Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery
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Otolaryngol Head Neck Surg · Dec 1994
Comparative StudyVasoconstrictive effects of cocaine and lidocaine with epinephrine in the hamster cheek pouch model.
Otolaryngologists frequently use cocaine and lidocaine with epinephrine for their anesthetic and vasoconstrictive effects. However, no studies have visually compared the vasoconstrictive effects of cocaine to lidocaine with epinephrine. This study used the everted hamster cheek pouch model to assess the vasoconstrictive effects of cocaine and lidocaine with epinephrine by measuring the diameter changes of arterioles. ⋯ Topical NaCl and injected NaCl controls showed no significant arteriolar reduction. Vasoconstrictive differences between the preparations were statistically significant (p < 0.05). Five percent cocaine is a much weaker vasoconstrictor than locally injected 1% lidocaine with 1:100,000 units epinephrine.
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Otolaryngol Head Neck Surg · Dec 1994
Hemostatic assessment of patients before tonsillectomy: a prospective study.
The purpose of this prospective study in patients undergoing tonsillectomy was to determine whether perioperative bleeding could be predicted by use of a standardized questionnaire concerning bleeding risk combined with measurement of the activated partial thromboplastin time and prothrombin time. Of the 96 patients enrolled in the study, none had a history of a severe bleeding disorder, but 6 (6%) had histories suggestive of a mild bleeding disorder. Further evaluation showed possible von Willebrand's disease in one of these patients. ⋯ The data provide further evidence that routine measurement of the activated partial thromboplastin time and prothrombin time in asymptomatic patients is not useful for predicting postoperative bleeding. In addition, histories suggestive of a mild bleeding disorder are also not accurate predictors of postoperative bleeding. Excessive bleeding associated with tonsillectomy is usually not a result of an identifiable coagulation disorder.
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We reviewed 36 patients with gentamicin vestibulotoxicity to determine its relationship to gentamicin dosage, serum gentamicin levels, and the development of gentamicin nephrotoxicity. Thirty of the patients had received intravenous or intramuscular gentamicin; six had received intraperitoneal gentamicin. Sixteen of the 30 patients treated with intramuscular or intravenous gentamicin had received less than the recommended maximum dose of 5 mg/kg/day for less than the recommended maximum period of 10 days. ⋯ Gentamicin vestibulotoxicity was not recognized before discharge from hospital in 32 of the 36 patients. We conclude that as far as the vestibular system is concerned there is no safe gentamicin dose and no safe serum gentamicin level, and there is an increased risk of vestibulotoxicity in patients in whom nephrotoxicity develops. Physicians who use gentamicin should become more aware of the clinical features of vestibulotoxicity because stopping gentamicin as soon as symptoms of vestibulotoxicity appear could prevent permanent impairment of vestibular function.
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Otolaryngol Head Neck Surg · Nov 1994
Intraoperative monitoring of the visual evoked potential during endoscopic sinus surgery.
Iatrogenic blindness resulting from conventional and endoscopic sinus surgery continues to be a major concern to the head and neck surgeon. A new electrophysiologic monitoring technique has been developed that can help avoid damage to the optic nerve and visual system. The approach involves monitoring the visual evoked potential with presentation of flash stimuli to the eyes. ⋯ Visual evoked potential monitoring may prevent a surgeon from continuing a bilateral procedure when there is indication of iatrogenic visual loss from dissection on the first side. Visual evoked potential also reassures the operator that no damage has occurred to the visual pathway at the conclusion of a case. Methods, case selection, operative technique, and documentation of monitoring will be discussed.