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Biomedical subjects

D Bracco

Publications and source records attributed to D Bracco.

At least 19 recordsLinked to original sources

[Place of normovolemic hemodilution in oncologic cervicofacial and ENT surgery].

OBJECTIVE: Evaluate the use of normovolaemic haemodilution in cervico-facial oncologic surgery. STUDY DESIGN: Prospective, randomised, simple blinded study. PATIENTS AND METHODS: 38 ASA I and II patients were studied: a control group (n = 21) and a haemodilution group (n = 17) in whom 5.5-8 mL.kg-1 blood were withdrawn before induction, replaced by an equivalent amount of colloids. In both groups, the transfusional strategy was to keep the haemoglobin level above 100 g.L-1 throughout the procedure and the recovery phase, using in priority the autologous blood in the haemodilution group. Blood losses during surgery were evaluated by weighing the sponges and by measuring the aspirated blood. RESULTS: Demographic and anaesthetic data, and blood losses were similar. The haemoglobin levels dropped significantly in the haemodilution group (138 +/- 10 g.L-1 to 107 +/- 11 g.L-1) as well as in the control group (131 +/- 11 g.L-1 to 110 +/- 10 g.L-1). Infectious complications were slightly higher in the haemodilution group, although this difference did not reach the level of significance. CONCLUSION: Normovalaemic haemodilution does not seem to be indicated in cervico-facial and ENT oncologic surgery.

Aged↗

Human errors in a multidisciplinary intensive care unit: a 1-year prospective study.

OBJECTIVES: To determine the incidence and identify risk factors of critical incidents in an ICU. DESIGN: Prospective observational study of consecutive patients admitted over 1 year to an ICU. Critical incidents were recorded using predefined criteria. Their causes and consequences were analysed. The causes were classified as technical failure, patient's underlying disease, or human errors (subclassified as planning, execution, or surveillance). The consequences were classified as lethal, leading to sequelae, prolonging the ICU stay, minor, or without consequences. The correlation between critical incidents and specific factors including patient's diagnosis and severity score, use of monitoring and therapeutic modalities was analysed by uni- and multivariate analysis. SETTING: An 11-bed multidisciplinary ICU in a non-university teaching hospital. PATIENTS: 1,024 consecutive patients admitted to the ICU. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The median length of ICU stay by the 1,024 patients was 1.9 days. Of the 777 critical incidents reported 2% were due to technical failure and 67 % to secondary to underlying disease. There were 241 human errors (31%) in 161 patients, evenly distributed among planning (n = 75), execution (n = 88), and surveillance (n = 78). One error was lethal, two led to sequelae, 26 % prolonged ICU stay, and 57 % were minor and 16 % without consequence. Errors with significant consequences were related mainly to planning. Human errors prolonged ICU stay by 425 patient-days, amounting to 15 % of ICU time. Readmitted patients had more frequent and more severe critical incidents than primarily admitted patients. CONCLUSIONS: Critical incidents add morbidity, workload, and financial burden. A substantial proportion of them are related to human factors with dire consequences. Efforts must focus on timely, appropriate care to avoid planning and execution mishaps at the beginning of the ICU stay; surveillance intensity must be maintained, specially after the fourth day.

Adolescent↗

[Hyponatremia in neurologic intensive care: cerebral salt wasting syndrome and inappropriate antidiuretic hormone secretion].

Hyponatraemia is a frequent complication in neurologically injured patients; it is a secondary cerebral injury. Hyponatraemia leads to consciousness problems, convulsions, worsening of the neurological status and thus the neurological evaluation. Hyponatraemia is secondary to free water retention (inappropriate ADH secretion) or to renal salt loss. The cerebral salt wasting syndrome (CSWS) has been described with head injury, subarachnoid haemorrhage and after several sorts of brain insults. It is characterised by an increased natriuresis and diuresis. Diagnosis is based on hyponatraemia, hypernatriuresis, increased diuresis and hypovolaemia. However, inappropriate ADH secretion and CSWS share several diagnostic criteria. The atrial natriuretic factor and the C-type natriuretic factors play a role in the development of the CSWS. The diagnostic approach and monitoring are based on the assessment of sodium and water losses. Therapy is based on correction of the circulating volume and natraemia. Speed of correction is a matter of debate: slow correction presents the risk of further neurological injury whereas rapid correction presents the risk of central pontine myelinosis.

Brain Chemistry↗

Comparison of the effects of clonidine and hydroxyzine on haemodynamic and catecholamine reactions to microlaryngoscopy.

BACKGROUND AND OBJECTIVE: This study compares the effect of oral clonidine vs. hydroxyzine on the haemodynamic and catecholamine responses to microlaryngoscopy. METHODS: Thirty-five ASA II-III patients were included in this double-blind randomized trial. The patients received either hydroxyzine 1 mg kg-1 (n = 18) or clonidine 3 micrograms kg-1 (n = 17) for their oral premedication 100 min before an intravenous induction of anaesthesia using propofol (2-3 mg kg-1) and fentanyl (2 micrograms kg-1). Arterial pressure and heart rate were measured before premedication, and throughout the procedure and recovery. Plasma catecholamine levels were determined before premedication, after induction, and 1.5, 30 and 120 min after laryngoscopy. RESULTS: Mean arterial pressure was significantly lower after clonidine, whereas there was no difference in heart rate and plasma catecholamine levels between the two groups. CONCLUSIONS: Clonidine for premedication significantly decreased mean arterial pressure during microlaryngoscopy and the following recovery phase but did not modify the overall haemodynamic response to the suspension microlaryngoscopic nociceptive stimulus.

Adrenergic alpha-Agonists↗

Reference values of fat-free and fat masses by bioelectrical impedance analysis in 3393 healthy subjects.

Determination of fat-free mass (FFM) and fat mass (FM) is of considerable interest in the evaluation of nutritional status. In recent years, bioelectrical impedance analysis (BIA) has emerged as a simple, reproducible method used for the evaluation of FFM and FM, but the lack of reference values reduces its utility to evaluate nutritional status. The aim of this study was to determine reference values for FFM, FM, and %FM by BIA in a white population of healthy subjects, to observe the changes in these values with age, and to develop percentile distributions for these parameters. Whole-body resistance of 1838 healthy white men and 1555 women, aged 15-64 y, was determined by using four skin electrodes on the right hand and foot. FFM and FM were calculated according to formulas validated for the subject groups and analyzed for age decades. This is the first study to present BIA-determined age- and sex-specific percentiles for FFM, FM, and %FM for healthy subjects, aged 15-64 y. Mean FM and %FM increased progressively in men and after age 45 y in women. The results suggest that any weight gain noted with age is due to a gain in FM. In conclusion, the data presented as percentiles can serve as reference to evaluate the normality of body composition of healthy and ill subject groups at a given age.

Adipose Tissue↗

Segmental bioelectrical impedance analysis to assess perioperative fluid changes.

OBJECTIVES: Perioperative fluid accumulation determination is a challenge for the clinician. Bioelectrical impedance analysis (BIA) is a noninvasive method based on the electrical properties of tissues, which can assess body fluid compartments. The study aimed at assessing their changes in three types of surgery (thoracic, abdominal, and intracranial) requiring various regimens of fluid administration. DESIGN: Prospective descriptive trial. PATIENTS: A total of 26 patients scheduled for elective surgery were separated into three groups according to site of surgery: thoracic (n = 8), abdominal aortic (n = 8), and brain surgery (n = 10). SETTING: University teaching hospital. INTERVENTION: None. MEASUREMENTS: Whole body, segmental (arm, trunk, and legs) BIA at multiple frequency (0.5, 50, 100 kHz) was used to assess perioperative fluid accumulation after surgery. The fluid balances were calculated from the charts. RESULTS: The patients were aged 62+/-4 yrs. Fluid balances were 4.8+/-1.0 L, 4.1+/-0.5 L, and 1.9+/-0.3 L, respectively, in the three groups. In trunk surgery patients, fluid accumulation was detected as a drop in impedance in the operated area at all frequencies. In the operated area, there was an expansion of both intra- and extracellular compartments. A reduction in high frequencies' impedance in the legs was only detected after aortic surgery. Fluid accumulation and trunk impedance changes were strongly correlated. Neurosurgery only induced minor body fluid changes. CONCLUSIONS: Segmental BIA is able to detect and localize perioperative fluid accumulation. It may become a bedside tool to quantify and to localize fluid accumulation.

Abdomen↗

Fatal fat embolism syndrome: a case report.

Fat embolism syndrome is a dire complication of long bone trauma. It is usually associated with neurological, hematological and respiratory involvement, the latter being the major cause of death. We present a case of severe fat embolism syndrome occurring 3 hours after a long bone injury, leading to permanent vegetative state and death without any respiratory signs. The diagnosis was confirmed by cytology of the bronchoalveolar lavage fluid. Clinical presentation of the puzzling fat embolism syndrome and diagnostic tests in suspected fat embolism syndrome are reviewed.

Accidental Falls↗

[Vasospasm treatment in intensive care].

Vasopasm is a dreadful complication of SAH associated with an important mortality and morbidity. Therapy begins with adequate monitoring and lines, and prevention of secondary brain injuries. 3-H therapy (hypervolemia--hypertension--hemodilution--hyperdynamism) aims to increase perfusion in ischemia areas. 3-H therapy is associated with systemic complication precluding it's prophylactic use. Calcium antagonists, in particular nimodipine, improve outcome and parenteral route is better than oral administration. Tirilazad seems to improve outcome of severe grades. Numerous experiments are performed with drugs interfering with the biochemical cascade leading to vasospasm, but up to today no drug is used in current clinical practice. Intraaortic balloon is still considered as experimental and may have a role in patients presenting with concomitant cardiac failure. Invasive radiology must be considered in vasospasm not improving with standard therapies. Vasopasm is a dire complication after SAH. Support and specific therapies allow a 3-fold reduction in morbidity associated with vasospasm. Vasospasm is a vital emergency, and intervention has to be quick and aggressive.

Calcium Channel Blockers↗

[Malignant hyperthermia].

Malignant hyperthermia is a serious anesthetic complication, presenting with various manifestations, with high mortality and morbidity. There are several incomplete and abortive forms, and the clinicians must be aware of the possibility of malignant hyperthermia, and recognize the first signs of the hyperthermic crisis hyperthermia, hypermetabolism and muscular rigidity. Screening is performed by in vitro contracture testing on a muscular biopsy. Treatment is based on discontinuation of triggering agents and dantrolene administration, as well as supportive care. Cellular investigations demonstrate that the malignant hyperthermia crisis presents as an intracellular flooding with calcium, leading to an abnormal muscular contracture. Several mutations in particular involving the ryanodine receptor gene have been linked to malignant hyperthermia.

Biopsy↗

[Renal-protective dose of dopamine: myth or reality?].

Low dose dopamine is widely used to improve diuresis and renal function. This practice is defended by some and fought by others. Acute renal failure in the ICU is often due to tubular necrosis and is a predictor of worse prognosis. Dopamine at low doses is a delta agonist and stimulation of these receptors leads to diuresis and natriuresis. This natriuresis requires additional ATP consumption by the kidney. Low dose dopamine has also systemic hemodynamic effects and these effects can't be dissociated from direct renal effects. Clinical studies of systematic dopamine use in selected high risk patients fail to show a benefit, and side effects of catecholamine administration may lead to additional cardiovascular morbidity. We conclude that low dose dopamine has a demonstrated renal effect but its systematic use to prevent or treat a renal failure cannot be warranted.

Acute Kidney Injury↗

Pulmonary injury after ski wax inhalation exposure.

A wide variety of irritants can lead to respiratory failure after inhalation injuries. We present a case of adult respiratory distress syndrome after exposure to a fluorocarbon resin (PFF 1020) used as ski wax. The patient sustained a mild but prolonged exposure to this substance, which subsequently led to symptoms of severe respiratory failure over the next 24 hours. Except for hypocalcemia, there were no systemic manifestations and recovery was uneventful. Ski wax is considered to be nontoxic and there are no reported side effects of these products. Injury was related to the heated fluorocarbon particles. This case report of a severe lung inhalation injury points out the increasing risk of environmental hazards associated with the use of synthetic substances.

Administration, Inhalation↗

Bedside determination of fluid accumulation after cardiac surgery using segmental bioelectrical impedance.

OBJECTIVES: Bioelectrical impedance analysis (BIA) is based on the physical property of tissues to conduct electrical currents, impedance being inversely related to tissue fluid content. At high frequency, the electrical current flows across both intracellular and extracellular pathways, making the assessment of fat-free mass possible while a low-frequency current flows through the extracellular space. Similarly, segmental BIA may be used to assess segmental body fluid repartition. The aim of this study was to assess fluid accumulation after cardiac surgery by multiple frequency segmental BIA. DESIGN: Observational, clinical study. SETTING: A 17-bed, surgical intensive care unit in a university hospital. PATIENTS: Twenty-six patients before and after open-heart surgery with cardiopulmonary bypass. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After surgery, fluid accumulation resulted in a decrease in whole-body and segmental bioelectrical impedance in the arm and in the trunk. There was a good correlation between the fluid accumulation measured by fluid balance and by whole-body or segmental impedance changes. The major part (71%) of fluid accumulation occurred in the trunk. Multiple frequency measurements did not indicate a fluid shift between the intra- and extracellular compartments. CONCLUSION: Cardiac surgery produced a significant decrease in segmental trunk BIA, reflecting fluid accumulation at the trunk level.

Aged↗

[Cerebral hemodynamics and intracranial hypertension].

Various cerebral aggressions, either primary or secondary, can lead to the development of raised intracranial pressure. The presence of an elevated intracranial pressure often results in cerebral ischaemia/hypoxia and, eventually, neuronal death. In face of this cascade of events, several therapeutic approaches have been suggested. Two management concepts for patients with raised intracranial pressure have retained the most attention in recent years: the first suggests a therapeutic increase in cerebral perfusion pressure with the objectives to improve perilesional collateral perfusion and decreased cerebral blood volume, and consequently intracranial pressure in areas where autoregulation is preserved. The second concept supports the diminution in perilesional capillary pressure with the aim of decreasing vasogenic oedema. Although these two concepts are antagonistic and cannot be used simultaneously, they are probably complementary in the sequence of therapeutic events of patients experiencing severe head injury. This article reviews these therapeutic concepts and their clinical applications.

Anesthetics, Intravenous↗

Changes in sleeping and basal energy expenditure and substrate oxidation induced by short term thyroxin administration in man.

The present study was designed to explore the thermogenic effect of thyroid hormone administration and the resulting changes in nitrogen homeostasis. Normal male volunteers (n = 7) received thyroxin during 6 weeks. The first 3-week period served to suppress endogenous thyroid secretion (180 micrograms T4/day). This dose was doubled for the next 3 weeks. Sleeping energy expenditure (respiratory chamber) and BMR (hood) were measured by indirect calorimetry, under standardized conditions. Sleeping heart rate was continuously recorded and urine was collected during this 12-hour period to assess nitrogen excretion. The changes in energy expenditure, heart rate and nitrogen balance were then related to the excess thyroxin administered. After 3 weeks of treatment, serum TSH level fell to 0.15 mU/L, indicating an almost complete inhibition of the pituitary-thyroid axis. During this phase of treatment there was an increase in sleeping EE and sleeping heart rate, which increased further by doubling the T4 dose (delta EE: +8.5 +/- 2.3%, delta heart rate +16.1 +/- 2.2%). The T4 dose, which is currently used as a substitutive dose, lead to a borderline hyperthyroid state, with an increase in EE and heart rate. Exogenous T4 administration provoked a significant increase in urinary nitrogen excretion averaging 40%. It is concluded that T4 provokes an important stimulation of EE, which is mostly mediated by an excess protein oxidation.

Adult↗

Segmental body composition assessed by bioelectrical impedance analysis and DEXA in humans.

The present study assessed the relative contribution of each body segment to whole body fat-free mass (FFM) and impedance and explored the use of segmental bioelectrical impedance analysis to estimate segmental tissue composition. Multiple frequencies of whole body and segmental impedances were measured in 51 normal and overweight women. Segmental tissue composition was independently assessed by dual-energy X-ray absorptiometry. The sum of the segmental impedance values corresponded to the whole body value (100.5 +/- 1.9% at 50 kHz). The arms and legs contributed to 47.6 and 43.0%, respectively, of whole body impedance at 50 kHz, whereas they represented only 10.6 and 34.8% of total FFM, as determined by dual-energy X-ray absorptiometry. The trunk averaged 10.0% of total impedance but represented 48.2% of FFM. For each segment, there was an excellent correlation between the specific impedance index (length2/impedance) and FFM (r = 0.55, 0.62, and 0.64 for arm, trunk, and leg, respectively). The specific resistivity was in a similar range for the limbs (159 +/- 23 cm for the arm and 193 +/- 39 cm for the leg at 50 kHz) but was higher for the trunk (457 +/- 71 cm). This study shows the potential interest of segmental body composition by bioelectrical impedance analysis and provides specific segmental body composition equations for use in normal and overweight women.

Absorptiometry, Photon↗