Hypokalemia of various etiologies complicating elective surgical procedures

Anti-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor encephalitis developed after ovarian cancer cytoreduction surgery: a case report and literature review

BACKGROUND

Anti-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis, a rare subtype of autoimmune encephalitis (AE), is often found associated with tumors such as thymoma, lung cancer, ovarian tumors, and breast cancer, and the tumors were generally detected during the screening process after the encephalitis initiated. The tumor is considered a trigger of AE, but the mechanism remains unclear.

CASE PRESENTATION

A 53-year-old woman presented short-term memory loss two days after the primary cytoreduction for high-grade serous ovarian cancer (HGSOC, FIGO stage IC3). Cell-based assay found AMPAR CluA2 IgG positive in both serum (1:3.2) and cerebrospinal fluid (1:32). Moreover, mild AMPAR GluA1 and strong GluA2 expressions were also found positive in the paraffin sections of ovarian tumor tissue, indicating the ovarian cytoreduction surgery might stimulate the release of receptor antigens into the circulation system. The patient's condition deteriorated within two weeks, developing consciousness and autonomic dysfunction, leading to ICU admission. With oral steroids, intravenous immunoglobulin, plasmapheresis, and rituximab treatment, the patient's consciousness markedly improved after three months.

CONCLUSION

We presented the first case of anti-AMPAR encephalitis developed right after the primary cytoreduction of a patient with HGSOC and retrieved paraneoplastic anti-AMPAR encephalitis cases (n = 66). Gynecologists should pay attention to patients who develop cognitive dysfunction or psychiatric symptoms shortly after the ovarian tumor resection and always include AE in the differentiation diagnosis.

Clonidine premedication prevents preoperative hypokalemia

STUDY OBJECTIVE

To test the hypothesis that clonidine premedication could prevent an increase of plasma epinephrine occurring as a result of anxiety, and a decrease of the serum potassium (K+) levels before the induction of anesthesia.

DESIGN

Randomized, double-blinded study.

SETTING

University Hospital of Seoul.

PATIENTS

44 ASA physical status I and II patients, aged 20 to 50 years, scheduled for knee, ear, or nose surgery.

INTERVENTION

44 patients were randomly allocated into one of two groups: 22 patients (clonidine group) received clonidine 300 microg orally at 120 minutes before the induction of anesthesia. The other 22 patients (control group) received a placebo.

MEASUREMENTS AND MAIN RESULTS

Anxiety level, serum K+, and plasma epinephrine were measured at an outpatient clinic, and immediately before the induction of anesthesia. There were no differences between groups in degree of anxiety experienced, serum K+, or plasma epinephrine levels as measured at the out-patient clinic. Immediately before the induction of anesthesia, the serum K+ levels of the clonidine group were higher than those of the control group (3.89 +/- 0.26 mEq/L vs. 3.50 +/- 0.36 mEq/L), and anxiety and plasma epinephrine levels of clonidine group were lower than those of the control group (p < 0.05). The frequency of hypokalemia (K+ < or = 3.5 mEq/L) of the clonidine group immediately before the induction of anesthesia was significantly lower than that of the control group (0% vs. 50%).

CONCLUSIONS

Clonidine premedication was effective in preventing hypokalemic episodes occurring before the induction of anesthesia.

The causes of cancelled elective surgery

We reviewed causes of cancelled elective surgery in a community hospital. Over a 6-month period, during which 4100 operating room procedures were completed, cancellations occurred in 13% of cases scheduled for outpatient surgery, 9% of cases scheduled for admission the same day, and 17% of cases scheduled for inpatient surgery. Dental procedures had significantly higher rates of cancellation among outpatient procedures, and cardiovascular surgical procedures had significantly higher rates among inpatient procedures. Chart review of cancelled inpatient cases showed 43% due to administrative reasons with unsigned consent the most common cause. Medical factors were responsible in the remaining cases, with reevaluation of the surgical condition and associated medical illnesses equally common as reasons in this category. Appreciation of the usual reasons for cancellation can improve utilization by permitting administrators and providers to anticipate those cases in which problems might arise so that additional attention can be paid to them.