MANAGEMENT OF THE POSTOPERATIVE CARDIAC SURGERY PATIENT

General Principles

• Admission notes: preop – comorbidities cardiac investigations medications

intraop – operation notes and anaesthetic record particular problems – weaning off bypass, ventricular function, bleeding • Examination – vitals, circulation, drains, pacemaker wires • Routine bloods – CBP, Clotting, LFT, RFT, ACT, ABG • CXR, ECG • Follow target filling pressures by surgeons • Medications: Cefuroxime 750mg Q8H for 3 doses (unless allergy) Bactroban topical nasal tds Continue inotropes and/or vasodilators from OT and wean as appropriate. If increasing inotropic support is required – inform ICU senior and surgeon Important ***:

• Keep patients on GTN infusion for patients with LIMA graft (to reduce vasospasm risk)

• The cardiac surgeons in our hospital has specifically requested that we keep a low-dose dopamine infusion on for at least the first 24 hours post-operatively, irrespective of a good BP or diuresis. You may have to end up using an anti-hypertensive to maintain BP within agreed parameters and fluids to maintain CVP

• Intravenous fluids: 5% dextrose with KCl 20mmol in 500 ml solution at 1ml/kg/hr. If K+ level > 5.5 mmol/l omit KCl supplement

• ABG on admission: if K+ level between 4.5-5.5 mmol/l repeat ABG Q2H for 24 hours. If K+ level < 4.5 or > 5.5mmol/l, repeat ABG until corrected.

• Glucose control: follow glucose nomogram • If urine output < 1ml/kg/hr, consider frusemide especially in patients

receiving it preoperatively and if CVP/PCWP > 14mmHg with good peripheral perfusion

• Pacemaker at the bedside of all cardiac patients while in ICU Identify if pacing wires present If pacemaker from OT attached and operational, continue with appropriate pacing. If no pacemaker from OT or patient is NOT being paced by OT pacemaker, replace OT pacemaker with ICU pacemaker

Intensive Care Unit, Prince of Wales Hospital, Chinese University of Hong Kong

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Respiratory Management

• Following surgery commence all patients on an ICU ventilator • After the first ABG, adjust the FiO2 to maintain a PaO2 >10kPa • Wean from ventilation according to past medical history, surgery

performed and current clinical status • Extubation criteria:

Temperature > 360C Awake, analgesed, able to protect airway with a good cough Cardiovascularly stable - MAP >60mmHg, pH 7.35-7.45 Adequate gaseous exchange – PaO2 >10kPa on FiO2 0.4 Minimal bleeding – drain output <100ml/hour

• Respiratory failure post-op secondary to collapse/consolidation is common. Ensure good analgesia and frequent, effective physiotherapy.

Management of Bleeding • *** Call cardiac surgeon early whilst you are continuing with your

management • Perform appropriate investigations: ACT, INR, APTT, platelet count • Treat abnormalities of above:

Protamine 50mg if ACT >150 s FFP if INR abnormal If no response then platelet transfusion of 5 units, irrespective of platelet count

• If on aprotinin, continue at 50ml/hr (500,000 units) until bleeding <50ml/hr from pericardial drain

• If bleeding continues or is brisk, perform CXR (look for enlarging heart shadow) and echocardiogram* to exclude tamponade and obtain early review by cardiothoracic surgeons.

• * echocardiogram can be performed by some of our ICU doctors. Otherwise get on-call cardiologist. Check with chief cardiac surgeon first before you consult cardiologist.

• Ensure that bedside sternotomy set ready at all times • Consider re-opening if:

bleeding >200ml/hr for 3-4 hours bleeding >400ml/hr in 1 hour total loss >1500-2000mls

Hypotension (SBP <100mmHg or MAP <60mmHg) Gradual decline in BP

Intensive Care Unit, Prince of Wales Hospital, Chinese University of Hong Kong

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• Correct fluid/blood losses as appropriate using blood or colloid • Early ECG, Echo and inform cardiothoracic surgeons • Treat reversible causes – bleeding, pneumothorax, tamponade, kinked

graft, graft vasospasm • Treat arrhythmia • Inotropes

Dopamine/dolbutamine – mild hypotension Adrenaline Noradrenaline – severe resistant hypotension with low SVR IABP

Sudden and severe hypotension • Call chief cardiac surgeon and senior ICU staff immediately. Inform

theatre • While routine resuscitation underway – exclude tension pneumothorax,

echocardiography, consider opening chest in ICU

Hypertension • The MAP is to be kept quite strictly at about 60-80mmHg for the first 24-

36hours • This may vary according to the patient’s preoperative blood pressure and

condition (e.g. carotid stenosis). Must discuss with cardiothoracic team if the targets need to be adjusted

• Ensure adequate analgesia: give morphine if patient is in pain • Titrate GTN infusion or Nitroprusside infusion to maintain MAP of 60-

80mmHg • If hypertension persists – (please discuss with ICU senior and surgeon

first) β blocker: atenolol 1-2mg IV or esmolol 10-25mg IV (if no contraindication and good LV). Must be used cautiously after valve surgery.

Arrhythmias

• Treat electrolyte abnormalities, hypoxia, hypercarbia, tamponade, hypotension

• Bradycardia – AV sequential pacing first if < 60 beats per minute • Atrial fibrillation – if K+< 4 give potassium, if K+ >4.5 give amiodarone,

cardioversion (inform ICU senior and surgeon first) • VPB – lignocaine – check K+ and Mg++ • Pulseless VT or VF – defibrillate (observe protocol for defibrillation, inform

ICU senior and surgeon) • Note

o Defibrillation for monophasic defibrillators: 200J, 300J, 360J o Defibrillation for biphasic defibrillators: 150J non-escalating

Intensive Care Unit, Prince of Wales Hospital, Chinese University of Hong Kong

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Anticoagulation

• Patients with saphenous vein grafts should receive aspirin 160mg oral after 24 hours if not bleeding

• Commence patients with valve replacements on warfarin from the second post-operative day if extubated (we very rarely have to prescribe as majority of patients discharged by then. Dosing, best check with surgeon first)

• Patients with a valve replacement ventilated >48hours may require heparinisation

ST Segment Elevation (new! Pending approval from ICU director and chief cardiac surgeon)

• All cardiac patients should have continuously ST segment monitoring • Note pattern of ST elevation (site, up slopping etc) • Check patient’s clinical status (e.g. check vitals, ask for chest pain, check

if patient cold and sweaty, check peripheral circulation and auscultate for pericardial rub)

• Check preoperative ECG and compare • Inform cardiac surgeon • For patients with arterial grafts, continue GTN infusion.

Consider diltiazem if suspect graft vasospasm (discuss with ICU senior and cardiothoracic surgeons first)

If a cardiac patient deteriorates acutely for whatever reason: • Call cardiac surgeon (as well as chief) and ICU senior stat • Immediate availability of sternotomy set, gowns, gloves, towels,

betadine • Immediate availability of resuscitation trolley • Inform OT control and request OT nurse for assisting surgeon

Intensive Care Unit, Prince of Wales Hospital, Chinese University of Hong Kong

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