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PubMed1985

[Influence of various premedication agents, inhalation anesthetics and adjuvants on anesthesia with an opioid, alfentanyl].

Alfentanil mask anaesthesia was performed in 63 patients undergoing termination of pregnancy or curettage. Three different types of premedication were used: a) pethidine, promethazine, and atropine; b) diazepam and atropine; c) atropine. The patients were ventilated either with nitrous oxide and oxygen or with halothane and oxygen. Halothane reduced the frequency of muscular rigidity (32%; N2O 75%), postoperative sickness, and vomiting (23%; N2O 50%). On the other hand, patients regained consciousness earlier if nitrous oxide was used. Premedication a) also reduced the frequency of nausea and emesis (21%; other premedications 63%).-Alfentanil intubation anaesthesia was performed in 52 patients undergoing laparoscopy. Premedication and inhalation anaesthetic varied as described above in the group with mask anaesthesia. Muscular rigidity did not occur, and nausea/emesis were rare events (8%). Halothane prolonged the recovery phase of consciousness and respiration. Premedication a) also resulted in respiratory depression.

Abortion, Induced↗
PubMed1984

[High-dose thalamonal-rohypnol for premedication. A randomized double-blind study].

The combination of fentanyl and droperidol, Innovar, was compared to flunitrazepam (1-2 mg) in a higher dosage (2.5-5 ml) for i.m. premedication. We measured psychological (ESB) and physiological (blood pressure, heart rate, p.cortisol) stress parameters before and after premedication. Side effects were registered. The day after surgery the patients were asked about the quality of premedication. Flunitrazepam reduced anxiety; Innovar did not. After Innovar the feeling of weakness increased significantly compared to flunitrazepam. Two patients panicked and refused operation. Other severe side effects were not observed. There were slight advantages for flunitrazepam on physiological stress. Patients were more satisfied with flunitrazepam than with Innovar premedication. The results show that Innovar also in a higher dosage cannot be recommended for premedication.

Adolescent↗
PubMed1984

Propranolol premedication blunts stress response to nitroprusside hypotension.

Hypotension was induced in sixteen patients with nitroprusside during anesthesia for surgical correction of cerebral aneurysms. Eight patients were premedicated with propranolol (180 mg orally) for one day and the other eight were not. Before the start of anesthesia, the untreated patients had a mean arterial pressure of 102 +/- 3 mm Hg, a heart rate of 76 +/- 2 beats/min, and plasma epinephrine and norepinephrine concentrations of 114 +/- 21 and 258 +/- 34 pg/ml, respectively. The propranolol-premedicated patients came to the operating room in a significantly different clinical state with a mean arterial pressure of 92 +/- 3 mm Hg, a heart rate of 71 +/- 2 beats/min, and plasma epinephrine and norepinephrine concentrations of 76 +/- 28 and 144 +/- 28 pg/ml. During induced hypotension, plasma epinephrine and norepinephrine concentrations increased significantly in both groups (454 +/- 42 and 730 +/- 58 pg/ml in the untreated patients, 160 +/- 48 and 419 +/- 67 pg/ml in the propranolol premedicated patients), but the increase in catecholamines was significantly greater in the untreated patients. Thirty minutes after nitroprusside was discontinued, epinephrine and norepinephrine concentrations were higher than in the awake state in untreated patients and were associated with rebound hypertension and tachycardia. In contrast, in propranolol-premedicated patients, plasma epinephrine and norepinephrine concentrations decreased towards the preanesthesia values, mean arterial pressure gradually returned to the prehypotension level, and heart rate remained unchanged. This study thus demonstrates that propranolol premedication attenuates the release of catecholamines in response to nitroprusside-induced hypotension.

Adult↗
PubMed1985

The role of H2 receptor antagonist premedication in pregnant day care patients.

In a randomised study of 132 pregnant outpatients, the effect on gastric volume and pH of oral premedication with a single dose of an H2 antagonist was investigated. Either cimetidine 400 mg (n = 33), or ranitidine 150 mg (n = 33), were given 90 to 120 minutes before scheduled surgery. Mean pH was significantly higher in cimetidine (5.0) and ranitidine (5.2) groups, and mean volume was significantly lower in cimetidine (13.2 ml) and ranitidine (11.1 ml) groups compared with 66 untreated patients (pH 1.6, volume 22.1 ml). A gastric pH less than or equal to 2.5 was found in 97 per cent of unpremedicated patients and 35 per cent of these patients also had a gastric volume greater than or equal to 25 ml. Eighty-three per cent of patients received their premedication within 75-200 minutes of surgery. Patients premedicated within that range had a significantly lower incidence of either a gastric pH less than or equal to 2.5 or a volume greater than or equal to 25 ml (p less than 0.01). Both cimetidine and ranitidine significantly reduced the number of patients with these risk factors. Four patients, however, in the cimetidine group had both a pH less than or equal to 2.5 and a volume greater than or equal to 25 ml. Pharmacological manipulation of the gastric environment does not prevent aspiration and clearly cannot be substituted for careful airway management and vigilance on the part of the anaesthetist. However, premedication of pregnant outpatients with a single, oral dose of an H2 antagonist is a simple, inexpensive, safe and effective way of reducing the risk of a severe aspiration pneumonitis.

Abortion, Therapeutic↗
PubMed2000

Diclofenac premedication but not intra-articular ropivacaine alleviates pain following day-case knee arthroscopy.

PURPOSE: To compare the postoperative analgesic effects of 50 mg diclofenac p.o. before surgery and intra-articular ropivacaine injected after diagnostic day-case knee arthroscopy performed under spinal anesthesia. METHODS: In a randomized, double-blind investigation, 200 ASA physical status 1-2 outpatients, age 18-60 yr, received either 50 mg diclofenac p.o. or placebo one hour before operation (100 patients per group), and intraarticular injections of either 20 ml of ropivacaine 0.5% or 20 ml of saline 0.9% (50 patients in each premedication groups). Patients received 50 mg diclofenac p.o. prn and, if needed, 0.1 mg x kg(-1) oxycodone im for postoperative pain relief. Patients were discharged home with a supply of 50 mg diclofenac tablets and were given a sheet of paper with knee pain VAS scales and a questionnaire of analgesics taken. Patients rated their VAS scores eight hours after surgery and in the moming and at the end of the first and the second postoperative days, respectively. RESULTS: The only statistically significant difference was found when the diclofenac groups were combined and compared with the combined placebo premedication groups. The VAS scores of knee pain at eight hours after the operation were 19+/-22 in the two diclofenac premedication groups and 32+/-28 in the two placebo groups (P = 0.001). CONCLUSIONS: Diclofenac premedication p.o. reduced the VAS scores at eight hours postoperatively while intra-articular ropivacaine did not.

Administration, Oral↗
PubMed2006

Comparison of glucagon and scopolamine butylbromide as premedication for colonoscopy in unsedated patients.

PURPOSE: Premedication with glucagon or hyoscyamine is reported to be effective in reducing colonic spasm. However, these drugs can be associated with unfavorable events. This prospective study was designed to compare the effects of premedication with glucagon with those of scopolamine butylbromide on cardiopulmonary parameters, intubation time, and patient discomfort in unsedated patients undergoing diagnostic colonoscopy. METHODS: One hundred consecutive adult patients (65 males) undergoing colonoscopy without sedation were randomized to receive 1 mg of glucagon (n = 50) or 20 mg of scopolamine butylbromide (n = 50), intramuscularly. Physiologic changes, including systolic blood pressure, heart rate, and oxygen saturation, were monitored before colonoscope insertion and at three-minute intervals during colonoscopy. The percentages of completed procedure and time to cecal intubation were recorded. Patients were asked to rate pain by using a five-point pain score (0 = no pain; 4 = severe pain). RESULTS: The percentages of completed procedure (96 vs. 98 percent), time to cecal intubation (16.3 vs. 14.5 minutes), and pain score (1.7 vs. 1.5) did not differ significantly between two groups. An increase in heart rate of more than ten beats per minute from baseline during colonoscopy occurred significantly more often in scopolamine group (44 percent of 50 patients) than in the glucagon group (12 percent of 50 patients; P = 0.0004). There were no significant differences between the two study groups with regard to changes in systolic blood pressure and decrease in oxygen saturation during colonoscopy. CONCLUSIONS: Premedication with 1 mg of glucagon facilitates favorable examination with respect to physiologic changes compared with 20 mg of scopolamine. These features favor glucagon as the preferred premedication for patients undergoing colonoscopy.

Aged↗
PubMed1988

Postoperative orthopaedic pain--the effect of opiate premedication and local anaesthetic blocks.

The postoperative analgesic effect of opiate premedication and local anaesthetic blocks was studied in 929 patients having orthopaedic surgery. The median time to first request for postoperative analgesia was less than 2 h when neither opiate premedication nor block was used; opiate premedication increased the time significantly to more than 5 h; local anaesthetic block produced a further significant increase to 8 h and opiate premedication used with local anaesthetic block extended the median time further to more than 9 h. Women requested analgesia significantly earlier than men, independent of treatment. Age had no significant effect. Prolonging the time before more pain relief is required may be worthwhile for both patients and staff.

Adolescent↗
PubMed1992

Does opiate premedication influence postoperative analgesia? A prospective study.

The influence of opiate premedication on analgesic requirements postoperatively was investigated. Out of 98 patients with a lumbar disc prolapse 50 were premedicated with flunitrazepam orally, 48 with pethidine and triflupromazine intramuscularly. The operations were performed under inhalational anaesthesia. The average time up to the first demand for an analgesic was longer following opiate premedication (351 vs. 219 min). Only 45.8% of the patients treated with opiates demanded analgesics postoperatively, compared to 80.0% of those who had a benzodiazepine premedication (P less than 0.01). These clinical data confirm the experimental evidence that pretreatment with opiates diminishes the sustained hyperexcitation of the central nervous system caused by peripheral lesions.

Analgesia↗
PubMed2006

Comparison of buccal and intramuscular dexmedetomidine premedication for arthroscopic knee surgery.

STUDY OBJECTIVE: To compare the sedative, anxiolytic, analgesic, hemodynamic, and respiratory effects of buccal dexmedetomidine with intramuscular (IM) dexmedetomidine for premedication in patients undergoing arthroscopic knee surgery during spinal anesthesia. DESIGN: Randomized, placebo-controlled trial. SETTING: University medical center. PATIENTS: 75 ASA physical status I and II patients undergoing arthroscopic knee surgery with spinal anesthesia. INTERVENTIONS: Patients were randomized to one of three groups for premedication: group B, buccal dexmedetomidine 2.5 microg kg(-1); group IM, IM dexmedetomidine 2.5 microg kg(-1); and group P, buccal 0.9% and NaCl 2 mL. MEASUREMENTS: Noninvasive blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation were recorded. Sedation and anxiety levels were consecutively assessed with Ramsay sedation scores and Visual Analog Scale (VAS) scores of anxiety before premedication, before spinal anesthesia, during surgery, and at the end of surgery. Two, 4, and 8 hours after surgery, sedation levels, postoperative VAS pain scores, and consumption of analgesics (diclofenac sodium) were recorded. MAIN RESULTS: Before spinal anesthesia, during surgery, and at the end of surgery, sedation and anxiety scores of the patients receiving buccal or IM dexmedetomidine were, respectively, higher and lower than in group P. Patients receiving buccal dexmedetomidine (group B) had lower requirement of diclofenac sodium than group P and lower pain scores than groups P and IM. Mild hypotension and bradycardia were observed in the buccal and IM dexmedetomidine patients. CONCLUSIONS: Buccal dexmedetomidine for premedication in arthroscopic knee surgery provided equal levels of sedation and anxiolysis, and more evident analgesia compared with IM dexmedetomidine.

Administration, Buccal↗
PubMed1998

Midazolam premedication improves tolerance of transesophageal echocardiography.

Patient premedication for transesophageal echocardiography (TEE) is still under debate, especially the use of sedatives. We performed a double-blind, placebo-controlled study to clarify the efficacy of low-dose intravenous midazolam as premedication for TEE. Placebo or midazolam (< or =50 kg, 2.0 mg intravenously; 50 to 80 kg, 2.5 mg; and > or =80 kg, 3.0 mg intravenously) was given in addition to topical anesthesia to 200 consecutive in- and outpatients. Blood pressure, heart rate, and oxygen saturation were monitored. Patients were interviewed immediately, and 2 to 10 days after TEE. Sixteen patients received an additional dose of midazolam, and in 12 follow-up was incomplete. Patients taking midazolam reported less gag reflex at probe introduction and during TEE, as did the examiners (p < 0.05 to 0.0001). Probe manipulations were found to produce less discomfort after midazolam administration (p < 0.005). Midazolam patients experienced less dyspnea (p < 0.01) despite a minimal decrease in oxygen saturation of 2% (p < 0.0001). The following day patients taking midazolam reported less sore throats, and painful swallowing was less frequent (p < 0.01 to 0.001). Systolic blood pressure decreased slightly in the midazolam group (132 +/- 24 to 121 +/- 20 mm Hg, p < 0.0001). The rate of minor complications showed no difference. Thus, TEE probe introduction and manipulation was tolerated better after low-dose midazolam premedication, and patients experienced less pharyngeal discomfort the day after. Midazolam was well tolerated and the complication rate did not increase. Thus low-dose, short-acting benzodiazepine premedication improves patient comfort during and after TEE and generous use can be recommended.

Anesthetics, Intravenous↗
PubMed1998

Effectiveness of premedication with pronase for improving visibility during gastroendoscopy: a randomized controlled trial.

BACKGROUND: Minute early gastric cancers can be removed with endoscopic mucosal resection techniques. However, early detection of these minute cancers with endoscopy is still difficult. For this purpose, use of a dye is helpful. To increase visibility further, gastric mucus should be removed before endoscopic examination. In this study, the effectiveness of premedication with pronase for improving visibility during gastroendoscopy was investigated. METHODS: From January through July 1996, outpatients scheduled for gastroendoscopy were randomly assigned to oral premedication with the antifoam agent dimethylpolysiloxane alone (n=34), with dimethylpolysiloxane plus sodium bicarbonate (n=32), or with dimethylpolysiloxane, sodium bicarbonate, and pronase (n=34). All were given about 10 minutes before the start of endoscopy. After inserting the endoscope, the endoscopist gave visibility scores at conventional endoscopy and after methylene blue spraying. RESULTS: Premedication with pronase significantly improved visibility before and after methylene blue spraying as compared with the two other groups pretreated without pronase. Pronase also significantly shortened the times for chromoendoscopic examination. Pronase had no significant effect on the culture of Helicobacter pylori. CONCLUSION: Premedication with pronase improved endoscopic visualization during conventional endoscopy and chromoendoscopy. Its routine use at gastroendoscopy is therefore recommended.

Adult↗
PubMed1998

Oral clonidine premedication does not prolong analgesia after herniorrhaphy under subarachnoid anesthesia.

STUDY OBJECTIVE: To determine the effect of oral clonidine premedication on duration of sensory and motor block, postoperative analgesia, hemodynamic stability, sedation, and respiratory parameters after subarachnoid anesthesia (SA). DESIGN: Prospective, double blind, randomized, placebo-controlled study. PATIENTS: 80 ASA physical status I patients were randomized into four equal groups to receive oral premedication with either clonidine 5 mcg/kg (C5), clonidine 2.5 mcg/kg (C2.5), diazepam 100 mcg/kg (D), or placebo (PL). MEASUREMENTS AND MAIN RESULTS: The following parameters were measured: duration of motor and sensory block, requirement for postoperative analgesia; systolic (SBP), diastolic (DBP), and mean (MBP) blood pressures; heart rate (HR); sedation and anxiolysis scales; respiratory rate (RR); oxyhemoglobin saturation; and complications. (1) The duration of sensory and motor block did not differ significantly among the groups. (2) There were no differences in the time to first request for analgesia and in requirements for analgesia in the first 24 postoperative hours. (3) Clonidine premedication before SA did not produce episodes of significant hypotension. HR did not differ significantly among the groups. Baseline SBP was significantly higher (p = 0.037) in group PL than in groups C5 and C2.5. Three minutes after SA significant decrease in the following parameters was observed: SBP in group PL compared with the other three groups (p = 0.004), DBP in group PL vs. groups C5 and C2.5 (p = 0.002), and MBP in group PL vs. groups C5 and C2.5 (p = 0.003). (4) Sedation and anxiolysis were more pronounced (p = 0.0001) in groups C5 and C2.5 than in groups D and PL and in group C5 than in group C2.5. (5) RR was significantly lower (p = 0.0024) in group C5 than in groups D and PL. (6) Complications consisted of three episodes (15%) of bradycardia in the C5 group and two of bradypnea (10%) in the same group. CONCLUSIONS: In healthy patients, premedication with oral clonidine provided useful sedation and anxiolysis and stable hemodynamics, without prolongation of sensory and motor block. Side effects occurred only with clonidine 5 mcg/kg. Thus, a dose of 2.5 mcg/kg is recommended.

Administration, Oral↗
PubMed2001

Oral midazolam premedication for day case breast surgery, a randomised prospective double-blind placebo-controlled study.

We conducted a randomised prospective double-blind placebo-controlled study to assess the efficacy of oral midazolam premedication in 50 ASA I and II female patients scheduled to undergo day case breast surgery. Anxiety was assessed using 100-mm visual analogue scales (VAS) and The State-Trait Anxiety Inventory (STAI) psychometric questionnaire. Midazolam premedication did not significantly reduce either VAS or STAI score, although heart rate and systolic arterial pressure immediately before induction of anaesthesia were significantly lower in patients who received midazolam (p = 0.006 and 0.039, respectively). Induction of anaesthesia was achieved with a lower dose of propofol (p = 0.0009) and excellent (Grade I) conditions for insertion of a laryngeal mask airway were achieved more often after midazolam premedication (p = 0.038). Arterial desaturation during induction of anaesthesia and insertion of a laryngeal mask airway occurred more often in patients who received placebo (p = 0.022). There was a good correlation between VAS and STAI used to assess the anxiolytic effects of premedication. (Spearman coefficient 0.58, p < 0.0001).

Adolescent↗
PubMed1981

Influence of an antiarrhythmic premedication on the development of premature ventricular contractions during fiberoptic gastroduodenoscopy.

Heart rate, blood pressure and ECG changes during fiberoptic gastroscopy were examined in 128 patients, 60 of whom had been orally premedicated with Mexiletine. 55% of the non-premedicated patients developed occasional, and 22% of this group developed accumulated or frequent, premature ventricular contractions. In the patient group with antiarrhythmic premedication, the respective figures were 25% and 8%, and in this group patients with a normal ECG developed premature ventricular contractions less frequently than patients with pathological changes in the ST segment. The antiarrhythmic premedication had no influence on pulse or blood pressure.

Arrhythmias, Cardiac↗
PubMed2005

Tramadol premedication in operative extraction of the mandibular third molar: a placebo-controlled crossover study.

Anxiolytic drugs are widely used for premedication in oral surgery. Since anxiety is usually associated with the fear of pain, we tested the effects of the analgesic tramadol in premedication before operative extraction of the mandibular third molar under local anesthesia. In a double-blind crossover study, 20 patients were randomized to receive 100 mg oral tramadol or placebo 1 h before operation. Anxiety, nausea, dryness of the mouth, pain and discomfort were recorded before administration of the drug, immediately before and after operation, and 0.5, 1, and 2 h postoperatively using ungraded 0-100 mm VAS scales. Blood pressure and heart rate were measured at the same times; vigilance was tested using the Maddox Wing Test and sensorimotor performance using the Trieger Dot Test; hemoglobin oxygen saturation (SpO2) was measured using a pulse oximeter. In addition, SpO2 and heart rate were recorded continuously in nine patients using a pulse oximeter connected to a computer. The surgeon assessed the quality of operating conditions on the VAS scale. Tramadol delayed and decreased the need of analgesics on the day of operation (p < 0.05). The operating conditions were better in patients on tramadol premedication than in those on placebo during the first operation (p < 0.05), but no differences were seen in patient well-being between treatments. The second operation was less stressful than the first. Tramadol is recommended only with special indications for premedication of patients undergoing third molar extraction under local anesthesia.

Adult↗
PubMed2007

Premedication with controlled-release oxycodone does not improve management of postoperative pain after day-case gynaecological laparoscopic surgery.

BACKGROUND: Controlled-release (CR) oxycodone provides an option for the prevention of postoperative pain. We designed this randomized double-blinded placebo controlled study to evaluate the control of pain after premedication with CR oxycodone 15 mg in addition to ibuprofen 800 mg orally in day-case gynaecological laparoscopic surgery. METHODS: Sixty consenting patients were anaesthetized in a standardized fashion. Postoperative analgesia was provided by ibuprofen 800 mg twice a day in combination with fentanyl i.v. in the recovery room and normal-release (NR) oxycodone orally after the recovery room. The visual analogue scale (VAS) scores for pain and side-effects, and the amounts of postoperative analgesics were recorded for 24 h after discharge from the hospital. After a statistical analysis of the original study, we extended the study to investigate another 10 patients, who received CR oxycodone 15 mg orally in an open-labelled fashion 60 min before surgery. The plasma concentrations of oxycodone were measured from samples drawn before and 2, 4, 6 and 8 h after premedication. RESULTS: The amounts of fentanyl [100 microg (0-330) in the CR oxycodone group; 125 microg (0-330) in the placebo group], NR oxycodone, or the VAS scores for pain during the first 24 h after the discharge from the hospital did not differ after the premedication with CR oxycodone or placebo. In the extension study group, the peak plasma concentration (C(max)) of oxycodone was 10.0 (4.6-14.7) ng ml(-1), indicating possibly a sub-therapeutic level. CONCLUSION: Oral premedication with CR oxycodone did not improve management of postoperative pain after day-case gynaecological laparoscopic surgery.

Adult↗
PubMed1997

Oral clonidine premedication does not alter the efficacy of simulated intravenous test dose containing low dose epinephrine in awake volunteers.

BACKGROUND: Clonidine premedication modifies the hemodynamic responses to sympathomimetics. The present study was designed to test whether clonidine altered the response to a small intravenous dose of epinephrine, such as that which might be used in an epidural test dose. METHODS: In 18 healthy volunteers, four series of determinations were performed in random order and were separated by a minimum 72 h: (1) no premedication followed by intravenous saline 3 ml, (2) no premedication followed by intravenous test dose containing 3 ml of 1.5% lidocaine + 15 microg epinephrine, (3) oral clonidine (5 microg/kg 1.5 h before hemodynamic determinations) followed by intravenous saline, and (4) oral clonidine followed by intravenous epinephrine-containing test dose. Systolic blood pressure (SBP) and heart rate (HR) were measured continuously, and symptoms associated with central nervous system toxicity were noted. RESULTS: After the test dose injections, HR and SBP increased with or without clonidine premedication. The 95% confidence intervals for the maximum HR increases with and without clonidine were 49-61 and 44-54 beats/min, respectively, indicating that one could not be absolutely certain that everyone would develop a positive HR response. The HR increase was > or = 20 beats/min in 18 of 18 volunteers given epinephrine with or without clonidine and in 0 of 18 volunteers given saline. Calculated sensitivities, specificities, and positive and negative predictive values were all 100% based on the conventional HR criterion and were unaltered by clonidine. Subjective symptoms were not affected by clonidine. CONCLUSIONS: Oral clonidine does not alter the efficacy of epinephrine-containing test doses used for detecting intravascular injection.

Administration, Oral↗
PubMed1997

Oral clonidine premedication reduces minimum alveolar concentration of sevoflurane for tracheal intubation in children.

BACKGROUND: Sevoflurane is a useful anesthetic for inhalational induction in children because of its low solubility in blood and relatively nonpungent odor. Clonidine has sedative and anxiolytic properties and reduces the requirement for inhalation agents. Nitrous oxide (N2O) also decreases the requirement of inhaled anesthetics, but the effect is variable. The minimum alveolar concentration for tracheal intubation (MAC(TI)) of sevoflurane was assessed with and without N2O and clonidine premedication. METHODS: Seventy-two patients, aged 3-11 yr, were assigned to one of six groups (n = 12 each). They received one of three preanesthetic medications (two groups for each premedication): placebo (control), 2 microg/kg oral clonidine or 4 microg/kg oral clonidine. In one group of each premedication, anesthesia was induced with sevoflurane in oxygen; in the other group, anesthesia was induced with sevoflurane in the presence of 60% N2O. Each concentration of sevoflurane at which tracheal intubation was attempted was predetermined according to Dixon's up-and-down method and held constant for at least 20 min before the trial RESULTS: The MAC(TI) of sevoflurane in the absence of N2O (mean +/- SEM) was 3.2 +/- 0.2%, 2.5 +/- 0.1%, and 1.9 +/- 0.2% in the control, 2-microg/kg clonidine, and 4-microg/kg clonidine groups, respectively. Nitrous oxide (60%) decreased the MAC(TI) of sevoflurane by 26%, 24%, and 27% in the control, 2-microg/kg clonidine, and 4-microg/kg clonidine groups. CONCLUSIONS: Oral clonidine premedication decreased the MAC(TI) of sevoflurane. Nitrous oxide also decreased the MAC(TI). The combination of clonidine and N2O lessened the MAC(TI) of sevoflurane more than did either drug alone.

Administration, Oral↗