Repeated administration of vasopressin but not epinephrine maintains coronary perfusion pressure after early and late administration during prolonged cardiopulmonary resuscitation in pigs.
BACKGROUND: It is unknown whether repeated dosages of vasopressin or epinephrine given early or late during basic life support cardiopulmonary resuscitation (CPR) may be able to increase coronary perfusion pressure above a threshold between 20 and 30 mm Hg that renders defibrillation successful. METHODS AND RESULTS: After 4 minutes of cardiac arrest, followed by 3 minutes of basic life support CPR, 12 animals were randomly assigned to receive, every 5 minutes, either vasopressin (early vasopressin: 0.4, 0.4, and 0.8 U/kg, respectively; n=6) or epinephrine (early epinephrine: 45, 45, and 200 microg/kg, respectively; n=6). Another 12 animals were randomly allocated after 4 minutes of cardiac arrest, followed by 8 minutes of basic life support CPR, to receive, every 5 minutes, either vasopressin (late vasopressin: 0.4 and 0.8 U/kg, respectively; n=6), or epinephrine (late epinephrine: 45 and 200 microg/kg, respectively; n=6). Defibrillation was attempted after 22 minutes of cardiac arrest. Mean+/-SEM coronary perfusion pressure was significantly higher 90 seconds after early vasopressin compared with early epinephrine (50+/-4 versus 34+/-3 mm Hg, P<0.02; 42+/-5 versus 15+/-3 mm Hg, P<0.0008; and 37+/-5 versus 11+/-3 mm Hg, P<0. 002, respectively). Mean+/-SEM coronary perfusion pressure was significantly higher 90 seconds after late vasopressin compared with late epinephrine (40+/-3 versus 22+/-4 mm Hg, P<0.004, and 32+/-4 versus 15+/-4 mm Hg, P<0.01, respectively). All vasopressin animals survived 60 minutes, whereas no epinephrine pig had return of spontaneous circulation (P<0.05). CONCLUSIONS: Repeated administration of vasopressin but only the first epinephrine dose given early and late during basic life support CPR maintained coronary perfusion pressure above the threshold that is needed for successful defibrillation. (+info)
Is peer tutoring beneficial in the context of school resuscitation training?
First year pupils at a Cardiff comprehensive school were trained in cardiopulmonary resuscitation, 106 by the teacher only and 137 by the teacher assisted by older pupils (peer tutoring). Scores in a multiple choice theory test and in practical skill assessment showed no significant difference between instruction methods, but boys taught by the teacher assisted by older pupils expressed less willingness to resuscitate in an emergency than girls instructed by either method (P < 0.01). Girls had higher scores in the multiple choice paper (P < 0.025) and in the skills assessment (P < 0.01). Those pupils who reported some prior knowledge of resuscitation techniques performed better during skill assessment than novice trainees (P < 0.025). (+info)
Cardiopulmonary resuscitation: effect of CPAP on gas exchange during chest compressions.
BACKGROUND: Conventional cardiopulmonary resuscitation (CPR) includes 80-100/min precordial compressions with intermittent positive pressure ventilation (IPPV) after every fifth compression. To prevent gastric insufflation, chest compressions are held during IPPV if the patient is not intubated. Elimination of IPPV would simplify CPR and might offer physiologic advantages, but compression-induced ventilation without IPPV has been shown to result in hypercapnia. The authors hypothesized that application of continuous positive airway pressure (CPAP) might increase CO2 elimination during chest compressions. METHODS: After appropriate instrumentation and measurement of baseline data, ventricular fibrillation was induced in 18 pigs. Conventional CPR was performed as a control (CPR(C)) for 5 min. Pauses were then discontinued, and animals were assigned randomly to receive alternate trials of uninterrupted chest compressions at a rate of 80/min without IPPV, either at atmospheric airway pressure (CPR(ATM)) or with CPAP (CPR(CPAP)). CPAP was adjusted to produce a minute ventilation of 75% of the animal's baseline ventilation. Data were summarized as mean +/- SD and compared with Student t test for paired observations. RESULTS: During CPR without IPPV, CPAP decreased PaCO2 (55+/-28 vs. 100+/-16 mmHg) and increased SaO2 (0.86+/-0.19 vs. 0.50+/-0.18%; P < 0.001). CPAP also increased arteriovenous oxygen content difference (10.7+/-3.1 vs. 5.5+/-2.3 ml/dl blood) and CO2 elimination (120+/-20 vs. 12+/-20 ml/min; P < 0.01). Differences between CPR(CPAP) and CPR(ATM) in aortic blood pressure, cardiac output, and stroke volume were not significant. CONCLUSIONS: Mechanical ventilation may not be necessary during CPR as long as CPAP is applied. Discontinuation of IPPV will simplify CPR and may offer physiologic advantage. (+info)
Resuscitation from out-of-hospital cardiac arrest: is survival dependent on who is available at the scene?
OBJECTIVE: To determine whether survival from out-of-hospital cardiac arrest is influenced by the on-scene availability of different grades of ambulance personnel and other health professionals. DESIGN: Population based, retrospective, observational study. SETTING: County of Nottinghamshire with a population of one million. SUBJECTS: All 2094 patients who had resuscitation attempted by Nottinghamshire Ambulance Service crew from 1991 to 1994; study of 1547 patients whose arrest were of cardiac aetiology. MAIN OUTCOME MEASURES: Survival to hospital admission and survival to hospital discharge. RESULTS: Overall survival from out-of-hospital cardiac arrest remains poor: 221 patients (14.3%) survived to reach hospital alive and only 94 (6.1%) survived to be discharged from hospital. Multivariate logistic regression analysis showed that the chances of those resuscitated by technician crew reaching hospital alive were poor but were greater when paramedic crew were either called to assist technicians or dealt with the arrest themselves (odds ratio 6.9 (95% confidence interval 3.92 to 26.61)). Compared to technician crew, survival to hospital discharge was only significantly improved with paramedic crew (3.55 (1.62 to 7.79)) and further improved when paramedics were assisted by either a health professional (9.91 (3.12 to 26.61)) or a medical practitioner (20.88 (6.72 to 64.94)). CONCLUSIONS: Survival from out-of-hospital cardiac arrest remains poor despite attendance at the scene of the arrest by ambulance crew and other health professionals. Patients resuscitated by a paramedic from out-of-hospital cardiac arrest caused by cardiac disease were more likely to survive to hospital discharge than when resuscitation was provided by an ambulance technician. Resuscitation by a paramedic assisted by a medical practitioner offers a patient the best chances of surviving the event. (+info)
Influence of ambulance crew's length of experience on the outcome of out-of-hospital cardiac arrest.
AIMS: To investigate whether an ambulance crew's length of experience affected the outcome of out-of-hospital cardiac arrest. METHODS AND RESULTS: This was a population-based, retrospective observational study of attempted resuscitations in 1547 consecutive arrests of cardiac aetiology by Nottinghamshire Emergency Ambulance Service crew. One thousand and seventy-one patients were managed by either a paramedic or a technician crew without assistance from other trained individuals at the scene of arrest. Overall, the chances of a patient surviving to be discharged from hospital alive did not appear to be affected by the paramedic's length of experience (among survivors, 18 months experience vs non-survivors 16 months experience, P = 0.347) but there appears to be a trend in the effect of a technician's length of experience on survival (among survivors, 60 months experience vs non-survivors 28 months experience, P = 0.075). However, when a technician had 4 years of experience or more and a paramedic 1 year's experience, survival rates did improve. Logistic regression analysis, adjusted for factors known to influence outcome, revealed that chances of survival increased once technicians had over 4 years of experience after qualification (odds ratio 2.71, 95% CI 1.17 to 6.32, P = 0.02) and paramedics after just 1 year of experience (odds ratio 2.68, 95% CI 1.05 to 6.82, P = 0.04). CONCLUSIONS: Survival from out-of-hospital cardiac arrest varies with the type of ambulance crew and length of experience after qualification. Experience in the field seems important as paramedics achieve better survival rates after just 1 year's experience, while technicians need to have more than 4 years' experience to improve survival. (+info)
Preparing for medical emergencies in the dental office.
If you discover an unconscious patient in your office, attend to the ABCs while you evaluate the patient's medical history and piece together the events leading up to the emergency. These actions will help you arrive at a diagnosis. Then as the emergency cart and team arrive, you will be able to provide good, safe care to stabilize the patient and get him or her to a medical facility. (+info)
A comparison of standard cardiopulmonary resuscitation and active compression-decompression resuscitation for out-of-hospital cardiac arrest. French Active Compression-Decompression Cardiopulmonary Resuscitation Study Group.
BACKGROUND: We previously observed that short-term survival after out-of-hospital cardiac arrest was greater with active compression-decompression cardiopulmonary resuscitation (CPR) than with standard CPR. In the current study, we assessed the effects of the active compression-decompression method on one-year survival. METHODS: Patients who had cardiac arrest in the Paris metropolitan area or in Thionville, France, more than 80 percent of whom had asystole, were assigned to receive either standard CPR (377 patients) or active compression-decompression CPR (373 patients) according to whether their arrest occurred on an even or odd day of the month, respectively. The primary end point was survival at one year. The rate of survival to hospital discharge without neurologic impairment and the neurologic outcome were secondary end points. RESULTS: Both the rate of hospital discharge without neurologic impairment (6 percent vs. 2 percent, P=0.01) and the one-year survival rate (5 percent vs. 2 percent, P=0.03) were significantly higher among patients who received active compression-decompression CPR than among those who received standard CPR. All patients who survived to one year had cardiac arrests that were witnessed. Nine of 17 one-year survivors in the active compression-decompression group and 2 of 7 in the standard group, respectively, initially had asystole or pulseless electrical activity. In 12 of the 17 survivors who had received active compression-decompression CPR, neurologic status returned to base line, as compared with 3 of 7 survivors who had received standard CPR (P=0.34). CONCLUSIONS: Active compression-decompression CPR performed during advanced life support significantly improved long-term survival rates among patients who had cardiac arrest outside the hospital. (+info)
Effects of the AMPA receptor antagonist NBQX on outcome of newborn pigs after asphyxic cardiac arrest.
In neonates, asphyxia is a common cause of neuronal injury and often results in seizures. The authors evaluated whether blockade of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors during asphyxia and early recovery with 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo-(F)-quinoxaline (NBQX) ameliorates neurologic deficit and histopathology in 1-week-old piglets. Anesthetized piglets were exposed to a sequence of 30 minutes of hypoxia, 5 minutes of room air ventilation, 7 minutes of airway occlusion, and cardiopulmonary resuscitation. Vehicle or NBQX was administered intravenously before asphyxia (30 mg/kg) and during the first 4 hours of recovery (15 mg/kg/h). Neuropathologic findings were evaluated at 96 hours of recovery by light microscopic and cytochrome oxidase histochemical study. Cardiac arrest occurred at 5 to 6 minutes of airway occlusion, and cardiopulmonary resuscitation restored spontaneous circulation independent of treatment modalities in about 2 to 3 minutes. Neurologic deficit over the 96-hour recovery period was not ameliorated by NBQX. Seizure activity began after 24 to 48 hours in 7 of 10 animals with vehicle and in 9 of 10 of animals with NBQX. In each group, four animals died in status epilepticus. Neuropathologic outcomes were not improved by NBQX. The density of remaining viable neurons was decreased in parietal cortex and putamen by NBQX treatment. Metabolic defects in cytochrome oxidase activity were worsened by NBQX treatment. Seizure activity during recovery was associated with reduced neuronal viability in neocortex and striatum in piglets from both groups that survived for 96 hours. This neonatal model of asphyxic cardiac arrest and resuscitation generates neurologic deficits, clinical seizure activity, and selective damage in regions of basal ganglia and sensorimotor cortex. In contrast to other studies in mature brain, AMPA receptor blockade with NBQX failed to protect against neurologic damage in the immature piglet and worsened postasphyxic histopathologic outcome in neocortex and putamen. (+info)