HIT and heparin alternatives

Took care of a patient who came to OR for a redo-sternotomy and triple valve replacement on ECMO.

Scroll down to see how we managed the patient’s possible HIT.  The patient had a low score on her 4Ts assessment.  Therefore, we opted to move forward before the functional assay came back with results as the patient was in dire need of triple valve replacement.

 


HIT Basics

Heparin Induced Thrombocytopenia and Cardiac Surgery: A Comprehensive Review. J Blood Disord Transfus 2011, S2.

Screen Shot 2018-12-19 at 8.13.39 PM
From https://www.omicsonline.org/open-access/heparin-induced-thrombocytopenia-and-cardiac-surgery-a-comprehensive-review-2155-9864-S2-003.pdf

The goals of treatment for HIT are threefold: Interrupt the pathological immune response, inhibit the uncontrolled generation of thrombin, and minimize the complications.

Cessation of heparin alone does not sufficiently reduce the risk of thrombosis. The next step in management targets the uncontrolled generation of thrombin with the use of direct thrombin inhibitors (DTIs).  Argatroban is preferred in patients with renal insufficiency, whereas lepirudin is the drug of choice for patients with liver disease.  Bivalirudin is another hirudin analog that differs from lepirudin in that it is hemodialyzable and primarily undergoes enzymatic elimination. Its half-life is the shortest, 20-25 minutes, making bivalirudin the safest option since there are no reversal agents available.

All three agents can be monitored using the activated partial thromboplastin time (aPTT) to levels of 1.5 to 2.0 above baseline. Once the platelet count has increased to a minimum of 150,000/µL bridging therapy to warfarin is essential for the safe transition from DTIs.

Iloprost is a prostacyclin analogue that reversibly inhibits platelet aggregation.  Plasma exchange was successful in reducing anti-P4/heparin antibodies and allowed for the restoration of a normal platelet count, essentially reversing the disease.

A-suggested-approach-to-diagnosis-and-initial-management-of-patients-with-suspected-HIT
From https://www.researchgate.net/figure/A-suggested-approach-to-diagnosis-and-initial-management-of-patients-with-suspected-HIT_fig1_236255402

HIT/HITT and alternative anticoagulation: current concepts. BJA: British Journal of Anaesthesia, Volume 90, Issue 5, 1 May 2003, Pages 676–685.

Heparin-induced thrombocytopenia and cardiac surgery. Curr Opin Anaesthesiol, 2010; 23:74–79.

Perioperative care in cardiac anesthesia and surgery.  Chapter 19: HIT and heparin alternatives.  

Handbook of patient care in cardiac surgery. Chapter 2: Operative management.


Prostacyclins in Cardiac Surgery: Coming of Age.  Seminars in Cardiothoracic and Vascular Anesthesia 22(3):108925321774929 · December 2017.

Intraoperative infusion of epoprostenol sodium for patients with heparin-induced thrombocytopenia undergoing cardiac surgery. The Japanese Journal of Thoracic and Cardiovascular Surgery. Volume 54, Issue 8, pp 348–350.

Cardiac Surgery With Cardiopulmonary Bypass in Patients With Type II Heparin-Induced Thrombocytopenia. Ann Thorac Surg 2001;71:678–83.

HIT and urgent open heart surgery: a sticky situation. Grand Rounds, Hematology. UW 2015. 


Screen Shot 2018-12-19 at 8.45.41 PM
From https://www.omicsonline.org/open-access/percutaneous-coronary-intervention-in-patients-with-heparin-inducedthrombocytopenia-case-report-and-review-of-literature-2329-6607-1000202.php?aid=82752

Bivalirudin for Cardiopulmonary Bypass in the Setting of Heparin-Induced Thrombocytopenia and Combined Heart and Kidney Transplantation— Diagnostic and Therapeutic Challenges. Journal of Cardiothoracic and Vascular Anesthesia 31 (2017) 354–364.

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From https://www.jcvaonline.com/article/S1053-0770(16)30273-7/fulltext

Cardiac Bypass Surgery in the Setting of Heparin Induced Thrombocytopenia.  BIDMC guidelines.

Anticoagulation during Cardiopulmonary Bypass in Patients with Heparin-induced Thrombocytopenia Type II and Renal Impairment Using Heparin and the Platelet Glycoprotein IIb–IIIa Antagonist Tirofiban. Anesthesiology 2 2001, Vol.94, 245-251. 

Management of anticoagulation in patients with subacute heparin-induced thrombocytopenia scheduled for heart transplantation. BLOOD, 15 NOVEMBER 2008 VOLUME 112, NUMBER 10; 4024-4027.

Screen Shot 2018-12-19 at 8.56.04 PM
From http://www.bloodjournal.org/content/bloodjournal/112/10/4024.full.pdf?sso-checked=true

 

What we did:

  • Prior to giving heparin, we started alprostadil (PGE1) infusion at 1mcg/min and increased the doseage as tolerated to 5mcg/min.  We did offset the hypotension with levophed and vasopressin.
  • We gave our routine dose of heparin.
  • No heparin resistance noted.  Because this would be a long pump run, we opted to give an antifibrinolytic infusion as well as bolus.
  • This patient required higher than normal amounts of pressors and ultimately received methylene blue to help with vasoplegia.
  • We reversed the heparin with protamine and stopped the PGE1 at that time.
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Methylene Blue

Case: 65 yo male with septic endocarditis and septic emboli with + valve vegetations.  Severe MR, mod AI, mod TR, no PFO, EF 60-70%. Mild pericardial effusion. Large bilateral pleural effusions.

 

Vasoplegic syndrome—the role of methylene blue. European Journal of Cardio-Thoracic Surgery, Volume 28, Issue 5, 1 November 2005, Pages 705–710.

OpenAnesthesia: Methylene Blue

Dose:
2 mg/kg bolus –> 0.5 mg/kg/hr x 12 hours
Worked wonderfully for vasoplegia unresponsive to levophed or vasopressin.

ERAS for Cardiac Surgery

ERAS for cardiac surgery. #eras #pain #multimodal #opioids #surgery #cardiac #perfusion #perfusionist

I have been utilizing ERAS in general surgery, OB, and ortho cases.  Diving into one of my more tricky populations, I opted to see what ERAS practices are out there for cardiac surgery.  Careful what you look for my friends.  There’s actually a good amount of information out there!

ACCRAC podcast: ERAS for Cardiac Surgery

ERAS Cardiac Consensus Abstract – April 2018

Enhanced recovery after surgery pathway for patients undergoing cardiac surgery: a randomized clinical trial. European Journal of Cardio-Thoracic Surgery, Volume 54, Issue 3, 1 September 2018, Pages 491–497, https://doi.org/10.1093/ejcts/ezy100

** Audio PPT ** American Association for Thoracic Surgery: Enhanced Recovery After Cardiac Surgery. April 2018

The impact of enhanced recovery after surgery (ERAS) protocol compliance on morbidity from resection for primary lung cancer.  The Journal of Thoracic and Cardiovascular Surgery. April 2018Volume 155, Issue 4, Pages 1843–1852. 

Enhanced Recovery for Cardiac Surgery. J Cardiothorac Vasc Anesth. 2018 Jan 31. pii: S1053-0770(18)30049-1. DOI: https://doi.org/10.1053/j.jvca.2018.01.045

ERAS
From Journal of Anesthesiology

Enhanced Recovery After Cardiac Surgery Society

My blog posts:

Key Points

  • Level 1 (Class of recommendation=Strong Benefit):
    • Tranexamic acid or epsilon aminocaproic acid should be administered for on-pump cardiac surgical procedures to reduce blood loss.
    • Perioperative glycemic control is recommended (BS 70-180; [110-150]).
    • A care bundle of best practices should be performed to reduce surgical site infection.
    • Goal-directed therapy should be performed to reduce postoperative complications.
    • A multimodal, opioid-sparing, pain management plan is recommended postoperatively
    • Persistent hypothermia (T<35o C) after CPB should be avoided in the early postoperative period. Additionally, hyperthermia (T>38oC) should be avoided in the early postoperative period.
    • Active maintenance of chest tube patency is effective at preventing retained blood syndrome.
    • Post-operative systematic delirium screening is recommended at least once per nursing shift.
    • An ICU liberation bundle should be implemented including delirium screening, appropriate sedation and early mobilization.
    • Screening and treatment for excessive alcohol and cigarette smoking should be performed preoperatively when feasible.
  • Level IIa (Class of recommendation=Moderate Benefit)
    • Biomarkers can be beneficial in identifying patients at risk for acute kidney injury.
    • Rigid sternal fixation can be useful to reduce mediastinal wound complications.
    • Prehabilitation is beneficial for patients undergoing elective cardiac surgery with multiple comorbidities or significant deconditioning.
    • Insulin infusion is reasonable to be performed to treat hyperglycemia in all patients in the perioperative period.
    • Early extubation strategies after surgery are reasonable to be employed.
    • Patient engagement through online or application-based systems to promote education, compliance, and patient reported outcomes can be useful.
    • Chemical thromboprophylaxis can be beneficial following cardiac surgery.
    • Preoperative assessment of hemoglobin A1c and albumin is reasonable to be performed.
    • Correction of nutritional deficiency, when feasible, can be beneficial.
  • Level IIb (Class of recommendation=Weak Benefit)
    • A clear liquid diet may be considered to be continued up until 4 hours before general anesthesia.
    • Carbohydrate loading may be considered before surgery.

 

ERAS for cardiac surgery. Journal of Cardiothoracic and Vascular Anesthesia

Erector Spinae Plane Block

After speaking to a colleague of mine regarding regional anesthesia for thoracotomy and mastectomy, I am reading up on Erector Spinae Plane (ESP) block.

 

Indications:

 

 

Other regional blocks

Continuous ESP block catheter (my current regimen and what I’m able to get at my institution):

  • Braun Periflex catheter through 17g epidural needle
  • Cranial-to-caudal approach @ T5 (mastectomy, vats, rib fractures)
  • 20ml 0.25% bupi + epi prior to catheter
  • Catheter 5cm in space
  • 5 ml 0.25% bupi + epi after catheter placed
  • Mix: 0.125% bupi + fentanyl @ 10 ml/hr
  • If PCEA available, bolus 15ml every 3 hours; continuous as mix above.

Cardiac anesthesiologists and LVAD patients: Pro vs Cons

There’s been a big debate re: who should care for LVAD patients… a general anesthesiologist or a cardiac anesthesiologist?  See below for pros and cons of each.  Ultimately, I think all anesthesiologists should be comfortable caring for these patients as we’ll see more and more LVAD patients undergoing procedures.

Troubleshooting the Left Ventricular Assist Device.  Emergency Medicine. 2016 February;48(2):58-63.

RTEmagicC_em048020061_t1.jpg
From Emergency Medicine, Feb 2016.
LVAD Parameter Abnormalities:
  • High power, low-pulsatility index and fluctuating pump speed: Consider pump thrombosis or hypotension, vasodilation, initial response to exercise.
  • High power with high pulsatility index: Consider fluid overload, normal physiological response to increased demand; myocardial recovery.
  • Low power, low pulsatility index, and unchanging speed: Consider hypertension or inflow/outflow obstruction, LV failure, dysrhythmia.
  • Low power with normal or high pulsatility index: Consider suction event.

Pro: Cardiothoracic Anesthesiologists Should Provide Anesthetic Care for Patients With Ventricular Assist Devices Undergoing Noncardiac Surgery. JCVA, February 2017. Volume 31, Issue 1, Pages 378–381

Con: Cardiothoracic Anesthesiologists Are Not Necessary for the Management of Patients With Ventricular Assist Devices Undergoing Noncardiac Surgery. JCVA, February 2017. Volume 31, Issue 1, Pages 382–387.


VAD-2
From LifeInTheFastLane.com

Ventricular assist devices and non-cardiac surgery.  BMC Anesthesiology201515:185

  • Goals of care for LVAD patients undergoing non-cardiac surgery should be directed at maintaining forward flow and adequate perfusion. Three main factors that affect LVAD flow are preload, RV function, and afterload.
  • The right ventricle is the primary means of LVAD filling; therefore, maintaining RV function is imperative.
  • Marked increases in systemic vascular resistance should be avoided.
  • Generally, decreases in pump flow should first be treated with a fluid challenge. Hypovolemia should be avoided and intraoperative losses should be replaced aggressively. Second line treatment should include inotropic support for the right ventricle.
  • Low-dose vasopressin (<2.4 U/h) may be the vasopressor of choice due to its minimal effect on pulmonary vascular resistance.
  • Standard Advanced Cardiovascular Life Support Guidelines should be followed; however, external chest compressions should be avoided during cardiac arrest.
  • Steep Trendelenburg may increase venous return, risking RV strain. Peritoneal insufflation for laparoscopic surgery also increases afterload and has detrimental effects on preload.  Insufflation should utilize minimum pressures and be increased in a gradual, step-wise fashion.
  • TEE can be extremely valuable in diagnosing the cause of obstruction.

Perioperative management of patients with left ventricular assist devices undergoing noncardiac surgery. Annals of cardiac anaesthesia 2016. Vol 19, Issue 4: 676-686.

LVAD: What Should I report? Feb 2017 ASE conference. **ECHO**

  • Higher the RPMs (pump speed)
    • More LV compression, smaller LV size
    • Less functional MR
    • More AI, less AV opening
    • Less LVED diameter
  • De Novo Aortic Regurgitation Post LVAD
    • Proposed mechanisms
      • Aortic valve remains closed during systole
      • Commissural fusion of the aortic valve from disuse
      • Subsequent degeneration of valve
      • Turbulent blood backflow from small outflow cannula onto a closed valve
      • Persistent elevation of aortic root pressure –> aortic root dilation and valve incompetence
    • Treatment
      • Lower LVAD speed (but that may worsen mitral regurgitation)
      • Aortic valve surgery or percutaneous intervention
      • Heart transplant
  • RV Fractional Area Change (RV FAC)
    • RVFAC is a rough measure of RV systolic function (4 chamber view)
    • RVFAC = (RVEDA – RVESA) / RVEDA
    • Normal RVFAC = 35 – 63%

Ventricular Assist Device (VAD). LifeInTheFastLane.com. .

Care of the LVAD patient PPT. Summit 2014.

  • Pulsatility Index:
    • —normally decrease as pump speed is increased

LVAD: Understanding equipment and Alarms. Duke Heart Center PPT.

LVAD Management in the ICU. Crit Care Med 2014; 42:158–168. 

Screen Shot 2018-11-26 at 11.20.26 AM
From Left Ventricular Assist Device Management in the ICU Pratt, Alexandra K. MD1; Shah, Nimesh S. MD1; Boyce, Steven W. MD2 Critical Care Medicine: January 2014 – Volume 42 – Issue 1 – p 158–168 doi: 10.1097/01.ccm.0000435675.91305.76 Concise Definitive Review
Screen Shot 2018-11-26 at 11.20.47 AM
Left Ventricular Assist Device Management in the ICU Pratt, Alexandra K. MD1; Shah, Nimesh S. MD1; Boyce, Steven W. MD2 Critical Care Medicine: January 2014 – Volume 42 – Issue 1 – p 158–168 doi: 10.1097/01.ccm.0000435675.91305.76 Concise Definitive Review

 

Anesthesia for Left Ventricular Assist Device Insertion: A Case Series and Review. Ochsner J. 2011 Spring; 11(1): 70–77.

Medical Management of Patients With Continuous-Flow Left Ventricular Assist Devices. Curr Treat Options Cardiovasc Med. 2014 Feb; 16(2): 283.

 


My blog posts:

HeartWare vs. HeartMate LVAD

Ventricular Assist Devices: Impella

Antithrombin III

The other day we had a patient come in for a CABG. Aside for some coronary artery disease, hypertension, and chronic kidney disease, the patient was pretty healthy. They were not on anticoagulation prior to the procedure.

After I gave full dose heparin for going on bypass (41,000U in this case), the ACT only came up to 422. An additional 10,000U of heparin was given with a repeat ACT of 457. Still, our surgeon was not quite comfortable with that number and requested an additional 10,000U heparin. The ACT came to 477.

If the ACT stayed in the low 400s, would you go on bypass? What if the ACT had not responded to the repeated heparin dosings?

Management of coagulation during cardiopulmonary bypass. Continuing Education in Anaesthesia Critical Care & Pain, Volume 7, Issue 6, 1 December 2007, Pages 195–198, https://doi.org/10.1093/bjaceaccp/mkm036.

Antithrombin III concentrate to treat heparin resistance in patients undergoing cardiac surgery. J Thorac Cardiovasc Surg. 2002 Feb;123(2):213-7.

Would you give antithrombin III or plasma?

Treating Heparin Resistance With Antithrombin or Fresh Frozen Plasma. The Annals of Thoracic Surgery. June 2008Volume 85, Issue 6, Pages 2153–2160.

Is there evidence that fresh frozen plasma is superior to antithrombin administration to treat heparin resistance in cardiac surgery? Interact Cardiovasc Thorac Surg. 2014 Jan; 18(1): 117–120.

We ultimately decided to go on bypass. Repeat ACTs on bypass were in the 500s. No antithrombin was given. After separation from cardiopulmonary bypass and administration of protamine, repeat ACT was 111. Protamine was dosed accordingly to heparin administration and ACTs while on bypass.

Recommendations for the use of antithrombin concentrates and prothrombin complex concentrates. Blood Transfus. 2009 Oct; 7(4): 325–334.

Thrombate (antithrombin III) package insert