Duration of amnesia associated with midazolam/fentanyl intravenous sedation

Lack of recall after sedation for cataract surgery and its effect on the validity of measuring patient satisfaction

BACKGROUND

We evaluated the validity of assessing patient satisfaction with the sedation regimen among patients being discharged 45 min after receiving midazolam. If most patients do not have recall, then the sedation cannot be considered complete at the time of evaluation.

METHODS

In this prospective cohort study, 20 patients underwent cataract surgery with nurse-administered midazolam and fentanyl. The 11-item Iowa Satisfaction with Anesthesia Scale was administered  30 min after sedation in the recovery room. Recalled items were evaluated the next morning.

RESULTS

Eleven patients recalled 0 themes, 4 recalled 1, 4 recalled 2, and 1 recalled 3 themes. Thus, 15/20 patients (75%) recalled 0 or 1 of the 11 themes (P = 0.021 versus half the patients). The 95% one-sided lower confidence limit for 0, 1, or 2 themes was 80% of patients (P < 0.001 versus half). Patients who received less midazolam recalled more themes (Kendall's τb = 0.43, P = 0.039).

CONCLUSIONS

Evaluating patient satisfaction with sedation shortly after admission to the post-anesthesia care unit is invalid because of a lack of recall; the sedation/amnesia is ongoing. Patient comfort may be assessed, but comfort is not synonymous with satisfaction; 'satisfaction' implies presence of recall. Because we studied sedation with low doses of midazolam and fentanyl, the same conclusion reliably would apply to larger doses of anxiolytics administered intraoperatively. The results match previous findings that when patients receive preoperative midazolam prior to meeting the anesthesiologist, even if the patient fully answers questions, they may have negligible recall of having met the anesthesiologist.

Retrograde amnesia after intravenous sedation and general anaesthesia in a dental hospital

Midazolam, a benzodiazepine, is commonly used for intravenous sedation for dental procedures and, together with other benzodiazepines, can cause anterograde amnesia. Retrograde amnesia, however, is rare. It is defined as a loss of access to memory of events that occurred, or information that was learned, before the injury or event that caused the amnesia. We know of no reports of this occurring after the intravenous use of midazolam alone and few after general anaesthesia. We present two cases of retrograde amnesia: one after intravenous sedation and one after general anaesthesia.

Effect of a low dose of midazolam on high blood pressure in dental patients: a randomised, double-blind, placebo-controlled, two-centre study

Some patients have transient hypertension before dental treatment as a result of anxiety and stress. Midazolam is an anxiolytic, and thought to be effective for the management of this sort of transient hypertension. We have evaluated in a randomised, controlled trial whether a low dose of midazolam can lower blood pressure in dental patients to an acceptable level without excessive sedation. Suitable patients were randomised to be given midazolam (trial group) or physiological saline (control group) intravenously. Blood pressure, heart rate, degree of anxiety, and amount of sedation were measured before and after injection. After injection, blood pressure in the trial group significantly decreased to clinically acceptable levels compared with controls. The degree of anxiety in the trial group was also significantly less than that in the control group, but there were no significant differences in sedation. These results suggest that injection of a low dose of midazolam stabilises the blood pressure of dental patients with transient hypertension.

The "ouchless emergency department". Getting closer: advances in decreasing distress during painful procedures in the emergency department

Painful and frightening injuries and illnesses are frequent reasons for children to seek care in an emergency department. Painful therapeutic procedures are often a necessary part of emergency care and are very distressful for the children, their parents, and healthcare providers. Inadequately relieved pain and distress have acute and long-term consequences, yet methods for pain and anxiety reduction during frightening minor and major procedures are often not used because of lack of detailed knowledge of techniques and fear of adverse effects. This article reviews psychologic and pharmacologic means of safe and effective reduction of anxiety and pain during emergency department procedures.

Comparison of fentanyl/midazolam with ketamine/midazolam for pediatric orthopedic emergencies

OBJECTIVE

Emergency management of pediatric fractures and dislocations requires effective analgesia, yet children's pain is often undertreated. We compared the safety and efficacy of fentanyl- versus ketamine- based protocols.

METHODOLOGY

Patients 5 to 15 years of age needing emergency fracture or joint reduction (FR) were randomized to receive intravenous midazolam plus either fentanyl (F/M) or ketamine (K/M). Measures of efficacy were observational distress scores and self- and parental-report. Measures of safety were frequency of abnormalities in and need for support of cardiopulmonary function and other adverse effects.

RESULTS

During FR, K/M subjects (n = 130) had lower distress scores and parental ratings of pain and anxiety than did F/M subjects (n = 130). Although both regimens equally facilitated reductions, deep sedation, and procedural amnesia, orthopedists favored K/M. Recovery was 14 minutes longer for K/M. Fewer K/M subjects had hypoxia (6% vs 25%), needed breathing cues (1% vs 12%), or required oxygen (10% vs 20%) than did F/M subjects. Two K/M subjects required assisted ventilation briefly. More K/M subjects vomited. Adverse emergence reactions were rare but equivalent between regimens.

CONCLUSIONS

During emergency pediatric orthopedic procedures, K/M is more effective than F/M for pain and anxiety relief. Respiratory complications occurred less frequently with K/M, but respiratory support may be needed with either regimen. Both regimens facilitate reduction, produce amnesia, and rarely cause emergence delirium. Vomiting is more frequent and recovery more prolonged with K/M.

Comparison of the amnesic effects of midazolam and diazepam

Thirty patients undergoing gastroscopy received intravenous premedication with either midazolam or diazepam in a randomised double blind study. Mean dosages were similar for the midazolam (6.13 mg) and diazepam (6.4 mg) groups. Neuropsychological testing pre- and post-medication comprised the Wechsler Memory Scale, Complex Figure Test, Word Association Test, and a Tactile Memory Test. There was a significant impairment on post-medication tests requiring delayed recall of verbal, visual and tactile stimuli. Midazolam produced significantly greater anterograde amnesia than diazepam at similar mean dosages. With the exception of Digit Span and Associate Learning, cognitive tasks which do not require delayed recall were not affected. It is concluded that the amnesic deficit is discrete and not secondary to sedative effects.