From the Guidelines
Preoperative labs showing hyperglycemia, hyperkalemia, and elevated BUN/creatinine ratio are not acceptable for clearance for eye surgery under local anesthetic without further evaluation and possible correction. These abnormalities should be addressed before proceeding with surgery, even for procedures using local anesthesia. For hyperglycemia, blood glucose should ideally be controlled to below 180 mg/dL before surgery to reduce infection risk and improve wound healing, as suggested by the target range for blood glucose in the perioperative period of 100-180 mg/dL 1. Hyperkalemia, with a potassium level of 5.4 mEq/L, should be corrected to below 5.5 mEq/L to prevent cardiac arrhythmias during surgery. The elevated BUN/creatinine ratio suggests possible dehydration or renal dysfunction, which should be evaluated and treated with appropriate hydration or medication adjustment. Even though eye surgery under local anesthesia is less physiologically stressful than procedures requiring general anesthesia, these metabolic derangements can still lead to complications such as cardiac events, poor wound healing, or exacerbation of renal dysfunction 1. Key considerations for management include:
- Monitoring blood glucose at least every 2-4 hours while the individual takes nothing by mouth and dosing with short- or rapid-acting insulin as needed 1
- Holding any other oral glucose-lowering agents the morning of surgery or procedure and giving half of NPH dose or 75-80% doses of long-acting analog or insulin pump basal insulin based on the type of diabetes and clinical judgment 1
- The anesthesiologist and surgeon should be consulted to determine if the surgery needs to be postponed until these abnormalities are corrected, or if the procedure can proceed with appropriate perioperative management and monitoring.
From the Research
Preoperative Clearance for Eye Surgery under Local Anesthetic
The provided lab results show hyperglycemia (glucose 181), hyperkalemia (potassium 5.4), and an elevated BUN/creatinine ratio (29).
- Hyperglycemia: According to 2, the metabolic changes in connection with fasting, anesthesia, and surgery in diabetic patients are reviewed, and various perioperative forms of treatment are described. However, this study does not directly address the acceptability of hyperglycemia for preoperative clearance.
- Hyperkalemia: None of the provided studies directly address the acceptability of hyperkalemia for preoperative clearance for eye surgery under local anesthetic.
- Elevated BUN/creatinine ratio: None of the provided studies directly address the acceptability of an elevated BUN/creatinine ratio for preoperative clearance for eye surgery under local anesthetic.
Acceptability of Labs for Preoperative Clearance
The provided studies do not directly address the acceptability of the given lab results for preoperative clearance for eye surgery under local anesthetic. However, 3 and 4 discuss the safety of continuing anticoagulant and antiplatelet therapy during cataract surgery, which may be relevant to the overall preoperative assessment. Additionally, 5 reviews the literature on visual loss as a complication of non-ophthalmic surgery and discusses the importance of careful patient positioning and monitoring, but does not directly address lab results.
Relevance of Provided Studies
While the provided studies do not directly address the acceptability of the given lab results, they do provide information on the safety of certain medications and procedures during eye surgery. For example, 3 and 4 suggest that anticoagulant and antiplatelet therapy can be safely continued during cataract surgery, and 6 discusses the choices of local anesthetic solutions for ocular surgery. However, the studies do not provide clear guidance on the acceptability of hyperglycemia, hyperkalemia, and an elevated BUN/creatinine ratio for preoperative clearance.