Remifentanil for use during conscious sedation in outpatient oral surgery.

PURPOSE: Remifentanil is a new, short-acting opioid that is similar pharmacodynamically to currently available opioids but differs in its pharmacokinetics. In the present study, we compared the use of remifentanil with the use of meperidine during intravenous conscious sedation for third molar surgery. PATIENTS AND METHODS: Forty patients who were scheduled for the removal of impacted third molars were randomly assigned to undergo 1 of 2 intravenous conscious sedation techniques. For both groups, 50:50 nitrous oxide oxygen were administered via nasal hood, and midazolam was titrated to Verril's sign. Twenty patients each then received either remifentanil 0.05 microgram/kg/min or meperidine 50 mg. Both patients and surgeons were blinded to the narcotic that was used. Blood pressure, heart rate, and oxygen saturation were determined before sedation and every 5 minutes during surgery. Recovery was measured using serial Trieger tests every 5 minutes after surgery. Patient and surgeon satisfaction of the quality of sedation was measured with a visual analog scale. RESULTS: Peak heart rate (91 beats/min for remifentanil vs 107 beats/min for meperidine, P <.01) and peak systolic blood pressure (131 mm Hg for remifentanil vs. 142 mm Hg for meperidine, P <.05) were significantly lower for the remifentanil group. Although there was a trend toward increased surgeon satisfaction with remifentanil (86 of 100 with remifentanil vs. 73 of 100 with meperidine), it was not found to be statistically significant. Likewise, other physiologic parameters were not found to be statistically significant. CONCLUSIONS: The lower peak heart rate and systolic blood pressure levels indicate that remifentanil may allow for less fluctuation in cardiovascular parameters. This could prove beneficial in patients with cardiovascular compromise.     

Attentional demands of continuously monitoring orientation using vestibular information.

The aim of this series of experiments was to determine whether attention is normally required for continuously processing vestibular information concerning orientation, or is required only when orientation is disrupted (eg by vestibular dysfunction or by conflicting visual and vestibular orientation cues). In the first two studies, healthy subjects were passively oscillated, and indicated when they perceived they were passing through their starting position. There was only weak evidence for interference between performance on this 'continuous orientation monitoring task' and on concurrent mental tasks. However, a third study showed that when patients with vestibular imbalance carried out the continuous orientation monitoring task their performance on a concurrent mental arithmetic task was substantially impaired. This dual task interference was correlated with inaccuracy in judging orientation on the continuous orientation monitoring task, which in turn correlated with severity of recent vestibular symptomatology (assessed by questionnaire). In a fourth experiment, disorientation was induced in healthy subjects by rotating the visual field about the line of sight. Bidirectional interference was observed between monitoring orientation (assessed by accuracy in setting a rod to the perceived vertical) and performance of an arithmetic task. Dual task interference was correlated with baseline levels of disorientation induced by the visual field, as indicated by inaccuracy in judging the visual vertical. These findings suggest that monitoring orientation makes significant demands upon cortical processing resources when disorientation is induced, whether the disorientation results from deficient sensory functioning or from ambiguous perceptual information.     

Acoustic variations in reading produced by speakers with spasmodic dysphonia pre-botox injection and within early stages of post-botox injection.

Acoustic analysis of a reading passage was used to identify the abnormal phonatory events associated with adductor spasmodic dysphonia (ADSD) pre- and postinjection of Botulinum Toxin A (Botox). Thirty-one patients (age 22 to 74 years) diagnosed with ADSD were included for study. All patients were new recipients of Botox, and the examination of their voice occurred before and after their initial injection of Botox. Acoustic events were identified from reading samples of the Rainbow Passage produced by each of the patients. These events were examined from sentences containing primarily voiced sound segments. Dependent variables included the number of phonatory breaks, frequency shifts, and aperiodic segments--all variables previously defined by the investigators. Additionally, calculated variables were made of the percentage of time these events occurred relative to the duration of the cumulative voiced segments. A sex- and age-matched control group (+/-2 years) was included for statistical comparison. Results indicated that those with ADSD produced more aberrant acoustic events than the controls. Aperiodicity was the predominant acoustic event produced during the reading, followed by frequency shifts and phonatory breaks. Within the ADSD group, the number of atypical acoustic events decreased following Botox injection. It is important that the occurrence of specific abnormal acoustic events was sufficient to differentiate the disordered speakers from the controls following as well as preceding initial Botox injection, as indicated by discriminant function analysis. This paper complements our previous work using this acoustic analysis method for defining the abnormal events present in the voice of those with ADSD and further suggests that these measures can be used in conjunction with perceptual impressions to differentiate speakers on the basis of initial severity.     

Quality in Clinical Practice

This paper reports the proceedings of the discussion panel assigned to look at clinical aspects of quality in emergency medicine. One of the seven stated objectives of the Academic Emergency Medicine consensus conference on quality in emergency medicine was to educate emergency physicians regarding quality measures and quality improvement as essential aspects of the practice of emergency medicine. Another topic of interest was a discussion of the value of information technology in facilitating quality care in the clinical practice of emergency medicine. It is important to note that this is not intended to be a comprehensive review of this extensive topic, but instead is designed to report the discussion that occurred at this session of the consensus conference.     

Ischemic rat brain extracts induce human marrow stromal cell growth factor production

Intravenous administration of human bone marrow stromal cells (hMSCs) after middle cerebral artery occlusion (MCAo) in rats provides functional benefit. We tested the hypothesis that these functional benefits are derived in part from hMSC production of growth and trophic factors. Quantitative sandwich enzyme‐linked immunosorbent assay (ELISA) of hMSCs cultured with normal and MCAo brain extracts were performed. hMSCs cultured in supernatant derived from ischemic brain extracts increased production of brain‐derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). These neurotrophins and angiogenic growth factors increased in a post‐ischemia time‐dependent manner. The hMSC capacity to increase expression of growth and trophic factors may be the key to the benefit provided by transplanted hMSCs in the ischemic brain.