The Tenuous Transplant

A 36-year old man with a history of cystic fibrosis has undergone a bilateral lung transplant and is on the ICU 3 days following the surgery.

History:

He has chronic colonization with Pseudomonas aeruginosa and Burkholderia cepacia. He received pancreatic enzyme replacement, but was not insulin requiring. He had mild pulmonary hypertension with right heart hypertrophy, but preserved function. He was losing weight prior to surgery, was becoming progressively short of breath and was quite debilitated at the time of surgery. He was CMV negative prior to transplant. Home medications include pancreatic supplementation, albuterol, and oxygen. No epidural was placed for fear of infection. The surgery proceeded with cardiopulmonary bypass as the pulmonary pressures escalated dramatically with clamping of a pulmonary artery. The estimated blood loss was 1.5 L and the patient received 3 L of crystalloid and 2 units of blood during the surgery.

Intra-operative TEE showed normal LV function with RV hypertrophy, mild TR and dilated pulmonary arteries. There was no PFO. The flow velocities in the four pulmonary veins were normal following transplantation. No clots were seen. There was mild RV dysfunction following cardiopulmonary bypass.

Examination:

He weighs 55 kg and is 1.7m tall. He is intubated on the ICU.

The PAP = 45/25 mmHg, the CVP is 13 mmHg, the HR is 115/min and irregularly irregular, the BP is 95/60 mmHg and the temperature is 37.9 degrees Celsius.

The ventilation mode is volume control ventilation; the respiratory rate is 12/min, the tidal volume = 500 ml, the I:E ratio is 1:2, the FiO2 is 0.8, and the PEEP is 5 cmH2O.

Cardiorespiratory examination reveals normal heart sounds with an irregularly irregular rate, bilateral breath sounds, faint crackles and diminished sounds in the lower zones.

Urine output has been 20 and 15 ml/hr for the last two hours.

Special Investigations:

Blood results reveal a hemoglobin of 8.2 g/dL, platelet count of 90 x 1000/mcL and white blood count of 18.3 x1000/mcL.

There are no electrolyte abnormalities, the BUN is 29 mg/dL, the creatinine is 1.6 mg/dL (Baseline BUN was 12 and creatinine was 0.8) and the blood glucose is 210 mg/dL.

The arterial blood gas shows a pH = 7.33, PO2 = 71 mmHg, a PCO2 = 58 mmHg, and bicarbonate = 29 mmol/L.

The CXR shows the tracheal tube and the PA catheter appropriately positioned. There are significant bilateral patchy opacifications, with the right side markedly more affected than the left.

The ECG shows atrial fibrillation, mild ST elevation in precordial and inferior leads, and troponin I is mildly elevated (1.1 mcg/L), but trending down from a postoperative peak of 2.1 mcg/L.

Medications:

Propofol and fentanyl for sedation and analgesia.
Dobutamine at 3 mcg/kg/min for right heart failure.
Norepinephrine at 0.04 mcg/kg/min for hypotension.
Inhaled prostacyclin for pulmonary hypertension.
Meropenem, vancomycin, inhaled tobramycin, and inhaled colistin to cover previous infection.
Ganciclovir and trimethoprim/sulfamethoxezole for prophylaxis.
Methylprednisolone, tacrolimus and azathioprine for immunosuppression.
Subsutaneous heparin for DVT prophylaxis.
Famotidine for ulcer prophylaxis.

Questions:

Based on the information presented and the most up to date evidence, decide on the following management conundrums for this particular patient, critically citing peer reviewed literature to support your decisions. When you cite evidence, comment on its validity, its importance, and its applicability to this patient.

1) Would you give a blood transfusion?

2) Would you give a fluid challenge?

3) Would you target a blood sugar range of 80-120 mg/dL?

4) Would you promote diuresis?

5) Would you continue dobutamine?

6) Would you add vasopressin?

7) Would you cardiovert for atrial fibrillation?

8) Would you anti-coagulate for atrial fibrillation?

9) Would you treat atrial fibrillation with amiodarone or beta blockers?

10) Would you alter mechanical ventilation?

11) Would you alter sedation?

12) Would you plan to do a tracheostomy?

13) Would you change antimicrobial therapy?

14) Would you change immunosuppressive therapy?


Posted by Alex Chen and Michael Avidan.