Midazolam and pethidine versus propofol and fentanyl patient controlled sedation/analgesia for upper gastrointestinal tract ultrasound endoscopy: a prospective randomized controlled trial.

BACKGROUND AND OBJECTIVES: The aim of this prospective, randomized study was to compare the standard regimen of midazolam and pethidine administered by the gastroenterologist versus patient controlled sedation with a propofol-fentanyl mixture during upper gastrointestinal tract endoscopic ultrasonography. Our primary end-points were patient satisfaction and patient cooperation assessed by endoscopist. METHODS: Fifty-four consecutive patients, undergoing endoscopic ultrasonography, received sedation with midazolam and pethidine (Group M: n=27) or propofol and fentanyl (Group P: n=27). Group M: pethidine 0.7mg/kg midazolam 0.04mg/kg before examination; boluses of same drugs if the sedation was insufficient plus a sham patient controlled sedation analgesia; Group P: propofol 17mg plus fentanyl 15microg before examination and a patient controlled sedation analgesia pump containing 170mg propofol plus 150microg fentanyl injecting 0.5ml every time the patient pressed the button (no "lock out"). Boluses of 1ml of the same mixture if the sedation was insufficient. RESULTS: Group M: mean dosage of pethidine and midazolam 88.6 and 5mg, respectively. Group P: mean dosage of propofol and fentanyl 119.7mg and 106microg, respectively. Both groups were similar for duration and difficulty of the procedure, the grade of sedation (Observer's Assessment of Alertness/Sedation Score) and judgement by endoscopist and patient about cooperation and satisfaction. The only difference between groups was about the extra boluses administered during the procedure. CONCLUSION: This study demonstrated that a patient controlled sedation analgesia with propofol and fentanyl is an effective and safe technique for upper gastrointestinal tract endoscopic ultrasonography procedures and results in a high level of satisfaction both for patients and operator.

Target-controlled infusion during monitored anesthesia care in patients undergoing EUS: propofol alone versus midazolam plus propofol. A prospective double-blind randomised controlled trial.

BACKGROUND: It has been speculated that midazolam may be effective in reducing the required dose of propofol during sedation. AIM: To evaluate the sparing effect of midazolam during target-controlled propofol infusion. METHODS: Two hundred-seventy patients undergoing upper endoscopic ultrasound were randomised to receive sedation with propofol plus placebo (group A) or plus midazolam (group B). Outcome parameters were the procedure duration, the discharge time and the satisfaction of patients, operator and nurse about the quality of sedation. RESULTS: The mean propofol dose administered was 364+/-207 mg in group A and 394+/-204 mg in group B. Mean procedure duration (group A: 32+/-17 min, group B: 35+/-22 min) and discharge time (group A: 39+/-30 min, group B: 38+/-24 min) were similar in both groups. No severe complications were observed. The quality of sedation was judged satisfactory for all patients by both the endoscopist and the nurse assistant without any difference between the two groups. No patient remembered the procedure or reported it as unpleasant. CONCLUSIONS: Target-controlled propofol infusion provides safe and effective sedation; premedication with low dose of midazolam does not reduce the total amount of propofol administered. Further studies are needed to compare propofol alone with propofol co-administered with opioid.

Squeezed states in second-harmonic generation.

We consider the process of second-harmonic generation with the nonlinear crystal placed in a resonant cavity. Both the fundamental and the second-harmonic mode are shown to exhibit squeezing. An analysis is made for the general values of the ratio between the damping constants of the two modes. We suggest that second-harmonic generation is the most suitable system to use for an experimental observation of the squeezing effect.