Page 1584 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 115: The Transplant Patient 1103

Immunosuppression: Universal induction therapy for heart transplant pulmonary hypertension being offered heart transplant, some patients
remains controversial. Most centers will implement induction in the with milder preexisting pulmonary hypertension may experience
setting of high acute rejection risk for presensitized patients with anti- post-operative right heart failure. Right heart failure results because
thymocyte polyclonal antibodies and the IL-2 receptor antagonists. the newly transplanted right ventricle (which is accustomed to pump-
Similar to lung and liver transplantation, most maintenance regimes ing against a normal pulmonary vascular resistance) is placed in a
include two to three drug combinations of a calcineurin inhibitor, an circuit characterized by an increase in PVR and is unable to over-
antiproliferative agent, and corticosteroids. come the imposed afterload. Tricuspid regurgitation is often present
Sirolimus is sometimes used by certain centers in patients with cardiac following the transplant (especially if the biatrial technique was used),
allograft vasculopathy, renal insufficiency, or malignancies given its and may be exacerbated by an increase in right ventricular afterload.
inhibitory effect on smooth muscle proliferation and ability to slow pro- Through its effects as a pulmonary vasodilator, isoproterenol can
gression of malignancy. Sirolimus has been found to be useful to slow often reduce the right ventricular afterload. However, when sig-
disease progression. The high incidence of side effects including poor nificant postoperative pulmonary hypertension persists, intravenous
wound healing has limited its routine use. 118,119 nitroglycerine, nitroprusside, and prostaglandin E1 may be required.
■ POSTOPERATIVE COMPLICATIONS Systemic infusion of α-agonists such as norepinephrine or phenylephrine
may be needed to support the systemic arterial pressure. Inhaled
Primary Heart Graft Failure: Primary heart graft failure (PHGF) domi- nitric oxide is often used to acutely reduce right ventricular after-
nates the causes of perioperative or early (<30 day) mortality post-heart load. By virtue of its mode of delivery, inhaled nitric oxide acts as a
transplant, accounting for 20% to 40% of early postoperative deaths. selective pulmonary vasodilator with minimal systemic effects and
120
122-126
PHGF occurs when a mismatch exists between the capabilities of the reduces intrapulmonary shunting. More recently, sildenafil,
new heart and the demands imposed upon it by its new circulatory a cyclic guanosine monophosphate (cGMP)–specific phosphodi-
environment. It is defined as severe dysfunction of the graft that is char- esterase type 5 inhibitor has been used with success for persistent
acterized by shock, low cardiac output, and high filling pressures in the pulmonary hypertension, and to prevent rebound after withdrawal
127
absence of secondary causes such as hyperacute rejection, pulmonary of inhaled NO. Owing to the expense associated with the use of
hypertension, or surgical complications. 121 inhaled NO, other inhaled therapies have been evaluated (NO donors
and prostaglandin analogues) and appear to be of equal benefit. 128-130
Right Ventricular Failure and Pulmonary Hypertension: Although pre- However, the half-lives of these medications mandate repeated
operative selection has reduced the number of patients with severe dosing. Figure 115-6 outlines an approach to RV failure posttransplant.

Preload Hemodynamically Maintenance of Ventilatory
optimization unstable SR and AV synchrony support

Volume overload state Acute RVMI or PE or Cardioversion Avoid
especially acute/chronic hypovolemic state Antiarrhythmics as required Inspiratory pressure
RV failure Consider 300-600 mL Pacemaker implantation >30 mm Hg
Mild progressive diuresis N saline volume challenge Consider resynchronization Auto-PEEP
negative 500 mL-1 L daily (D/C if unresponsive) therapy Hypercapnia
Acidosis
Unresponsive Unresponsive Hypoxemia

Continuous perfusion of Inotrope- Preferred use
loop diuretic and/or vasopressor
combination of diuretics Dobutamine Normotensive
Milrinone Normotensive, chronic BB
Unresponsive
Dopamine Hypotensive, non tachycardic
Norepinephrine Hypotensive
Consider CVVHF or Phenylephrine Hypotensive-tachycardic
ultrafiltration Vasopressine Hypotensive-tachycardic
Epinephrine Hypotensive-unresponsive
Combination Based on response

Also consider
Minimize transfusions
Nitric oxide trial (inhaled)
or inhaled prostanoids

Unresponsive
Atrial septostomy
RV assist device
ECMO
Transplantation
Surgery (experimental)

FIGURE 115-6. An approach to RV failure posttransplant. (Adapted with permission from Haddad F, Doyle R, Murphy DJ, Hunt SA. Right ventricular function in cardiovascular disease, part
II: pathophysiology, clinical importance, and management of right ventricular failure. Circulation. April 1, 2008;117(13):1717-1731.)

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