Rise of Mechanical Ventilation of Asthmatic Patients in a Pre-Hospital Setting - Essay Example

? Risks of Mechanical Ventilation of Asthmatic Patients in a Pre-Hospital Setting Asthma is a chronic inflammatory disease that affects the air passages of a patient. This type of disease may cause the patient to develop exacerbations that can lead to respiratory failure. In these types of situations, patients are at risk and require careful assessment. Rapid application of appropriate treatment is critical to have a favourable outcome. Mechanical ventilation is needed depending on the severity of the condition of the patient in order to facilitate the entry of oxygen into the lungs and to get rid of carbon dioxide as well. This paper will outline the risks that are involved in the mechanical ventilation of patients in a prehospital setting. Risks of Mechanical Ventilation of Asthmatic Patients in a Pre-Hospital Setting Asthma is a chronic inflammatory disease of air passage of patients that often develops exacerbations and leads to respiratory failure. The disease is prevalent worldwide with 100 to 150 million affected individuals and causes 180,000 deaths annually. In India alone, there are about 15 to 20 million people that are affected by the disease. Lifetime asthma in the US has significantly decreased, though still alarming, at 11.9% or roughly 24.7 million in 2002 which is relatively smaller than the previous decades. Mortality rates associated with asthma have also significantly decreased from 1978 with about 5000 deaths per year and declined to about 38.4% in 2002 (Soubra and Guntupalli, 2006). One of the most challenging conditions that can be faced by respiratory care experts is the management of patients with status asthmaticus that require immediate ventilator support (Medoff, 2008). These cases become even more difficult in prehospital settings and would require trained and expert medical response teams. Another dilemma to the situation is that there is no definite data on the incidence and prevalence of an acute severe asthma episode that would require ventilatory support. Asthma related hospitalizations and mortality have also declined through recent years as discussed above and, thus, resulted in a decline in the need of mechanical ventilation for asthma patients (Medoff, 2008). Despite the decline of reported deaths associated with asthma, the prevalence of the disease has increased worldwide and the mortality rate still approaches 10% in these affected patients. Thus it is still of paramount importance for medical teams to be familiar with the care of for patients with this sever illness and an in-depth understanding of respiratory failure in asthma patients should never be undermined (Medoff, 2008). Though the occurrence of asthma conditions that requires mechanical ventilation is relatively rare, patients that undergo mechanical ventilation are at high risk of having high morbidity and mortality. The term Near-Fatal Asthma (NFA) is an experience that is designated by a condition wherein a patient with a severe asthma attack survives the episode through the help of endotracheal incubation and mechanical ventilation to address the respiratory failure. It is also essential for the patients to be able to recognize the occurrence of a severe attack and be able to take systematic corticosteroids (SC) treatment before an episode (Dhuper, Maggione, Chung, and Shim, 2003). In addition, Mechanical ventilation improves chronic alveolar hypoventilation during spontaneous breathing and can improve the survival of a patient (Banfi, Redolfi, and Robert, 2007). Administering intubation to asthmatic patients requires a multifactorial and careful decision. Studies show that patients affected with asthma are able to be treated without resorting to intubation. In the past 10 years, over 2,094 patients were admitted for asthma. Out of these patients, only 80 were admitted to the ICU and among them only 24 required mechanical ventilation (Leatherman, 2007). Intubation was also prevented in the treatment of the severe acute asthma due to a mortality rate of 10% to 20%. Also, patients often respond to first and second line therapies such as ?2-afrnergic agonist, corticosteroids, anticholinergic agents, magnesium, aminophyline, and systemic catecholamines (Stanley and Tunnicliffe, 2008). In the event where the patients fail to respond to the first and second line of treatments, there are also some special treatments that can be employed in order to veer away from using intubation (Brenner, Corbridge, and Kazzi, 2007). Non-invasive ventilation methods are also widely accepted nowadays. The mechanical of ventilation of asthma patients in a prehospital setting is very risky since there are some clinical and laboratory criteria that should be met before administering intubation to the patient. There are four indicators for intubation including cardiac arrest, respiratory arrest, physical exhaustion, and altered sensorium such as lethargy or agitation, oxygen delivery interference, or anti-asthma therapy. Arterial blood gases are also obtained from asthmatic patients that show signs of bronchopasm. Conditions such as a pH of less than 7.2, carbon dioxide pressure increase, or oxygen pressure that is less than 60 mmHg on 100% delivered oxygen indicates the need of intubation and mechanical ventilation. However, these criterions cannot be easily determined on a prehospital setting and the medical team can only rely on other indicators such as respiratory rate greater than 40 breaths per minute, having a silent chest despite respiratory effort, indications of complicating barotraumas, or unresolving lactic acidosis can be taken in consideration (Brenner, Corbridge, and Kazzi, 2007). In the event that a decision is made to intubate a patient, the next challenge is choosing the appropriate method for achieving intubation. The four methods of intubation include awake nasotracheal intubation, awake orotracheal intubation, orotracheal intubation with sedation, or orotracheal intubation with sedation and neuromascular blocks. The above said methods have its own risk factors and benefits along with it. Nasotracheal Intubation presents risks of epistaxis and purulent sinusitis while its benefits is that is requires minimal sedation, rapidity of preparation, greater post intubation comfort for awake patient, maintenance of semi upright posture, maintenance of spontaneous respiration, and decreases the likelihood of aspiration (Brenner, Corbridge, and Kazzi, 2007). In addition, Orotracheal intubation benefits from a larfer-sized endotracheal tube, direct visualization, and relative ease of obtaining pharyngeal anaesthesia. It poses risks of having oral or tracheal trauma, oesophageal intubation, and vocal cord injury. Awake orotracheal intubation has a benefit of avoiding the rendering of patient apnoeic while it poses several risks such as oral and tracheal trauma, oesophageal intubation, vocal cord injury, aspiration, the patient might be unable to tolerate the procedure, and coughing reflex can be triggered (Brenner, Corbridge, and Kazzi, 2007). Orotracheal intubation with sedation has the benefits of having a rapid procedure, less traumatic than awake and the intubation might be easier to accomplish. On the other hand, it provides risks of having oral and tracheal trauma, oesophageal intubation, vocal cord injury, aspiration, hypertension caused by excessive sedation, and opioids might cause bronchospasms. The last method is the Orotracheal intubation with neuromascular blockade with provides benefits in increasing the ease of intubation by reducing the muscular resistance; it also eliminates the risk of coughing and might provide superior control during intubation as compared with using sedatives. The risks that are associated with this method are few and rarely serious, the side effects of neuromuscular agents can be experienced, sedation may also be necessary in addition to neuromuscular blockade, and airway loss can be caused by the inability to intubate, ventilate, or both (Brenner, Corbridge, and Kazzi, 2007). A common treatment for patients that subjected to intubation includes the use of continuous aerosolized bronchodilators that continuously nebulises the patient with beta-2 specific sympathomimetics (Widder, 1999). Some other methods can also be used as alternative to intubation and mechanical ventilation has been proposed, though the availability and effectiveness of these methods are still under study. These include intravenous magnesium sulphate, general anaesthesia, bronchoscopic lavage, heliox, and extracorporeal membrane oxygenation. The Intravenous magnesium sulphate functions as a bronchodilating agent that improves the pulmonary function of patients with severe asthma. Heliox is also another alternative wherein a blend of helium and oxygen at 70:30 ratio is administered to the patient, since it is less dense than air, it will permit higher flow rates in the airway (Slather and Stewart, 2005).Mechanical Ventilatory support may also be used such as a positive-pressure ventilation with endotracheal tube, for the conventional intubation method. Noninvasive Positive Pressure Ventilation (NPPV) is used to prevent the complications that are associated with the conventional method (Koh, 2001). According to the American Thoracic Society (2005), mechanical ventilations has some post-intubation risks such as infections, collapsed lung (pneumothorax), Lung damage, Side effects of medication, maintenance of life. In addition, ventilators can malfunction on some rare occasions and it often installed with alarms and system checks to prevent harm to the patient (Torpy, Campbell, and Glass, 2010). Intubation and Mechanical Ventilation, which sometimes can be only solution to save an individual from severe episode of disease, poses several risks to the patient’s health and well-being. Intubation method makes the patient susceptible to infections, other disease, and traumatic experience associated with the method. Mortality rate is also increased with the intubation method. Thus, medical response teams should be careful in deciding whether to resort to an intubation method to treat acute severe asthmatic patients as it has several risks involved with it. References American Thoracic Society (ATS). (2005). Mechanical Ventilation. American Journal of Respiratory and Critical Care Medicine, 172(P1). Retrieved from http://patients.thoracic.org/information-series/en/resources/mechanical-ventilation.pdf Banfi, P., Redolfi, S., & Robert, D. (2007). Home Treatment of Infection-Related Acute Respiratory Failure in Kyphoscoliotic Patients on Long-Term Mechanical Ventilation Respiratory Care, 52(6), 713-719. Retrieved from http://www.rcjournal.com/contents/06.07/06.07.0713.pdf Brenner, B., Corbridge, T, & Kazzi, A. (2009). Intubation and Mechanical Ventilation of the Asthmatic Patient in Respiratory Failure. Proceedings of the American Thoracic Society,6, 371-379. doi: 10.1513/pats.P09ST4 Dhuper, S., Maggione, D., Chung, V., & Shim, C. (2003). Profile of Near-Fatal Asthma in an Inner-City Hospital. Chest, 124, 1880-1884. doi: 10.1378/chest.124.5.1880 Koh, Y. (2001). Ventilatory Management of Patients with Severe Asthma. Retrieved from http://www.portalsaudebrasil.com/artigosuti/resp072.pdf Leatherman, J. W. (2007). Mechanical Ventilation for Severe Asthma. Respiratory Care, 52(11), 1460-1462. Retrieved from http://www.rcjournal.com/contents/11.07/11.07.1460.pdf Medoff, B. D. (2008). Invasive and Noninvasive Ventilation in Patients With Asthma. Respiratory Care, 53(6), 740-748. Retrieved from http://www.rcjournal.com/contents/06.08/06.08.0740.pdf Slather, D. R., & Stewart, T. E. (2005). Clinical review Mechanical Ventilation in severe asthma. Critical Care, 9, 581-587. doi:10.1186/cc3733 Soubra, S. H., & Guntupali, K. K. (2006). Acute respiratory failure in asthma. Retrieved from http://www.bioline.org.br/pdf?cm05035 Stanley, D., & Tunnicliffe, W. (2008). Management of life-threatening asthma in adults. Continuing Education in Anaesthesia, Critical Care & Pain, 8(3), 95-99. doi: 10.1093/bjaceaccp/mkn012 Torpy, J. M., Campbell, A. D., & Glass, R. M. (2010). Mechanical Ventilation. Journal of American Medical Association, 1303(9), 902. doi:10.1001/jama.303.9.902 Widder, N. A. (1999). Mechanical Ventilation of the Asthma Patient. AARC Times. Retrieved from http://www.aarc.org/marketplace/reference_articles/01.99.065.pdf Read More