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Case studies in perioperative management: Challenges, controversies, and common ground

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ABSTRACT

This collection of case studies is designed to illustrate challenging and controversial aspects of perioperative medicine. The authors guide readers through four case narratives punctuated by practical multiple-choice questions followed by the authors’ commentary on the evidence supporting various answer choices and related considerations. The objective is to examine issues and key evidence that should inform the decision-making process in important aspects of perioperative management.


 

References

CASE 1: RADICAL PROSTATECTOMY IN A MAN WITH ACUTE DEEP VEIN THROMBOSIS

A 69-year-old man is seen in the preoperative clinic 1 week before a scheduled radical prostatectomy. He has been diagnosed with femoral deep vein thrombosis (DVT) following a complaint of calf soreness.

Question 1.1: How would you treat him for his DVT?

A. Intravenous (IV) unfractionated heparin (UFH)

B. Low-molecular-weight heparin (LMWH)

C. Inferior vena cava (IVC) filter

D. Combination of pharmacologic therapy and then an IVC filter

Dr. Steven L. Cohn: The latest edition of the American College of Chest Physicians (ACCP) evidence-based guidelines on antithrombotic therapy recommends the use of therapeutic-dose subcutaneous LMWH over IV UFH for initial treatment of acute DVT in the outpatient or inpatient setting.1 Additionally, indications for an IVC filter include the prevention of pulmonary embolism (PE) in a patient with DVT who requires full-dose anticoagulation but cannot receive it, as would be the case here if the patient proceeds with surgery as scheduled. So if surgery will be postponed, the best option is LMWH; if surgery will not be postponed, the best answer is a combination of pharmacologic therapy with low-dose LMWH and an IVC filter, preferably a retrievable one.2

Question 1.2: You recommend postponing surgery, but the patient is worried about metastatic disease. For how long should surgery be postponed?

A. 2 weeks

B. 1 month

C. 2 months

D. 3 months

E. 6 months

Dr. Cohn: In the absence of anticoagulation therapy, the risk of venous thromboembolism (VTE) is approximately 40% (~1% per day) during the first month following an acute VTE and then declines markedly, to approximately 10%, during the second and third months following the acute event.3 Therefore, I would suggest that the patient wait at least 1 month after an acute DVT before undergoing surgery.

Dr. BobbieJean Sweitzer: This patient is in a hypercoagulable state, and the surgery itself will induce excess hypercoagulability. With a femoral DVT already present, his risk of VTE or PE is likely to be greater than 1% per day during the first month. If he does develop a PE, it may potentially be fatal.

Question 1.3: According to the patient, the surgeon and the internist discussed options, but the surgeon “doesn’t believe in filters” and the patient doesn’t want to postpone the procedure, despite your recommendation. Two weeks later he shows up for surgery having stopped his LMWH 3 days before. What would you do?

A. Cancel the surgery and restart full-dose LMWH

B. Proceed with prophylactic-dose LMWH

C. Proceed after giving a full therapeutic dose

D. Insert a filter and give DVT prophylaxis

Dr. Cohn: A bridging protocol should have been discussed with the surgeon and anesthesiologist before the procedure. Therapeutic levels of LMWH persist as long as 18 hours after discontinuation; therefore, the ACCP recommends interrupting LMWH 24 hours before surgery.4

Dr. Sweitzer: The lack of a bridging protocol in this case created a problem. The patient was afraid to continue anticoagulation after hearing the internist and surgeon disagree about the plan, and thus stopped it entirely, and he did not want to delay surgery because he was fearful of metastasis. The surgeon was adamant that IVC filters don’t work. The internist was concerned that the patient was at high risk for a PE. Even though the documented risk of postponing radical prostatectomy for a short time is inconsequential, I was convinced that the patient would not believe this if metastasis were to develop in the future.

Question 1.4: How would you have managed his anticoagulation perioperatively?

A. Stop LMWH 12 hours before surgery and restart at full dose 12 to 24 hours after surgery

B. Stop LMWH 24 hours before surgery and restart at full dose 24 hours after surgery

C. Stop LMWH 24 hours before surgery and restart prophylactic dosing 12 to 24 hours after surgery, and then full-dose LMWH in 48 to 72 hours

D. Stop LMWH 24 hours before surgery and restart at full dose 72 hours after surgery

Dr. Cohn: The correct timing for stopping LMWH is 24 hours before surgery. As for how to resume anticoagulation in patients at high risk for VTE or those undergoing major surgery, the latest ACCP guidelines recommend the following4:

  • Reinitiation of anticoagulation 12 to 24 hours postoperatively, assuming adequate hemostasis in patients not at high risk for bleeding
  • Use of a prophylactic dose or no anticoagulation for up to 72 hours if the patient is at high risk for bleeding.

These recommendations are a departure from previous practice, in which we routinely restarted anticoagulation 6 to 12 hours postoperatively.

Dr. Sweitzer: According to guidelines from the American Society of Regional Anesthesia and Pain Medicine (ASRA),5 if twice-daily LMWH is stopped 24 hours ahead of time (as long as patients have normal renal function), it is safe to perform epidural or spinal anesthesia, if either is an option. If full-dose UFH is used, the partial thrombo­plastin time (PTT) is monitored and central neuraxial blockade may be done if the PTT is in the normal range, which typically is 2 to 6 hours after UFH is stopped.

Additionally, the platelet count should be checked every 3 days postoperatively while the patient is on UFH or LMWH. It may be just as important to monitor the platelet count preoperatively if the patient has been on UFH or LMWH for an extended duration, especially if a central neuraxial anesthetic technique is planned.

Dr. Cohn: The reason for monitoring the platelet count is the potential for heparin-induced thrombocytopenia in patients on UFH. I recently encountered a patient who developed postoperative heparin-induced thrombo­cytopenia with thrombosis while on LMWH, which is relatively uncommon compared with UFH.

Case resolution

After much discussion of the risk of a significant PE with the patient, family, urologist, and vascular surgeon, it is decided that a temporary IVC filter will be placed in the operating room immediately after induction of general anesthesia and before the prostatectomy. The operation is delayed about 1 hour to allow this option. The patient is successfully treated and has the IVC filter removed 1 month postoperatively.

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