Peri-op  

THE BELLFLOWER PERIOPERATIVE POCKET MANUAL
Maracus Magallanes, MD 2001

6. ENDOCRINOLOGIC CONCERNS

DIABETES

*Perioperative morbidity/mortality is significantly higher in diabetic patients as a group, particularly with regard to infection and cardiac complications. (Diabetics have a 3-4 times greater incidence of MI in general.) However, several studies suggest that diabetes itself may NOT be an independent risk factor for cardiac morbidity/mortality after surgery. This is still a controversial issue.

The traditional goal for BS control perioperatively has been in the 150 to 250 range. Newer data suggests benefit in keeping the BS lower at between 100 to 200.

(SS = sliding scale and RR = recovery room in the following guidelines.)

DIET-CONTROLLED DIABETICS

PRE-OP: no specific intervention.

INTRA-OP: check BS upon arrival to OR. If BS <200, no specific intervention necessary. If BS >200, manage as Type II DM on oral agents.

POST-OP: SS regular insulin SQ q6 hrs until eating, then qAC + qHS.

TYPE II DM on oral agents

PRE-OP: hold all oral agents on the day of procedure.

INTRA-OP: check BS upon arrival to OR and then post-op in RR. Cover with SS regular insulin SQ. *Alternatively, if BS control is more of a concern, check BS upon arrival to OR and q2 hrs intraoperatively; cover with SS regular insulin IVP (instead of SQ). IVF should have D5 in it.

POST-OP: SS regular insulin SQ q6 hrs until taking PO's, then qAC + qHS. Continue IVF with D5 in it until taking PO's. Resume oral agents when PO's are adequate, with the exception of metformin. It is recommended that metformin be held throughout the hospitalization.

TYPE II DM on INSULIN

PRE-OP: ½ of total morning insulin dose to be given only as SQ NPH on the morning of surgery.

INTRA-OP: manage as Type II DM on oral agents.

POST-OP: one effective strategy is a standing dose of SQ regular insulin q6 hrs (based on usual total daily insulin requirement divided by 4-but generally I'll start off with less than that) AND additional SS regular insulin SQ q6 hrs until taking PO's, then qAC + qHS. Continue IVF with D5 in it until taking PO's. Switch back to usual insulin regimen when PO's are adequate.

TYPE I DM

PRE-OP: ½ of total morning insulin dose to be given only as SQ NPH on the morning of surgery.

INTRA-OP: check BS upon arrival to OR and q1-2 hrs intra-operatively. Cover with SS regular insulin IVP, or run insulin drip IVPB and adjust rate based on BS readings. IVF should have D5 in it.

POST-OP: again, one effective strategy is a standing dose of SQ regular insulin q6 hrs (based on usual total daily insulin requirement divided by 4-but generally I'll start off with less than that) AND additional SS regular insulin SQ q6 hrs until taking PO's, then qAC + qHS. Continue IVF with D5 in it until taking PO's. Switch back to usual insulin regimen when PO's are adequate.

UNCONTROLLED DM

*Goal is to control blood sugar pre-operatively prior to elective procedure.

*If blood sugar is severely uncontrolled but patient MUST go to the OR for an urgent/emergent procedure, then manage with an insulin drip-begin before the OR to try to control sugars as much as possible. May also give bolus regular insulin IVP acutely for very high blood sugars.

SAMPLE SLIDING SCALES (regular insulin only)

SQ or IVP: BS 200-249, give 2 units; 250-299, give 4 units; 300-349, give 6 units; 350-399, give 8 units; 400 or more, give 10 units. (NOTE: this is a LOW sliding scale. Units may easily be doubled or tripled depending on insulin resistance.)

*If tighter control is desired, begin coverage at BS 150.

*Patients on TPN should simply have insulin put in the bag (in addition to some sliding scale coverage). Sugars will run higher and be more difficult to control when TPN is on-board.

INSULIN DRIP: Mix 50 units regular insulin in 500cc ½NS = 1 unit/10cc.

BS under 80, give one amp D50 IVP and hold drip; 80-99, hold drip only; 100-149, run 1unit/hr; 150-199, run 1½ units/hr; 200-249, run 2 units/hr; 250-299, run 2½ units/hr; 300-349, run 3 units/hr; 350-399, run 3½ units/hr; 400 or more, run 4 units/hr AND give additional IVP insulin dose (10-20 units).

*Continuous IVF containing dextrose should be run with insulin drip. This IVF can be written to hold for BS over 250 (or 300).

*Insulin requirement may increase manifold in the presence of obesity, infection, steroids, etc. Scale usually needs to be adjusted.

*BS check on insulin drip should be every 1 or 2 hours.

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THYROID DISEASE      Hyperthyroidism  |  Hypothyroidism

HYPERTHYROIDISM

*Perioperative morbidity/mortality is generally increased in patients with untreated hyperthyroidism, particularly Graves' disease; the greatest risk is associated with thyroid storm, which may be precipitated by surgery.

MANAGEMENT:

1) Beta-blockers-all are useful in thyrotoxicosis, although propranolol may have some theoretical advantage over the more selective beta-blocking agents. (Propranolol decreases peripheral conversion of T4 to T3.) Titrate to HR (if possible, keep resting HR at 80 or less).

2) Anti-thyroid agents-PTU (or methimazole). For rapid initiation, give loading dose of PTU 1000 mg followed by 100 mg TID. Only PO forms of PTU or methimazole are available.

3) Iodide-acute inhibitor of thyroid hormone release. It is particularly useful in thyrotoxic patients who need to go to surgery urgently. Give Sodium Iodide 1000 mg IV q 8 to 12 hrs OR a single dose of Orograffin 3 gm PO. (Ideally, the iodide should be administered only after PTU has been started.)

4) Stress dose steroids-Hydrocortisone 100 mg IV q8 hrs for thyrotoxic patients, beginning at the start of surgery; taper postoperatively as acute stress subsides and hyperthyroidism is under control.

5) Fluid management (high insensible losses) and arrhythmias (particularly atrial fib and SVT).

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HYPOTHYROIDISM

*Perioperative morbidity/mortality is significantly increased in patients with untreated severe hypothyroidism; however, the surgical risk in patients with mild to moderate disease is unclear (even if untreated) but in all likelihood it is just slightly increased in this group, if at all.

MANAGEMENT:

1) Thyroid replacement therapy-Synthroid 50 to 100 mcg daily can be given for mild to moderate disease. If hypothyroidism is severe and surgery is to be performed urgently, a loading dose of Synthroid 500 to 1000 mcg can be given followed by the daily maintenance dose. (If needed, an IV form of Synthroid can be administered as a slow infusion over 30 minutes.)

2) Stress dose steroids-recommended for severely hypothyroid patients only. Give hydrocortisone 100 mg IV q 8hrs; taper postoperatively as acute stress subsides and thyroid replacement has taken effect.

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