Oral sedation

"I fear a trip to the dentist more than I fear death" is the response one person gave in a national survey recently cited in USA Today. While clearly representing an extreme, the results of many surveys suggest that fear of dentistry is still prevalent and is a measure of the failure of current therapeutic approaches to reduce pain and anxiety sufficiently to enable people, especially those with special needs, to visit the dentist. Patients who are fearful would likely seek oral health care more regularly if anesthesia and sedation were more readily available. Taking into consideration that the safety of anxiolytic drugs is highly dependent on the drug, dose, and route of administration used, oral premedication should be the sedative technique used by most dentists because it is efficacious, requires little monitoring when appropriate doses are used, and is unlikely to result in serious morbidity.     

Patients requiring sedation

Recent advances in the pharmacology of sedative drugs have expanded their use in the intensive care unit. Indications and endpoints for sedation, however, often are defined poorly and are difficult to assess. Nevertheless, the complications of sedative drug administration are real. New indications for sedation have been proposed in recent years, including enforcing sleep/wake cycles, manipulating cellular metabolism, and preventing myocardial ischemia. The evidence supporting the efficacy of these new indications is not yet complete.     

Understanding conscious sedation in the operating room

Conscious sedation is an appropriate choice for patients who do not require a general anesthetic, but rather need sedation to alleviate anxiety, minimize the discomfort of less invasive surgical procedures, or even to tolerate a regional or local anesthetic. New pharmaceutical agents, with their short half lives, provide amnesia, analgesia, and sedation quite safely. This concept, combined with standardized and controlled safety monitoring, offers an anesthetic alternative quite acceptable to many patients and health care providers. Standards and guidelines have been extensively developed by the American Society of Anesthesiologists, and the American Association of Nurse Anesthetists, to set forth a practice for all providers that will promote patient safety and provider vigilance (AANA, 1998). The purpose of this article is to review the process of conscious sedation.     

Fatal outcome after propofol sedation in children

This study was conducted to determine how phaco-emulsification combined with trabeculectomy influenced intraocular pressure and need for glaucoma medication postoperatively. A retrospective analysis was undertaken of results relating to 243 eyes of 195 patients who had undergone phaco-emulsification combined with trabeculectomy. Pre-operative intraocular pressure decreased from a mean of 22.0 mmHg to 12.5 mmHg one week postoperatively with an average change of 9.5 mmHg. One month postoperatively, 70% of patients were without glaucoma medication. Visual acuity had improved in 80% of eyes. Phaco-emulsification combined with trabeculectomy resulted in excellent glaucoma control, good visual recovery and a need for fewer glaucoma drugs.     

Dynamics of MLAEP changes in midazolam-induced sedation

This study aimed at assessing the effects of midazolam (MDZ) sedation on auditory brainstem (BAEP) and middle latency (MLAEP) evoked potentials in intensive care conditions. Ten ventilated comatose patients were receiving an intravenous MDZ bolus dose (0.2 mg/kg) followed by a 2 h continuous infusion (0.1 mg/kg/h). MLAEPs and BAEPs elicited by clicks (90 dB HL + masking) were simultaneously and continuously monitored during the first 6 h and for 30 min the next morning. We found no effect of MDZ sedation on BAEPs. Only MLAEP components were modified. However, none of the patients presented any total abolition of the MLAEPs. Bolus injection led to very early alteration of cortical responses, beginning after 5 min and lasting almost 1 h (maximum Pa latency increase, 3.1 ms; maximum Pa-Nb amplitude decrease, 46%). During continuous infusion, MLAEPs remained slightly, although significantly, altered (Pa latency, +1.3 ms; Pa-Nb amplitude, 27%). The Nb wave seemed to be modified earlier and to return to normality later than the Pa wave. These findings incite a careful interpretation of MLAEP tracings acquired during the first hour following MDZ bolus injection. If possible, MDZ should be administered as continuous infusion for reliable interpretation of evoked potential changes in intensive care unit, or during surgery.     

Tips for RN-administered conscious sedation

The RN should know his or her state Board of Nursing position, national standards, hospital policy, and procedure before assuming this role. The RN delivering conscious sedation must focus on patient education, assessment, and monitoring. The successful practice requires consistency of care in all departments and continuity of care at all costs.     

Selectivity of atipamezole, yohimbine and tolazoline for alpha-2 adrenergic receptor subtypes: implications for clinical reversal of alpha-2 adrenergic receptor mediated sedation in sheep

The alpha2-adrenergic receptor antagonists, yohimbine, atipamezole and tolazoline, are used in veterinary medicine as reversal agents for the sedative/hypnotic effects of alpha2-agonists. Ruminants have increased sensitivity to the sedative/hypnotic effects of alpha2-agonists compared to other species. The receptors mediating the sedative effects of alpha2-agonists are located primarily on locus coeruleus neurons in the pons of the lower brainstem. Four pharmacological subtypes of the alpha2-adrenergic receptor (A,B, C and D) have been identified based on differences in ligand affinity. The aim of this study was to: 1) determine the pharmacological profile of atipamezole, yohimbine and tolazoline at the four alpha2-adrenergic receptor subtypes and; 2) determine whether these agents differ in their affinities at the alpha2-adrenergic receptor present in the sheep brainstem. In inhibition binding studies against the selective alpha2-adrenergic receptor ligand [3H]-MK-912, tolazoline showed the lowest affinity for all four alpha2-adrenergic receptor subtypes compared to yohimbine and atipamezole. The affinities of yohimbine and atipamezole were similar at the alpha2A-, alpha2B- and alpha2C-adrenergic receptors but differed by approximately 100 fold at the alpha2D-adrenergic receptor. Atipamezole had a 100 fold higher affinity at the alpha2D-adrenergic receptor when compared to yohimbine. To determine the ligand binding characteristics of these agents at the alpha2-adrenergic receptor in sheep brainstem, membranes were labelled with [3H]-MK-912 and inhibition competition curves were performed. Atipamezole showed approximately a 100 fold higher affinity for the sheep brainstem alpha2-adrenergic receptor compared to yohimbine which was similar to what was observed for the alpha2D-adrenergic receptor in PC12 cells transfected with RG-20. The results from these studies suggest that atipamezole has a high affinity for the alpha2D-adrenergic receptor that appears to be the receptor subtype in sheep brainstem.     

Domestication-related behavior in sheep

Chronic nicotine exposure in the rat produces a characteristic increase in neuronal nicotinic binding sites in many brain regions. The conventional method for inducing such increases utilizes twice daily subcutaneous injections of a near maximal, sub-convulsive dose of nicotine. Alternatively, nicotine may be chronically infused via an osmotic mini-pump. However, little is known about how administration of nicotine by chronic infusion compares to multiple injections in producing nicotinic receptor upregulation. This study used [3H]-epibatidine, a high potency neuronal nicotinic agonist radioligand, to compare the increases in receptor levels in rat brain, spinal cord and trigeminal ganglion tissues following chronic nicotine administration via either twice daily injections (2 mg/kg s.c.) or an osmotic mini-pump (1 mg/kg/hr) for 10 days. All central and peripheral nervous system tissues examined demonstrated significant neuronal nicotinic receptor up-regulation following chronic infusion of nicotine. Only the cerebral cortex and hippocampus displayed significant up-regulation following nicotine administration by injections. Moreover, in all tissues studied, the receptor levels measured were significantly higher in the animals that received nicotine by chronic infusion compared with multiple injections. These data indicate that chronic infusion of nicotine is a convenient and efficacious alternative to multiple injections for producing neuronal nicotinic receptor up-regulation in both central and peripheral nervous tissues.     

Lymphocyte antigens in sheep

This paper describes the detection of 13 lymphocyte antigens in sheep. The results obtained from family studies are consistent with the hypothesis that at least 12 antigens are under the control of a single genetic system. The distribution of antigens in the population suggests that the system contains two loci. The 13 antigens were compared with those previously reported. Only one additional specificity was found.     

Acute pain, analgesia and sedation in children (IV): analgesia and sedation in medical procedure and in emergency room

Clinicians are confronted with a complex challenge when a patient is admitted to a critical care unit (CCU) with a significant chest roentgenography (CXR) abnormality. The etiology of a new infiltrate seen on CXR in a patient already in the CCU is more difficult to establish, but is of equal concern.     

Administering conscious sedation. Operational guidelines

The nurse must be aware of her or his role and responsibilities when implementing IVCS guidelines. Nurses performing IVCS must be knowledgeable of state and institutional guidelines for IVCS, medications included in IVCS, and the assessment, monitoring, and documentation required in caring for the patient receiving IVCS. The process of IVCS may seem tedious, but if an institution has clearly defined expectations, as provided in the IVCS guidelines, the process is much more understandable and can be readily instituted. The patient undergoing IVCS deserves the highest quality care possible with the fewest complications, a situation that can be achieved with proper preparation and implementation of an IVCS program.     

Oral midazolam: pediatric conscious sedation

Dentists attempt to overcome patients' fears by using various oral, intramuscular, intravenous, and inhalational anxiolytic agents. This article discusses the use of oral midazolam as an alternative to oral diazepam in the management of the pediatric patient.     

Diprivan: sedation for difficult intubation

No study has compared anaesthetic protocols appropriate for the sedation for fiberoptic tracheal intubation. Extrapolation of results of randomised studies comparing sedation techniques for diagnostic bronchoscopy under local anaesthesia enables the following conclusions: 1. Possible hypnotic agents for this procedure are benzodiazepines, barbiturates and propofol. Fentanyl improves the conditions for bronchoscopy. 2. Sedation using propofol is a well established technique. The induction dose, given as a bolus injection is 1 mg.kg-1, followed by continuous maintenance infusion of 1 mg.kg.h-1. 3. Irrespective of the sedation protocol used, there is always respiratory depression which justifies the need for preoxygenation, continuous oxygenation and Spo2 monitoring. Reversal of benzodiazepine and opioid effects may temporarily protect against respiratory depression.