A 76-year-old female is admitted to the ICU following elective aortic and mitral valve replacement. Trans- oesophageal echo assessment at the end of surgery showed an ejection fraction of 20%. Her preoperative creatinine was 340 μmol/L. Total bypass time was 240 minutes.
On arrival in Intensive Care Unit the patient has the following indices:
- Temperature 35C
- Atrial pacing (AAI) 80/min
- Systemic blood pressure 85/55 mmHg
- Pulmonary artery pressure 60/30 mmHg
- Cardiac index 1.5 L/min/m2
- Systemic vascular resistance indexed (SVRI) 1700 dyn.sec.cm-5
- Pulmonary artery wedge pressure 10 mmHg
- Central venous pressure 8 mmHg
The patient is currently on adrenaline 4μg/min by infusion.
- a) List the specific clinical and haemodynamic issues for this patient on admission to ICU. (40% marks)
- b) Outline your management of these issues. (60% marks)
Answer and interpretation
a) List the specific clinical and haemodynamic issues for this patient on admission to ICU. (40% marks)
The main clinical and haemodynamic issues identified are:
- Elderly female patient post double valve surgery.
- Pre-existing renal impairment.
- Long bypass time.
- Systemic hypotension (MAP 65 unlikely to be adequate for this patient).
- Low output state (CI, EF post bypass).
- Increased afterload / vascular impedance (SVR).
- Probable fluid responsiveness (PAWP, CVP).
- Moderate pulmonary hypertension.
- Low core temperature.
b) Outline your management of these issues. (60% marks)
This patient is high risk (female, age, long bypass time, pre-existing renal impairment, low EF). Management consists of:
- Judicious fluid replacement as she re-warms.
- Improved volume state may augment CI but given poor EF unlikely to be sole intervention
- Titration of adrenaline infusion, aiming for CI > 2.2
- Bedside echo to evaluate effect of fluid and increased adrenaline, exclude tamponade and
check valve function (mitral regurgitation can increase PAP and decrease cardiac output).
- Consideration of other vasoactive agents (dobutamine, milrinone, levosimendan) or IABP
insertion if persisting low output state.
- Assess adequacy of pacing and consider changing mode to A-V pacing (heart block common
after AVR) and /or increasing rate to 90 bpm.
- Correct post-op coagulopathy and replace blood losses to maintain Hb > 80 G/L. Surgical
review if significant blood loss via drains.
- Evaluation of any other cause of low output state e.g. tension pneumothorax, dynamic
- Close monitoring of renal function and early institution of renal replacement therapy if oligo-
anuric or rising creatinine.
- Consideration of inhaled nitric oxide to reduce pulmonary hypertension and RV afterload.
Pass rate: 95%
Highest mark: 9.75