Paramedic activities, drug administration and survival from out of hospital cardiac arrest.

OBJECTIVE: To examine the impact of administration of cardioactive drugs on the outcome from out of hospital cardiac arrest. DESIGN: Longitudinal observational cohort study with historical controls before and after the introduction of drug use in cardiac arrest by paramedics. SUBJECTS: Adult patients who had sustained an out of hospital cardiac arrest of cardiac aetiology and were treated by paramedics. SETTING: Edinburgh, Scotland. OUTCOME MEASURES: Return of spontaneous circulation, admission to and discharge from hospital. RESULTS: There was no significant difference in the demographics between Period 1 (prior to drug administration) and Period 2 (after). There was no difference in outcome between Period 1 and Period 2 for all three parameters, return of spontaneous output 30.1 versus 35%, admission to hospital 18.9 versus 24.5% and discharge 5.8 versus 6.5%. If the presenting rhythm of VF/pulseless VT alone was considered survival to hospital discharge was 12.1% in Period 1 and 10.3% in Period 2. CONCLUSION: The addition of cardioactive drug administration to the treatment of out of hospital cardiac arrest does not improve survival.

Can the full range of paramedic skills improve survival from out of hospital cardiac arrests?

OBJECTIVE: To examine the effect of full implementation of advanced skills by ambulance personnel on the outcome from out of hospital cardiac arrest. SETTING: Patients with cardiac arrest treated at the accident and emergency department of the Royal Infirmary of Edinburgh. METHODS: All cardiorespiratory arrests occurring in the community were studied over a one year period. For patients arresting before the arrival of an ambulance crew, outcome of 92 patients treated by emergency medical technicians equipped with defibrillators was compared with that of 155 treated by paramedic crews. The proportions of patients whose arrest was witnessed by lay persons and those that had bystander cardiopulmonary resuscitation (CPR) were similar in both groups. RESULTS: There was no difference in the presenting rhythm between the two groups. Eight of the 92 patients (8.7%) treated by technicians survived to discharge compared with eight of 155 (5.2%) treated by paramedics (NS). Of those in ventricular fibrillation or pulseless ventricular tachycardia, eight of 43 (18.6%) in the technician group and seven of 80 (8.8%) in the paramedic group survived to hospital discharge (NS). For patients arresting in the presence of an ambulance crew, four of 13 patients treated by technicians compared with seven of 15 by paramedics survived to hospital discharge. Only two patients surviving to hospital discharge received drug treatment before the return of spontaneous circulation. CONCLUSIONS: No improvement in survival was demonstrated with more advanced prehospital care.

Comparison of two emergency response systems and their effect on survival from out of hospital cardiac arrest.

The pre-hospital care provided by emergency response systems will have an effect on the outcome of patients who have sustained an out of hospital cardiac arrest. This study compares the results of resuscitation in two centres, one in the UK (Edinburgh) and the other in the USA (Milwaukee), and examines the demographics in both centres. An overall greater proportion of patients survived to hospital discharge in Edinburgh, 12.4%, compared with 7.2% in Milwaukee (P < 0.01). However patients were more likely to have a witnessed collapse in Edinburgh 65.7%, compared with 25% (P < 0.001) and significantly more of those patients received bystander cardiopulmonary resuscitation (CPR) 42.3%, compared with 27.1% (P < 0.005). When these two effects are accounted for there is no difference in outcome. The importance of early alerting of emergency services and early bystander CPR should not be underestimated.

Active decompression improves the haemodynamic state during cardiopulmonary resuscitation.

OBJECTIVE: To examine whether use of the active compression-decompression device improves the haemodynamics of cardiopulmonary resuscitation compared with those of conventional cardiopulmonary resuscitation. DESIGN: Prospective crossover study. SETTING: The accident and emergency department of a university teaching hospital. PATIENTS: 36 adult patients with non-traumatic, normothermic, out of hospital cardiac arrest. INTERVENTIONS: Cardiopulmonary resuscitation was performed during resuscitation in alternating 3 min cycles of conventional and active compression-decompression cardiopulmonary resuscitation. MAIN OUTCOME MEASURES: The end tidal carbon dioxide (ETCO2), femoral arterial pressure, and acid-base analysis of central venous blood measured during the last 30 s of each 3 minute cardiopulmonary resuscitation cycle. RESULTS: ETCO2 was monitored in 36 patients during conventional and active compression-decompression cardiopulmonary resuscitation. Active compression-decompression cardiopulmonary resuscitation caused a significant increase in ETCO2 (P < 0.0002), indicating improved cardiac output. Arterial pressure measurement was carried out in 10 patients. Systolic pressure was significantly greater with active compression-decompression than conventional cardiopulmonary resuscitation (P < 0.007). Central venous blood was taken for acid-base analysis in 11 patients. There was a significant increase in the central venous hydrogen ion concentration (P = 0.025) with rises in the partial pressures of carbon dioxide and oxygen, suggesting improved venous return. CONCLUSIONS: This study confirms that active compression-decompression cardiopulmonary resuscitation is associated with better haemodynamic status than conventional resuscitation.

Paramedics and technicians are equally successful at managing cardiac arrest outside hospital.

OBJECTIVE: To examine the effect on survival of treatment by ambulance paramedics and ambulance technicians after cardiac arrest outside hospital. DESIGN: Prospective study over two years from 1 April 1992 to 31 March 1994. SETTING: Accident and emergency department of university teaching hospital. SUBJECTS: 502 consecutive adult patients with out of hospital cardiopulmonary arrest of cardiac origin. INTERVENTIONS: Treatment by ambulance technicians or paramedics both equipped with semiautomatic defibrillators. MAIN OUTCOME MEASURES: Rate of return of spontaneous circulation, hospital admission, and survival to hospital discharge. RESULTS: Rates of return of spontaneous circulation, hospital admission, and survival to hospital discharge were not significantly different for patients treated by paramedics as opposed to ambulance technicians. Paramedics spent significantly longer at the scene of the arrest than technicians (P < 0.0001). CONCLUSIONS: The response of ambulance paramedics to patients with cardiopulmonary arrest outside hospital does not provide improved outcome when compared with ambulance technicians using basic techniques and equipped with semi-automatic defibrillators.

Mechanism of closed chest cardiopulmonary resuscitation investigated by transoesophageal echocardiography.

Transoesophageal echocardiography (TOE) was performed during closed chest cardiopulmonary resuscitation (CPR) in 18 subjects in cardiac arrest. Compression of all four cardiac chambers resulted in forward flow in the pulmonary and systemic circulations, retrograde pulmonary vein flow and incomplete mitral valve closure. Antegrade pulmonary vein flow and left ventricular filling occurred exclusively during the relaxation phase. These findings support the cardiac pump theory of CPR and are incompatible with the thoracic pump mechanism. TOE merits further investigation as a device to monitor and guide resuscitation efforts during CPR.

Assessment of the active compression-decompression device (ACD) in cardiopulmonary resuscitation using transoesophageal echocardiography.

Transoesophageal echocardiography was used to investigate the haemodynamic profile achieved during active compression-decompression cardiopulmonary resuscitation in humans. The mechanism of antegrade blood flow achieved by ACD-CPR is consistent with the cardiac pump theory. Improved right heart compression, antegrade blood flow patterns and left ventricular filling were observed in some patients during ACD-CPR.

Post-traumatic acute renal failure, 1956-1988.

Eighty patients with acute renal failure secondary to trauma treated between 1956 and 1988 are reviewed. The overall mortality was 46.3%. Factors associated with increased mortality were age, high Injury Severity Score, and injury to the abdomen and pelvic contents. The number of injuries, the delay between injury and the institution of dialysis, and the level of urea on starting dialysis did not affect mortality. The declining incidence of traumatic acute renal failure highlights the importance of prompt effective resuscitation of injured patients.

Preclinical anxiety: the stress associated with a viva voce examination.

It is shown that the state anxiety scores of 75 preclinical students taking a series of written and oral examinations, and measured just prior to taking a viva voce examination, were substantially raised. There was no correlation of anxiety with overall examination performance.