ABSTRACT



Analysis on Emergency Care to the Patients with Acute Myocardial Infarction in Pre-hospital and In-hospital Phase


Han-Na Lee


Department of Emergency Medical Service
Graduate School of Kongju National University
Gong ju, Korea


(Supervised by professor Keun-Ja Cho)


Objective: This study aims to provide basic data to strengthen pre-hospital phase emergency care for AMI(Acute Myocardial Infarction) patients through prompt detection, transfer and professional emergency care by analyzing AMI patients’ clinical characteristics and current emergency care situations.

Methods: This study analyzed medical records of 385 AMI patients and ambulance records of 107 among the 385 transferred to emergency medical centers of university hospitals located in Gyeonggi-do province and data was collected for 3.6 years between June 1st, 2009 and June 30th, 2012. The collected data were analyzed by evaluating frequency, percentage, mean, standard deviation, Chi-square-test or Fisher''s Exact test a by using SPSS 18.0 program.

Results:
1. General Characteristics of AMI Patients
Total number of subjects of this study was 385 and among them, 29.6%(114 patients) was transferred by 119 ambulances while 70.4%(271 patients) was transferred by other means of transportation. In gender, male patients exceeded female with 78.7%(303 patients) and in age, patients in their 50’s had the biggest portion with 31.2%(120 patients).

2. Analysis of Ambulance Records
1) 63.6%(68 patients) transferred by 119 ambulances had symptom onset at home and 60.7%(65 patients) was transferred to medical centers chosen by patients themselves or their guidances.
2) Medical contact to door time of 28%(21 patients) was within 25 minutes with the biggest portion and average time was 23.2 minutes.
3) In pre-hospital phase, mental state of 87.9%(94 patients) was alert with the biggest portion and chief complaints were chest pain 58.9%(63 patients), dyspnea 21.5%(23 patients), nausea and vomiting 10.3%(11 patients) and other pains 9.3%(10 patients).
4) Regarding emergency care practiced in pre-hospital phase, respiratory support 62.5%(67 patients), ECG 51.4%(55 patients) and IV access 2.8%(3 patients) were carried out for cardiopulmonary complaints as essential care and airway maintenance 32.7%(35 patients) and drug administration 4.7%(5 patients) were done as optional care. In addition, medical direction was practiced for 6.5%(7 patients).
5) Emergency care practiced by paramedics in pre-hospital phase has shown statistically significant increase in airway maintenance (p<.001), respiratory support (p<.05), ECG (p<.001), AED monitoring (p<.01) as it approaches more recent years.
6) Regrading appropriateness of emergency care for cardiopulmonary complaints in pre-hospital phase, “high”, “medium”, “low” and “very low” was 29.4%, 17.6%, 36.8% and 16.2%, respectively and as for cardiorespiratory arrest, “high” “medium” and “low” was 62.5%, 25% and 12.5%.
Appropriateness of pre-hospital phase emergency care for cardiopulmonary complaints practiced by paramedics has shown statistically significant increase as it comes to more recent years (p<.001).

3. Analysis of Medical Records
1) In-hospital phase, patients Generally complaint about sweating 13%(50 patients) and general weakness 11.2%(43 patients). As for Chest, chest pain 81%(312 patients), chest tightness 29.4%(113 patients) and dyspnea 23.6%(91 patients) were chief complaints, while nausea 9.1%(35 patients), vomiting 7.0%(27 patients) and epigastric pain 6.2%(24 patients) were cited as Abdomen and as for Back and extremities, back pain 5.2%(20 patients) and tingling or other paresthesis 1.6%(6 patients) were chief complaints.
2) In-hospital phase, emergency care were practiced in the order of drug administration 1499 cases, respiratory support 96.1%(370 cases), CAG 95.8%(369 cases), PCI 92.2%(355 cases), Defibrillation 6.3%(24 cases), CPR 5.5%(21 cases), ECMO 2.1%(8 cases), CABG 1.0%(4 cases) and TCP 1.0%(4 cases). Drugs like Anticoagulants, Antithrombotics, Vasodilators, and Analgesics were mainly administrated.
3) As for 12-lead ECG in-hospital phase, 12.5%(48 patients) showed normal sinus rhythm, while 23.9% (92 patients) and 8.3%(47 patients) showed more than 2 ST-segment elevation and ST-segment depression, respectively. As for 3-lead ECG, more than 2 ST-segment elevation was shown by 7.3%(28 patients), while more than 2 ST-segment depression was presented by 1.8%(7 patients).
4) Regarding the level of cardiac enzyme which is the indicator of myocardial necrosis, CK-MB was increased in 43.0%(165 cases) while Troponin T and Troponin I were increased in 43.4%(82 cases) and 78.9%(45 cases). As symptom onset to door time got longer, the level of cardiac enzyme recorded higher ranges.
5) When transferred by 119 ambulances, symptom onset to door time was less than 1 hour in 53.5% (61 patients) and when other means were used, the time was recorded between longer than 1 hour and less than 3 hours in 29.9%(81 patients) taking biggest portion. Regarding symptom onset to balloon time, more than 1 hour and less than 3 hours took the biggest portion both 911 ambulance and other means of transportation with 46.5%(53 patients) and 25.5%(69 patients) respectively, showing statistical significance (p<.001).
6) In-hospital phase, 94.8%(365 patients) was cared in an intensive care unit and 36.4%(140 patients) were hospitalized for 6-7 days, taking the biggest portion. After medical intervention, 91.7%(353 patients) were recovered while 5.7%(22 patients) were dead. In the recovery case, 38.0%(136 patients) were dehospitalized after 6-7 days and in case of death, 30.4% (7 patients) was dead after 1-3 days of treatment, taking the highest percentage.

Conclusion: Regarding emergency care for AMI patients in pre-hospital phase, 47.0% care was above medium level, but it was mainly basic life support. Since prognosis of AMI shows vast differences depending on prompt detection and medical intervention, organic cooperation between pre-hospital and in-hospital phase is highly required. To this end, 119 emergency medical technicians should be trained for accurate diagnosis and emergency care and medical direction should be promoted. In addition, regulation on 12-lead ECG, cardiac enzyme analysis, use of analgesics and antithrombotics should be improved.

Key Words: Acute myocardial infarction, Emergency care, Prehospital, In-hospital