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Biomedical subjects

J F Bion

Publications and source records attributed to J F Bion.

At least 37 records · Page 2Linked to original sources
PubMed1994

Selective decontamination of the digestive tract reduces gram-negative pulmonary colonization but not systemic endotoxemia in patients undergoing elective liver transplantation.

OBJECTIVE: To examine the effect of selective antibiotic decontamination of the digestive tract in patients undergoing elective orthotopic liver transplantation. DESIGN: Prospective, randomized, concurrent allocation to either selective decontamination or standard antibiotic prophylaxis. SETTING: Operating theater and intensive care unit at a tertiary referral, university teaching hospital. PATIENTS: Fifty-nine adult patients were recruited into the study and underwent liver transplantation. INTERVENTIONS: Thirty-two patients were randomized to standard treatment (control group) and 27 patients were randomized to receive selective decontamination. After early deaths and exclusions, 31 controls and 21 decontamination patients were available for analysis. MEASUREMENTS AND MAIN RESULTS: Portal and systemic endotoxemia, colonization and infection rates, severity of illness (organ system failures, Acute Physiology and Chronic Health Evaluation II score, Therapeutic Intervention Scoring System score), antibiotic costs, and hospital survival rates were measured. Selective decontamination significantly reduced pulmonary infections and enteric, aerobic, and Gram-negative bacillary colonization without facilitating the emergence of resistant organisms, but selective decontamination had no effect on endotoxemia or the development of organ system failures. The financial costs of the selective decontamination regimen outweighed the advantages gained from an associated reduction in antibiotic usage. CONCLUSION: The failure of selective decontamination to enhance survival rates in many studies of the regimen in critically ill patients may, in part, be related to the inability of selective decontamination to abolish endotoxemia.

Adult↗
PubMed1994

Antibiotic-induced release of endotoxin from bacteria in vitro.

The ability of cefotaxime, ciprofloxacin, piperacillin and tobramycin to cause release of endotoxin was examined in vitro with cultures of Enterobacter cloacae and Escherichia coli. Endotoxin was measured by a quantitative limulus amoebocyte lysate assay and its presence was confirmed by silver staining of the lipopolysaccharide moiety following SDS-PAGE. The morphology of the bacteria during antibiotic exposure was examined by scanning electronmicroscopy. Cefotaxime, ciprofloxacin and piperacillin caused significant endotoxin release, correlating with their ability to affect cell-wall morphology, causing filamentation, wall breakage and cell lysis. In contrast, little endotoxin was released when bacteria were exposed to tobramycin and no morphological changes were observed when bacteria were exposed to bactericidal concentrations of this aminoglycoside. Its antimicrobial spectrum and bactericidal activity make tobramycin an appropriate agent for treatment of sepsis caused by gram-negative bacteria and its lack of propensity to elicit excessive release of endotoxin may avoid exacerbation of endotoxin-related shock in sepsis.

Anti-Bacterial Agents↗
PubMed1993

Atracurium infusions in patients with fulminant hepatic failure awaiting liver transplantation.

OBJECTIVE: To determine the pharmacokinetics and pharmacodynamics of the neuromuscular blocking agent atracurium besylate in patients with fulminant hepatic failure (FHF). DESIGN: Open study of patients receiving atracurium infusions to facilitate mechanical ventilation. SETTING: Intensive care unit in a tertiary referral university teaching hospital. PATIENTS: Ten encephalopathic patients with FHF requiring mechanical ventilation while awaiting orthotopic liver transplantation. Three patients died before transplantation could be performed, three died after transplantation, and four survived following successful transplantation. METHODS: Plasma, urine and dialysate fluid were analysed for atracurium and its metabolites using HPLC. Neuromuscular blockade was measured using transcutaneous ulnar nerve stimulation and an accelerometer. Electroencephalography and liver function tests were performed daily. RESULTS: Patients received atracurium infusions for a period ranging from 38 to 217 h. Six patients required continuous arteriovenous haemodiafiltration (CAVHD) to replace renal function. Atracurium mean steady state clearance was 8.6 ml/min/kg, and train-of-four recovery ratio to 75% took 63 min (range 32-108). Laudanosine clearance was markedly reduced in the non-survivors; the half-life was 38.5 hrs compared with 5.3 h in the 4 patients who underwent successful transplantation. Laudanosine accumulation could be observed in all patients before transplantation, but kinetics returned to normal after successful transplantation. The highest laudanosine level recorded was 6,860 ng/ml. There was no evidence of adverse central neurological effects attributable to laudanosine. CAVHD did not contribute significantly to clearance of atracurium or its metabolites. CONCLUSIONS: Atracurium kinetics and dynamics are near-normal even in patients with fulminant hepatic failure and renal failure; laudanosine accumulation will occur, but this is not associated with measurable central neurological effects. Implantation of a functioning liver graft results in clearance of laudanosine, which seems to be independent of renal function. Atracurium is an appropriate choice for producing neuromuscular blockade for periods of several days in patients with fulminant hepatic failure and renal impairment.

Adult↗
PubMed1988

Sickness scoring and response to treatment as predictors of outcome from critical illness.

A physiological sickness scoring system (SS), based on the APACHE II score, has been used to assess outcome from critical illness in 128 patients admitted to a general intensive care unit. Physiological data were collected on each patient from admission until death or discharge from the unit, and survival was recorded as survival to home. The admission SS correctly classified 80.6% of survivors, and 70.4% of non-survivors. Predictive power did not improve with time using the daily SS. However, when the proportional change in SS over time was included in the analysis, predictive power improved; and at day 4, 87.1% of survivors and 75% of non-survivors were correctly classified. At intermediate levels of sickness severity (admission score of 13-18), a reduction in SS of 30% by day 4 reduced the risk of death by 32%; at higher levels (greater than 18) a similar reduction in SS was associated with a 47% reduction in death-risk. Failure to obtain a reduction in score by day 4 was associated with increased risk of death. Survivors consistently showed a greater fall in SS by day 4 than non-survivors. The APACHE score and its modifications provide an accurate, unitary measure of physiological disturbance. Correction of abnormal physiology, and the measurement of responsiveness to therapy are important components in the prediction of outcome from critical illness.

Adult↗
PubMed1986

Sedation in intensive care: morphine and renal function.

Intravenous morphine infusions have been administered to 12 critically-ill patients during controlled ventilation. Acute oliguric renal failure was present in 4 patients, who were treated with a combination of haemofiltration and haemodialysis. Severity of physiological disturbance was assessed using a modified APACHE Score, level of sedation by a linear-analogue scale, and blood morphine levels by high-pressure liquid chromatography. Morphine clearance was impaired in renal failure, and was dependent on haemofiltration volumes; accumulation of morphine did not occur during this form of treatment. Conscious level was clearly more closely related to the degree of physiological disturbance than blood morphine levels; and for a given blood morphine level, depression of consciousness was more pronounced the greater the degree of physiological disturbance. Use of a physiological sickness score may help to clarify some of the factors influencing cerebral function during critical illness. Careful clinical monitoring of level of sedation is important in patients with oliguric renal failure receiving morphine, and haemofiltration appears to reduce the risk of morphine accumulation in these patients.

Acute Kidney Injury↗
PubMed1985

Validation of a prognostic score in critically ill patients undergoing transport.

Fifty consecutive critically ill patients transported between hospitals by a mobile intensive care team were assessed prospectively using a modification of the acute physiology and chronic health evaluation (APACHE II) sickness scoring system. Assessments were made before and after resuscitation, on return to base, and after 24 hours of intensive care. No patient died during transport. Twenty two patients died subsequently in hospital and 28 survived to return home. The mean score for the non-survivors before resuscitation was 21.7 and for the survivors 12.2 (p less than 0.0005). Among the non-survivors there was a significant fall in score with resuscitation but this did not alter their subsequent outcome. Neither group deteriorated during transport. The sickness score is a powerful method for determining prognosis, and employed longitudinally it may be useful in the assessment of treatment. It has important implications for the administration and organisation of regional intensive care services.

Adult↗
PubMed1984

Isobaric bupivacaine for spinal anaesthesia in acute war injuries.

Twenty nine patients with acute war injuries of the lower limbs or perineum were anaesthetised with intrathecal bupivacaine. Eleven patients (38%) were shocked on arrival with systolic arterial blood pressures less than 90 mmHg; in three the blood pressure was unrecordable . All patients were resuscitated and ready for surgery within 30 minutes of arrival at the field hospital. Hypotension occurred two minutes after injection of bupivacaine in three of the eleven shocked patients, but was corrected with fluids and metaraminol without difficulty. Patients with a fever were found to be less likely to develop hypotension. The early onset of hypotension and the necessity for a head-down tilt gives bupivacaine a significant advantage over hyperbaric agents, and the technique can be recommended.

Acute Disease↗
PubMed1984

Infusion analgesia for acute war injuries. A comparison of pentazocine and ketamine.

Continuous intravenous infusions of ketamine and pentazocine have been used to provide analgesia in 18 patients with acute war injuries. The drugs were given alternately. Both drugs produced effective pain relief, but the quality of analgesia was superior following pentazocine because of its sedative properties. Arterial blood pressure and respiratory rate were maintained following ketamine but tended to fall after pentazocine. It is suggested that ketamine would be the better agent in patients with hypovolaemia or respiratory depression.

Adult↗
PubMed1984

Intrathecal ketamine for war surgery. A preliminary study under field conditions.

Intrathecal ketamine, which has not previously been described in man, has been administered to 16 patients with war injuries of the lower limbs. The first five received varying doses from 5 to 50 mg in a volume of 3 ml of 5% dextrose, to determine a dose-response curve (Group 1). The optimal dose was then administered to a further 11 patients who received ketamine 50 mg in a volume of 3 ml in 5% dextrose with the addition of adrenaline 0.1 mg (Group 2). A distinct sensory level was obtained in all patients. In Group 2, nine of the eleven patients obtained satisfactory surgical analgesia and two required supplementation with local anaesthetic. Central effects (drowsiness, dizziness, and nystagmus) also occurred in nine patients, but they remained conscious throughout; one patient experienced no central effects, and one patient developed dissociative anaesthesia. Central effects were more intense the higher level of block. There were no significant changes in mean systolic arterial blood pressure, pulse, or respiratory rates. Surgical analgesia for the blocked dermatomes lasted for a mean of 58 minutes (range 45-90), and recovery was complete and uncomplicated; mild generalised analgesia persisted for a further one to three hours following return of sensation. Ketamine alone did not produce motor block, but addition of adrenaline resulted in complete motor block, and may have intensified sensory blockade. Motor loss persisted for the same duration as surgical analgesia. Adrenaline neither delayed the onset of central effects, nor reduced their intensity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗