Part of "Chapter 6 - Preoperative Care"
Preoperative care includes not only preoperative evaluation and laboratory testing, but also any medical or gynecologic management in the months preceding the surgical procedure to help achieve maximal physical status.
Achieving this goal is rewarded by a less complicated surgical procedure with better outcomes. Examples of this medical or gynecologic management includes a number of options. Ovarian suppression through the use of a gonadotropin-releasing hormone agonist in the 3 months before surgery has proven to be beneficial in hysteroscopic resection of uterine submucous leiomyomas larger than 2 cm in size and in myomectomies when the uterine volume is equivalent to or larger than a 12-week pregnant uterus size. A similar suppression is also useful in decreasing the thickness of the endometrial lining in an endometrial ablation, although an endometrial suction curettage can achieve a somewhat similar result. Perioperative antibiotic treatment of postmenopausal women undergoing reparative surgery for genital prolapse can be beneficial in reducing recurrent cystitis but has not been shown to significantly alter the outcome of surgery.
Use of preoperative vaginal estrogen cream starting 4 to 6 weeks before surgery may help in controlling uropathogens as well as thickening the vaginal mucosa, which results in an easier dissection of the vagina and in reducing postoperative morbidity. Routine preoperative endometrial sampling before hysterectomy has not been found to be cost effective unless there is suspicion of endometrial pathology such as manifested by abnormal perimenopausal or menopausal bleeding or the presence of abnormal glandular cells on Papanicolaou smear. In the latter case endocervical sampling additionally is necessary.
Another area of preoperative planning requiring an experienced decision by the gynecologist and possibly the anesthesiologist is the regulation of medications taken by the patient prior to surgery. When and how to modify insulin in diabetic women, surgery on women taking anticoagulants, and continuation or discontinuation of birth control pills are examples of issues that must be addressed in the preoperative period and conveyed to the patient in a manner that she understands. Because of the uniqueness of each patient it is not possible to provide a table of preoperative medication management that can be applied to every patient. However, some general suggestions serve as guidelines in the preoperative management of the more common concurrent diseases.
Preoperative insulin control in patients with diabetes is thought to be essential to achieve good surgical outcome. Older animal data has shown a relationship between hyperglycemia and wound healing with reduced tensile strength and wound failure. Experience has suggested a similar relationship in the gynecologic patient. It is therefore important to co-manage each diabetic woman undergoing gynecologic surgery with her primary care physician or internist to achieve this optimal control, and once achieved to continue the insulin regime right up to the time of surgery. Every attempt should be made to schedule the diabetic patient's surgery as a first morning case to minimize the time period between the patient's last oral intake and the onset of the surgical procedure. A protocol for patient preoperative management of insulin regulation may be found in Table 6.5. Patients who are scheduled for gynecologic surgery who are on coumadin (warfarin), heparin or low-molecular-weight heparin (LMWH) represent another preoperative management issue. A number of options are available for converting the patient from warfarin to heparin.
Experience has suggested that stopping the warfarin 4 to 5 days prior to the planned gynecologic surgery and at the same time converting to low dose heparin 5,000 U subcutaneously every 12 hours provides satisfactory anticoagulation protection. The low-dose heparin can be continued postoperatively until the patient is back on oral feeding, at which time the warfarin can be reinitiated. It is further suggested that these women use elastic stockings or intermittent pneumatic compression (IPC) at the beginning of the surgery and continue with this mechanical support through to the point of full postoperative ambulation.
TABLE 6.5. Recommendation for Preoperative Insulin Management Classic “Nontight Control”
Regimen of Roizen
Day before surgery: Patient should be given nothing by mouth after midnight; a 13-ounce glass of clear orange juice should be at the bedside or in the car for emergency use.
At 6 a.m. on the day of surgery, institute intravenous fluids using plastic cannulae and a solution containing 5% dextrose, infused at a rate of 125 mL/h/70 kg body weight.
After institution of intravenous infusion, give one-half the usual morning insulin dose (and usual type of insulin) subcutaneously.
Continue 5% dextrose solutions through operative period, giving at least 125 mL/h/70 kg body weight.
In recovery room, monitor blood glucose concentration and treat on a sliding scale.
Roizen MF. Anesthetic implications of concurrent diseases. In: Miller RD, ed. Anesthesia, 5th ed. Philadelphia: Churchill Livingstone, 2000:903, with permission.
Another preoperative medication issue involves the continuation or discontinuation of oral contraceptive pills prior to gynecologic surgery. Studies in the 1970s suggested a relationship between use of
preoperative oral contraceptive pills and intraoperative or postoperative venous thrombosis. For this reason it has been the practice to discontinue oral contraceptive pills 2 to 4 weeks before surgery and convert to mechanical contraception. This practice, however, is unsupported by any current prospective controlled studies and places the patient at risk for unwanted pregnancy as well as menstrual
irregularities. Therefore, routine discontinuation of oral contraception prior to gynecologic surgery is not recommended, but instead mechanical venous support such as elastic stockings or intermittent pneumatic compression be used at the time of surgery.
The immediate preoperative preparation of the patient includes the preoperative examination by the gynecologic surgeon and the anesthesia assessment in the anesthesia preoperative clinic or by an individual anesthesiologist. In most cases the assessment for anesthesia risks is accomplished before the day of surgery. If significant anesthesia risk is present, such as cardiovascular or pulmonary pathology, this allows time for relevant information to be obtained, additional testing accomplished, other consultation carried out, and treatment instituted in an attempt to have the patient in optimal condition on the day of surgery. In some cases involving low-risk ambulatory procedures, however, the anesthesia assessment is accomplished on the day of surgery. Experience suggests that an open dialog between the gynecologic surgeon and the anesthesiologist regarding the planned surgery is an essential element in achieving a successful outcome with the lowest patient risk.
Most gynecologic surgical patients are admitted on the day of surgery. Because of this, preoperative guidelines and instructions for patient activity and actions at home are important and need to be made clear to every patient. The goal is to have the patient rested and in the optimal physical condition with an empty stomach and reduced contents in the lower gastrointestinal tract at the time of surgery. There is no evidence to support the idea that marked reduction of activity on the day before surgery is beneficial;
however, it would be reasonable to recommend planning activities so that the patient is not overstressed.
Food intake on the day before surgery need not be restricted except for the evening meal before the morning of surgery, which should be light and easily digestible. An overloaded intestinal tract during surgery is particularly hazardous not only because it poses an anesthetic risk but also because it increases postoperative nausea and gas formation. The patient should be instructed to not eat or drink after midnight on the evening before surgery unless the surgery is scheduled for the late afternoon. Some exceptions to this rule might occur with the taking of indicated medications with water. Such an exception should be discussed between the gynecologist and the anesthesiologist in the preoperative evaluation sessions. Women who are scheduled for a late afternoon surgery may have a light breakfast of a liquid
diet if taken no fewer than 6 hours preoperatively.
Women undergoing major abdominal surgery in which bowel entry or injury is anticipated (or is a high probability) should undergo a complete bowel prep. This bowel preparation should consist of the single use of a commercially available cleansing preparation such as GoLYTELY or NuLYTELY (Braintree Laboratories, Inc., Braintree, MA). In all other major abdominal cases the lower colon should be cleansed by a preoperative enema the evening before surgery. If the colon is not completely emptied, then a repeat enema may need to be given prior to performing the operation, allowing adequate time for evacuation. The patient needs to be given careful instructions for the use of enemas at home and the possible need for a repeat enema in the hospital prior to surgery. This issue is often overlooked in preoperative care and results in a more difficult surgical procedure because of space limitation and a less comfortable patient in the postoperative period. An adequate night's rest before surgery is also important for the patient. In some cases the use of a mild sedative is advisable.
Preoperative prophylactic broad-spectrum antibiotics or surgical antimicrobial prophylaxis has frequently been used in gynecologic surgery on the basis of the potential for vaginal flora contamination of the operative field and because of the close proximity of the rectum and intestinal tract. Data do not support the routine use of preoperative broad-spectrum antibiotics in uncomplicated, noninfected gynecologic surgery except in the case of vaginal hysterectomy or possibly abdominal hysterectomy. In these procedures the occurrence of postoperative cuff cellulitis and pelvic abscess has been significantly reduced with use of a preoperative antibiotic. First-, second-, or third-generation cephalosporins (e.g., cefazolin, cefotetan, or cefotaxime, 2 g i.m./i.v.) are effective as a prophylactic coverage, as are many of the semisynthetic penicillin family (e.g., ampicillin 1g i.m./i.v.) or the semisynthetic broad spectrum B-lactamase penicillin combinations (e.g., piperacillin tazobactam 3.75 g i.v. or ticarcillin clavulanate 3.1 g i.v.). When used, the prophylactic antibiotic should be given as a single dose approximately 1 to 2 hours prior to beginning surgery and may be repeated if the operation lasts longer than 3 hours or if there is significant blood loss (in excess of 1,500 mL). If the preoperative examination and testing identifies vaginal infections such as bacterial vaginosis, treatment prior to surgery with metronidazole intravaginal gel (0.75%) or clindamycin vaginal cream (2%) should be accomplished. In like manner, any sexually
transmitted disease discovered during preoperative examination and testing should be fully treated prior to surgery.
Infections occurring after surgery in the female reproductive tract arise from the introduction of normal vaginal flora into the surgical field. Surgery on the reproductive tract accomplished through a
bacteriologically contaminated field (e.g., the vagina), seeds bacteria into the pedicles and surgical margins of pelvic tissues and provides an excellent nidus for infection in devitalized tissue beds.
Therefore, pelvic surgery provides an ideal condition for aerobic (principally polymicrobial rather than monomicrobial) infections. Tissue destruction and sutures lowers the tissue oxidation-reduction (redox) potential. Lower tissue oxygen levels enhance the growth of facultative anaerobes that normally inhabit the vagina. As tissue hypoxia progresses, primary anaerobic bacteria survive and proliferate. Therefore, the usual postoperative infection in the vaginal vault, although initially polymicrobial, usually can be prevented with the use of the preoperative prophylactic antibiotic when the vaginal apex has been opened during a vaginal or abdominal hysterectomy.
Although prophylactic antibiotics are effective in reducing the incidence of postoperative infectious morbidity, they should never be used as a substitute for the time-honored principles of adequate
hemostasis and gentle handling of tissue. Despite Wangensteen's disparaging statement that, “antibiotics will turn a third-class surgeon into a second-class surgeon, but will never turn a second-class surgeon into a first-class surgeon,” current data suggest that even in the hands of a highly skilled surgeon prophylactic preoperative antibiotics offer improved outcomes in gynecologic pelvic surgery such as vaginal and abdominal hysterectomy.