 infants. These infants had a mean age of 5.9 +/- 3.3 months and a mean weight of 7.3 +/- 4.9 kg; they received a median dose of 50 mg/kg of body weight. The mean time required to sedate was 19 +/- 14 min for infants receiving oral pentobarbital sodium and 16 +/- 11 min for infants receiving oral chloral hydrate (p = 0.02); the mean time required to discharge was 100 +/- 35 min for infants in the oral pentobarbital sodium group and 103 +/- 36 min for infants in the oral chloral hydrate group (p = 0.31); the mean length of sedation was 81 +/- 34 min for the oral pentobarbital sodium group and 86 +/- 36 min for the oral chloral hydrate group (p = 0.07); and median American Society of Anesthesiologists classification for both groups was P1. Oral pentobarbital sodium was inadequate for sedation in one patient (0.3%) and chloral hydrate was inadequate for sedation in another (0.3%) (p = 1.00). Adverse events were recorded for five patients (1.6%) in the oral pentobarbital sodium group and for six patients (1.7%) in the chloral hydrate group (p = 0.99).

CONCLUSION

Oral pentobarbital sodium is as safe and efficacious as oral chloral hydrate for sedating infants.

A case of suicide disguised as natural death

A case report describing the suicide of a physician classified initially as a natural death. Faced with the vehement protest of the family of the deceased the magistrate decided to request a 'preventive' forensic autopsy. Forensic investigations revealed the cause of death as being a pentobarbital intoxication and the circumstances favoured the hypothesis of a genuine suicide. This case illustrates that the tendency of magistrates to request or not an autopsy is related to their experience or intuition.

Plasma pentobarbitone levels. Estimation by gas-liquid chromatography after clinical doses

A simple and relatively quick method of estimating pentobarbitone in plasma samples is reported using an ether extraction and gas-liquid chromatography. Glutethimide was used as the internal standard and proved reliable. Reproducible results were obtained in plasma following 100 mg pentobarbitone given by mouth or intramuscular injection. Evaporation in a heating block at 37 degrees C and storage of samples at -20 degrees C prior to analysis is recommended.