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PubMed1993

Potential pharmacokinetic interactions of nocloprost clathrate with retarded theophylline and enteric coated diclofenac after single and repeated premedication in healthy volunteers.

Pharmacokinetic interactions of cytoprotective prostaglandin E2 analog nocloprost clathrate with theophylline and diclofenac were studied in two placebo controlled, single-blind studies with parallel groups (n = 8) in healthy male volunteers (age 20-32 years, body weight 63-95 kg, body height 169-193 cm, Broca index 0.81-1.18). Nocloprost (200 micrograms) or placebo tablets were given twice daily (07:00 h a.m. and p.m.) for 8 days. Thirty min after the first administration on the first day (single) and 30 min after the last administration in the morning of the 8th day (repeated premedication), pharmacokinetic examinations with retarded theophylline capsules (250 mg) or enteric coated tablets of diclofenac (50 mg) were performed. Theophylline was measured using an HPLC- and diclofenac with a GC-method. Both single and repeated premedication with nocloprost did not significantly change any pharmacokinetic parameter of theophylline. There was only a tendency towards lower AUC of theophylline after both regimens of premedication. As far as diclofenac is concerned, single premedication increased significantly the rate of absorption and total body clearance but lowered the AUC of the NSAID. After repeated premedication, no parameter was significantly influenced. All pharmacokinetic changes observed are most likely without any clinical importance.

Absorption↗
PubMed1998

Comparison of psychomotor functions and sedation following premedication with oral diazepam and clonidine in children.

In a prospective, double-blind, controlled, randomized study, the psychomotor functions and sedation were assessed after premedication with diazepam and clonidine in children. Forty children in the age-group of 5-8 years, undergoing elective surgery under general anesthesia were studied. Twenty children (group 1) received oral clonidine 4 microg/kg, and 20 children (group 2) received oral diazepam 0.2 mg/kg, 120 minutes before induction of anesthesia. Sedation and psychomotor functions were assessed in both groups, before and after 60-90 minutes of administration of premedication. The results of the study showed that mean sedation score in group 1 was 8 +/- 1.07, and 9 +/- 0.64 in group 2. On intergroup comparison the sedation was found to be comparatively better in group 2 than group 1 (p < 0.05). The performance of psychomotor functions decreased after premedication in both the groups as compared to that before premedication (p < 0.05). The psychomotor functions were depressed more in diazepam group than in the clonidine group (p < 0.05). Thus, it is concluded that clonidine produces good sedation and causes less effect on psychomotor functions and therefore can be used for premedication in children.

Administration, Oral↗
PubMed1988

Arterial oxygen saturation following premedication in children with cyanotic congenital heart disease.

To determine the effects of premedication on arterial oxygen saturation (SaO2) and heart rate (HR), 11 children (ages three to seven years) scheduled for elective repair of cyanotic congenital heart defects were studied. Patients were premedicated with oral or rectal pentobarbitone 2 mg.kg-1 90 minutes prior to induction of anaesthesia followed by intramuscular morphine 0.2 mg.kg-1 and atropine 0.02 mg.kg-1 60 minutes prior to induction. The SaO2 and HR of each child were monitored continuously using a Nellcor pulse oximeter during two 90 minute periods: a control period commencing 25.5 hours preoperatively (day 1) and a post premedication period commencing 1.5 hours preoperatively (day 2). Data were compared at time 0 (corresponding to the time of administration of pentobarbitone on day 2), 30 (corresponding to the administration of intramuscular morphine and atropine on day 2), 60 and 90 minutes (the latter corresponding to the time of induction on day 2) after the administration of pentobarbitone. There were no significant differences in SaO2 or HR between day 1 and day 2 at time 0, 60, and 90 minutes. The SaO2 (mean +/- SD) decreased significantly immediately following intramuscular premedication at time 30 minutes on day 2 (72.7 +/- 5.9 per cent) compared to the corresponding time on day 1 (83.9 +/- 2.9 per cent) (p less than 0.05). The duration of this desaturation was 2.5 +/- 1.9 minutes. Heart rate (mean +/- SD) increased from 109.2 +/- 21.3 beats.min-1 at time 30 minutes on day 1 to 142 +/- 20.4 beats.min-1 on day 2 (p less than 0.05). We conclude that administration of intramuscular premedication preceded by oral or rectal pentobarbitone causes transient arterial desaturation and tachycardia in children with cyanotic congenital heart disease.

Child↗
PubMed1997

Comparison of lorazepam alone vs lorazepam, morphine, and perphenazine for cardiac premedication.

PURPOSE: To compare the effects of two premedication regimens on cardiorespiratory variables, sedation, and anxiety in patients scheduled for coronary artery bypass graft (CABG) surgery. METHODS: This was a prospective randomized, double-blind clinical trial. Sixty-eight patients were monitored for 1.5 hr before and 2.0 hr after premedication with lorazepam (0.03 mg.kg-1 sl), morphine (0.15 mg.kg-1 im), and perphenazine (0.05 mg.kg-1 im) [Group 1], or with lorazepam (0.03 mg.kg-1 sl) and saline (1.5 ml im) [Group 2]. All were continuously monitored with a 12-lead ECG ST monitors, respiratory inductive plethysmography (RIP), digital pulse oximetry, intra-arterial blood pressure, and arterial blood gas analysis. Sedation and anxiety scores were also recorded. RESULTS: The incidence and duration of myocardial ischaemia was low and similar in Groups 1 and 2. Patients in Group 1, but not in Group 2, had a greater number of events (P < 0.04) and duration (P < 0.02) of O2 desaturation; higher PaCO2 (P < 0.001), and more haemodynamic events (P < 0.006) after premedication when compared with baseline. There was no difference in RIP or ECG variables between the two groups. Following premedication, both groups reported reduced anxiety scores and elevated sedation scores (P < 0.01), with sedation greater in Group 1 than in Group 2 (P < 0.01). CONCLUSION: In CABG patients, premedication with lorazepam provides adequate anxiolysis and sedation, and the addition of morphine and perphenazine results in elevated PaCO2, arterial haemoglobin desaturation, and potentially adverse haemodynamic changes.

Aged↗
PubMed2001

Midazolam premedication reduces propofol dose requirements for multiple anesthetic endpoints.

PURPOSE: This study investigates the interactions between midazolam premedication and propofol infusion induction of anesthesia for multiple anesthetic endpoints including: loss of verbal contact (LVC; hypnotic), dropping an infusion flex (DF; motor), loss of reaction to painful stimulation (LRP; antinociceptive) and attainment of electroencephalographic burst suppression (BUR; EEG). METHODS: In a double blind, controlled, randomized and prospective study, 24 ASA I-II patients received either midazolam 0.05 mg x kg(-1) (PM; n = 13) or saline placebo (PO; n = 11) i.v. as premedication. Twenty minutes later, anesthesia was induced by propofol infusion at 30 mg x kg(-1) x hr(-1). ED50, ED95 and group medians for times and doses were determined and compared at multiple anesthetic endpoints. RESULTS: At the hypnotic, motor and EEG endpoints, midazolam premedication significantly and similarly reduced propofol ED50 (reduction: 18%, 13% and 20% respectively; P <0.05 vs unpremedicated patients) and ED95 (reduction: 20%, 11% and 20% respectively; P <0.05 vs unpremedicated patients). For antinociception (LRP), dose reduction by premedication was greater for propofol ED95 (reduction: 41%; P <0.05 vs unpremedicated patients) than ED50 (reduction: 18%; P <0.05 vs unpremedicated patients). Hemodynamic values were similar in both groups at the various endpoints. CONCLUSIONS: Midazolam premedication 20 min prior to induction of anesthesia reduces the propofol doses necessary to attain the multiple anesthetic endpoints studied without affecting hemodynamics in this otherwise healthy population. The interaction differs for different anesthetic endpoints (e.g., antinociception vs hypnosis) and propofol doses (e.g., ED50 vs ED95).

Adult↗
PubMed2004

Perioperative effects of melatonin and midazolam premedication on sedation, orientation, anxiety scores and psychomotor performance.

BACKGROUND AND OBJECTIVE: To compare the perioperative effects of melatonin and midazolam given in premedication, on sedation, orientation, anxiety scores and psychomotor performance. METHODS: Exogenous administration of melatonin not only facilitates the onset of sleep but also improves its quality. A prospective, randomized, double-blind, placebo-controlled study was performed in 66 patients undergoing laparoscopic cholecystectomy. Patients were given melatonin 5 mg, midazolam 15 mg or placebo, 90 min before anaesthesia, sublingually. Sedation, orientation and anxiety were quantified before; 10, 30, 60 and 90 min after premedication; and 15, 30, 60 and 90 min after admission to the recovery room. Neurocognitive performance was evaluated at these times, using the Trail Making A and B and Word Fluency tests. The differences between the groups were analysed by ANOVA. Two-way comparisons were performed by Scheffé analysis. Sedation and amnesia were analysed by the chi2 test. RESULTS: Patients who received premedication with either melatonin or midazolam had a significant increase in sedation and decrease in anxiety before operation compared with controls. After operation, there was no difference in sedation scores of all groups. Whereas, 30, 60 and 90 min after premedication the melatonin and midazolam groups exhibited a significantly poorer performance in Trail Making A and B tests compared with placebo, there were no significant differences among the groups in terms of neuropsychological performance after the operation. Amnesia was notable only in the midazolam group for one preoperative event. CONCLUSION: Melatonin premedication was associated with preoperative anxiolysis and sedation without postoperative impairment of psychomotor performance.

Adult↗
PubMed2000

[Premedication in maxillofacial surgery under total intravenous anesthesia . Effects of clonidine compared to midazolam on the perioperative course].

OBJECTIVE: The effects of the currently favoured preanaesthetic drugs (benzodiazepines, alpha 2-adrenoceptor agonists) on the perioperative course are inadequately investigated for new ways of performing anaesthesia with recently introduced drugs (e.g. remifentanil). Therefore clonidine and midazolam were used for premedication in maxillo-facial surgery under total intravenous anesthesia, and the perioperative courses were analyzed. METHODS: Thirty patients (ASA 1-2) were included in the present doubleblinded, prospective study. 60-90 minutes preoperatively these patients got an oral premedication with 5 micrograms kg-1 clonidine or 100 micrograms kg-1 midazolam. For anaesthesia a standardized procedure with propofol, remifentanil and rocuronium was performed. After induction of anaesthesia the infusion of remifentanil was regulated by using spectral edge frequency (target-SEF90, 10-13 Hz). The efficiency of the premedication as well as the emergence and recovery were assessed by using established standardized tests. The perioperative stress response was assessed by recording the effects on haemodynamic parameters (NIBP. heart rate. Holter-ECG). RESULTS: Referring to the effects of premedication (sedation, anxiety) there were no differences between the groups. The clonidine group required a lower remifentanil rate in keeping a steady-target-SEF90 (-24%). The time until emergence and recovery was not significantly different. Even the occurrence of PONV, VAS or the postoperative analgetic requirement did not differ between the two groups. However, the incidence of postoperative shivering was significantly higher in the midazolam group. Intraoperatively the values of MAP were quite equal between the groups. However, heart rate was significantly lower in the clonidine group. Postoperatively both MAP as well as heart rate were lower in the clonidine group. Furthermore, in the midazolam group there was a significantly higher cumulative duration of tachycardia (heart rate > 100 min-1; following descripted as medium with 25% and 75%-percentage; clonidine: 29/0/563 sec.: midazolam: 1058/232/3171 sec.). CONCLUSION: After remifentanil supplemented anesthesia there is, especially in the postoperative period, a benefit in using clonidine compared to the premedication with midazolam.

Adjuvants, Anesthesia↗
PubMed2002

[Clonidine vs. Midazolam for premedication - comparison of the anxiolytic effect by using the STAI-test].

OBJECTIVE: Many investigations described a positive effect of clonidine for premedication (reduction of perioperative stress response, analgetic effect, anaesthetic-saving effect, prophylaxis of postoperative shivering). The most important objective in premedication is undisputed anxiolysis. The anxiolytic effect of clonidine is differently discussed. Therefore we investigated the anxiolytic effect of clonidine in comparison to midazolam. METHODS: 50 patients (ASA 1 - 3) were included in the present doubleblinded, prospective study. These patients got an oral premedication with 1 mg flunitrazepam in the evening before surgery and 5 microg/kg(-1) clonidine or 100 microg/kg(-1) midazolam 60 - 90 minutes before surgery. By using Spielbergers State-Trait Anxiety Inventory (STAI-G X1) we registered the degree of state-anxiety before and after premedication. RESULTS: Both clonidine as well as midazolam showed a significant reduction of the state-anxiety over time (p < 0,001). Between the groups there were no differences in the STAI-scores at any time (p > 0,05). The degree of reduction in the state-anxiety were comparable between the groups. CONCLUSION: In addition to the higher up listed effects clonidine showed a anxiolytic effect, which is comparable to midazolam. Therefore clonidine is an interesting alternative to benzodiazepines, which are commonly used drugs for premedication.

Adrenergic alpha-Agonists↗
PubMed1996

[Premedication of coronary risk patients--results of a survey].

AIM: The perioperative risk in patients undergoing coronary artery bypass grafting (CABG) might be influenced by premedication procedures. This study was undertaken to evaluate present premedication regimens in CABG patients in Germany. METHODS: Using a detailed written questionnaire, each of the 58 German centres of cardioanaesthesia were asked to complete it. RESULTS: 37 (64%) of all questionnaires were returned and analysed. All centres used orally administered drugs for premedication in the evening before the operation. Flunitrazepam is the most often administered drug (54%), followed by dipotassium clorazepat (8%), and diazepam (8%). Premedication in the morning on the day of surgery is performed orally in 29 centres (78%), of which 18 centres (49%) prefer flunitrazepam and 6 centres (16%) midazolam as first choice. In contrast, 7 centres (19%) used intramuscularly administered regimens. 5 centres (14%) combined intramuscularly opioids with sedatives for that indication. If anaesthesia was induced late in the morning or in the afternoon, respectively, 11 centres (30%) administered additional benzodiazepines early in the morning. 68% of all centres maintained the administration of chronic treatment with ss-blockers until the morning of the operating day. Chronic treatment with nitrates is continued in 65%, treatment with calcium-channel blockers in 62%. Angiotensin converting enzyme inhibitors are continued in 30%, alpha 2-agonists in 27%, other antihypertensive drugs in 19%, and inotropic glycosids in 11%. 31 of 37 centres (84%) discontinued the administration of acetylsalicylic acid 5 or more days prior to surgery, but 68% tolerate individual exceptions from this principle. CONCLUSIONS: The results of our survey indicate that most of the German cardioanaesthesia centres use oral premedication regimens in patients undergoing coronary revascularisation. Anti-anginal medications, with the exception of anti-platelet agents, were continued until the day of surgery in most of the centres.

Cardiovascular Agents↗
PubMed1995

[Effect of premedication and barbiturate hypnotics on motor evoked potentials induced by magnetic cortex stimulation].

OBJECTIVE: The aim of this study was to investigate the influence of the premedication and the influence of the two barbiturates methohexital and thiopental on magnetically evoked compound muscle action potentials (magnet MEP) in humans. METHODS: 40 Patients (ASA-PS I-II) undergoing lumbar nucleotomy were included in this study after obtaining written informed consent. The study was approved by the local ethical committee. All patients were premedicated with 0.5 mg atropine, 25 mg promethazine and 50 mg pethidine. For induction of anaesthesia patients randomly received methohexital or thiopental by continuous infusion with increasing infusion rates every 15 seconds up to a minimal anaesthesia level in 15 minutes. Transcranial magnetic stimulation was delivered by the magstim 200 magnetic stimulator. Magnetic MEPs were recorded from the surface of the short abductor pollices muscle. MEP-examination was performed preoperatively, after premedication and every two minutes during the induction of anaesthesia. Every other two minutes the patients level of consciousness were assessed and documented. Statistical calculations were performed with the U-test. RESULTS: No statistical differences were found for the mean induction time in the two groups. No statistical difference in amplitude and latency could be observed between the preoperative values and the values measured after premedication. During anaesthesia induction the amplitude decreased in both groups. In 25 of the 40 cases, the MEP disappeared completely before the patients fell asleep. The thiopental group showed a significantly lower incidence of MEP preservation (20%) compared to methohexital (50%). CONCLUSIONS: Premedication with atropine, promethazine and pethidine has no influence on magnetic MEP. Methohexital allows the highest incidence of successful MEP recordings with sufficient anaesthesia. A success rate of only 50% even in cases without motorpathway affection makes the application of magnetic MEP an unreliable tool for intraoperative monitoring.

Adjuvants, Anesthesia↗
PubMedDate not supplied

Ketamine anesthesia with or without diazepam premedication for bone marrow punctures in children with acute lymphoblastic leukemia.

Ketamine is a drug widely used for analgesia and sedation of children for diagnostic and therapeutic procedures. The authors investigated in a randomized controlled clinical trial if diazepam premedication would have a beneficial effect on side effects related to ketamine anesthesia for bone marrow punctures (BMPs) in children with acute lymphoblastic leukemia (ALL). Sixteen children 4 years or older at the time of BMP were eligible. The first 2 BMPs after complete remission was obtained were studied. BMPs were performed under ketamine anesthesia (1.0-1.5 mg/kg i.v.), as usual. Patients were randomized to receive 1 h before the first BMP blinded, either diazepam or placebo orally and before the second BMP the other way round. Blood pressure, heart rate, and oxygen saturation were monitored, and patients were observed for signs of anxiety, pain, and other side effects. The patients were interviewed after each BMP and asked for their preference 1 week after the second BMP. Ketamine anesthesia appeared as safe and effective after diazepam premedication as after placebo premedication. From the interviews and questionnaires, it was clear that half of the children preferred diazepam premedication because of less awful dreaming and more gradual falling asleep and waking up. Diazepam premedication may be useful for selected children with ALL receiving ketamine anesthesia for BMPs.

Adjuvants, Anesthesia↗
PubMed1995

Effects of propofol and thiopentone, and benzodiazepine premedication on heart rate variability measured by spectral analysis.

We studied the effects of temazepam premedication and induction of anaesthesia with thiopentone or propofol on the heart rate power spectrum in 47 patients undergoing elective minor surgery. Eighteen patients received temazepam 20 mg orally as premedication. There was a significant reduction in high frequency power and total power, and an increase in the ratio of low to high frequency power after induction of anaesthesia with either propofol or thiopentone. Patients who had received temazepam premedication had significantly greater low frequency, high frequency and total power than those who were not premedicated. There was no significant difference between premedicated and unpremedicated patients in the ratio of low to ventilatory frequency power.

Adult↗
PubMed1997

Premedication in the United States: a status report.

We undertook a mailing survey study to assess the current practice of sedative premedication in anesthesia. A total of 5396 questionnaires were mailed to randomly selected physician members of the American Society of Anesthesiologists. Forty-six percent (n = 2421) of those sampled returned the questionnaire after two mailings. The reported rate of sedative premedication in the United States varied widely among age groups and geographical locations. Premedicant sedative drugs were least often used with children younger than age 3 years and most often used with adults less than 65 years of age (25% vs 75%, P = 0.001). Midazolam was the most frequently used premedicant both in adults and children (> 75%). When analyzed based on geographical locations, use of sedative premedicants among adults was least frequent in the Northeast region and most frequent in the Southeast region (50% vs 90%, P = 0.001). When the frequency of premedication was examined against health maintenance organization (HMO) penetration (i.e., HMO enrollment by total population) in the various geographical regions, correlation coefficients (r) ranged from -0.96 to -0.54. Multivariable analysis revealed that HMO penetration is an independent predictor for the use of premedication in adults and children. The marked variation among geographical areas in premedicant usage patterns underscores the lack of consensus among anesthesiologists about the need for premedication. The data suggest that HMO participation may affect delivery of this component of anesthetic care.

Adolescent↗
PubMed2000

The combined effect of age and premedication on the propofol requirements for induction by target-controlled infusion.

In this prospective study, we evaluated the combined influence of age and premedication on propofol requirements for the induction of anesthesia and their hemodynamic effects using a target-controlled infusion. We studied 180 patients separated into three age groups: 20-39 yr, 40-59 yr, and more than 59 yr. In each age group, patients were randomly allocated to receive either no premedication (n = 20), fentanyl (2 microg/kg) (n = 20), or midazolam (0.03 mg/kg) plus fentanyl (2 microg/kg) (n = 20). The concentration of propofol targeted for the induction was 5 microg/mL, to be reached in 2 min. The dose, time, and predicted plasma concentration of propofol at hypnosis were measured. Baseline and postinduction heart rate and arterial blood pressure were registered. Computer simulation was used to calculate the effect site propofol concentration at hypnosis. The concentration of propofol, effect site propofol concentration, time, and induction dose and their hemodynamic effect were significantly different among groups with respect to age and premedication. The combined effect of the two factors was additive, but without significant interaction. The propofol requirements were significantly less in the midazolam-fentanyl groups, regardless of age, and among the premedicated patients older than 60 yr compared with the other age groups. We conclude that the combined effect of age and premedication on the requirements of propofol for the induction of anesthesia should be considered when the concentration is targeted with a target-controlled infusion system.

Adjuvants, Anesthesia↗
PubMed2000

The comparative dose-response effects of melatonin and midazolam for premedication of adult patients: a double-blinded, placebo-controlled study.

UNLABELLED: We designed this prospective, randomized, double-blinded, placebo-controlled study to compare the perioperative effects of different doses of melatonin and midazolam. Doses of 0.05, 0.1, or 0. 2 mg/kg sublingual midazolam or melatonin or placebo were given to 84 women, approximately 100 min before a standard anesthetic. Sedation, anxiety, and orientation were quantified before, 10, 30, 60, and 90 min after premedication, and 15, 30, 60, and 90 min after admission to the recovery room. Psychomotor performance of the patient was evaluated at these times also, by using the digit-symbol substitution test and Trieger dot test. Patients who received premedication with either midazolam or melatonin had a significant decrease in anxiety levels and increase in levels of sedation preoperatively compared with control subjects. Patients in the three midazolam groups experienced significant psychomotor impairment in the preoperative period compared with melatonin or placebo. After operation, patients who received 0.2 mg/kg midazolam premedication had increased levels of sedation at 90 min compared with 0.05 and 0. 1 mg/kg melatonin groups. In addition, patients in the three midazolam groups had impairment of performance on the digit-symbol substitution test at all times compared with the 0.05 mg/kg melatonin group. Premedication with 0.05 mg/kg melatonin was associated with preoperative anxiolysis and sedation without impairment of cognitive and psychomotor skills or affecting the quality of recovery. IMPLICATIONS: Premedication with 0.05 mg/kg melatonin was associated with preoperative anxiolysis and sedation without impairment of cognitive and psychomotor skills or affecting the quality of recovery.

Adolescent↗
PubMed2000

Oral clonidine premedication does not change efficacy of simulated epidural test dose in sevoflurane-anesthetized children.

BACKGROUND: Caudal epidural anesthesia is often used as an adjunct to general anesthesia and for postoperative pain relief in children. In anesthetized children, epinephrine and isoproterenol are reliable indicators to detect accidental intravascular injection of a test dose. Oral clonidine, a useful premedicant in pediatric anesthesia, modifies hemodynamic responses to sympathomimetics, including catecholamines. The aim of the current study was to determine whether oral clonidine premedication alters the efficacy of a simulated intravascular test dose containing epinephrine or isoproterenol in sevoflurane-anesthetized children. METHODS: One hundred twenty children (aged 1-7 yr) were randomly divided into six groups; control-saline, control-epinephrine, control-isoproterenol, clonidine-saline, clonidine-epinephrine, and clonidine-isoproterenol. The three clonidine groups received oral clonidine 4 microg/kg [DOSAGE ERROR CORRECTED] as premedication, whereas the three control groups did not receive any premedication. Anesthesia was maintained with sevoflurane at a level of 1.2 minimum alveolar concentration. After hemodynamics were stable, 0.1 ml/kg of 1% lidocaine containing epinephrine 0.5 mg/kg or isoproterenol 75 ng/kg was intravenously given to the two epinephrine or isoproterenol groups, respectively, to simulate intravascular injection of a test dose. The saline groups received saline alone instead of the test dose. Heart rate, blood pressure, and T-wave amplitude of electrocardiogram were recorded before and after administration of study drugs for subsequent analysis. RESULTS: Test solution containing epinephrine increased heart rate, systolic blood pressure, and T-wave amplitude. Oral clonidine had no effect on elevation of these variables in response to epinephrine. The isoproterenol-containing test dose produced a prominent increase in heart rate and a less pronounced increase in systolic blood pressure and T-wave amplitude. Oral clonidine also failed to modify isoproterenol-induced hemodynamic and T-wave changes. Calculated sensitivity and specificity of epinephrine or isoproterenol were all 100% based on a new heart rate criterion (positive if >/= 10 beats/min) and were unaltered by oral clonidine premedication. CONCLUSIONS: Epinephrine or isoproterenol is a reliable marker to detect accidental intravascular injection of a test dose with 100% sensitivity and specificity based on a new heart rate criterion in sevoflurane-anesthetized children. These data suggest that oral clonidine premedication does not alter the efficacy of a simulated epidural test dose containing epinephrine or isoproterenol.

Administration, Oral↗
PubMed1982

The predictive value of the premedical grade-point average.

The study reported here assessed the relative utility of premedical grade-point average (GPA) in distinguishing among prospective medical students and in predicting the medical school performance of accepted applicants. Students from each of two medical classes were grouped into one of four categories depending on the "selectivity" rating of their premedical, undergraduate institution. Group differences were assessed according to premedical GPAs, Science subtest scores of the Medical College Admission Test, medical school course work, and scores on the Part I and Part II examinations of the National Board of Medical Examiners. Results indicated that although the groups differed significantly on premedical GPA (with mean scores from the less competitive undergraduate colleges exceeding those of the most selective schools), on all other dependent measures no significant differences resulted. It was concluded that "raw" premedical GPA is susceptible to a number of extraneous sources of variance that, unless identified and eliminated, negate its effectiveness in assessing individual differences in past academic achievement and in predicting future medical school performance.

Achievement↗
PubMed1986

Premedication with oral and rectal diazepam.

It has been postulated that esophageal retention of diazepam tablets is a problem of clinical significance, and that rectal administration is an advantageous alternative. To test this hypothesis, 100 patients were randomly allocated to premedication with either 15 mg diazepam orally or 10 mg diazepam as a rectal solution. A double dummy technique was used. A sedative effect was seen in 23 (50%) of the patients premedicated by mouth (O-group), but only in eight (20%) of those premedicated rectally (R-group) (P less than 0.05). Four patients (9%) in the O-group and seven (18%) in the R-group were unacceptably anxious before induction (n.s.). The plasma concentrations in the tablet group were nearly twice the concentrations found in the rectal-solution group, but no correlation between premedication effect and plasma concentration was found. Timing of premedication was very inaccurate, and this favored oral administration because of a more prolonged effect. No evidence of persistent esophageal retention was found.

Administration, Oral↗