Cardiac Arrest Research Paper

Running Head: IS THERAPEUTIC HYPOTHERMIA MORE BENEFICIAL?
Is Therapeutic Hypothermia More Beneficial Than Maintaining
Normothermia Post-Cardiac Arrest?NUR 2243 Management of Nursing Care
IS THERAPEUTIC HYPOTHERMIA MORE BENEFICIAL?
Is Therapeutic Hypothermia More Beneficial Than Maintaining
Normothermia Post-Cardiac Arrest?
To what extent does inducing hypothermia benefit patients? What exactly are the benefits, and do they come with risks? There have been many trials dealing with therapeutic hypothermia that exhibit advantageous neurological outcomes post-cardiac arrest. Most of these trials lead to a decrease in the mortality rate of the patients. Our team decided on this topic after hearing about how induced hypothermia helped in
several different clinical situations during our emergency lecture. Further research on this topic led to our discovery of benefits, risks, and trials related to therapeutic hypothermia post-cardiac arrest.
The research question is: is therapeutic hypothermia more beneficial than maintaining normothermia post-cardiac arrest?
“Animal data and human studies suggest that achievement of target hypothermic temperature may be associated with improved neurological outcomes” (Binks et al., 2010). In 2002, it was discovered that maintaining a core temperature of 33 degrees Celsius (94 degrees Fahrenheit) for twelve or more hours after resuscitating from cardiac arrest led to increased chances of a client being discharged to home or a rehabilitation facility. After a six month time period had passed, these same patients were discovered to have full neurological recoveries. The patients who had not received the induced hypothermia and remained normothermic had increased mortality rates and more severe long-term damage (Logan, Sangkachand, & Funk, 2011). The goal of therapeutic hypothermia after cardiac arrest is to decrease metabolic activity,
IS THERAPEUTIC HYPOTHERMIA MORE BENEFICIAL? leading to a reduction in oxygen consumption. In other words, the body requires less oxygen to do its job. Subsequently, more oxygen is made available to the body and brain. Reperfusion is crucial for a favorable prognosis post-cardiac arrest. A comparison study has also shown that therapeutic hypothermia does, in fact, benefit the patient. In this particular study, twelve patients were treated with hypothermia, while seven patients received conventional therapy, or standard supportive care. The studies reported a 58% survival rate in the hypothermic group compared to a 14% survival rate in the normothermic group. Promising neurological outcomes were documented in 100% of the surviving patients in the hypothermic group (Alkadri & McMullan, 2009).
A randomized controlled trial was conducted in Europe that tested patients with return of spontaneous circulation (ROSC) and persistent coma following out of hospital cardiac arrest. Icepacks and cooling blankets were applied to the core of these patients with a target temperature between 32 and 34 degrees Celsius. Therapeutic hypothermia was maintained for 24 hours and followed by passive rewarming. Patients undergoing the normothermic study received standard care in the ICU with a target temperature of 37 degrees Celsius. The results of this trial concluded with favorable outcomes. Patients that endured therapeutic hypothermia had desirable neurological outcomes that included Pittsburgh Cerebral Performance score of 1 (good recovery) and 2 (moderate disability). This trial was highly exclusive, being very selective with the patients that were chosen (Morcom, 2003). There is concern that the induction of hypothermia can affect acid-base balances, immune system functioning, and adversely affect coagulation. Accidental hypothermia has been associated with septicemia and increased mortality among patients with trauma and sepsis (Gentiletto et.al and Clemmer et. Al, 1997). The results of this European trial
IS THERAPEUTIC HYPOTHERMIA MORE BENEFICIAL? concluded that the patients who received normothermia versus hypothermia experienced no significant complications (Morcom, 2003).
It is unclear exactly why keeping the body temperature lower helps to preserve the brain. The only documented reason scientists can produce to explain this phenomena is that, at normal temperatures, the restoration of blood flow to the body after cardiac arrest rescue triggers a cascade of inflammatory and other responses. This can lead to injury of the brain’s sensitive tissue and result in lethality. Icing the body slows down metabolic rates and protects the brain from at least some of the damage caused by the restored blood flow. This reasoning is inconclusive, and more research may eventually be driven to discover and fully understand what is happening when the body is cooled post-cardiac arrest (Hay et al., 2008).
The best practice, based on evidence from several different studies and clinical trials, would be to induce therapeutic hypothermia immediately following cardiac arrest resuscitation. Continuous monitoring must be implemented when undergoing this practice. The nurse must be skilled in assessment and must maintain the core temperature targeted by the physician. Typically, after 24 hours have passed, the body is then rewarmed and the patient is re-evaluated (Logan, Sangkachand, & Funk, 2011).
The research that has been conducted on this subject has shown considerable progress in how neurological function is maintained when a patient is recovering from cardiac arrest.
“Hypothermia is currently the only neuroprotectant with proven benefits in the prevention of
PCA anoxic brain injury and is currently recommended…” (Alkadri & McMullan, 2009). As further investigations unfold, all healthcare systems may implement therapeutic hypothermia
IS THERAPEUTIC HYPOTHERMIA MORE BENEFICIAL? post-arrest. This research could improve all practices by prolonging the life of cardiac arrest patients. As most of these patients die from the lack of oxygen to the brain, being able to preserve the brain tissue will lead to more desired outcomes and decrease the mortality rate associated.
Therapeutic hypothermia in the treatment of PCA patients is rapidly taking root, but the frequency of its application in the United States is still quite limited. An internet-based physician survey in 2006 found that 74% of responding physicians had never used therapeutic hypothermia. Adoption among intensivists was 34%, while only 16% of emergency medicine physicians reported use. (Alkadri & McMullan, 2009, p.
279-280)
From what this quotation is observing, many healthcare providers are unaware of the benefits of induced hypothermia. As more studies develop, the implementation of this element may increase. As such, less brain death may occur post-cardiac arrest. Evidence-based practice supports the usage of therapeutic hypothermia after cardiac arrest.
IS THERAPEUTIC HYPOTHERMIA MORE BENEFICIAL?
References
Alkadri, M. E., & McMullan P. (2009). Induced Hypothermia as a Neuroprotectant in Post-Cardiac Arrest. The Oschner Journal, 9:278-281.
Binks, A. C., Murphy, R. E., Prout, R. E., Bhayani, S. S., Griffiths, C. A., Mitchell, T. T., & ... Nolan, J. P. (2010). Therapeutic hypothermia after cardiac arrest – implementation in UK intensive care units. Anaesthesia, 65(3), 260-265. doi:10.1111/j.1365-2044.2009.06227.x
Hay, A. W., Swann, D. G., Bell, K. K., Walsh, T. S., & Cook, B. B. (2008). Therapeutic hypothermia in comatose patients after out-of-hospital cardiac arrest. Anaesthesia, 63(1), 15-19. doi:10.1111/j.1365-2044.2007.05262.x
Keresztes, P. A., & Brick, K. (2006). Therapeutic Hypothermia After Cardiac Arrest. (cover story). Dimensions Of Critical Care Nursing, 25(2), 71-76.
Logan, A., Sangkachand, P., & Funk, M. (2011). Optimal Management of Shivering During Therapeutic Hypothermia After Cardiac Arrest. Critical Care Nurse, 31(6), e18-e30. doi:10.4037/ccn2011618
Morcom, F. (2003). CHILL OUT: THERAPEUTIC HYPOTHERMIA IMPROVES SURVIVAL. Emergency Nurse, 11(4),
24.