A comparative study of dexmedetomidine with midazolam and midazolam alone for sedation during elective awake fiberoptic intubation.

STUDY OBJECTIVE: To evaluate the efficacy of dexmedetomidine with midazolam (DEX-MDZ) versus midazolam only (MDZ) for sedation during awake fiberoptic intubation (AFOI). DESIGN: Randomized, double-blinded study. SETTING: Academic medical center. SUBJECTS: 55 ASA physical status I, II, III, and IV patients, aged 18-85 years, scheduled for non-emergency surgery with AFOI. INTERVENTIONS: All patients received intravenous (IV) glycopyrrolate 0.2 mg premedication, oxygen by nasal cannula, and topical local anesthetics to the airway. MDZ subjects received IV midazolam 0.05 mg/kg with additional doses to achieve a Ramsay Sedation Scale (RSS) score of >or= 2. DEX-MDZ patients received midazolam 0.02 mg/kg followed by dexmedetomidine one microg/kg, then an infusion of dexmedetomidine 0.1 microg/kg/hr and titrated to 0.7 microg/kg/hr to achieve RSS>or=2. MEASUREMENTS: Observers' Assessment of Alertness/Sedation (OAA/S) and RSS were evaluated. The anesthesiologist rated AFOI ease of placement. Two observers rated patients' comfort and reaction to placement at three time points: preoxygenation, at introduction of the fiberoptic laryngoscope, and at introduction of the endotracheal tube (ET) before surgery. Following surgery, patients were asked if they recalled the AFOI and also to rate their satisfaction with the intubation. RESULTS: DEX-MDZ patients were significantly calmer and more cooperative during AFOI and had fewer adverse reactions to AFOI than did the MDZ patients. They also were more satisfied with the AFOI (P < 0.001) than were the midazolam-only patients. There were no significant hemodynamic differences between the two subject groups. CONCLUSIONS: Dexmedetomidine in combination with low doses of midazolam is more effective than midazolam alone for sedation in AFOI.

Myocardial electrical activity does not affect myocardial electrical impedance measurements.

OBJECTIVE: Myocardial electrical impedance (MEI) has shown to be an effective indicator of myocardial ischemia. We have previously developed a novel monitor for measuring MEI in near-real time. The object of this study was to test whether drug-induced changes in the frequency of the periodic myocardial electrical activity, as measured by the heart rate (HR), affect MEI measurements made with our monitor. METHODS: Thirty dogs were randomly assigned to one of three study groups (placebo, isoproterenol or esmolol) and then anesthetized with sodium thiamylal, intubated, ventilated, given isoflurane, and had venous, arterial, and pulmonary artery catheters placed. Median sternotomy was performed to facilitate myocardial exposure and to allow the left anterior descending (LAD) coronary artery to be isolated. Following baseline measurements, saline (control), isoproterenol or esmolol was administered and the LAD coronary artery was occluded in a timed sequence in order to study the effects of heart rate changes and demonstrate induced myocardial ischemia on MEI. RESULTS: Isoproterenol raised the HR and esmolol lowered the HR without affecting our MEI measurements. Myocardial electrical impedance increased during LAD coronary artery occlusion in all groups, as previously shown. CONCLUSION: These results demonstrate that our MEI monitor is unaffected by the frequency of the periodic myocardial electrical activity that generates the HR.

Dexmedetomidine for conscious sedation in difficult awake fiberoptic intubation cases.

Currently used methods of sedation for fiberoptic intubation such as benzodiazepines, propofol, or opioids have their limitations. Dexmedetomidine (DEX) is a selective alpha-2 adrenergic agonist that has been used clinically for its sympatholytic, analgesic, and sedative properties. We report on 4 patients with particularly difficult airways who underwent successful awake fiberoptic intubation with DEX. Dexmedetomidine was used to provide a moderate level of conscious sedation without causing respiratory distress or hemodynamic instability during fiberoptic intubation.

The qualifications of pain physicians in Ohio.

Pain physicians in Ohio come from many medical backgrounds and use different medical boards to claim board certification in the field of pain medicine. Our goal was to explore the number, demographics, and qualifications of pain physicians in Ohio. The names of Ohio physicians designating themselves as pain physicians were collected from the State Medical Board of Ohio and the American Medical Association. The directories of the American Board of Medical Specialties (ABMS), the American Board of Pain Medicine, the American Academy of Pain Management, and the American Board of Medical Acupuncture were referenced for certification in pain medicine, pain management, or medical acupuncture. The requirements for these credentials vary widely, yet they have all been used to claim "board certification." Board certification in medicine implies recognition by an ABMS member board as having completed the required training, met the standards, and then passed an examination that validates qualifications, and knowledge in a specific medical field. In 2002, there were 335 Ohio physicians designating themselves as pain physicians. Two-hundred-eighteen (65%) had at least one pain board certification. Ninety-six (29%) of the Ohio pain physicians were certified in pain medicine by the American Board of Anesthesiology, the American Board of Physical Medicine and Rehabilitation, or the American Board of Psychiatry and Neurology, which are all member boards of the ABMS. One-hundred-seventeen (35%) of the self-declared Ohio pain physicians held no pain-related board certification. Anesthesiologists comprise the majority of all pain physicians and are the majority in all four pain boards.

Comparison of effects of lidocaine hydrochloride, buffered lidocaine, diphenhydramine, and normal saline after intradermal injection.

STUDY OBJECTIVE: To evaluate pain and the spread of analgesia when local anesthetics are given as an intradermal injection into the dorsal aspect of the hand. DESIGN: Randomized, double-blinded, placebo-controlled study. SETTING: University medical center. PATIENTS: 40 consenting adult volunteers. INTERVENTIONS: Volunteers were randomly assigned to receive a 0.25-mL injection of either lidocaine hydrochloride (1%), buffered lidocaine, diphenhydramine (1%), or placebo (0.9% sodium chloride solution) into the dorsal aspect of both hands. MEASUREMENTS: The volunteers used a visual analog scale to compare the pain of needle insertion and solution injection. Then at 1, 2, 5, 10, 20, and 30 minutes after intradermal injection, the extent of the analgesic area was marked on a strip of tape placed horizontally across the hand. Then at 32 minutes after intradermal injection, the extent of the analgesic area was marked on a strip of tape placed vertically across the hand. The volunteers were called each day and asked the duration of their numbness or hyperesthesia until their hands were no longer numb or sore. MAIN RESULTS: Buffered lidocaine during intradermal infiltration was found to be significantly (p < 0.05) less painful than either lidocaine hydrochloride or diphenhydramine and equivalent to placebo. Diphenhydramine and lidocaine hydrochloride during intradermal infiltration induced significantly (p < 0.05) more pain than buffered lidocaine or placebo. Lidocaine hydrochloride displayed a significantly (p < 0.05) larger diameter of analgesia than placebo by 1 minute after the injection, buffered lidocaine by 2 minutes after injection, and diphenhydramine by 5 minutes after injection. By 20 minutes after injection, diphenhydramine diameter of analgesia was significantly (p < 0.05) larger than placebo but significantly less than buffered lidocaine. By 30 minutes after injection, diphenhydramine diameter of analgesia was equivalent to placebo whereas buffered lidocaine and lidocaine diameters were still significantly (p < 0.05) larger than placebo. Diphenhydramine injection resulted in numbness that lasted significantly (p < 0.05) longer than other study solutions whereas buffered lidocaine and lidocaine injections resulted in numbness that lasted significantly longer than placebo. Diphenhydramine injection resulted in hyperesthesia that lasted for 2 or more days in 12 of the volunteers. CONCLUSION: There is a reduction of infiltration pain using buffered lidocaine as opposed to lidocaine and diphenhydramine. Although lidocaine injection resulted in a slightly faster spread of analgesic diameter, buffered lidocaine was equivalent to lidocaine from minute 2 until minute 30. Therefore, to obtain optimal anesthetic conditions, we recommend that buffered lidocaine be given 2 minutes before performing catheterization, whereas diphenhydramine should be given 5 minutes before catheterization, but only when buffered lidocaine cannot be used.