Assessment of neurological prognosis in comatose survivors of cardiac arrest. BRCT I Study Group.

When a patient resuscitated from cardiac arrest remains unconscious the clinician would like to have a reliable early method for predicting the outcome. The objective of our study was to predict cerebral outcome after cardiac arrest by clinical neurological examination. The data were drawn from an international multicentre controlled clinical trial of thiopentone. Twelve hospitals in nine countries took part. 262 comatose cardiac arrest survivors were followed up for one year. These patients were given advanced life support (American Heart Association guidelines) followed by intensive care to a standardised protocol. Glasgow and Glasgow-Pittsburgh coma scores and their constituent signs were recorded at fixed times. Outcome was taken to be the best cerebral performance at any time during follow-up, and for that purpose we used cerebral performance categories (CPC 1-5) of the Glasgow outcome categories. A poor outcome (CPC 3-5) could be predicted immediately after reperfusion (at entry into the study) with an accuracy ranging from 52% to 84% for various signs and scores. On the third day it was possible to identify severely disabled or permanently comatose survivors without false predictions using both coma scores and several of their constituent variables. The best predictor was absence of motor response to pain. This modelling exercise now needs to be repeated on a new series of patients but the results do suggest that, after 3 days, stringent ethical criteria can be met and used in decision-making about termination of care in comatose cardiac arrest survivors.

Brain-oriented intensive care after resuscitation from cardiac arrest.

The 'chain-of-survival' concept has gained general acceptance in the care of cardiac arrest victims. Most standards and guidelines for cardiopulmonary resuscitation, however, focus on the initial links in the chain. We consider appropriate in-hospital care for the survivors a logical extension of the chain of survival. In recent years extensive research activity has probed the pathophysiology and pharmacology of postischemic reperfusion. The present review discusses the current understanding of mechanisms for cerebral damage following global ischemia. Promising pharmacological principles for protection or resuscitation from cerebral ischemia are reviewed. None of them are considered ready for clinical application. Clinical guidelines are proposed, based on the reviewed data and previously published clinical observations. Cornerstones of the proposed brain-oriented intensive care protocol are: (1) hemodynamic monitoring and meticulous treatment of circulatory disturbances, (2) controlled ventilation providing normoventilation and normoxia to all comatose patients, (3) avoiding hyperglycemia and hyperthermia in comatose patients, (4) adequate analgesia and sedation, tempered by the understanding that oversedation impedes neurological evaluation without promoting recovery. An accurate prognosis can usually be made 48-72 h after resuscitation. This permits reevaluation and assignment to an appropriate level of continued hospital care.

The ethics of resuscitation; differences between Europe and the USA--Europe should not adopt American guidelines without debate.

There are differences between Europe and the USA in the style of medical decision-making for patients who are critically ill or requiring CPR. These differences are both legal and philosophical. They concern principally the degree of influence the patient and next of kin should have on critical medical decisions. Currently American physicians transfer more of the decision-making to patients and relatives than do their European counterparts. The current state of the art in cardio-pulmonary resuscitation (CPR) from cardiac arrest occurring out-of-hospital requires public education programmes. These heighten public awareness of CPR-related questions. There has been a wide acceptance in Europe of the American guidelines for CPR. Cultural and legal differences, however, should encourage the acceptance of specific European guidelines. The author believes that it is important to introduce in the European CPR programmes discussions on the ethical dilemmas that may occur. This may help to conserve the relatively high level of public trust that facilitates the patient-doctor relationship in Europe, compared with the USA. Arguments are also put forward for a heightened sensitivity in the European medical profession concerning communication with the patients and their next of kin and with the mass media, in view of the increasing public sophistication and interest that the citizen CPR programmes are generating.

An experimental randomized study of five different ventilatory modes in a piglet model of severe respiratory distress.

OBJECTIVES: To characterize different modes of pressure- or volume-controlled mechanical ventilation with respect to their short-term effects on oxygen delivery (DO2). Furthermore to investigate whether such differences are caused by differences in pulmonary gas exchange or by airway-pressure-mediated effects on the central hemodynamics. DESIGN: After inducing severe respiratory distress in piglets by removing surfactant, 5 ventilatory modes were randomly and sequentially applied to each animal. SETTING: Experimental laboratory of a university department of Anesthesiology and Intensive Care. ANIMALS: 15 piglets after repeated bronchoalveolar lavage. INTERVENTIONS: Volume-controlled intermittent positive-pressure ventilation (IPPV) with either 8 or 15 cmH2O PEEP; pressure-controlled inverse ratio ventilation (IRV); pressure-controlled high-frequency positive-pressure ventilation (HFPPV) and pressure-controlled high frequency ventilation with inspiratory pulses superimposed (combined high frequency ventilation, CHFV). The prefix (L) indicates that lavage has been performed. MEASUREMENTS AND RESULTS: Measurements of gas exchange, airway pressures, hemodynamics, functional residual capacity (using the SF6 method), intrathoracic fluid volumes (using a double-indicator dilution technique) and metabolism were performed during ventilatory and hemodynamic steady state. The peak inspiratory pressures (PIP) were significantly higher in the volume-controlled low frequency modes (43 cmH2O for L-IPPV-8 and L-IPPV-15) than in the pressure-controlled modes (39 cmH2O for L-IRV, 35 cmH2O for L-HFPPV and 33 cmH2O for L-CHFV, with PIP in the high-frequency modes being significantly lower than in inverse ratio ventilation). The mean airway pressure (MPAW) after lavage was highest with L-IRV (26 cmH2O). In the ventilatory modes with a PEEP > 8 cmH2O PaO2 did not differ significantly and beyond this "opening threshold" MPAW did not further improve PaO2. Central hemodynamics were depressed by increasing airway pressures. This is especially true for L-IRV in which we found the highest MPAW and at the same time the lowest stroke index (74% of IPPV). CONCLUSIONS: In this model, as far as oxygenation is concerned, it does not matter in which specific way the airway pressures are produced. As far as oxygen transport is concerned, i.e. aiming at increasing DO2, we conclude that optimizing the circulatory status must take into account the circulatory influence of different modes of positive pressure ventilation.

[Crisis in the American health care system]. / Krisen i den amerikanska sjukvården.

According to Federal US law it is forbidden to reject patients or to curtail their care. The law may be seen as a democratic expression of the American people's wish to give all citizens access to the country's health services. Nevertheless it is estimated that millions of people in the USA wholly lack health insurance and very few of them succeed in paying their hospital bills. The problems of collection are so great that hospitals frequently refrain from even making the attempt. The law has a paradoxical effect; the health services are impoverished since no resources are set aside to cover the rising costs.

An experimental study of different ventilatory modes in piglets in severe respiratory distress induced by surfactant depletion.

In 19 anesthetized piglets 3 ventilatory modes were studied after inducing pulmonary insufficiency by bronchoalveolar lavage by the method of Lachmann. The lavage model was considered suitable for reproduction of severe respiratory distress. This model was reproducible and stable with respect to alveolar collapse, decrease in static chest-lung compliance and increase in extravascular lung water. The ventilatory modes studied were volume-controlled intermittent positive-pressure ventilation (IPPV), pressure-controlled inverse ratio ventilation (IRV), and pressure-controlled high-frequency positive-pressure ventilation (HFPPV). The 3 ventilatory modes were used in random sequence for at least 30 min to produce a ventilatory steady state. Ventilation with no PEEP, permitting alveolar collapse, was interposed between each experimental mode. The ability to open collapsed alveoli, i.e. alveolar recruitment, was different. The recruitment rate for IPPV was 74%, but for IRV and HFPPV it was 95%, respectively. Although IRV provided the best PaO2, this was at the expense of high airway pressures with circulatory interference and reduced oxygen transport. In contrast to this, HFPPV provided lower airway pressures, less circulatory interference and improved oxygen transport. In the clinical setting there might be negative effects on vital organs and functions unless the ventilatory modes are continuously and cautiously adapted to the individual requirements in different phases of severe respiratory distress. Therefore, one ventilatory strategy could be to "open the airways" with IRV, but then switch to HFPPV in an attempt to maintain the airways open with lesser risk of barotrauma and with improved oxygen transport.

The presenting ECG pattern in survivors of cardiac arrest and its relation to the subsequent long-term survival. Brain Resuscitation Clinical Trial I Study Group.

In a prospective multi-center study, 262 patients were given general intensive care therapy following cardiopulmonary resuscitation if they were still comatose and unresponsive to pain 10 min after restored spontaneous circulation. Mortality (mainly cardiac) was 53.4% over the first 10 days, and 49% of the remaining survivors died between 10 days and 6 months. In the subsequent 6 months few patients died. Presenting electrocardiograms (ECG) showed ventricular fibrillation (VF) in 54.2%, asystole in 29.8% and electromechanical dissociation (EMD) in 9.2% of the patients. One-year survival, 14.1% for asystole, 4.2% for EMD and 26.0% for VF and VT (ventricular tachycardia), differed significantly (P less than 0.01). VF/VT patients were older and had more cardiovascular disease. Adjustments of these and other covariates increased the significance of difference between ECG groups. Successful resuscitations from asystole or EMD appeared to be more common than has previously been reported, but this group of patients experienced an extremely high cardiac mortality over the first 6 months following resuscitation.

Prediction of outcome after cardiac arrest.

Neurologic outcome of hypoxic ischemic coma after cardiac arrest was studied in 32 patients. Observations were made and samples collected 24 and 48 h after the ischemic insult. The Glasgow-Pittsburgh coma score was assessed for its prognostic value. Other variables studied were the EEG and adenylate kinase, lactate and glutathione in the cerebrospinal fluid (CSF). Outcome was termed good if the patients resumed an independent life within a 6-month follow-up period. The closest correlations between prediction and good outcome occurred with the Glasgow-Pittsburgh coma score (94%) and the EEG (77%) at the 48-h examination, a modified coma score (96%) at 48 h, and CSF lactate (78%) at 24 h. Some simple neurologic signs (e.g., no withdrawal response to pain) at stated points in time was 100% associated with a bad outcome, although their absence was not associated necessarily with a good prognosis.