Mechanical CPR; ETCO2 and Tube Placement; Parents of Seizing Kids

Mechanical Chest Compressions and Cardiac Arrest Survival
Steen S, Sjoberg T, Olsson P, Young M. Treatment of out-of-hospital cardiac arrest with LUCAS, a new device for automatic mechanical compression and active decompression resuscitation. Resuscitation 67(1):25 - 30, Oct. 2005.

Abstract: The Lund University Cardiopulmonary Assist System (LUCAS) is a new gas-driven CPR device providing automatic chest compression and active decompression. This is a report of the first 100 consecutive cases treated with LUCAS due to out-of-hospital cardiac arrest (58% asystole, 42% ventricular fibrillation). Safety aspects were also investigated, and it was found that LUCAS can be used safely regarding noise levels and oxygen concentrations within the ambulance. A crash test (10G) showed no displacement of the device from the manikin.

Of the 71 patients with witnessed cardiac arrest, 39% received bystander CPR. In those 28 patients where LUCAS CPR was initiated more than 15 minutes after the ambulance alarm, as well as in the 29 unwitnessed cases, no patient survived for 30 days. Of the 43 witnessed cases treated with LUCAS within 15 minutes, 24 had VF, and 15 (63%) of these cases achieved a stable return of spontaneous circulation (ROSC). Six (25%) of these patients survived with good neurological recovery after 30 days. Five (26%) of the 19 patients with asystole achieved ROSC, and one (5%) survived for over 30 days. One patient in whom ROSC could not be achieved was transported with ongoing LUCAS CPR to a catheter laboratory; after PCI for an occluded LAD, a stable ROSC occurred, but the patient never regained consciousness and died 15 days later.

To conclude, establishment of an adequate cerebral circulation as quickly as possible after cardiac arrest is mandatory for a good outcome. In this report patients with a witnessed cardiac arrest receiving LUCAS CPR within 15 minutes from the ambulance call had a 30-day survival of 25% in VF and 5% in asystole, but if the interval was more than 15 minutes, there were no 30-day survivors.

Comment: Vest CPR devices have been in development for over 20 years, and have recently been the topic of increased discussion. This study, along with other similar reports, points out that they do have promise, but have not been shown to be better than traditional CPR in improving outcome - i.e., increasing survival and discharge from the hospital. Here, the survival in witnessed ventricular fibrillation treated within 15 minutes was 25%. These results are good, but not better than reports from many EMS systems that have early-defibrillation programs. Mechanical chest compression devices may improve outcomes, or they may, as we saw with ACD (active compression-decompression, or "toilet plunger") CPR, provide no benefit over standard CPR. We need to wait for outcome studies to see which it will be.

ETCO2 Monitoring and Tube Misplacement
Silvestri S, Ralls GA, Krauss B, et al. The effectiveness of out-of-hospital use of continuous end-tidal carbon dioxide monitoring on the rate of unrecognized misplaced intubation within a regional EMS system. Ann Emerg Med 45(5):497 - 503, May 2005.

Abstract: Study Objective - Authors evaluate the association between out-of-hospital use of continuous end-tidal carbon dioxide (ETCO2) monitoring and unrecognized misplaced intubations within a regional emergency medical services (EMS) system. Methods - This was a prospective, observational study conducted during a 10-month period on all patients arriving at a regional Level I trauma center emergency department who underwent out-of-hospital endotracheal intubation. The regional EMS system that serves the trauma service area is composed of multiple countywide systems containing numerous EMS agencies. Some of the EMS agencies had independently implemented continuous ETCO2 monitoring before the start of the study. The main outcome measure was the unrecognized misplaced intubation rate with and without use of continuous ETCO2 monitoring. Results - A total of 248 patients received out-of-hospital airway management, of whom 153 received intubation. Of the 153 patients, 93 (61%) had continuous ETCO2 monitoring, and 60 (39%) did not. Forty-nine (32%) were medical patients, 104 (68%) were trauma patients, and 51 (33%) were in cardiac arrest. The overall incidence of unrecognized misplaced intubations was 9%. The rate of unrecognized misplaced intubations in the group for which continuous ETCO2 monitoring was used was zero, and the rate in the group for which continuous ETCO2 monitoring was not used was 23.3% (95% confidence interval, 13.4% - 36%). Conclusion - No unrecognized misplaced intubations were found in patients for whom paramedics used continuous ETCO2 monitoring. Failure to use continuous ETCO2 monitoring was associated with a 23% unrecognized misplaced intubation rate.

Comment: This study follows an alarming report from the same hospital, published in 2001, in which 17% of 108 patients had unrecognized esophageal intubations. A number of other studies have shown smaller, but still unacceptably high, rates of undetected esophageal intubations. Many have advocated the use of continuous waveform capnography, which is a highly sensitive and specific indicator of correct tube placement. One of the weaknesses of this study is that it was not randomized, and that the paramedics without capnography may also not have the skill level of those who have it. However, this provides us with good evidence that waveform capnography can be a helpful tool in confirming and monitoring the position of the endotracheal tube. There are a number of systems in California, including my own, that have had similar experiences. Capnography is particularly valuable in the cardiac arrest patient with low CO2 production that may be unmeasurable with the CO2 detector, and provides a printed record for use in QI and risk-management activities. EMS systems should strongly consider using this device.

Parents' Reactions to Children's Seizures
Besag FM, Nomayo A, Pool F. The reactions of parents who think that a child is dying in a seizure - In their own words. Epilepsy Behav 7(3):517 - 23, Nov. 2005. (Epub Sep 27, 2005.)

Abstract: The goal of this work was to report the words parents use to describe seizures in which they thought their children were dying, so as to increase the awareness of professionals with respect to the impact seizures may have on family life. Methods - An audit was carried out on 234 cases from a specialist epilepsy center and 35 cases from a tertiary referral outpatient clinic. Results - Of the 54 parents who thought their children were dying in seizures, in 45 cases the parents' exact words were recorded in the first person, and in nine cases, their words were reported in the third person. Many parents took actions that illustrated their high degree of concern: 32 children were taken to hospitals, 18 by ambulance, and three parents gave mouth-to-mouth resuscitation. Conclusions - Seizures often cause major concern in parents, and many think their children are dying. Prolonged seizures and limpness and/or cyanosis appear to be associated with this fear. Professionals can gain valuable insight into the impact of seizures on parents by asking them about their reactions to seeing their children having seizures.

Comment: We have all treated children after seizures, and we know the vast majority have uncomplicated recoveries. It is important, though, to recognize that parents often have very different views - particularly if their children are having first or more complex seizures. Here, almost one in five parents thought their child was actually dying. We need to keep in mind that seizures can be frightening to observers, especially parents, and it would be helpful to acknowledge their concerns and reassure them whenever possible.