Identification of cardiac arrest

Patients in the ICU are highly monitored and an arrest is most likely to be signalled by monitoring alarms where absence of pulsation or perfusing pressure on the arterial line, loss of pulse oximeter, pulmonary artery (PA) trace, or end-tidal CO₂ trace can be sufficient to indicate cardiac arrest without the need to palpate a central pulse.

Starting CPR

Start external chest compressions immediately in all patients who collapse without an output. Consider reversible causes: hypoxia – check tube position, ventilate with 100% oxygen; tension pneumothorax – clinical examination, thoracic ultrasound; hypovolaemia, pacing failure. In asystole, secondary to a loss of cardiac pacing, external massage may be delayed momentarily as long as the surgically inserted temporary pacing wires can be connected rapidly and pacing re-established (DDD at 100 min⁻¹ at maximum amplitude). The effectiveness of compressions may be verified by looking at the arterial trace, aiming to achieve a systolic blood pressure of at least 80 mmHg at a rate of 100 min⁻¹. Inability to attain this pressure may indicate tamponade, tension pneumothorax, or exanguinating haemorrhage and should precipitate emergency resternotomy. Intra-aortic balloon pumps should be changed to pressure triggering during CPR. In PEA, switch off the pacemaker – a temporary pacemaker may potentially hide underlying VF.

Defibrillation

There is concern that external chest compressions can cause sternal disruption or cardiac damage.^{403, 404, 405, and 406} x P.M. Kempen, R. Allgood. Right ventricular rupture during closed-chest cardiopulmonary resuscitation after pneumonectomy with pericardiotomy: a case report. Crit Care Med 27 (1999) (1378 - 1379) x H. Bohrer, R. Gust, B.W. Bottiger. Cardiopulmonary resuscitation after cardiac surgery. J Cardiothorac Vasc Anesth 9 (1995) (352) x M. Klintschar, M. Darok, H. Radner. Massive injury to the heart after attempted active compression–decompression cardiopulmonary resuscitation. Int J Legal Med 111 (1998) (93 - 96) x E. Fosse, H. Lindberg. Left ventricular rupture following external chest compression. Acta Anaesthesiol Scand 40 (1996) (502 - 504) In the post-cardiac surgery ICU, a witnessed and monitored VF/VT cardiac arrest should be treated immediately with up to three quick successive (stacked) defibrillation attempts. Three failed shocks in the post-cardiac surgery setting should trigger the need for emergency resternotomy. Further defibrillation is attempted as indicated in the universal algorithm and should be performed with internal paddles at 20 J if resternotomy has been performed.

Emergency drugs

Use adrenaline very cautiously and titrate to effect (intravenous doses of 100 or less micrograms in adults). In order to exclude a medication error as the cause of the arrest, stop all drug infusions and check if they are correct. If there is concern about patient awareness, restart the anaesthetic drugs. Atropine is no longer recommended for the treatment of cardiac arrest as there is little evidence to show it is effective in patients who have been given adrenaline. Individual clinicians may use atropine at their discretion in post-cardiac surgery cardiac arrest if they feel it is indicated. Treat bradycardia with atropine, according to the bradycardia algorithm (see Section 4 Advanced Life Support). ^24a x European Resuscitation Council Guidelines for Resuscitation 2010: Section 4: Adult advanced life support. Resuscitation 2010; 81:1305–52.

Give amiodarone 300 mg after the 3rd failed defibrillation attempt but do not delay resternotomy. An irritable myocardium following cardiac surgery is caused most commonly by myocardial ischaemia and correction of this, rather than giving amiodarone, is more likely to achieve myocardial stability.

Emergency resternotomy

This is an integral part of resuscitation after cardiac surgery, once all other reversible causes have been excluded. Once adequate an airway and ventilation has been established, and if three attempts at defibrillation have failed in VF/VT, undertake resternotomy without delay. Emergency resternotomy is also indicated in asystole or PEA, when other treatments have failed. Resuscitation teams should be well rehearsed in this technique so that it can be performed safely within 5 min of the onset of cardiac arrest. Resternotomy equipment should be prepared as soon as an arrest is identified. Simplification of the resternotomy tray and regular manikin rehearsals are key measures to ensure a prompt resternotomy.^{407 and 408} x J. Dunning, J. Nandi, S. Ariffin, J. Jerstice, D. Danitsch, A. Levine. The Cardiac Surgery Advanced Life Support Course (CALS): delivering significant improvements in emergency cardiothoracic care. Ann Thorac Surg 81 (2006) (1767 - 1772) x J. Dunning, A. Fabbri, P.H. Kolh, et al.. Guideline for resuscitation in cardiac arrest after cardiac surgery. Eur J Cardiothorac Surg 36 (2009) (3 - 28) All medical members of the patient care team should be trained to perform resternotomy if a surgeon is not available within 5 min. Improved survival and better quality of life is well documented with rapid resternotomy.^{394, 395, and 409} x A. Pottle, I. Bullock, J. Thomas, L. Scott. Survival to discharge following Open Chest Cardiac Compression (OCCC). A 4-year retrospective audit in a cardiothoracic specialist centre – Royal Brompton and Harefield NHS Trust, United Kingdom. Resuscitation 52 (2002) (269 - 272) x J.H. Mackay, S.J. Powell, J. Osgathorp, C.J. Rozario. Six-year prospective audit of chest reopening after cardiac arrest. Eur J Cardiothorac Surg 22 (2002) (421 - 425) x J. Raman, R.F. Saldanha, J.M. Branch, et al.. Open cardiac compression in the postoperative cardiac intensive care unit. Anaesth Intensive Care 17 (1989) (129 - 135)

Resternotomy should be a standard part of resuscitation within 10 days after cardiac surgery. The overall survival to discharge following internal cardiac massage is 17% ³⁹⁴ x A. Pottle, I. Bullock, J. Thomas, L. Scott. Survival to discharge following Open Chest Cardiac Compression (OCCC). A 4-year retrospective audit in a cardiothoracic specialist centre – Royal Brompton and Harefield NHS Trust, United Kingdom. Resuscitation 52 (2002) (269 - 272) to 25% ³⁹⁵ x J.H. Mackay, S.J. Powell, J. Osgathorp, C.J. Rozario. Six-year prospective audit of chest reopening after cardiac arrest. Eur J Cardiothorac Surg 22 (2002) (421 - 425) although survival rates are much lower when chest opening is performed outside the specialised environment of the post-cardiac surgery ICU. ³⁹⁵ x J.H. Mackay, S.J. Powell, J. Osgathorp, C.J. Rozario. Six-year prospective audit of chest reopening after cardiac arrest. Eur J Cardiothorac Surg 22 (2002) (421 - 425)

Reinstitution of emergency cardiopulmonary bypass

The need for emergency cardiopulmonary bypass (CPB) occurs in approximately 0.8% patients at a mean of 7 h post-operatively ³⁹⁶ x I. Birdi, N. Chaudhuri, K. Lenthall, S. Reddy, S.A. Nashef. Emergency reinstitution of cardiopulmonary bypass following cardiac surgery: outcome justifies the cost. Eur J Cardiothorac Surg 17 (2000) (743 - 746) and is usually indicated to correct surgical bleeding or graft occlusion and rest the myocardium. Emergency institution of CPB should be available on all units undertaking cardiac surgery. Survival to discharge rates of 32%, ³⁹⁵ x J.H. Mackay, S.J. Powell, J. Osgathorp, C.J. Rozario. Six-year prospective audit of chest reopening after cardiac arrest. Eur J Cardiothorac Surg 22 (2002) (421 - 425) 42% ³⁹⁶ x I. Birdi, N. Chaudhuri, K. Lenthall, S. Reddy, S.A. Nashef. Emergency reinstitution of cardiopulmonary bypass following cardiac surgery: outcome justifies the cost. Eur J Cardiothorac Surg 17 (2000) (743 - 746) and 56.3% ⁴¹⁰ x J.A. Rousou, R.M. Engelman, J.E. Flack 3rd, D.W. Deaton, S.G. Owen. Emergency cardiopulmonary bypass in the cardiac surgical unit can be a lifesaving measure in postoperative cardiac arrest. Circulation 90 (1994) (II280 - II284) have been reported when CPB is reinstituted on the ICU.

Survival rates decline rapidly when this procedure is undertaken more than 24 h after surgery and when performed on the ward rather than the ICU. Emergency CPB should probably be restricted to patients who arrest within 72 h of surgery, as surgically remediable problems are unlikely after this time. ³⁹⁵ x J.H. Mackay, S.J. Powell, J. Osgathorp, C.J. Rozario. Six-year prospective audit of chest reopening after cardiac arrest. Eur J Cardiothorac Surg 22 (2002) (421 - 425) Ensuring adequate anticoagulation before starting CPB, or the use of a heparin-bonded circuit, is important. The need for a further period of cross-clamping does not preclude a favourable outcome. ³⁹⁶ x I. Birdi, N. Chaudhuri, K. Lenthall, S. Reddy, S.A. Nashef. Emergency reinstitution of cardiopulmonary bypass following cardiac surgery: outcome justifies the cost. Eur J Cardiothorac Surg 17 (2000) (743 - 746)

Patients with non-sternotomy cardiac surgery

These guidelines are appropriate for patients following non-sternotomy cardiac surgery, but surgeons performing these operations should have already given clear instructions for chest reopening. Patients undergoing port-access mitral procedures or minimally invasive coronary bypass graft surgery are likely to require an emergency sternotomy, as very poor access is obtained by opening or extending a mini-thoracotomy incision. Equipment and guidelines should be kept close to the patient.

Children

The incidence of cardiac arrest after cardiac surgery in children is 4% ⁴¹¹ x D.A. Parra, B.R. Totapally, E. Zahn, et al.. Outcome of cardiopulmonary resuscitation in a pediatric cardiac intensive care unit. Crit Care Med 28 (2000) (3296 - 3300) and survival rates are similar to those of adults. The causes are also similar, although one case-series documented primary respiratory arrest in 11%. The guidance given in this section is equally applicable to children, with appropriate modification of defibrillation energy and drug doses (see Section 6 Paediatric Life Support). ^411a x European Resuscitation Council Guidelines for Resuscitation 2010: Section 6: Paediatric life support. Resuscitation 2010; 81:1364–88. Use extreme caution and check doses carefully when giving intravenous adrenaline doses to children in cardiac arrest after cardiac surgery. Use smaller doses of adrenaline in this setting (e.g., 1 μg kg⁻¹) under the guidance of experienced clinicians.

Internal defibrillation

Internal defibrillation using paddles applied directly across the ventricles requires considerably less energy than that used for external defibrillation. Biphasic shocks are more effective than monophasic shocks for direct defibrillation. ⁴¹² x B. Schwarz, T.A. Bowdle, G.K. Jett, et al.. Biphasic shocks compared with monophasic damped sine wave shocks for direct ventricular defibrillation during open heart surgery. Anesthesiology 98 (2003) (1063 - 1069) For biphasic shocks, starting at 5 J creates the optimum conditions for lowest threshold and cumulative energy, whereas 10–20 J offers optimum conditions for more rapid defibrillation and fewer shocks, ⁴¹² x B. Schwarz, T.A. Bowdle, G.K. Jett, et al.. Biphasic shocks compared with monophasic damped sine wave shocks for direct ventricular defibrillation during open heart surgery. Anesthesiology 98 (2003) (1063 - 1069) thus 20 J is the most applicable energy in an arrest situation, whereas 5 J would be adequate if the patient has been placed on cardiopulmonary bypass.

Continuing cardiac compressions using the internal paddles whilst charging the defibrillator and delivering the shock during the decompression phase of compressions may improve shock success.^{413 and 414} x Y. Li, H. Wang, J.H. Cho, et al.. Defibrillation delivered during the upstroke phase of manual chest compression improves shock success. Crit Care Med 38 (2010) (910 - 915) x Y. Li, T. Yu, G. Ristagno, et al.. The optimal phasic relationship between synchronized shock and mechanical chest compressions. Resuscitation 81 (2010) (724 - 729)

It is acceptable to perform external defibrillation after emergency resternotomy. Apply external pads preoperatively to all patients undergoing resternotomy surgery. ⁴¹⁵ x A.L. Knaggs, K.T. Delis, K.G. Spearpoint, D.A. Zideman. Automated external defibrillation in cardiac surgery. Resuscitation 55 (2002) (341 - 345) Use the defibrillation energy level indicated in the universal algorithm. If the sternum is widely open the impedence may be significantly increased – if external defibrillation is chosen over internal defibrillation close the sternal retractor before shock delivery.