Critical care medicine
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Critical care medicine · Dec 1993
ReviewBrain death in the pediatric patient: historical, sociological, medical, religious, cultural, legal, and ethical considerations.
To detail the origins of the definition of death, the development of the criterion of whole brain death as fulfilling the definition of death, and the tests used to fulfill that criterion. ⋯ A human being is a man, woman, or child who is a composite of two intricately related but conceptually distinguishable components: the biological entity and the person. Therefore, human beings can suffer more than one death: a biological death and decay, and another death. Biological death is a cessation of processes of biological synthesis and replication, and is an irreversible loss of integration of the biological units. The reasons for having criteria for death are to diagnose death and pronounce a person dead. Society can then begin to engage in grief, religious rites, funerals, and burials, and accept biological death. Wills can be read, property distributed, insurance claimed, individuals can remarry, succession can take place, and legal proceedings can begin. Also, organ donation can take place, which entails difficult ethical decisions. The Harvard criteria of 1968 were devised to set forth brain-death criteria with whole brain death in mind. Currently, there are several controversies regarding these criteria: a) whether they apply to infants and children; b) whether ancillary tests are necessary; c) what the intervals of observation and testing are; and d) are there exceptions to the whole brain death criteria. Concerning the use of the adult criteria for infants and children, most researchers now agree that the adult criteria apply to infants and children who are full term and > 7 days of age. Concerning ancillary tests, there has been, in our machine- and technology-oriented profession, a great deal of emphasis on the different tests and their ability to fulfill the criteria of whole brain death. However, clinical examination and the apnea test are usually sufficient to fulfill the criteria. Ancillary tests may be desired in some cases, and a variety of these tests is available. (ABSTRACT TR
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Critical care medicine · Dec 1993
Prognostic and clinical relevance of pupillary responses, intracranial pressure monitoring, and brainstem auditory evoked potentials in comatose patients with acute supratentorial mass lesions.
To test the hypothesis that the clinical condition and outcome in patients with acute supratentorial mass lesions can be assessed by determination of pupillary abnormalities, measurement of intracranial pressure, and results of brainstem auditory evoked potentials. ⋯ Pupillary abnormalities may serve as a reliable parameter, which may even be superior to brainstem auditory evoked potential testing and intracranial pressure monitoring for prediction of outcome in comatose individuals with supratentorial mass lesions. Brainstem auditory evoked potentials can be used to support the clinical relevance of abnormal pupillary status and increased intracranial pressure but are of no prognostic value. Increased intracranial pressure is associated with abnormalities in pupillary status and brainstem auditory evoked potentials. Examination for pupillary abnormalities in combination with intracranial pressure monitoring and brainstem auditory evoked potential testing seems to be a useful strategy in managing patients with supratentorial mass lesions in critical care units.
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Critical care medicine · Dec 1993
Cardiac arrest presenting with rhythms other than ventricular fibrillation: contribution of resuscitative efforts toward total survivorship.
The medical literature portrays a bleak prognosis for out-of-hospital cardiac arrest cases presenting with asystole, idioventricular rhythms with pulselessness, or primary electromechanical dissociation. In view of evolving philosophies to waive resuscitation attempts in such cases, we sought to delineate the actual contribution toward overall survivorship that is provided by resuscitation efforts for patients who have these electrocardiographic presentations. ⋯ Despite poor survival "rates," resuscitative efforts for patients presenting with asystole, electromechanical dissociation, and idioventricular rhythms with pulselessness all contribute significantly toward a community's total survivorship from out-of-hospital cardiac arrest. Initial, aggressive attempts at resuscitation still should be emphasized in such patients.
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Critical care medicine · Dec 1993
Comparative StudyMetabolic acidemia with hypoxia attenuates the hemodynamic responses to epinephrine during resuscitation in lambs.
To examine the effects of metabolic acidemia and hypoxia on the hemodynamic responses to epinephrine in an intact neonatal animal model. ⋯ During the physiologic conditions associated with neonatal resuscitation, that is, hypoxia with a compromised hemodynamic state, metabolic acidemia significantly attenuates the hemodynamic responses to resuscitation with epinephrine and oxygen. Correction of metabolic acidosis may be warranted in newborn resuscitation.
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Critical care medicine · Dec 1993
Central contribution to hypoventilation during severe inspiratory resistive loads.
Recent observations suggest that central hypoventilation with slowing of respiratory frequency contributes to hypoventilation during severe inspiratory resistive loads. We carried out a study to further characterize this bradypneic response. ⋯ Centrally mediated bradypnea contributed to hypoventilation in respiratory failure associated with inspiratory loading. Bradypnea preceded evidence of muscle fatigue. This change in respiratory cycle timing occurred under anesthesia, and thus, did not depend on conscious perception of dyspnea. Bradypnea does not depend on either hypercapnia or hypoxia.