An Aspect of Resuscitation Practice - Coursework Example

RESUSCITATION PRACTICE Resuscitation can be defined as: A procedure designed to restore normal breathing after cardiac arrest that includes the clearance of air passages to the lungs, the mouth-to-mouth method of artificial respiration and heart message by the exertion of pressure on the chest. [1] The Cardiopulmonary resuscitation is also called as CPR. It has two components: 1. Chest compressions, and 2. Lung ventilation. Resuscitation is an emergency medical procedure for a victim of cardiac or respiratory arrest. It is performed in the hospitals, or in the community or by the emergency response professionals. It is usually continued along with the Advanced Life Support, until the patient regains a heartbeat, called as the Return of Spontaneous Circulation or ROSC, or is declared dead. The main purpose of resuscitation is not to restart the heart; instead its purpose is to maintain a flow of oxygenated blood to the brain and the heart. This delays the tissue death and prevents the permanent brain damage. Defibrillation and Advanced Life Support are actually designed to restart the heart. [6] PHYSIOLOGY OF CARDIAC ARREST: An adequate oxygen supply is necessary for the maintenance of normal tissue metabolism, in a functioning circulatory system. The failure of delivery of oxygen to tissues, leads to following changes: 1. Hypoxia and 2. Acidosis. [3] Hypoxia: It is defined as Deficiency of oxygen reaching the tissues of the body. [1] A brief period after the occurrence of cardiac arrest, the partial pressure of oxygen in blood starts falling dramatically, as oxygen continues to be consumed. In addition to it, the progressive accumulation of carbon dioxide in blood shifts the oxygen-hemoglobin dissociation curve to the right. As a result of this, there is an initial improvement of oxygen transfer to the tissues, but without any further delivery, the tissue hypoxia ensues. As a result of these changes, the partial pressure of oxygen (PaO2) level in the brain falls from 13kPa to 2.5kPa within a duration of 15 seconds and the person becomes unconscious. After a minute of this, the PaO2 will have fallen to zero. [3] Acidosis: It is defined as: An abnormal condition of reduced alkalinity of the blood and tissues that is marked by sickly sweet breath, headache, nausea and vomiting and visual disturbances and is usually a result of excessive acid production. [5] The brain and the heart possess a relatively higher rate of oxygen consumption (4mls/min and 23mls/min respectively), and thus oxygen delivery to them will fall below the critical levels during cardiac arrest. In a patient of ventricular fibrillation, the rate of myocardial metabolism remains almost normal, thereby exhausting the oxygen and high energy phosphate supplies. This leads to an increased anaerobic metabolism, thus leading to acidosis. The next step is accumulation of carbon dioxide in the tissues, especially the brain and the heart. The degree of acidosis developing in the brain, even with provision of the basic life support, threatens the tissue survival within duration of only 5-6 minutes. Likewise, in the heart, even with the restoration of a perfuse rhythm, acidosis depresses contractility and there is a higher risk of further arrhythmias. Cardiovascular collapse leads to a massive stress response. There is a large amount of release of Catecholamines (epinephrine and nor epinephrine), together with the adrenal corticosteroids, anti-diuretic hormone and the other hormonal responses. The most possible detrimental effects of these changes include hyperglycemia, hypokalemia, increased lactate levels and a tendency towards further arrhythmias. [3] CHEST COMPRESSIONS: Chest compressions can be defined as: Consist of rhythmic applications of pressure over the lower half of the sternum. These compressions create blood flow by increasing the intra thoracic pressure and directly compressing the heart. IMPORTANCE OF PROPER CHEST COMPRESSIONS: The chest compressions lead to the generation of blood flow. This delivers a small, but critically important amount of oxygen and substrate to the brain and myocardium. In the patients having ventricular fibrillation, the chest compressions increase the chances of a successful ventricular defibrillation. These chest compressions are especially of importance, if first shock is delivered in about 4 minutes after collapse. [4] PHYSIOLOGY OF CHEST COMPRESSIONS: As mentioned earlier, the chest compressions create a blood flow by increasing the intra thoracic pressure and directly compressing the heart. Despite of the fact that properly performed chest compressions can produce systolic arterial pressure peaks of about 60 to 80 mmHg, the diastolic blood pressure is low. In the carotid artery, the mean arterial pressure, seldom exceeds 40 mmHg. [9] The chest compression done during resuscitation has two phases: 1. The active phase and 2. The passive phase 1. Active phase: The active phase is the one, when force is applied downwards on the chest. During the active phase, the chest compression squeezes the heart between the sternum and the spine. This produces a compression on the ventricles, thereby pumping the blood out of the heart into the lungs, and then after oxygenation, to the body. It is important to maintain the compression depth between four to five centimeters, for the active phase to be effective. 2. Passive phase: The passive is the one, when pressure is released and the chest is allowed to recoil to its normal shape. This phase is the phase of return of venous blood to the heart, flowing through the atria and into the ventricles. When the heart is in the state of arrest, the only condition for the venous blood to return to heart is when the intra thoracic pressure is less than the intra abdominal pressure. This can be regarded as the back bone of CPR. The coronary artery perfusion takes place during this phase, when the blood pumped through the aorta during the active phase, flushes back and is directed into the coronary arteries. A sufficient blood pressure is required to perfuse the coronary arteries. While in cardiac arrest, about 5-10 efficient chest compressions are required to bring the coronary artery perfusion pressure up to a level adequate for supply to the myocardium. If the chest compressions are interrupted, and stopped even for a few moments, the coronary perfusion pressure is affected dramatically, losing all the efforts made during the previous cycles of compressions. The hypoxia and acidosis can be corrected only if a constantly elevated coronary artery perfusion pressure is maintained. PHYSIOLOGY OF VENTILATION: Ventilation is the second component of cardiopulmonary resuscitation. It means providing oxygen to and removing carbon dioxide from the body. It is provided, either by mouth-to-mouth method, or by using the air bag, depending upon the conditions. Squeezing the resuscitation bag, forces the air into the lungs. This provides oxygen to the pulmonary arteries, and removes the carbon dioxide. The important point to note here is that, as the lungs are very efficient at extracting oxygen, thus removal of carbon dioxide is the more important component of the ventilation process, and it occurs primarily through the maintenance of a patent airway, and also by ensuring that a sufficient amount of air is being moved in and out of the lungs. This amount of air is also called as the ‘tidal volume’. Here, another important point to keep in mind is that, when the lungs are inflated with air, the intra thoracic pressure rises. This causes an inhibition of the venous blood return to the heart; as it has been mentioned previously that a negative intra thoracic pressure is necessary for the venous return to occur. Thus by the discussion so far, we can conclude that, for a CPR to be really effective, the following points are most considerable: 1. Maintenance of an adequate coronary artery perfusion by performing the chest compressions at an effective rate and depth. 2. Using such techniques which can lower the intra thoracic pressure, thus promoting the venous blood return to the heart. [8] GUIDELINES FOR AN EFFECTIVE CPR: The American Heart Association had released some guidelines for a CPR to be effective. Some of these were as follows: 1. The optimal compression rate should be no less than 100/minute. 2. There should be a minimum number of interruptions to CPR. 3. The optimal compression depth should be about 4-5 cm. It is very important to allow chest to recoil fully during the passive phase, in order to relieve all pressure off the chest. 4. The ratio of compressions to ventilations varies according to the number of rescuers. For one rescuer, this ratio comes out to be 30:2. While, with two rescuers performing the CPR, this ratio comes out to be 30:2 for adults, and 15:2 for children, until an advanced airway is in place. 5. The rate of ventilations should be 8-10 per minute. 6. Ventilations should be given in only one second. There should be a coincidence of the second breath with the first compression in next CPR cycle whenever possible. 7. After the insertion of an advanced airway, the ratio does not apply anymore and the chest compressions should be performed at a nonstop rate of 100 per minute. The breaths should be delivered at a rate of 8-10 per minute, without any pause in compressions for delivering ventilation. 8. Unless the patient develops a witnessed arrest, or the accident and emergency department is available immediately, the duration of CPR must be about two minutes, in order to raise the coronary artery perfusion pressure, wash out the hypoxic blood and improve the venous blood return to the heart. [8] IMPORTANCE OF CHEST COMPRESSONS OVER VENTILATION: Recent studies have shown that the even the chest compressions alone, if performed properly can be very helpful in saving the life of a patient, without performing the ventilations. This conclusion is proved in two studies published in the December 11 issue of the journal ‘Circulation’. Study 1: It was a Swedish research, studying about 11,275 cases of out-of-hospital cardiac arrest over 15 years. This study showed that the one month survival rates were similar for the patients who received standard CPR or who received the chest compressions alone, from by standers. These rates were, 7.2% and 6.7%, respectively. The name of this study author was Katrina Bohm, who said: If you hesitate to do CPR, remember that chest compressions only is better than doing nothing. The author further said: The advantages of CC-CPR include its simplicity, which in turn may lead to more out-of-hospital cardiac arrest patients receiving CC-CPR from the more hesitant potential rescuer. Study 2: This study was performed by the Japanese researchers. About 4,902 cases of out-of-hospital cardiac arrest over five years were studied. The results showed that there was a higher one year survival rate with favorable neurological symptoms in patients who had received CC-CPR or CPR alone, by the bystanders, than those who had not received any chest compressions or CPR. In all these cases, it took about 15 minutes for the emergency medical personnel to arrive. Another conclusion made by this study authors was that, CC-CPR may be superior to standard CPR when provided within five minutes of cardiac arrest, and that rescue breathing may be of some help in cases of very prolonged cardiac arrest. [7] According to the researchers in Arizona, the survival rates trebled with the introduction of a technique emphasizing the importance of non-stop chest compressions. But it was insisted by the researchers in the Journal of the American Medical Association that these rates could be improved. It was stated in the BBC one-minute news, in the light of these research results that: Minimally interrupted cardiac resuscitation (MICR) involves providing 200 uninterrupted compressions, administering adrenaline early and waiting a little longer to insert a tube into the trachea to ventilate the lungs. According to this news report, this practice of MICR was taught to the paramedics in two metropolitan cities. The data shows that, before this training was given to the paramedics, about 218 patients were attended after the heart attack, of whom about 1.8% survived long enough to reach a hospital. There was an increase in this figure to about 5.4% after the training was given to the paramedics. The ratio increased and 36 of 668 patients reached the hospital. According to Dr. Bentley Bobrow from the Mayo Clinic in Arizona: During resuscitation efforts, the forward blood flow produced by chest compressions is so marginal that any interruption of chest compressions is extremely harmful. Excessive interruptions of chest compressions by pre-hospital personnel are extremely common. Therefore, MICR emphasizes uninterrupted chest compressions. The current recommended practice in UK is that of about 30 compressions before the beginning of ventilation. [2] THE INCIDENCE OF CARDIAC ARREST IN UK: The incidences of cardiac arrest in different regions have been studied by many researchers. According to a study, the incidence of cardiac arrest in UK is estimated to be between 70,000 and 80,000 cases per anum, while majority of these incidences occurring at home. [10] IN HOSPITAL CADRIAC ARRESTS: Given below are the statics accumulated from various sources regarding the hospitalization after cardiac arrest: 1. 0.03% (3,795) of hospital consultant episodes were for cardiac arrest in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 2. 70% of hospital consultant episodes for cardiac arrest required hospital admission in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 3. 58% of hospital consultant episodes for cardiac arrest were for men in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 4. 42% of hospital consultant episodes for cardiac arrest were for women in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 5. 3% of hospital consultant episodes for cardiac arrest required emergency hospital admission in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 6. 9.9 days was the mean length of stay in hospitals for cardiac arrest in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 7. 3 days was the median length of stay in hospitals for cardiac arrest in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 8. 68 was the mean age of patients hospitalised for cardiac arrest in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 9. 19% of hospital consultant episodes for cardiac arrest occurred in 15-59 year olds in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 10. 45% of hospital consultant episodes for cardiac arrest occurred in people over 75 in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 11. 0% of hospital consultant episodes for cardiac arrest were single day episodes in England 2002-03 (Hospital Episode Statistics, Department of Health, England, 2002-03) 12. 0.046% (23,922) of hospital bed days were for cardiac arrest in England 2002-03 (Hospital EpisodeStatistics, Department of Health, England, 2002-03) [11] According to another study done at Royal Center of Defence Medicine, Selly Oak Hospital, Brimingham, the results were as follows: The purpose of this study was to establish the incidence of cardiac arrest among patients who had received the resuscitation practice in a district general hospital. The results showed that there were 32,348 adult admissions in 1999, with 1023 deaths. It was about 139 times that the cardiac arrest team was activated. Out of these, 118 times was for primary in-hospital cardiac arrest. The cardiac arrest rate, excluding the ‘do not attempt resuscitation’ (DNAR) policy came out to be 3.8/1000 admissions. Survival rate following the hospital discharge was found to be about 14%. Another interesting finding was that, the cardiac arrest were potentially more at the weekends, that between the weeks. The panel also concluded that 100% of potentially avoidable arrests were found to have received an inadequate prior treatment. The final conclusion made by the panel was that: Majority of treated in-hospital cardiac arrests are potentially avoidable. Multiple system failures include delays and errors in diagnosis, inadequate interpretation of investigations, incomplete treatment, inexperienced doctors and management in inappropriate clinical trials.[12] OUT OF HOSPITAL CARDIAC ARRESTS: Regarding the out of hospital cardiac arrests, the London Ambulance Service’s (LAS) 1997 database is mentioned below. The database provides details of about 3,759 out of hospital cardiac arrests. Out of these, about 2,772 arrests, either witnessed or un witnessed by the by standers, were analyzed focusing on by standers cardiopulmonary resuscitation and response timings. Their results showed that the witnessed arrests in ventricular fibrillation or tachycardia, who had received the cardiopulmonary resuscitation from the by standers, had a return of spontaneous circulation in the field, significantly more often than those who did not receive any resuscitation from the by standers. But, the likelihood of being admitted to the hospital and then getting discharged alive, was only marginally better for those who had received the resuscitation after arrest. [13] The results of another study showed that the out of hospital cardiac arrests survival is largely dependent upon the response time and distance travelled to the scene. The survival of a patient can be largely influenced by the geographical location. So, measures should be taken to strategically position the ambulance dispatch points. [14] CONCLUSION: By the discussion so far, we can conclude by saying that the cardiac arrest is a life threatening condition, yet the patient can have a better prognosis, if proper resuscitation practice is provided in time, and after initial life saving management, patient is lucky to reach a hospital setup and receive further management including the defibrillation etc. But resuscitation is a technique, which requires a proper training and great effort in itself. It is not a simple process of providing chest compressions and artificial breathing. There are further statistics describing the rate and depth of chest compressions and the rate of ventilation provided to be effective, so that we can save the life of patient. The ambulance staff is specially trained for this purpose. Now such studies are emerging that have concluded the importance of chest compressions alone, over the ventilation for a resuscitation practice to be effective. Some of these studies along with their results are already discussed. But this is a very important topic and a serious approach is required to prove it fully. According to a survey among the doctors and nurses, regarding this new concept, many were of the opinion that it is a very interesting finding in itself, that focusing on the chest compressions alone can be very helpful in saving a patient’s life during resuscitation, yet it is a very important issue and it cannot be implemented fully without any detailed research and studies. Regarding the ratio and prognosis of in and out patient cardiac arrests in UK alone, the statistical data is described above. It is also seen that the patients who have defibrillators at home have a better prognosis. Other patients receiving the resuscitation by the by standers, prior to the arrival of the ambulance staff and admission to hospital, have their prognosis dependent all upon the initial few minutes of resuscitation, because all the damage that occurs to vital organs, like brain and heart, is within the initial few moments of de oxygenation. If resuscitated properly, these vital organs will be able to still receive a percentage of oxygenated blood, and thus, preventing them from permanent damage. Otherwise, although the heart can be functional again, but many patients are pushed to permanent neurological damage, which cannot be reversed. The prognosis for the in hospital resuscitation is definitely better, as the patient is immediately provided the defibrillator shock and injectable medicines, like adrenaline, besides receiving a proper resuscitation technique from the trained staff. BIBLIOGRAPHY 1. Medline Plus medical dictionary [online] 2005 [cited April 24th, 2008]. Available from: http://www2.merriam-webster.com/cgi-bin/mwmednlm?book=Medical&va=cardiopulmonary+resuscitation 2. BBC News: Chest compression saves lives [online] 2008 [cited April 24th, 2008]. Available from: http://news.bbc.co.uk/2/hi/health/7291473.stm 3. Dr. David Birt, Mr BG Thomas, Dr. Iain Wilson. Resuscitation from cardiac arrest [online] 1999 [cited April 24th, 2008]. Available from: http://www.nda.ox.ac.uk/wfsa/html/u10/u1006_01.htm 4. LUCAS Chest compression system. [online] 2007 [cited April 24th, 2008]. Available from: http://www.physio-control.com/uploadedFiles/learning/clinical-topics/3207636-000%20LUCAS%20Chest%20Compression%20System%20Guidelines%20for%20Chest%20Compressions.pdf 5. Medline Plus medical dictionary [online] 2995 [cited April 24th, 2008]. Available from: http://www2.merriam-webster.com/cgi-bin/mwmednlm 6. Wikipedia: Cardiopulmonary Resuscitation [online] 2008 [cited April 24th, 2008]. Available from: https://health.live.com/article.aspx?id=articles%2fwp%2fpages%2fc%2fa%2fr%2fCardiopulmonary_resuscitation.html&qu=Cardiopulmonary+Resuscitation 7. Chest compressions effective in emergency cardiac arrest: MedicineNet.com [online] 2007 [cited April 24th, 2008]. Available from: http://www.medicinenet.com/script/main/art.asp?articlekey=85775 8. Improving the hemodynamics of CPR. EMSresponder.com [online] 2006 [cited April 24th, 2008]. Available from: http://www.emsmagazine.com/print/Emergency--Medical-Services/Improving-the-Hemodynamics-of-CPR/1$3063 9. American Heart Association Guidelines for Cardiopulmonary and Emergency Cardiovascular Care. Part 4. [online] 2005 [cited April 24th, 2008]. Available from: http://circ.ahajournals.org/cgi/content/full/112/24_suppl/IV-19 10. Home heart attack kits. University Hospitals of Leicester. [online] 2008 [cited April 24th, 2008]. Available from: http://www.uhl-tr.nhs.uk/aboutus/news/home-heart-attack-kits 11. Statistics about cardiac arrest. [online] 2008 [cited April 24th, 2008]. Available from: http://www.wrongdiagnosis.com/c/cardiac_arrest/stats.htm 12. Timothy J. Hodgetts, Gary Kenward, loannis Vlackonikolis, Susan Payne, Nicolas Castle, Robert Crouch, Neil lneson, Loua Shaikh. Incidence, location and reasons for avoidable in-hospital cardiac arrest in a district general hospital. [online] 2002 [cited April 24th, 2008]. Available from: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T19-45TY7NT-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=ab1956bf6d12e6d89c2d081dd740e6b9 13. Event-tree analysis of out of hospital cardiac arrest data. [online] 2003 [cited April 24th, 2008]. Available from: http://www.herc.ox.ac.uk/pubs/bibliography/Dowie2003 14. R M Lyon, S M Cobbe, J M Bradley, N R Grub. Surviving out of hospital cardiac arrest at home. [online] 2004 [cited April 24th, 2008]. Available from: http://emj.bmj.com/cgi/content/abstract/21/5/619 Read More