The Vexing Problem of VasoplegiaSCOTT SILVESTRY MD

FLORIDA HOSPITAL TRANSPLANT INSTITUTE

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Unexpected refractory hypotension from a severe SIRS response following cardiac surgery involving cardiopulmonary bypass (CPB)

The incidence of VS in cardiac surgical patients is 8% to 10 %, but may increase to upwards of 50% of patients taking renin-angiotensin system (RAS) antagonists.

Vasoplegia

No Standard Definition

Form of vasodilitory shock that occurs in the early postoperative period (< 6 hours after weaning from CBP), manifested by:

Hypotension [MAP < 70 without vasoactive agents]

Tachycardia

Normal or increased cardiac output [CI > 2.5 L / min / m2]

Low systemic vascular resistance [SVR < 800 dynes-s · cm−5 · m−2 ]

Vasoplegia SyndromePts have poor prognosis,

Especially norepinephrine-resistant vasoplegia.

Catecholamine resistant vasoplegia lasting for more than 36 to 48 hours has a mortality rate as high as 25%.

Associated with longer hospital stays, prolonged ICU stays, prolonged mechanical ventilation and more sternal infections

Prophylactic Vasopressin in Patients Receiving the Angiotensin-ConvertingEnzyme Inhibitor Ramipril Undergoing Coronary Artery Bypass Graft Surgery

A (n 16), patients discontinued ramipril 24 hours before surgery;B (n 16), patients continued ramipril until the morning of surgery; C (n 15), patients continued ramipril until the morning of surgery and received vasopressin infusion (0.03 U/min) from the onset ofrewarming

Journal of Cardiothoracic and Vascular Anesthesia, Vol 24, No 2 (April), 2010: pp 230-238

Preoperative Methylene Blue Administration in Patients at High Risk for Vasoplegic Syndrome During Cardiac Surgery

Ozal et al ATS 79(5)1615-1619 2005.

One hundred patients scheduled for coronary artery bypass graft surgery who were at high risk for vasoplegia because they were preoperatively using angiotensin-converting enzyme inhibitors, calcium channel blockers, and heparin were randomly assigned to either receive preoperative methylene blue (group 1, n = 50) or not receive it (group 2, controls, n = 50). Methylene blue (1% solution) was administered intravenously at a dose of 2 mg/kg for more than 30 minutes, beginning in the intensive care unit 1 hour before surgery.

Early vasopressor use Vasopressin: Infusion rates up to 0.06 units/min (maximum) – first line agentNorepinephrine: Infusion rates starting at 0.05 mcg/kg/min – second line agent, as these patients may be refractory to refractory catecholamines.

Other suggested treatments Methylene blue: 2 mg/kg IV

Correct underlying causes for a metabolic acidosis

Resuscitation goals

Target MAP between 70-80  Intravascular volume expansion – careful administration to avoid excessive volume loading

Statement 6: (grade C, level 2)In patients with vasodilatory shock requiring vasopressor support and with low filling pressures methylene blue may reduce the duration of the vasoplegic syndrome and the need for norepinephrine infusion.

Methylene blue may also reduce mortality and morbidity in these patients.

Statement 7: (grade C, level 2)Prophylactic use of methylene blue may reduce postoperative CPB hypotension and vasopressor requirements. Methylene blue in this setting may also be associated with shorter length of stay in the ICU.

Statement 8: (grade C, level 2)Prophylactic use of vasopressin reduces postoperative CPB hypotension and vasopressor requirements. Vasopressin in this setting may also be associated with shorter intubation time and length of stay in the ICU.

Role of EMCO/MCS ?LVAD/BIVADCase Reports

1 LVAD

BiVAD

ECMOTreated 2 patients post OHT

Normal Graft function/profound hypotension

Profound Acidosis

36 hrs ECMO

Flows 6-8 liters

Resolution of acidosis/hypotension

Both survived with normal function

Summary

Vasoplegia remains hard to predict and devastating in its impact.

Consider Discontinuing ACEi prior to cardiac surgery.

Consider prophylactic Vasopression/MB in high risk candidates.

Consider escalation of MCS ( ECMO/RVAD) in appropriate scenarios (LVAD, Heart transplant).

Thank you