Combining physostigmine with meperidine for sedation and analgesia during colonoscopy.

BACKGROUND AND STUDY AIM: Opiate or benzodiazepine drugs are often used during colonoscopy, but they are associated with respiratory depression and prolonged recovery. Physostigmine, a tertiary anticholinesterase agent, is known to enhance analgesia and to reverse the central nervous system depressant effects of these drugs. This study compared the effect of giving meperidine alone with the effect of giving meperidine in combination with physostigmine in patients who were undergoing complete colonoscopy. PATIENTS AND METHODS: A total of 44 outpatients undergoing elective colonoscopy were randomly assigned to receive analgesia with either meperidine 0.5 mg/kg intravenously (group 1, n=24) or physostigmine 10 micrograms/kg intravenously, followed 5 minutes later by meperidine 0.5 mg/kg intravenously (group 2; n=20). The patients were assessed with regard to oxygen saturation, hemodynamic changes, pain perception and sedation scores, readiness to go home, and adverse effects. RESULTS: The group 1 patients' oxygen saturations consistently fell, both during the procedure and in the recovery period; in group 2, oxygen saturations remained stable throughout the procedure and recovery period (95.88%+/-0.99 vs. 98.15+/-0.99, P<0.001). Patients in group 2 reported lower pain perception scores during the procedure (measured using a visual analog scale) than patients in group 1 (1.46+/-0.31 vs. 1.75+/-0.41; F1,42=6.484, P<0.015) and were less sedated during recovery (F1,41=6.56, P<0.015). No significant differences were found between the two groups with regard to heart rate or arterial blood pressure. All patients in group 2 were ready to go home after 25 minutes in the recovery area; three patients in group 1 were not ready to leave at 25 minutes and left the facility after 60 minutes. Four patients suffered from minor side effects of physostigmine (sweating and nausea). CONCLUSIONS: Combining physostigmine with meperidine as preparatory treatment for patients undergoing colonoscopy prevents respiratory depression, improves analgesia, and shortens recovery time, with only mild side effects.

Comparison of the Flexiblade levering laryngoscope with the English Macintosh laryngoscope in patients with a poor laryngoscopic view.

The effectiveness of two laryngoscopes, the English Macintosh and the Flexiblade (a levering laryngoscope), were compared in a clinical setting. An investigation was carried out in 100 patients admitted for surgery under general anaesthesia, to compare intubation with the Flexiblade or the Macintosh laryngoscope. The patients had two anatomical characteristics that may predict difficult intubation - Mallampati score II and III, and a thyromental distance

Design evaluation of commonly used rigid and levering laryngoscope blades.

BACKGROUND: The shape of a laryngoscope blade affects the exposition of the larynx. This study evaluates and compares some rigid and levering blade designs based on previous investigative X-ray laryngoscopic studies. METHODS: Five rigid laryngoscope blades (Miller #3, Standard Macintosh #3, Classical Macintosh #4 and English-Macintosh #3 and #4) and two levering laryngoscope blades (McCoy in neutral and maximally elevated positions and Flexiblade in three basic positions: straight, neutral, and maximally curved) were evaluated. This study assesses two parameters derived from the depth of insertion: the eye line deviation from the ideal straight view line to the vocal cords, and the space occupied by the blade behind the mandible, which affects the contact of the blade tip with the base of the tongue. RESULTS: The best results on larynx exposition were produced by the English-Macintosh #4 at all insertion depths between 5 and 14 cm. It surpassed the Classical Macintosh #4 and both the English and Standard Macintosh #3. Although the Miller and the Flexiblade in a straight position afford a nearly ideal view line, both blades reduce the space reserved for the tongue behind the mandible. The McCoy with its tip maximally elevated provides limited view, while activation of the Flexiblade provides various ranges of larynx exposition. CONCLUSION: The difference in shape and design of Macintosh blades affects their performance. The distal portion of a large-sized curved blade is more effective than the full length of a shorter blade. The #4 English Macintosh is a better choice for routine clinical use. The Flexiblade performs as a multiblade device and can therefore be used for both routine and difficult intubations.