Letter To The Editor

Cardiopulmonary resuscitation after cardiac surgery

Although the techniques and perioperative management in modern cardiac surgeries has improved, and mortality and morbidity have decreased dramatically, postoperative cardiac arrest after heart surgery (POCHS) is a life-threatening condition that should be assessed and managed precisely.

To determine the mortality rate and causes of death in postoperative cardiac arrest after heart surgery (POCHS).

A total of 3342 patients underwent cardiac surgery from 2010 to 2018 in Isfahan, Iran .142 of them experienced POCHS . POCHS patients were investigated for characteristics, causes of cardiopulmonary arrest, first-line treatment, and mortality. These items were compared between survived and deceased patients to find possible prognostic factors.

The incidence rate of cardiac arrest was 4.2% (142 ones from total of 3342). Success rate of cardiac arrest is 28.8% (41 from 142). Bradycardia was the most common cause of cardiorespiratory arrest (37.3%), followed by cardiogenic shock (30.3%) and ventricular fibrillation (23.2%). Younger patients (58±11.5 versus 62.9±11.3) and those who developed cardiopulmonary arrest due to ventricular fibrillation (42.4% versus 22.2%), bradycardia (21.2% versus 8.8%), and apnea (15.1% versus 6.6%) were more likely to survive, while, those with shock had the worst prognosis (P<0.05). The best response to resuscitation was found among those treated with defibrillator plus ECM (External Cardiac Massage) as compared to the other approaches (P-value=0.003).

Based on the current report, CPR success was found in 28.6% among whom respiratory etiology led to better outcomes than cardiac etiology. The second cause of cardiac arrest is ventricular fibrillation which immediate defibrillation has the best outcome. The highest numerical success in POCHS is combination of ECM with defibrillator.

The Society of Thoracic Surgeons Task Force on Resuscitation After Cardiac Surgery provides this professional society perspective on resuscitation in patients who arrest after cardiac surgery. This document was created using a multimodal methodology for evidence generation and includes information from existing guidelines, from the International Liaison Committee on Resuscitation, from our own structured literature reviews on issues particular to cardiac surgery, and from an international survey on resuscitation hosted by CTSNet.

In gathering evidence for this consensus paper, searches were conducted using the MEDLINE keywords “cardiac surgery,” “resuscitation,” “guideline,” “thoracic surgery,” “cardiac arrest,” and “cardiac massage.” Weight was given to clinical studies in humans, although some case studies, mannequin simulations of potential protocols, and animal models were also considered.

Consensus was reached using a modified Delphi method consisting of two rounds of voting until 75% agreement on appropriate wording and strength of the opinions was reached. The Society of Thoracic Surgeons Workforce on Critical Care was enlisted in this process to provide a wider variety of experiences and backgrounds in an effort to reinforce the opinions provided.

We start with the premise that external massage is ineffective for an arrest due to tamponade or hypovolemia (bleeding), and therefore these subsets of patients will receive inadequate cerebral perfusion during cardiac arrest in the absence of resternotomy. Because these two situations are common causes for an arrest after cardiac surgery, the inability to provide effective external cardiopulmonary resuscitation highlights the importance of early emergency resternotomy within 5 minutes. In addition, because internal massage is more effective than external massage, it should be used preferentially if other quickly reversible causes are not found.

We present a protocol for the cardiac arrest situation that includes the following recommendations: (1) successful treatment of a patient who arrests after cardiac surgery is a multidisciplinary activity with at least six key roles that should be allocated and rehearsed as a team on a regular basis; (2) patients who arrest with ventricular fibrillation should immediately receive three sequential attempts at defibrillation before external cardiac massage, and if this fails, emergency resternotomy should be performed; (3) patients with asystole or extreme bradycardia should undergo an attempt to pace if wires are available before external cardiac massage, then optionally external pacing followed by emergency resternotomy; and (4) pulseless electrical activity should receive prompt resternotomy after quickly reversible causes are excluded. Finally, we recommend that full doses of epinephrine should not be routinely given owing to the danger of extreme hypertension if a reversible cause is rapidly resolved.

Protocols are given for excluding reversible airway and breathing complications, for left ventricular assist device emergencies, for the nonsternotomy patient, and for safe emergency resternotomy. We believe that all cardiac units should have accredited policies and protocols in place to specifically address the resuscitation of patients who arrest after cardiac surgery.