Intravenous sedation for cataract surgery

Fifty-five unpremedicated outpatients scheduled for cataract surgery were randomly allocated to receive either a fixed dose of nalbuphine and methohexitone or fentanyl and diazepam administered in a dose adjusted to produce the required sedative effect. Statistical analysis revealed no difference between groups with regard to immediate side effects, intra-ocular pressure or postoperative nausea or vomiting. Recovery time from administration of the sedative until compliance with simple commands was significantly longer in the nalbuphine/morphine group (89 vs 196 seconds) but this was not felt to be of clinical importance. This combination was better in terms of sedation at the time of insertion of the nerve blocks, lack of recall of insertion of the nerve block, incidence of intra-operative complications, surgeon's assessment of operating conditions and patient acceptability. This fixed dose by weight drug combination for intravenous sedation should be applied widely.     

Intravenous sedation in dentistry and oral surgery

IV administration is the most precise and effective means of sedating a patient. Its desired effect is a comfortable and cooperative patient whose pain is alleviated by regional local anesthesia. It requires a patient who understands the difference between being lightly sedated and unconscious. Its primary purpose is to diminish anxiety and apprehension rather than to obtund protective reflexes. At all times, the patient should remain conscious and appropriately responsive to questions or commands. This state can be readily achieved in most patients by carefully titrating a single drug such as diazepam or midazolam to effect. The use of multiple drugs is to be discouraged, since it generally increases the level of sedation and the number of complications. Dosing should be individualized rather than averaged or arbitrary. The end point of titration is the patient's verbal acknowledgement of feeling more relaxed and the physical evidence of such relaxation. The "Verrill sign" indicates a level of deep sedation--too deep for most cases of conscious sedation in the office setting. I strongly oppose the routine use of narcotics for office sedation. Monitoring of vital signs before, during, and after surgery ensures the safety of the consciously sedated patient. The use of a pulse oximeter is an evolving standard in general anesthesia and may eventually prove important for patients receiving conscious sedation in the office setting.     

Comparison of two techniques for sedation in dental surgery

Forty-eight patients were randomised to receive sedation of outpatient dental surgery with midazolam. Sedation was given using the Verrill technique (24 patients) and the Glasgow Dental Hospital technique (24 patients). The differences in recovery and patient acceptability were assessed. There was no statistical difference in mean recovery times between the two groups. Memory function was examined using the Warrington memory test. Fewer patients in the Verrill group recalled the injection of local anaesthetic but they demonstrated memory defects 4 hours after sedation for words and 3 hours for faces. The Glasgow Dental Hospital group demonstrated memory defects for words up to 2 hours following sedation, but not for faces at any time. Thirty-eight patients would have dental surgery again with similar sedation. The dental surgeon found conditions for surgery inadequate in two patients. In view of the shorter duration of amnesia we recommend the Glasgow Dental Hospital technique.     

Intravenous sedation in 200 geriatric patients undergoing office oral surgery.

Two hundred geriatric patients ranging from age 65 to 92 yr (mean age 72 yr) were evaluated for office oral surgery and intravenous sedation. Surgical time ranged from 6 to 129 min. Monitored anesthesia care was utilized for the administration of fentanyl, midazolam or diazepam, and methohexital. No serious complications were seen and no patients were hospitalized.     

Intravenous sedation prior to peribulbar anaesthesia for cataract surgery in elderly patients

Purpose

To investigate if pre-block iv sedation using midazolam, alfentanil, or a midazolam-alfentanil combination minimizes pain, reduces pain recall, and attenuates haemodynamic responses to peribulbar block; and to determine other factors influencing oxygen saturation (SpO₂) following iv sedation.

Methods

In a randomized, double-blind, placebo-controlled study, 120 patients, mean age 73 yr, having cataract surgery with peribulbar anaesthesia, were randomized to receive either normal saline, 1 mg midazolam, 500 μg alfentanil, or 0.5 mg midazolam plus 250 μg alfentanil. Blood pressure (BP), heart rate (HR) and pulse oximetry readings were recorded before injection of the study drugs, immediately after completion of the peribulbar block, and 10 min after the block. Pain from the anaesthetic block was assessed immediately after the block and after surgery using a visual analog scale, and recall of pain was assessed by telephone on the day after surgery.

Results

Pain scores were low in all four groups. Midazolamalfentanil reduced pain perception, and all iv sedation used reduced pain recall. Midazolam reduced systolic BP; alfentanil ± midazolam reduced HR. All iv sedation reduced SpO₂ more than did saline, but not usually to a clinically important level. Nine patients had a SpO₂ S 90%; all had received alfentanil with or without midazolam. It was not possible to predicoxygen saturation levels by any factors other than iv sedation and baseline SpO₂ levels.

Conclusion

Intravenous sedation with midazolam or alfentanil or in combination reduced pain perception, pain recall, and haemodynamic responses from peribulbar anaesthesia. Fifteen percent of patients given alfentanil developed clinically important oxygen desaturation. The use of fine gauge needles combined with slow injection of anaesthetic solution causes minimal discomfort, and routine iv sedation may be unnecessary.     

A comparison of four sedation techniques for pediatric dental surgery

Background: We prospectively assessed the efficacy and side effects of four sedation techniques in our dental clinic: oral midazolam, intranasal (IN) midazolam, IN midazolam combined with oral transmucosal fentanyl citrate (OTFC), and IN midazolam combined with IN sufentanil. Materials & Methods: With IRB approval, a nonrandomized open label study of moderate sedation in children undergoing dental surgery was administered during a 6 ‐month period. The sedation regimen was rotated daily at the anesthesiologist’s discretion. Each sedation was monitored by a research nurse who assessed the quality of sedation and the frequency of complications. All children were monitored during the procedure and recovery for at least 20 min, before discharge based on the University of Michigan Sedation and Ohio State behavior rating scores. Results: One hundred and two children were sedated in the dental clinic during this period. The sedation was successful in 73% (range 64% to 88%) of the children. The time to onset was greatest with OTFC (37 min) and least with IN midazolam (17 min) compared with the other two groups (20 and 30 min). Recovery after OTFC was prolonged (39 min) significantly compared with the other three groups (26.5–30 min). Efficacy of sedation and frequency of complications (9% incidence of nausea and 6% of mild hemoglobin desaturation) were similar among the groups. Conclusions: All four sedation regimens were equally effective in this cohort of healthy children. The onset and recovery with OTFC was significantly delayed compared with the other regimens. The frequency of side effects was small; there were no side effects in the PO midazolam group.     

Intravenous sedation and regional analgesia

A double-blind study of 229 patients with the use of intravenous diazepam as compared with a placebo to produce sedation during local analgesia showed that significantly improved sedation occurred when diazepam was used. The diazepam was dissolved in cremophor and this reduced the pain of intravenous injection of the diazepam. One patient who received Cremophor only, showed a moderately severe allergic reaction. It is suggested that a small test dose should always be given before giving any drug which is dissolved in Cremophor.     

Intravenous lignocaine in dental anaesthesia

The prophylactic use of intravenous lignocaine 1.5 mg/kg given 1 minute prior to induction of anaesthesia has been shown to reduce significantly the incidence of dysrhythmias during dental anaesthesia, and reduce the rise in blood pressure associated with tracheal intubation.     

A comparison of dexmedetomidine sedation with and without midazolam for dental implant surgery

Dexmedetomidine (DEX) has a minimal respiratory depressive effect, which is beneficial for dentistry; however, it has the disadvantage of permitting an intraoperative arousal response such that the patient appears to be suddenly no longer sedated, and it has a variable amnestic effect. Since midazolam (MDZ) in an appropriate dose has a profound amnesic effect, we investigated whether additional MDZ compensates for the disadvantage of DEX and enables a better quality of sedation. Forty-three subjects were randomly divided into 4 groups. In group 1, MDZ (0.02 mg/kg) was administered intravenously, followed by a dose of 0.01 mg/kg every 45 minutes. After the first dose of MDZ, preloading with DEX (2 µg/kg/h for 10 minutes) was started and maintained with a dosage of 0.5 µg/kg/h. In group 2, MDZ was infused in the same manner as in group 1, followed by preloading with DEX (1 µg/kg/h for 10 minutes) and maintenance (0.3 µg/kg/h). In group 3, MDZ was infused 0.03 mg/kg, and a dose of 0.01 mg/kg was given every 30 minutes; DEX was administered at the same as in group 2. In group 4, DEX was infused using the same method as in group 1 without MDZ. The sedation levels, amnesia, and patient satisfaction were also investigated. Group 2 had a lower sedation level and a poor evaluation during the first half of the operation. Group 4 did not exhibit an amnesic effect at the beginning of the operation. An evaluation of the degree of patient satisfaction did not reveal any differences among the groups. Optimal sedation was achieved through the combined use of MDZ (0.02 mg/kg with the addition of 0.01 mg/kg every 45 minutes) and DEX (2 µg/kg/h for 10 minutes followed by 0.5 µg/kg/h).     

Intravenous ketamine sedation for painful oncology procedures

BACKGROUND: The aim of the study was to determine the efficacy and adverse effects of intravenous (i.v.) ketamine sedation administered by nonanesthetist physicians for painful procedures. METHODS: A single-agent, procedural sedation protocol using titrated doses of ketamine i.v. (maximum 2 mg.kg(-1)) was conducted in outpatient pediatric oncology patients undergoing lumbar puncture (LP), bone marrow biopsy/aspiration (BMBx/A) or combination (LP/BMBx/A) in a tertiary care setting. The efficacy of analgesia and sedation (ability to perform the procedure), procedure duration, recovery time and the occurrence of adverse events are described. RESULTS: Fifty-eight subjects of a median age of 5 years (1-13) and median weight of 20 kg (10.5-68) underwent 119 sedations. An LP was performed in 73% of cases, a BMBx/A in 13% and LP/BMBx/A in 13%. Efficacy was 100% and the mean dose of ketamine was 1.3 mg.kg(-1) (0.4). The mean duration of the procedure was 6.6 min (4.2) and the recovery time was 11 min (4-45). Two subjects (1.7%) had a hypoxemia (SpO2 of <94%). No major airway complications occurred. The prevalence of hypertension (systolic > 20% at 5 min) was 54%. The median pain visual analogue score (VAS) for an observer was 0 (range 0-3) and caregiver was 0 (range 0-4). The median VAS for satisfaction (observer) was 10 (range 7-10) and caregiver VAS was also 10 (range 5-10). At 24 h after discharge, the incidence of bad dreams was 3.3%; vomiting, 10.8%; and abnormal behavior, 4.2%. CONCLUSION: Ketamine i.v. up to 2 mg.kg(-1) is an effective sedative for oncology procedures using a defined protocol.