Simulation-based training at the University of Pittsburgh.

The following article reviews the experience of using human simulators for medical education at the University of Pittsburgh in the Department of Anesthesiology and Critical Care Medicine. The intent of the authors is to provide the reader with an overview of 1) what human simulators can do, 2) the components of a simulation training facility, 3) some of the economic considerations in operating a simulation training facility, and 4) how this centre is made use of.

Intra-aortic administration of epinephrine above aortic occlusion does not alter outcome of experimental cardiopulmonary resuscitation.

Intra-aortic balloon occlusion during experimental cardiopulmonary resuscitation (CPR) improves coronary perfusion pressure and resuscitability and provides unique access to the central circulation. It has been hypothesized that administration of epinephrine into the aortic arch in combination with aortic occlusion would further improve haemodynamics during CPR, resuscitability and 24 h survival. In 16 anaesthetised dogs intravascular catheters were placed for hemodynamic and blood gas monitoring. An aortic balloon catheter was placed by femoral artery insertion with its tip just distal to the left subclavian artery. Ventricular fibrillation for 7.5 min without CPR, 2.5 min of Basic Life Support with chest compressions and ventilation with 100% oxygen were followed by 30 min of Advanced Cardiac Life Support (ACLS) with systemic canine drug dosages. The intra-aortic balloon was inflated when ACLS started and gradually deflated shortly after restoration of spontaneous circulation (ROSC). Epinephrine, in 100 microg/kg boluses every 5 min until the heart was restarted or 30 min had elapsed was administered through the intra-aortic catheter in the experimental group (n = 8) and via a central venous catheter in the control group (n = 8). Coronary perfusion pressure increased during the ACLS period in both groups (P < 0.05) with no difference between the groups and there was no difference in the frequency of ROSC (experimental group 5/8, control group 4/8). Furthermore with respect to 24 h survival, there was no difference between the experimental group (2/8) and the control group (3/8). Severe macroscopic haemorrhagic necrosis of the myocardium in the dogs with ROSC was found in 4/5 in the experimental group compared to 1/4 in the control group. In conclusion, intra-aortic administration of 100 microg/kg epinephrine doses combined with aortic occlusion during experimental CPR did not alter outcome.

Improving the request process to increase family consent for organ donation.

The greatest impediment to organ donation is refusal of family consent. This study examined the impact of 3 modifiable elements of the donation request on family consent rates: (1) decoupling (i.e., the family understands and accepts brain death before discussion of organ donation is begun); (2) the procurement coordinator participates in the request for consent; and (3) donation is requested in a quiet, private place. Data on the request process were collected prospectively for 707 medically suitable potential donors who had been referred to 3 organ procurement organizations. The average rate of consent for donation was 62.2%. Higher consent rates were independently associated with the 3 characteristics studied. These components were summarized in the Request Process Scale. Multivariate regression analyses indicated that consent rates can be as high as 74% when all 3 process elements are present. Hospitals and organ procurement organizations should incorporate these elements into their standard of practice when requesting organ donation.

Future directions for resuscitation research. V. Ultra-advanced life support.

Standard external cardiopulmonary resuscitation (SECPR) frequently produces very low perfusion pressures, which are inadequate to achieve restoration of spontaneous circulation (ROSC) and intact survival, particularly when the heart is diseased. Ultra-advanced life support (UALS) techniques may allow support of vital organ systems until either the heart recovers or cardiac repair or replacement is performed. Closed-chest emergency cardiopulmonary bypass (CPB) provides control of blood flow, pressure, composition and temperature, but has so far been applied relatively late. This additional low-flow time may preclude conscious survival. An easy, quick method for vessel access and a small preprimed system that could be taken into the field are needed. Open-chest CPR (OCCPR) is physiologically superior to SECPR, but has also been initiated too late in prior studies. Its application in the field has recently proven feasible. Variations of OCCPR, which deserve clinical trials inside and outside hospitals, include 'minimally invasive direct cardiac massage' (MIDCM), using a pocket-size plunger-like device inserted via a small incision and 'direct mechanical ventricular actuation' (DMVA), using a machine that pneumatically drives a cup placed around the heart. Other novel UALS approaches for further research include the use of an aortic balloon catheter to improve coronary and cerebral blood flow during SECPR, aortic flush techniques and a double-balloon aortic catheter that could allow separate perfusion (and cooling) of the heart, brain and viscera for optimal resuscitation of each. Decision-making, initiation of UALS methods and diagnostic evaluations must be rapid to maximize the potential for ROSC and facilitate decision-making regarding long-term circulatory support versus withdrawal of life support for hopeless cases. Research and development of UALS techniques needs to be coordinated with cerebral resuscitation research.

Future directions for resuscitation research. I. Advanced airway control measures.

The efficacy of 'basic' airway control without equipment, using the combination of backward tilt of the head, forward displacement of the mandible, and separation of lips and teeth (i.e. the triple airway maneuver) has been well established. Direct mouth-to-mouth and mouth-to-nose ventilation must continue to be taught to the public. Further improvements are needed for pocket-size mouth-to-mouth barriers to combat infection risks. Dissemination of appropriate information on disease transmission is needed to ensure ventilation by health professionals, using exhaled air ventilation adjuncts and other devices. Much knowledge exists about the pathophysiology of airway obstruction. For patients in coma or anesthesia with airway obstruction, which resists basic airway control measures and standard tracheal intubation, available 'advanced' airway control measures should be mastered and improved. Preparedness for advanced airway control measures differs between elective management of the anticipated difficult airway for anesthesia and emergency airway control with unanticipated difficulties encountered during the ordinary sequential application of measures. Challenges include education research and development of new devices. For airway clearing, pharyngeal intubation, difficult tracheal intubation, cricothyrotomy, transtracheal jet ventilation and emergency use of oxygen - what could and should be taught, to whom, and how? Which new devices and training systems should be developed? The most important alternative to orotracheal or nasotracheal intubation recommended for the development of novel devices and teaching methods for health professionals, are cricothyrotomy (with wide enough airway to also enable spontaneous breathing of air), and translaryngeal or transtracheal oxygen jet ventilation. We recommend openness in communication and joint planning between anesthesiologists, emergency care providers, and appropriate educators, engineers and industries.

Resuscitation from severe brain trauma.

Severe traumatic brain injuries are extremely heterogeneous. At least seven of the secondary derangements in the brain that have been identified as occurring after most traumatic brain injuries also occur after cardiac arrest. These secondary derangements include posttraumatic brain ischemia. In addition, traumatic brain injury causes insults not present after cardiac arrest, i.e., mechanical tissue injury (including axonal injury and hemorrhages), followed by inflammation, brain swelling, and brain herniation. Brain herniation, in the absence of a mass lesion, is due to a still-to-be-clarified mix of edema and increased cerebral blood flow and blood volume. Glutamate release immediately after traumatic brain injury is proven. Late excitotoxicity needs exploration. Inflammation is a trigger for repair mechanisms. In the 1950s and 1960s, traumatic brain injury with coma was treated empirically with prolonged moderate hypothermia and intracranial pressure monitoring and control. Moderate hypothermia (30 degrees to 32 degrees C), but not mild hypothermia, can help prevent increases in intracranial pressure. How to achieve optimized hypothermia and rewarming without delayed brain herniation remains a challenge for research. Deoxyribonucleic acid (DNA) damage and triggering of programmed cell death (apoptosis) by trauma deserve exploration. Rodent models of cortical contusion are being used effectively to clarify the molecular and cellular responses of brain tissue to trauma and to study axonal and dendritic injury. However, in order to optimize therapeutic manipulations of posttraumatic intracranial dynamics and solve the problem of brain herniation, it may be necessary to use traumatic brain injury models in large animals (e.g., the dog), with long-term intensive care. Stepwise measures to prevent lethal brain swelling after traumatic brain injury need experimental exploration, based on the multifactorial mechanisms of brain swelling. Novel treatments have so far influenced primarily healthy tissue; future explorations should benefit damaged tissue in the penumbra zones and in remote brain regions. The prehospital arena is unexplored territory for traumatic brain injury research.

Systemic perfusion pressure and blood flow before and after administration of epinephrine during experimental cardiopulmonary resuscitation.

OBJECTIVES: To evaluate instantaneous blood flow variations in the compression and relaxation phases of cardiopulmonary resuscitation (CPR) and the effect of epinephrine administration. DESIGN: Prospective, randomized, controlled trial. SETTING: Experimental laboratory in a university hospital. SUBJECTS: Twenty-two anesthetized piglets. INTERVENTIONS: A tracheostomy was performed and arterial, central venous, and pulmonary arterial catheters were inserted, followed by thoracotomy with placement of pulmonary arterial, aortic, and left anterior descending coronary arterial (extended study group) flow probes and a left atrial catheter. Ventricular fibrillation for 2 mins was followed by 10 mins of either open-chest (n = 10) or closed-chest (n = 12) CPR. Seven minutes after the initiation of CPR, all piglets received 0.5 mg of epinephrine iv; at 12 mins, direct current shocks were applied. MEASUREMENTS AND MAIN RESULTS: Open-chest CPR generated greater systemic perfusion pressure than closed-chest CPR, especially during the relaxation phase, resulting in greater mean blood flow. With both open- and closed-chest CPR, antegrade pulmonary arterial and aortic blood flow occurred during compression, whereas antegrade left anterior descending coronary arterial blood flow occurred during relaxation. During relaxation, retrograde flow was found in the pulmonary artery and aorta. During compression, retrograde flow was found in the left anterior descending coronary artery. The administration of epinephrine had the following effects: a) increased the systemic perfusion pressure more during open- than closed-chest CPR; b) increased the systemic relaxation perfusion pressure more than the compression perfusion pressure; c) decreased mean pulmonary arterial and aortic blood flow, but substantially increased the mean left anterior descending coronary artery blood flow; and d) reduced the retrograde flow in the left anterior descending coronary artery. CONCLUSIONS: Open-chest CPR generated greater systemic perfusion pressure and blood flow than closed-chest CPR. Epinephrine increased left anterior descending coronary artery blood flow but decreased total cardiac output, such that cerebral perfusion might be endangered. This problem will be studied separately.

Intensive care for critically ill elderly: mortality, costs, and quality of life. Review of the literature.

The literature on outcomes of intensive care for the elderly with regard to intensive care unit utilization, mortality, hospital costs and charges, and quality of life after intensive care were reviewed. Publications in the English literature, which evaluated intensive care and included elderly populations, were obtained from review of Index Medicus and MEDLINE. We conclude that age alone is not an acceptable predictor of critical illness with regard to mortality and quality of life of survivors. A therapeutic trial and appropriately discontinuing life support may lead to better utilization of intensive care. Additional data are needed on long-term mortality and quality of life after hospital discharge.

Blood flow and perfusion pressure during open-chest versus closed-chest cardiopulmonary resuscitation in pigs.

OBJECTIVE: To evaluate the blood flow and perfusion pressure differences observed during open- vs. closed-chest cardiopulmonary resuscitation (CPR), including the effects of epinephrine and sodium bicarbonate administration. DESIGN: Prospective, randomized, controlled trial. SETTING: Experimental animal laboratory in a university hospital. SUBJECTS: A total of 35 anesthetized piglets. INTERVENTIONS: After tracheostomy and insertion of arterial, right atrial, and pulmonary arterial catheters, thoracotomy was performed with placement of a pulmonary arterial flow probe and left atrial catheter. Ventricular fibrillation was induced and followed by 15 mins of either open-chest (n = 14) or closed-chest (n = 21) CPR. A 4-min infusion of 50 mmol of sodium bicarbonate or saline was added at the start of CPR. After 8 mins of CPR, 0.5 mg of epinephrine was given intravenously, and after 15 mins, direct current (DC) shocks were used to revert the heart to sinus rhythm. MEASUREMENTS AND MAIN RESULTS: Blood flow was studied using transit-time ultrasound flowmetry. In an extended group, intrathoracic pressure was measured for calculation of transmural pressure. Before epinephrine administration, mean pulmonary arterial flow (cardiac output) was reduced: a) during closed-chest CPR relatively more than pulmonary perfusion pressure but in proportion to systemic perfusion pressure; b) during open-chest CPR relatively less than pulmonary perfusion pressure but still in proportion to systemic perfusion pressure. Epinephrine administration temporarily increased systemic perfusion pressure during both closed- and open-chest CPR but temporarily decreased pulmonary perfusion pressure only during closed-chest CPR. After epinephrine administration, cardiac output temporarily decreased during both closed-and open-chest CPR. CONCLUSIONS: Open-chest CPR resulted in better cardiac output and systemic perfusion pressure than closed-chest CPR. However, cardiac output values obtained with both methods were much lower than previously reported. After epinephrine administration, cardiac output became extremely low with both methods.

Teaching medical students complex cognitive skills in the intensive care unit.

OBJECTIVE: To determine if fourth-year medical students can learn the high-level cognitive skills needed to manage critically ill patients during a critical care medicine elective designed in accordance with established educational principles. DESIGN: Students were randomly assigned to take one of two examinations with ten short essay questions to complete on the initial day. After the elective, students completed the other examination in a crossover design. SETTING: Five surgical intensive care units (ICUs) in a tertiary care university teaching hospital. PARTICIPANTS: Fourth-year medical students enrolled in the critical care medicine elective. INTERVENTIONS: All students were enrolled in a critical care medicine elective consisting of an orientation, interactive conferences, technical skills laboratories, daily rounds, and patient-care experience. These components were designed to encourage problem-solving, improve analytical skills, and minimize the deterrents to education in the ICU. MEASUREMENTS: The primary outcome measure was the difference in examination scores before and after the rotation. Examinations were designed to test the student's skills in application, analysis, synthesis and evaluation. Specific questions concerning hemodynamic assessment were compared. MAIN RESULTS: The students' mean pre-elective scores were 58.8 +/- 10.8%, compared with 85.5 +/- 9.4% after the elective (p < .0001). CONCLUSION: Students can learn cognitive components of patient management skills using a format that encourages judgment, decision-making, and analytical skills, despite the liabilities inherent to education in an ICU.

Long-term outcome of critically ill elderly patients requiring intensive care.

OBJECTIVE: To evaluate the long-term mortality and morbidity of critically ill elderly patients requiring intensive care. DESIGN: Prospective comparison of outcome of critically ill patients aged 75 years and older with patients aged 65 to 74 years. PATIENTS: Critically ill patients aged 65 years and older who required intensive care and who were recruited during a 3-month period. MAIN OUTCOME MEASURES: Duration of hospitalization, hospital charges, procedures used in the intensive care unit, mortality in the hospital and during the follow-up period, and quality of life of survivors during the follow-up period. RESULTS: Ninety-seven patients were included in the study; 54 were 75 years or older and 43 were aged 65 to 74 years. No significant difference was noted between the two groups for length of stay in the hospital, hospital charges, or mortality at 1 year. Severity of illness, as assessed by Acute Physiology and Chronic Health Evaluation score at the time of intensive care unit admission, was a better predictor of survival than age. Quality of life, as assessed by activities of daily living, perceived quality of life, and Center for Epidemiologic Studies-Depression score, were not significantly different in either group at 1, 6, and 12 months after discharge from the hospital. Most patients in both groups described their quality of life as adequate and were willing to receive intensive care again, if necessary. CONCLUSION: Age alone is not an adequate predictor of long-term survival and quality of life in critically ill elderly patients.

History of organ donation by patients with cardiac death.

When successful solid organ transplantation was initiated almost 40 years ago, its current success rate was not anticipated. But continuous efforts were undertaken to overcome the two major obstacles to success: injury caused by interrupting nutrient supply to the organ and rejection of the implanted organ by normal host defense mechanisms. Solutions have resulted from technologic medical advances, but also from using organs from different sources. Each potential solution has raised ethical concerns and has variably resulted in societal acclaim, censure, and apathy. Transplant surgery is now well accepted, and the list of transplant candidates has grown far quicker than the availability of organs. More than 30,000 patients were awaiting organs for transplantation at the end of March 1993. While most organs came from donors declared dead by brain criteria, the increasing shortage of donated organs has prompted a reexamination of prior restrictions of donor groups. Recently, organ procurement from donors with cardiac death has been reintroduced in the United States. This practice has been mostly abandoned by the U.S. and some, though not all, other countries. Transplantation has been more successful using organs procured from heart-beating, "brain dead" cadavers than organs from non-heart-beating cadavers. However, recent advances have led to success rates with organs from non-heart-beating donors that may portend large increases in organ donation and procurement from this source.

Future of critical care.

Critical care, as a specialty in both nursing and medicine, is well recognized and the number of people requiring hospitalization for critical illnesses continues to increase. The purpose of this paper is to examine the future and the changes that lie ahead in critical care. New and expanding roles for nurses are projected along with a continued refinement and expansion of the critical care medicine subspecialty for physicians. A variety of changes in critical care are anticipated that reflect our increasing abilities in biotechnology, basic and clinical research, and data management. These changes are viewed for their obvious impact on cost, ethical controversies, and patient care and outcome.

Outcome of intensive care of the "oldest-old" critically ill patients.

OBJECTIVE: To determine the short-term and long-term outcome of critically ill "oldest-old" (greater than or equal to 85 yrs) patients. DESIGN: Retrospective chart review and follow-up telephone interview. SETTING: ICUs at a tertiary care hospital. METHODS: The medical records of all patients greater than or equal to 85 yrs of age admitted to the ICUs during 1988 were reviewed. Demographic information, severity of illness, major interventions, mortality rate, and hospital charges were examined. A follow-up telephone interview was conducted to determine the quality of life and mortality rate after discharge. RESULTS: Of 34 patients greater than or equal to 85 yrs of age admitted to the ICU, 21 (62%) survived to discharge from the hospital, and 13 (62%) of these 21 patients were discharged to home. Mean +/- SD hospital charges were $34,738 +/- 34,366. Seventeen of the 21 patients were contacted for long-term follow-up, and ten of these patients were alive at a mean follow-up time of 18 +/- 10 months (range 1 to 32). Eight of the ten patients described their quality of life as fair or good. CONCLUSION: These findings suggest that age alone may be an inappropriate criterion for allocation of ICU resources.

Approach to management of the heartbeating 'brain dead' organ donor.

In recent years, transplantation has assumed an important role in the treatment of patients with end-stage diseases of most major organ systems. However, the greatest limitation in organ transplantation today is organ supply. Among factors that can affect the organ supply favorably, donor management has received the least attention. This review addresses management of the multi-organ donor within the intensive care unit. With an increased awareness of donor management issues and the application of a rational physiological approach, the supply of functional organs for transplantation can be increased.

KIE: Clinical management of the brain dead, potential multi-organ donor within the intensive care unit is reviewed. The emphasis is on physiological maintenance until organ procurement. Among the topics discussed are donor recognition and evaluation, declaration of brain death, medical management, and organ procurement and coordination.

Ethical dilemmas in organ donation and transplantation.

Since the first successful organ transplantation in 1953, we have seen an explosive development in transplantation surgery, particularly during the 1980s. With it followed an abundance of legal controversies and ethical dilemmas. Optimal use of viable organs necessitated precise definition of brain death in heart-beating cadavers with artificially maintained ventilation and circulation. Viable organs must remain well perfused to be suitable for procurement and transplantation into carefully selected recipients on an equal-opportunity basis. Due consideration must be given to both medical and social indications. At present, homografts dominate the field of organ transplantation; however, because of the shortage of human organs, both artificial organs (especially hearts) and xenografts are expected to become increasingly common in the near future. No doubt, the use of such modern technology will introduce additional ethical problems.