Biomedical subjects

B D Mahoney

Publications and source records attributed to B D Mahoney.

7 recordsLinked to original sources

PubMed1998

Factors influencing hospital transport of patients in continuing cardiac arrest.

STUDY OBJECTIVE: Prior research has established the futility of continued resuscitation efforts for patients in cardiac arrest who fail to respond to out-of-hospital advanced cardiac life support. Determination of both medical and nonmedical factors resulting in the transport of patients in continuing cardiac arrest to the hospital may encourage the development of new systems or strategies to increase the appropriateness of these transports. METHODS: The attending paramedic completed a prospective survey after unsuccessful resuscitation efforts in our urban, hospital-based, two-tier emergency medical services (EMS) system. All nontraumatic adult arrests were included unless they were clearly noncardiac in nature. RESULTS: Paramedics responded to 259 cardiac arrests between September 12, 1996, and April 31, 1997. Seventy-nine patients were pronounced dead without resuscitation efforts. Of the remaining 180 patients, 44 had return of spontaneous circulation and were transported to the hospital, 68 were pronounced dead in the field, and 68 were transported to the hospital in continuing cardiac arrest. The 68 patients transported while in cardiac arrest are the focus of this study. Rare problems with field termination were identified. Reasons for transport of the 68 patients in continuing cardiac arrest included arrest in ambulance or going to ambulance (n = 6), arrest in a public place (n = 17), environmental factors (n = 6), road hazard to paramedics (n = 1), possible reversible cause (n = 4), persistent ventricular dysrhythmia (n = 5), no intravenous access (n = 5), airway difficulties (n = 5), family unable to accept field termination (n = 3), cultural or language barrier (n = 1), EMS physician ordered transport (n = 1), and obesity (n = 1). A protocol allowing pronouncement of death in the ambulance and transport of the body to a designated area could have prevented lights-and-siren transport to the emergency department in 24 of the 68 cases. CONCLUSION: Factors other than medical ones often influence the decision to transport patients in continuing cardiac arrest. In our urban system, physician, medical examiner, and paramedic education and protocols were needed to aid decision-making in this situation.

Cardiopulmonary Resuscitation↗

PubMed1984

Aortic compressor for aortic occlusion in hemorrhagic shock.

The aortic compressor is a device that allows rapid, simple, immediately reversible occlusion of the thoracic aorta, without the aortic dissection required to use an aortic cross-clamp. We evaluated the aortic compressor in a controlled study using a canine hemorrhagic shock model. Twelve mongrel dogs were exsanguinated to a mean arterial pressure (MAP) of 47 mm Hg and maintained at that level for 20 minutes. At that point, all animals had a left lateral thoracotomy. Six study animals had the thoracic aorta occluded at the diaphragm using the compressor. Five minutes after thoracotomy, with or without occlusion, the shed blood was reinfused. Application of the aortic compressor was the only variable. Use of the aortic compressor led to an immediate and statistically significant doubling of the study animals' MAP. The increased afterload of aortic occlusion did not impair cardiac output. The cardiac index of the study animals rose slightly, while that of the control animals fell. At the same time the compressor prevented blood flow to the abdominal aorta. If the canine model can be extrapolated to human application, then the aortic compressor would be expected to enhance perfusion of the heart and brain during hemorrhagic shock, prevent further arterial blood loss from intra-abdominal injury or ruptured abdominal aortic aneurysm, and preserve already diminished cardiac output. Because the aorta does not need to be dissected out to use the compressor, there is no risk of injury to nearby vascular structures.

Animals↗

PubMed1983

Efficacy of pneumatic trousers in refractory prehospital cardiopulmonary arrest.

Persons refractory to early application of advanced cardiac life support have a dismal prognosis. New modalities are needed to treat this almost universally lethal condition. We have evaluated pneumatic trousers in the treatment of refractory cardiopulmonary arrest. To date 136 patients have been entered into this controlled, prospective, randomized study. All patients were more than 20 years old and in cardiac arrest of apparent cardiac etiology. Patients were excluded if they had arrested secondary to trauma or overdose, or if an IV could not be started. In addition, patients had to be refractory to therapies included in our paramedic standing orders. If at the end of these standing orders the patient remained in arrest, he was entered into the study and pneumatic trousers were applied or not according to a randomized list. The attempted resuscitation was then continued with no other preset variables. The resuscitation and discharge rates for the control group were 21% and 4%, respectively. With pneumatic trousers, resuscitation increased to 33%, and discharge to 9%. The control group in ventricular fibrillation (VF) had a 27% resuscitation rate and a 5% discharge rate. The pneumatic trousers group with VF had a 35% resuscitation rate and a 12% discharge rate. In pulseless idioventricular rhythm (PIVR), the control group had a 0% resuscitation rate and a 0% discharge rate. In marked contrast, for PIVR the pneumatic trousers group had a 35% resuscitation rate and a 9% discharge rate. The control group in asystole (AS) had a 25% resuscitation rate and a 0% discharge rate. The pneumatic trousers group in AS had a 27% resuscitation rate and a 0% discharge rate. The improvement in resuscitation rate with pneumatic trousers was statistically significant only for the initial rhythm of PIVR (P less than .05). The pneumatic trousers improved resuscitation and discharge rates for refractory VF, but not to a statistically significant degree. These somewhat enhanced resuscitation and discharge rates with the pneumatic trousers make it an adjunct to be considered in refractory arrest.

Adult↗

PubMed1983

Acute resuscitation of the patient with head and spinal cord injuries.

The major immediate goal in the treatment of a patient with central nervous system injuries is to prevent secondary injuries resulting from hypotension, hypoxemia, hypercapnia, intracranial hypertension, infection, and unnecessary motion of an unstable spinal column. This combined with application of the fundamentals of trauma resuscitation should achieve optimal results.

Adrenal Cortex Hormones↗

PubMed1981

Emergency twist drill trephination.

We have used the rapid progression of post-traumatic uncal herniation in spite of intensive medical therapy as the indication for twist drill trephination in the emergency department. During a 54-month period, 51 trephinations were performed on 41 patients. The trephine was placed through the temporal bone ipsilateral to the dilated pupil, and the dura mater was opened to allow partial evacuation of the hematoma. All patients subsequently underwent craniotomy, autopsy, and/or cerebral computed tomography (CT). The trephination was diagnostically accurate for the absence or presence of an extracerebral hematoma in 42 of 51 trephinations (82%). In 6 of these cases the dilated pupil responded to partial hematoma evacuation by decreasing in size. In 3 of the 6 there was a marked overall improvement in neurological status subsequent to trephination. These 3 patients later recovered to an independent functional state. Only 23 of these 41 patients (56%) with herniation profiles actually had significant extracerebral hematomas. This fact emphasizes the inadvisability of taking this type of patient directly to the operating room without a diagnostic study. A rapidly performed CT scan is the obvious first choice. However, if there is any delay in obtaining this study or when uncal herniation occurs rapidly, a twist drill trephination can be of value in diagnosing the absence or presence of a treatable extracerebral hematoma. There were no complications related to this procedure in this group.

Adult↗

PubMedDate not supplied

Feasibility of paramedic treatment and referral of minor illnesses and injuries.

BACKGROUND: Approximately 40% of Hennepin County Medical Center's (HCMC's) ambulance runs are for minor medical conditions as defined by billing criteria ["ALS minor," i.e., no advanced life support (ALS) procedures done in the field]. Current metropolitan guidelines mandate that all such patients must be transported to a hospital unless they refuse this service. It has been proposed that some patients with minor medical conditions could be better served by treatment in the field by paramedics and referred to a clinic or hospital for early follow-up care. It is proposed that this approach would save costs and improve paramedic availability for patients with more serious conditions. OBJECTIVE: To evaluate the feasibility and safety of implementing such a program by identifying high-volume, low-complexity groupings of cases. Such high-volume, low-complexity cases would serve as the topics for curriculum development for paramedic training in field treatment and referral. METHODS: Data were obtained from ambulance run sheets and emergency department (ED) records for all patients transported by the HCMC ambulance service in 1996 who were covered by the Metropolitan Health Plan (MHP) and who were categorized for billing purposes as "ALS minor" transports. The data included demographic information, vital signs, presenting problem, diagnoses in the ED, and procedures, laboratory studies, or x-rays done in the ED. Patients were classified as "potentially treatable" in the field if they were treated and discharged from the ED without undergoing any procedures or diagnostic studies. Patients who required more extensive evaluation in the ED, or who were admitted, were classified as likely too "complex" to be treated at the scene and then referred for early follow-up. The data were analyzed to find the most common presenting problems and the numbers, characteristics, and dispositions of "potentially treatable" and "complex" patients in each group. This information was used to determine what, if any, types of patients could potentially be treated safely and effectively according to this scheme. RESULTS: The study group comprised 1,103 patients, representing 127 different presenting medical problems. There were 523 (47%) "potentially treatable" patients and 580 (53%) "complex" patients. The 127 medical problems were grouped and the 15 most common presenting problem groups were identified. Within these groups there was no single medical problem with high volume. Each of these 15 most common problem groups contained a substantial proportion of "complex" patients, ranging from 24% to 100%. CONCLUSIONS: None of the 15 most frequently encountered problem groups consisted of a high enough proportion of "potentially treatable" cases to serve as a high-volume, low-complexity category for paramedic treatment in the field with early follow-up. Without any identified high-volume, low-complexity categories, a treatment and referral program as proposed in this article would require a substantial investment in development of appropriate criteria and in training paramedics to apply the criteria for numerous clinical entities. This would limit any cost saving, and require great care to avoid compromising patient safety accompanied by substantial professional liability exposure.

Ambulances↗

PubMedDate not supplied

Prehospital sedation with intramuscular droperidol: a one-year pilot.

OBJECTIVE: Combative patients pose a threat to themselves and prehospital personnel, and are at risk for sudden death. Droperidol is an antipsychotic and sedative agent that might be effectively utilized by paramedics to assist in the management of uncontrollably violent patients. METHODS: A prospective observational study of patients requiring sedation was conducted in an urban third-service emergency medical services system (55,000 calls per year). Patients were scored by paramedics on a five-point agitation scale with 5 being extremely combative (continuous, vigorous fighting against restraints) and 1 being somnolent (sleeping or sleepy). Eligible (score 4-5) patients received 5 mg of intramuscular droperidol on direct physician order. Data including vital signs and agitation scores were recorded at 5-minute intervals until hospital arrival. Adverse effects were also recorded. RESULTS: Fifty-three patients received droperidol (51 patients received 5 mg; two received 2.5 mg) during the study period. The average predrug agitation score was 4.7 (+/- 0.1 SD). The average 5-minute postdrug score was 3.9 (+/- 0.1 SD, 95% CI 3.7-4.1. The average 10-minute postdrug score was 3.3 (+/- 0.1 SD, 95% CI 3.1-3.6). The average hospital arrival score was 2.8 (+/- 0.1 SD, 95% CI 2.5-3.1). One patient became obtunded and required supplemental oxygen; no other patient experienced an adverse event after receiving droperidol. Sedation was ineffective in seven patients, three of whom had head injuries, and one of whom received 2.5 mg of droperidol per physician order. Paramedics sustained no needlestick exposures. CONCLUSION: Intramuscular droperidol contributed to effective and rapid prehospital sedation in this observational series of 53 combative patients.

Aggression↗