Vena cava interruption may be necessary in situations in which anticoagulant therapy is ineffective in the prevention of rethrombosis and repeated embolization from the lower extremities or pelvis. A vena cava filter may be inserted percutaneously above the level of the thrombosis and caudad to the renal veins. In most cases, anticoagulant therapy is sufficient to prevent repeat thrombosis and embolism and to allow the patient’s own endogenous thrombolytic mechanisms to lyse the pulmonary embolus.
Management of Medical Problems
Endocrine Disease The three most frequent endocrine disorders that occur in patients undergoing gynecologic surgery are diabetes mellitus, thyroid disease, and adrenal abnormalities. The pathophysiology of these disorders aids in understanding the effects of surgery on patients with these problems.
Diabetes Mellitus According to the American Diabetes Association, 9.3 million American women, or 10.2% of all women older than 20 years, suffer from diabetes (149). Approximately 50% of individuals with diabetes mellitus (DM) will require surgery during their lives (150). Many of these procedures are a direct result of the complications of DM: retinopathy, nephropathy, large-and small-vessel occlusive disease, and coronary artery disease. It is the direct effect of DM on the end organs that determines the risk of surgery, rather than the type or duration of surgery, or the management of the condition itself. Diabetes mellitus is a complicated medical disorder of glucose metabolism that is related to a lack of production of, or resistance to, insulin.
Patients with DM experience exaggerated hyperglycemia during surgery. This hyperglycemia is multifactorial in origin and is secondary to increased catecholamine production, which inhibits pancreatic release of insulin and causes increased insulin resistance at the end organs. Elevations in instrumental hormones, such as cortisol, growth hormone, and glucagon, enhance gluconeogenesis and glycogenolysis (151). Goals of the preoperative assessment and perioperative management are to ensure metabolic homeostasis and to anticipate problems arising from preexisting complications.
Preoperative risk assessment for diabetes should begin with a review of systems. Nocturia, polyuria, polydipsia, glucosuria, obesity, previous gestational diabetes, ethnicity, and family history are relevant aspects of the history. The current criteria for diagnosis of diabetes include (152): 1.
Polyuria, polydipsia, or unexplained weight loss with a random nonfasting glucose of ≥200 mg/dL, or 2.
Fasting glucose ≥126 mg/dL (in which fasting is defined as no food intake for 8 hours), 3. Two-hour oral glucose tolerance test of 75 g, with serum glucose ≥200 mg/dL, or 4. Hemoglobin A1c ≥6.5%.
Confirmation of the diagnosis requires repeating the same test on a different day or concordant results of two different tests simultaneously.
Preoperative risk assessment in the previously diagnosed individual with diabetes should begin with the knowledge of the type of diabetes. Type 1 (insulin dependent) diabetes, or type 2 diabetes (noninsulin dependent), should be established because the perioperative management of each differs. The patient’s routine glucose management strategies, glucose levels, medications, and baseline hemoglobin A1c should be assessed (153). The presence of end-organ complications of diabetes should be documented.