UBP 2.7 (Short Form): Urology – TURP

Question 1

If this patient called you the day before surgery, what dose of insulin would you recommend he take prior to surgery?

(A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and stent placement at that time. His past medical history includes HTN, Type II DM, GERD, CAD, impotence, and hypothyroidism. His medications include HCTZ, lisinopril, synthroid, plavix, NPH insulin, and Lantus. Vital signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight = 82 kg.)

Answer 1

In order to reduce the risk of hypoglycemia secondary to preoperative fasting, I would – recommend that he take 2/3 of his normal dose of Glargine (Lantus) the night before, and avoid taking any diabetic medications the morning of surgery.

When the patient arrived the morning of surgery, I would –

• check the patient’s blood glucose level;
• consider starting an insulin infusion combined with an infusion of D5 1/2 NS (providing carbohydrate inhibits protein catabolism and hepatic glucose production); and
• check the patient’s serum glucose at least hourly during the perioperative period.

My goal would be to maintain a blood glucose level of 110-150 mg/dL throughout the perioperative period, while avoiding hypoglycemia

(some sources give an upper limit of 180 mg/dL, but there is evidence of improved outcomes when blood glucose levels are maintained below 150 mg/dL in the perioperative period).

If the patient were already in the hospital, I would start an insulin infusion the night before surgery and provide close monitoring of his serum glucose to avoid hypoglycemia.

Question 2

What would be your target blood glucose for this patient?

(A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and stent placement at that time. His past medical history includes HTN, Type II DM, GERD, CAD, impotence, and hypothyroidism. His medications include HCTZ, lisinopril, synthroid, plavix, NPH insulin, and Lantus. Vital signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight = 82 kg.)

Answer 2

As I mentioned, my goal would be to maintain blood glucose levels between 110-150 mg/dL.

Although tight glycemic control does increase the risk of perioperative hyoglycemia,

• it may improve wound healing;
• reduce the rate of infection;
• avoid exacerbating CNS injury associated with ischemia in the presence of increased serum glucose; and
• decrease the risk of dehydration secondary to osmotic diuresis.

Therefore, I would exercise a strategy of tight glycemic control, while at the same time, providing close monitoring of the patient’s serum glucose to avoid perioperative hypoglycemia (check the serum glucose hourly, or even every 30 minutes for patients with higher insulin requirements).

Question 3

Would Hgb A1C be helpful?

(A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and stent placement at that time. His past medical history includes HTN, Type II DM, GERD, CAD, impotence, and hypothyroidism. His medications include HCTZ, lisinopril, synthroid, plavix, NPH insulin, and Lantus. Vital signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight = 82 kg.)

Answer 3

A measure of the patient’s Hgb A1C would be helpful in assessing –

• his long-term glycemic control and,
• indirectly, his risk of end organ damage.

A reaction that occurs when hemoglobin is exposed to glucose results in glycosylated hemoglobin and the percentage of glycosylated hemoglobin molecules (measured by the Hgb A1C) is proportional to the patient’s serum glucose levels over the past 30-90 days. (the lifespan of a red blood cell).

This measure of long term glucose control is important because long-standing uncontrolled diabetes leads to –

• peripheral and autonomic neuropathy,
• coronary artery disease,
• HTN,
• increased risk of aspiration (gastroparesis), and
• renal insufficiency.

Therefore, I would conduct a focused history and physical to try and identify and determine the severity of any end organ disease associated with poorly controlled diabetes.

For example, this patient’s HTN and CAD may represent macrovascular complications of poor long-term glycemic control.

Other complications associated with poor glycemic control include – nephropathy, peripheral neuropathy, retinopathy, and autonomic neuropathy.

Question 4

Would you recommend discontinuing his ACE inhibitor prior to surgery?

(A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and stent placement at that time. His past medical history includes HTN, Type II DM, GERD, CAD, impotence, and hypothyroidism. His medications include HCTZ, lisinopril, synthroid, plavix, NPH insulin, and Lantus. Vital signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight = 82 kg.)

Answer 4

Due to the increased risk of significant perioperative hypotension associated with blockade of the angiotensin system, I would – recommend that his ACE inhibitor be discontinued 12-24 hours prior to surgery.

Moreover, this diabetic patient with resting tachycardia and impotence may suffer from significant diabetic neuropathy, further predisposing him to intra-operative hemodynamic instability.

This would be consistent with the recommendations of The American College of Physicans concerning preoperative discontinuation of ACE inhibitors and angiotensin receptor blockers.

However, some practitioners question this recommendation, and there is evidence demonstrating that patients on ACE inhibitors experiencing perioperative hypotension respond adequately to clinical doses of ephedrine and phenylephrine.

Therefore, I would not cancel or delay this case if this patient had taken his ACE inhibitor on the morning of surgery.

I would, however, consider using etomidate for induction and be prepared to quickly treat the occurrence of significant hypotension with fluids, trendelenburg positioning, ephedrine, and/or norepinephrine.

Question 5

How would you evaluate this patient’s cardiac status? Does he need further testing prior to surgery?

(A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and stent placement at that time. His past medical history includes HTN, Type II DM, GERD, CAD, impotence, and hypothyroidism. His medications include HCTZ, lisinopril, synthroid, plavix, NPH insulin, and Lantus. Vital signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight = 82 kg.)

Answer 5

First, I would perform a careful history and physical focused on the patient’s coronary artery disease, previous myocardial infarction, hypertension, diabetes, and all related surgical and pharmacological interventions (i.e. PTCA and stent placement).

This would include a review of previous medical records and tests related to cardiac function.

More specifically, I would like to determine the severity of his coronary artery disease, the affected coronary vessels, the type of coronary stent utilized, the patient’s coagulation status, and whether medical management has been optimized.

I would also attempt to identify any signs of autonomic neuropathy (patients with diabetic autonomic neuropathy may experience painless myocardial ischemia), cardiovascular instability (secondary to his hypertension), and/or myocardium at risk (angina, exercise intolerance, shortness of breath, etc.).

Since his coronary artery disease and insulin dependent diabetes place him at elevated risk for a major adverse cardiac event (MACE) (see below in Clinical Notes), I would: –

1. determine his functional status.
2. If his functional status were > 4 METs, I would – proceed with surgery without further testing.
3. If, however, his functional capacity were poor ( < 4 METs) or unknown (e.g. sedentary lifestyle), I would – consult with the surgeon and patient in an attempt to determine if the results of further cardiac testing would alter her care (e.g. would the surgeon still proceed with surgery or would the patient agree to undergo prior CABG or percutaneous coronary intervention).
4. If it were decided that positive test results would alter the management plan, I would – consider pharmacological stress testing (e.g. dobutamine stress echocardiography) to identify any myocardium at risk.

Clinical Notes:

• RCRI (Revised Cardiac Risk Index)
  
  • Predictors:
    
    1. History of ischemic heart disease
    2. History of compensated or prior heart failure
    3. History of cerebrovascular disease (stroke or TIA)
    4. Insulin-dependent diabetes mellitus
    5. Renal insufficiency (creatinine >/= 2 mg/dL)
    6. Undergoing supra-inguinal vascular, intraperitoneal, or intrathoracic surgery
• According to the 2014 ACC/AHA Guidelines:
  
  • 0-1 Predictors: = Low-risk of MACE
  • >/= 2 Predictors: = Elevated-risk of MACE

Question 6

You learn that the patient had a drug-eluting stent placed. Would you delay this elective surgery?

(A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and stent placement at that time. His past medical history includes HTN, Type II DM, GERD, CAD, impotence, and hypothyroidism. His medications include HCTZ, lisinopril, synthroid, plavix, NPH insulin, and Lantus. Vital signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight = 82 kg.)

Answer 6

Due to the high risk of stent thrombosis with subsequent myocardial ischemia and even death, this elective procedure, which would likely require the discontinuation of his thienopyridine therapy (clopidogrel), should be postponed for at least 365 days following drug eluting stent placement to allow for continued dual antiplatelet therapy (Class I recommendation – 2014 ACC/AHA Guidelines).

In a situation where it has been at least 180 days since drug-eluting stent placement, and the risk of further delaying surgery is considered to be greater than the expected risk of ischemia and stent thrombosis, proceeding with elective noncardiac surgery could be considered.

This is because with newer generation drug-eluting stents, the risk of stent thrombosis stabilizes about 6 months after implantation (Class IIb recommendation – 2014 ACC/AHA Guidelines).

• Clinical Note:*
• In the case of bare metal stent placement, elective surgery requiring the discontinuation of dual antiplatelet therapy should be delayed for at least 30 days.

Question 7

Let’s assume that bare metal stents were placed and his Plavix has been discontinued for 6 days. So, you decide to proceed with the case. What concerns do you have in caring for this patient?

(A 67-year-old male is scheduled for transurethral resection of the prostate (TURP). He has a history of COPD, but stopped smoking 8 years ago. He had a non-ST segment elevation myocardial infarction 4 months ago, and underwent percutaneous transluminal angioplasty (PTCA) and stent placement at that time. His past medical history includes HTN, Type II DM, GERD, CAD, impotence, and hypothyroidism. His medications include HCTZ, lisinopril, synthroid, plavix, NPH insulin, and Lantus. Vital signs: BP = 168/84 mmHg, HR = 104, RR = 20, Temp = 36.8 C, Weight = 82 kg.)

Answer 7

I have several concerns for this patient.

My primary concerns center around his –

coronary artery disease and subsequent risk of perioperative myocardial ischemia.

I am also concerned about perioperative complications associated with –

• his diabetes mellitus,
• hypertension (also consider: preoperative discontinuation of his ACE inhibitor → rebound hypertension and tachycardia),
• COPD,
• stent thrombosis (especially since his Plavix has been discontinued),
• hypothyroidism, and
• possible autonomic neuropathy (the patient’s resting tachycardia and impotence are consistent with this condition).

Additionally, I am concerned about the specific complications associated with –

transurethral resection of the prostate (TURP),

including hypothermia, bladder perforation, hemorrhage, hemolysis, fluid overload, disseminated intravascular coagulation (DIC), septicemia, hyponatremia, hyperglycinemia (glycine), hyperammonemia (glycine), and hyperglycemia (sorbitol).