Sole Sedative Agent Research Articles

Safe sedation?

Safe sedation?

Clonidine as a sole sedative agent for MRI study in a child with Joubert syndrome

Clonidine as a sole sedative agent for MRI study in a child with Joubert syndrome

Prolonged Recovery Associated With Dexmedetomidine When Used as a Sole Sedative Agent in Office-Based Oral and Maxillofacial Surgery Procedures

Office-based oral and maxillofacial surgical procedures that require sedation are popular. Dexmedetomidine has the advantages of having a minimal effect on respiration and an antisialogogue effect that could make it a good choice for dental procedures. We performed a prospective pilot study in which patients undergoing office-based oral and maxillofacial surgical procedures received dexmedetomidine as a sole sedative agent. The loading dose of dexmedetomidine (1 microg/kg infused over 10 minutes) was followed by a maintenance dose (0.2 to 0.8 microg/kg/hour) to achieve a Ramsay sedation score of 2 to 3. The demographic data were collected, and the pre- and intraprocedural vital signs and Ramsay sedation score were recorded every 5 minutes. The duration of the procedure, recovery time, and patient and surgeon satisfaction were documented. No statistically significant changes were found in the heart rate, respiratory rate, or oxygen saturation during the procedure when compared to baseline. However, we noticed a significant decrease in the heart rate at the end of the loading dose, and statistically significant change in the blood pressure between baseline and during the procedure (P < .05). The initial local anesthetic injections were recalled by 26% of the patients, and 73% had some recollection of the procedure. Nevertheless, the patient satisfaction score (range 1 to 10) was 8.6 +/- 2.3, and 86% of the patients would recommend this type of sedation. The surgeon satisfaction score (range, 1 to 5) was 3.9 +/- 1.3. The recovery time was prolonged (82.2 +/- 24.3 minutes) when compared with the total procedure time (44.6 +/- 27.9 minutes). Dexmedetomidine has demonstrated hemodynamic and respiratory stability when used as a sole sedative agent. Despite the discomfort on injection and the lack of reliable amnesic property, patient and surgeon satisfaction were high. However, the prolonged recovery time makes this drug unsuitable for busy office-based practices. We believe it should be reserved for patients with a high risk of respiratory complications (eg, obese patients or those with a history of sleep apnea).

Obesity, obstructive sleep apnoea, and diabetes mellitus: anaesthetic implications

Obesity is an epidemic in much of the Western World. The extent of this problem, combined with the increasing preference for ambulatory surgical procedures, has produced a difficult situation for many anaesthesiologists. Even the simplest anaesthetic procedures can become very complicated and potentially difficult in this population. Although there are numerous complications associated with obesity, perhaps obstructive sleep apnoea (OSA) and diabetes mellitus are among the more significant. Patients with OSA are often not ideal candidates for certain day-case procedures, but many outpatient procedures can be performed on patients with OSA as long as attention is paid to anaesthetic technique. Diabetic patients are prone to numerous complications in the perioperative period, including cardiac problems, but with careful management, they are able to undergo day-case surgical procedures safely.

High dose dexmedetomidine as the sole sedative for pediatric MRI

This large-scale retrospective review evaluates the sedation profile of dexmedetomidine. To determine the hemodynamic responses, efficacy and adverse events associated with the use of high dose dexmedetomidine as the sole sedative for magnetic resonance imaging (MRI) studies. Dexmedetomidine has been used at our institution since 2005 to provide sedation for pediatric radiological imaging studies. Over time, an effective protocol utilizing high dose dexmedetomidine as the sole sedative agent has evolved. As part of the ongoing Quality Assurance process, data on all sedations are reviewed monthly and protocols modified as needed. Data were analyzed from all 747 consecutive patients who received dexmedetomidine for MRI sedation from April 2005 to April 2007. Since 2005, the 10-min loading dose of our dexmedetomidine protocol increased from 2 to 3 microg.kg(-1), and the infusion rate increased from 1 to 1.5 to 2 microg.kg(-1).h(-1). The current sedation protocol progressively increased the rate of successful sedation (able to complete the imaging study) when using dexmedetomidine alone from 91.8% to 97.6% (P = 0.009), reducing the requirement for adjuvant pentobarbital in the event of sedation failure with dexmedetomidine alone and decreased the mean recovery time by 10 min (P < 0.001). Although dexmedetomidine sedation was associated with a 16% incidence of bradycardia, all concomitant mean arterial blood pressures were within 20% of age-adjusted normal range and oxygen saturations were 95% or higher. Dexmedetomidine in high doses provides adequate sedation for pediatric MRI studies. While use of high dose dexmedetomidine is associated with decreases in heart rate and blood pressure outside the established 'awake' norms, this deviation is generally within 20% of norms, and is not associated with adverse sequelae. Dexmedetomidine is useful as the sole sedative for pediatric MRI.

Dexmedetomidine Sedation During Awake Craniotomy for Seizure Resection: Effects on Electrocorticography

Patients with refractory seizures may undergo awake craniotomy and cortical resection of the seizure area, using intraoperative functional mapping and electrocorticography (ECoG). We used dexmedetomidine in 6 patients, transitioning successively from the asleep-awake-asleep method, through a combined propofol/dexmedetomidine sedative infusion, to dexmedetomidine as the only sedation. Initial experience with the asleep-awake-asleep method in 2 patients was successful with the replacement of propofol/laryngeal mask anesthesia, 20 to 30 minutes before ECoG testing, by dexmedetomidine infusion, maintained at 0.2 mcg kg-1 h-1 throughout neurocognitive testing. Propofol anesthesia was reintroduced for resection. One patient received combined dexmedetomidine (0.2 mcg kg-1 h-1) and propofol (200 mcg kg-1 min-1) infusions for sedation. Both infusions were stopped 15 minutes before ECoG. Subsequently, they were restarted and the epileptic foci resected. Three patients received dexmedetomidine as the sole sedative agent, together with scalp block local anesthesia, and incremental boluses totaling 150 to 175 mcg of fentanyl per case. Dexmedetomidine was started with 0.3 mcg kg-1 boluses and maintained with 0.2 to 0.7 mcg kg-1 h-1for craniotomy, testing, and resection. The infusion was paused for 20 minutes in 1 patient to allow improvement in neurocognitive testing. This occurred within 10 minutes. All patients enjoyed good hemodynamic control, with blood pressure maintained within 20% of initial values, and made uneventful recoveries. The surgical conditions were all reported as favorable. Dexmedetomidine can be used singly for sedation in awake craniotomy requiring ECoG. Individual dose ranges vary, but a bolus of 0.3 mcg kg-1 with an infusion of 0.2 mcg kg-1 min-1 is a good starting point, allowing accurate mapping of epileptic foci and subsequent resection.