Preoperative Medication: Sedative Hypnotics and Other Agents and Issues

4Steroids Overview: patients who may need need steroid administration  immediately before surgery Patients being treated for hypoadrenocorticism Patients who have pituitary-adrenal axis suppression due to ongoing or previous steroid treatment -- generally more suppression would be anticipated if the treatment had been for longer duration and at higher dosages General rule: consider preoperative treatment give the patient has been on steroids for one month in the last six months preceding surgery  The major clinical perioperative consequences of  pituitary-adrenal axis suppression is the inability of the patient to respond properly to surgical stress.  Accordingly, supplemental steroid protocols could include: Method #1:  25 mg of cortisol preoperatively followed by IV infusion of 100 mg cortisol during the next 12-24 hours (adult patients) Method #2: administration of 100 mg of hydrocortisone (Cortef, Solu-Cortef) intravenously before, during and then after the procedure.  This approach is an effort to estimate a maximal amount of steroids that would be released in response to surgical stress.  Generally, the risk-benefit ratio for steroid administration and dosage is small. Antibiotics: Antibiotics are considered for administration immediately before surgery for "contaminated, potentially contaminated, or dirty surgical wounds." Prophylactic antibiotics may be used for certain patients groups including: Elderly patients Immunosuppressed patients Patients taking steroids Patients who are at risk for development of endocarditis, including patients with valvular heart disease, patients who have mitral valve prolapse, and patients who have prosthetic valves. The reason that the anesthesia provider is involved in antibiotic administration is that the antibiotics will be administered immediately preceding the surgical procedure-just before potential contamination could occur. Approximately 60%-70% of patients receive antibiotics intraoperatively or just prior to the beginning of the procedure. The antibiotics class most commonly used is the cephalosporins.   Side effects and complications may occur with antibiotic administration.  The side effects may include: allergic reactions hypotension bronchospasm-examples here might be penicillin or vancomycin (Vancocin) Side effect frequency: Approximately 5% of patients have some "allergic" reaction to cephalosporin.  Furthermore, the cross-reactivity between cephalosporins and penicillins is estimated to be about 5%-20% Some antibiotics are noted for their tendency because nephrotoxicity (renal toxicity).   These antibiotics include the aminoglycosides, vancomycin (Vancocin) and polymixins. Ototoxicity is associated both with vancomycin (Vancocin) and aminoglycoside administration. A specific side reaction of clindamycin (Cleocin) use is pseudomembranous colitis.   Aminoglycosides enhanced neuromuscular-blocking properties of muscle relaxants. Insulin: Overview: Because of interruption of normal eating schedules and the stress associated with surgery, specific plans are required to manage the insulin-dependent patient.   Collaboration between the anesthesia provider surgeon and endocrinologist is the basis for determining how insulin will be provided. Several approaches (methods) are available. One approach is the administration of 1/4 to one-half of the usual daily intermediate-acting insulin dose preoperatively in the morning of surgery followed by a glucose-containing fluid infusion. A second approach is the administration of no insulin or no glucose preoperatively accompanied by intraoperative  blood glucose monitoring, allowing regular insulin or glucose administration intraoperatively and postoperatively as required A third approach is based on initiation of insulin and glucose infusion immediately preoperatively along with frequent serum glucose level determinations References: 1Preoperative Medication in Basis of Anesthesia, 4th Edition, Stoelting, R.K. and Miller, R., p 119- 130, 2000)  Hobbs, W.R, Rall, T.W., and Verdoorn, T.A., Hypnotics and Sedatives; Ethanol In, Goodman and Gillman's The Pharmacologial Basis of Therapeutics, pp. 364-367 (Hardman, J.G, Limbird, L.E, Molinoff, P.B., Ruddon, R.W, and Gilman, A.G.,eds) TheMcGraw-Hill Companies, Inc., 1996. 3Sno E. White The Preoperative Visit and Premedication in Clinical Anesthesia Practice pp.  576-583 (Robert Kirby & Nikolaus Gravenstein, eds) W.B.  Saunders Co., Philadelphia, 1994 4John R. Moyers and Carla M. Vincent Preoperative Medication in Clinical Anethesia, 4th edition, 551-565, (Paul G. Barash, Bruce. F. Cullen, Robert K. Stoelting, eds) Lippincott Williams & Wilkins, Philadelphia, PA, 2001 5Gertler, R., Brown, H. C, Mitchell, D.H and Silvius, E.N Dexmedetomidine (Precedex): a novel sedative-analgesic agent, BUMC Proceedings 2001; 14:13-21 (http://www.baylorhealth.com/proceedings/14_1/14_1_gertler.htm)