Genetic variations associated with red hair color and fear of dental pain, anxiety regarding dental care and avoidance of dental care.

Background: Red hair color is caused by variants of the melanocortin-1 receptor (MC1R) gene. People with naturally red hair are resistant to subcutaneous local anesthetics and, therefore, may experience increased anxiety regarding dental care. The authors tested the hypothesis that having natural red hair color, a MC1R gene variant or both could predict a patient's experiencing dental care-related anxiety and dental care avoidance.

Aestiva ventilation mode selector switch failures.

We describe three cases of previously unreported failures of the Bag-Ventilator Switch in Aestiva/5 anesthesia machines (GE Healthcare/Datex-Ohmeda, Madison, WI). Each failure mode produced a large breathing-circuit leak. Examination of the switches revealed a cracked toggle actuator, residue build-up, and a cracked selector switch housing as causes for the failures.

Alternative management techniques for the difficult airway: optical stylets.

Purpose Of Review: We present the newest devices being promoted for difficult-airway management. Our focus is on optical stylets which offer a forward view from the stylet end positioned within the tip of the endotracheal tube.

Recent Findings: Reports suggest that these devices are mastered quickly and offer effective airway management aid.

Women with red hair report a slightly increased rate of bruising but have normal coagulation tests.

There is an anecdotal impression that redheads experience more perioperative bleeding complications than do people with other hair colors. We, therefore, tested the hypothesis that perceived problems with hemostasis could be detected with commonly used coagulation tests. We studied healthy female Caucasian volunteers, 18 to 40 yr of age, comparable in terms of height, weight, and age, with natural bright red (n = 25) or black or dark brown (n = 26) hair.

Increased sensitivity to thermal pain and reduced subcutaneous lidocaine efficacy in redheads.

Background: Anesthetic requirement in redheads is exaggerated, suggesting that redheads may be especially sensitive to pain. Therefore, the authors tested the hypotheses that women with natural red hair are more sensitive to pain and that redheads are resistant to topical and subcutaneous lidocaine.

Methods: The authors evaluated pain sensitivity in red-haired (n = 30) or dark-haired (n = 30) women by determining the electrical current perception threshold, pain perception, and maximum pain tolerance with a Neurometer CPT/C (Neurotron, Inc.

Dexmedetomidine and meperidine additively reduce the shivering threshold in humans.

Background And Purpose: Hypothermia might prove to be therapeutically beneficial in stroke victims; however, even mild hypothermia provokes vigorous shivering. Meperidine and dexmedetomidine each linearly reduce the shivering threshold (triggering core temperature) with minimal sedation. We tested the hypothesis that meperidine and dexmedetomidine synergistically reduce the shivering threshold without producing substantial sedation or respiratory depression.