It is reported that 1750-7250 of approximately 250,000 patients that undergo major heart surgeries every year will have a post-operative cardiac arrest.
There is new evidence that chest compressions are not the best answer.
The current ACLS Standards for resuscitation researched and recommended from the American Heart Association include the use of chest compressions to represent and induce return of heart function.
However, in the environment of cardiac surgery, chest compressions can result in potentially irreparable damage to the surgical area or even death.
There are generally four types of heart surgery currently in practice:
1. CORONARY ARTERY BYPASSES: this surgery removes a part of a coronary artery that is obstructed and not providing blood and oxygen to the heart and replaces it with part of an arm or leg vein that will provide a clear pathway. Bypasses can include one to six bypasses in a single surgery.
2. HEART VALVE REPLACEMENTS: there are four heart valves: mitral valve, tricuspid valve, pulmonary valve and aortic valve. They provide doorways to different chambers of the heart. If the valves become weak, floppy or damaged by illness such as rheumatic fever, heart failures or trauma, they can increase the risk of blood clots and clots of bacteria that have the potential to travel to areas of the body including arms, legs, lungs and the brain and cause occlusions such as clots and stroke and systemic infections. Valve replacements can be tissue valve replacements from cows or pigs or mechanical replacements.
3. ANEURYSM REPAIR: aneurysms are weakened parts of veins or arteries that have the potential for rupture. Aneurysms found in veins or arteries around the heart such as the aorta have great risk for catastrophic events such as bleeding out causing a rapid death if the aneurysm area ruptures. Aneurysms that have been found and are either not ruptured or even have a small, slow leak, can be treated with intravenous medications that reduce the blood pressure in the heart and surgically repaired.
4. HEART TRANSPLANTS: patients with extreme heart failure and disease can receive a heart transplant if certain transplant criteria are met. This replaces the entire diseased heart including valves and coronary arteries with a healthier heart. This requires lifetime post care and medications to prevent transplant rejection.
Why is it all so intense after heart surgery?
After heart surgery, the patient is recovered, monitored and treated in the cardiac intensive care unit. They are cared for by intensive care nurses with special training in heart surgery class instruction, testing and apprentice orientation.
Receiving a patient into the cardiac intensive care unit after heart surgery resembles a tightly knit and executed military operation. Generally two to three CCU heart nurses and a critical care respiratory therapist receive the patient, each one with specific roles on getting monitoring, chest tube, intravenous medications and ventilator connections in place.
The post-operative patient can return with extensive monitoring equipment that can include:
1. A MECHANICAL VENTILATOR: to provide controlled breathing and oxygen as the patient recovers from the heart-lung bypass machine during surgery and surgical anesthesia
2. AN APPROXIMATELY 12 INCH LONG MIDLINE SURGICAL INCISION that covers the sternum that was taken out during surgery by cutting the connections between the sternum and all ribs bilaterally in order to provide access to the heart. The ribs have been wired back to the sternum connections to replace the protection over the heart. The wires will remain there permanently as the surgical incisions heal to provide sturdy reassembly between the ribs and sternum.
3. 2-3 CHEST TUBES that are situated in the bottom portion of the midline chest incision and drain any secretions, saline rinses and blood from the surgical procedure. The chest tubes are connected to a low suction in order to drain fluid from the surgical site. This prevents secretions and blood from pooling in the area around the heart and increasing pressure around the heart that could affect its function after surgery.
4. A MULTI PORT INTRAVENOUS CATHETER in a large vein in the right or left neck that has three to four ports in in it that can provide access for intravenous medications [including medications for sedation, pain management, blood pressure management and antibiotics], intravenous fluids for hydration and blood products as well as act as a source for blood specimens for lab tests. A special catheter called a Swan-Ganz is part of the intravenous catheter setup and has an intricate sensor that can monitor specific types of heart function.
5. AN INTRA-ARTERIAL CATHETER in an artery in the wrist that can provide blood pressure monitoring by the second as well as provide a source for blood specimens for blood tests and blood gas measurements that monitor oxygenation, carbon dioxide, bicarbonate and pH levels in the blood that are indicators for heart and lung function.
The care of a post-operative heart surgery patient is always a 1:1 assignment until the patient is off the ventilator and stable.
Even if the surgery goes well, there are BIG risks after cardiac surgery that might result in a cardiac arrest and require resuscitation:
1. THE SURGERY ON THE HEART ITSELF: the heart has been traumatized and even if this is for repair, surgery is an enormous stress on the heart.
2. THE AGE OF THE PATIENT: up to approximately 10 years ago, heart surgery on elderly patients was not recommended due to a general fragility. With advances in medicine including medications, surgeries and rehabilitation, people are living longer and in generally better health. Currently, heart surgeries have been done on patients as old as 90’s for coronary artery bypasses and valve replacements. However, age still presents risk as far as ability of the patient, organs and general systemic function to tolerate and recover from such intensive surgeries. Some seniors do not tolerate the prolonged anesthesia and heart bypass pump time well and have prolonged confusion in recovery.
3. THE GENERAL HEALTH OF THE PATIENT: our bodies are not compartmentalized. Each organ system affects the other. Patients with lung disease such as COPD [chronic obstructive pulmonary disease] and smoking, as well as kidney disease and diabetics as well as other co-existing diseases may have more trouble with their other diseases or, overall. This could increase risk for complications with respiratory, kidney and rehabilitation as examples. This increases the potential for prolonged hospitalization and the possibility of needing rehabilitation or skilled nursing admissions before they are able to return home.
4. THE TIME DURING SURGERY that the patient was on the heart-lung bypass pump: although the use of the pump has improved stability of the functions of multiple organs including the brain, lungs and kidneys during and after heart surgery, some patients with multiple co-existing diseases or in general poor health may not recover as easily as others.
Why would a patient need resuscitation after heart surgery?
Resuscitation is required if the patient’s heart stops. No heart function affects all major organs and systematically creates their failure. Without returning heart function, the patient dies.
A patient’s heart could stop for one or multiple of reasons including:
1. The heart muscle itself is weak and has poor function and did not tolerate the surgery resulting in cardiac arrhythmias including profound bradycardia, ventricular fibrillation, ventricular tachycardia or pulseless cardiac arrests.
2. Co-existing medical factors such as lung or kidney disease were exacerbated by the failing heart and could not overcome additional stressors of an intensive surgery.
3. Post-operative bleeding causes low blood pressure which affects all major organs.
4. Catecholamine and electrolyte changes from the effect on the heart muscle during surgery.
So why can cardiac compressions be so dangerous to a patient after heart surgery if ACLS is the standard of care?
AHA ACLS procedure requires that external chest compressions be delivered at a rate of 100 times per minute and at a depth of 2 inches for an adult.
Consider that for a moment… compressing a newly surgical chest with incisions, broken ribs, wires and chest tube to a depth of 2 inches… approximately the length of your index finger.
Even brief pressure from chest compressions on a heart surgery area can cause extensive complications:
1. Pericardial injury: injury to the heart itself.
2. Fractured sternum: re-breaking the newly surgically fractured and rewired sternum.
3. Rupture of heart chamber
4. Dehiscence of the prosthetic heart valves: the sutures are ripped apart and the valve becomes displaced which creates a hole between the atrial and ventricular heart chambers
5. Vascular dissection: tearing open the large veins and arteries around the heart from external pressure against internal elements such as broken ribs, wires, and newly sutured arteries and veins.
6. Displacement of the sternum: due to disruption of the newly surgically disconnected sternum and ribs with new wire re-attachments.
If any of these things happen, it becomes a surgical emergency in addition to the cardiac arrest. And the possibility of return of function as well as recovery now becomes extraordinarily slim.
The European Resuscitation Council (ERC) is the counterpart to our American Heart Association (AHA). The ERC provides research, standards, guidelines and education regarding resuscitation.
In a report by Dunning et al, the ERC advised important, evidence-based deviations from the standard ACLS protocols that the American Heart Association has evaluated for use in the United States.
The recommendations from the ERC are only related to patients of heart surgeries who had sternotomy (disconnection from ribs and removal of the sternum during heart surgery), who experience a cardiac arrest in the cardiac intensive care unit after their surgery.
These include: in the place of chest compressions [and specific to certain arrhythmias]:
1. Defibrillation [electric shock with a defibrillator]
2. External pacing
3. No use of epinephrine or vasopressin
4. In cases where all this fails, the ERC recommends rapid opening of the incision, removal of the wired sternum and provision of internal cardiac massage.
The European Resuscitation Council (ERC) reports favorable outcomes by using these adaptions to ACLS for post-operative heart surgery patients who have suffered a post-operative arrest:
1. Dimopoulou et al reported a 79% survival rate
2. 55% of these patients still alive 4 years after a post-operative arrest
3. 48% survival rate when emergency resternotomy was performed within 10 minutes
These improved outcomes are outstanding looking at these studies when you consider the potential outcomes of having to do chest compressions in a post-operative heart surgery patient.
So, when a patient who has undergone heart surgery arrests in the cardiac intensive care unit and receives chest compressions as part of the standard AHA ACLS protocol…
… I would wonder why.
[Jill Ley, RN, MS, CNS; Standards for Resuscitation After Cardiac Surgery; Critical Care Nurse; Vol 35, No 2. April 2015; pages 30-37.
[Original Post 04/15/2015]