Cimetidine versus ranitidine: single-dose, oral regimen for reducing gastric acidity and volume in ambulatory surgery patients.

This placebo-controlled trial compared the efficacy of single oral doses of cimetidine or ranitidine in maintaining intragastric pH and volume greater than 2.5 and less than 25 ml, respectively, in ambulatory surgery patients requiring general anesthesia. Patients were randomized to receive either placebo, ranitidine HCl 150 mg, or cimetidine HCl 400 mg upon rising on the morning of surgery. At induction, the cimetidine and ranitidine groups had significantly higher (p less than 0.05) gastric pH values than the placebo group. At extubation, the ranitidine group had a significantly higher (p less than 0.05) gastric pH than either the cimetidine or placebo group. Both H2-blocker groups had lower volumes when compared with the placebo group at extubation (p less than 0.05). There were more patients at risk for aspiration pneumonitis (pH less than 2.5 and/or volume greater than 25 ml) in the cimetidine group (46 percent) than in the ranitidine group (15 percent). All placebo-treated patients were at risk for aspiration pneumonitis. We did not find subjective clinical evidence of aspiration pneumonitis in our patients. We conclude that both ranitidine and cimetidine are superior to placebo, but ranitidine may be the preferred agent because of its more consistent effect on gastric pH and volume.

Preoperative physical therapy in primary total knee arthroplasty.

In order to evaluate the efficacy of preoperative physical therapy for patients undergoing elective primary total knee arthroplasty, 10 patients completed 6 weeks of physical therapy before surgery (PT group). Ten patients served as controls (C group). Subjects were tested at baseline (PT only), before surgery, 6 weeks after surgery, and 3 months after surgery using the Hospital for Special Surgery knee rating scale, range of motion, thigh circumference, walking speed, Cybex II isokinetic knee flexion, and extension testing, and computed tomography scanning for cross-sectional muscle area. Hospital stay and need for physical therapy after inpatient rehabilitation were also compared. Physical therapy produced modest gains in isokinetic flexion strength in these severely arthritic knees but no difference in extension strength. The decrease in isokinetic strength after surgery was not affected by preoperative physical therapy. Muscle area did not decrease significantly for the PT group, but it did decrease for the C group after surgery. While postoperative strength differences could not be demonstrated, preoperative physical therapy preserved thigh muscle area after surgery. The clinical significance of this finding is uncertain. Consequently, this study failed to support the routine use of preoperative physical therapy in knee replacement surgery.