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A Larcan

Publications and source records attributed to A Larcan.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Hemorheology in clinical practice. Introduction to the notion of hemorheologic profile].

Although the non-Newtonian characteristics of blood have now been accurately defined, the influence and effect of a hyperviscosity syndrome at the onset of ischemia and in oxygen transport to the tissues remains within the realm of assumptions. Using a simple theoretical approach it can be shown that oxygen transport capacity to the tissues is proportional to the radio H/eta s (where H = hematocrit, eta s = blood viscosity), as long as vascular bed geometry remains constant (with no sign of compensatory vasodilation). With the help of examples, the authors show the changes in oxygen transport as a function of various rheological parameters (red cell aggregation ans deformability). Further, the authors introduce the concept of a hemorheological profile for taking all the hemorheological parameters into consideration and for standardising the presentation of the results for hyperviscosity syndromes.

Blood Viscosity↗
PubMed1990

Effects of epinephrine on hemodynamics and oxygen metabolism in dopamine-resistant septic shock.

The hemodynamic effects of epinephrine were prospectively studied in 13 patients with septic shock who remained hypotensive after both fluid loading and dopamine. Hemodynamic measurements were performed before and one hour after the start of epinephrine infusion. Systolic, diastolic, and mean arterial pressure increased in all patients (p less than 0.01). Cardiac index and systemic vascular resistance increased by 34 and 32 percent, respectively (p less than 0.05), but heart rate and pulmonary vascular resistance remained unchanged. There was a concomitant increase in oxygen delivery (p less than 0.01) and oxygen consumption (p less than 0.05), the magnitude of the latter being related to baseline lactacidemia (p less than 0.01). In view of the generally recognized physiologic goals of septic shock management, we conclude that epinephrine could be an appropriate alternative where fluid loading and dopamine have failed.

Adolescent↗
PubMed1990

[Not Available].

Explore the source record for details and available documents.

France↗
PubMed1990

[Polytraumatized patient. First aid care, transport and resuscitation].

The initial management of multiple trauma must achieve a triple aim: performing the actions required by a vital emergency, preventing as well as possible the complications associated with the initial lesions, and, most importantly, bringing the injured person into hospital in the best possible conditions for emergency surgery. Achieving these aims requires a perfect coordination of medical and nonmedical rescue. A rough initial categorization is important to decide whether additional medical staff is desirable, choose the type of transport planned (by ambulance, helicopter...) as well as the department or hospital due to receive the patient. Four actions must be accomplished, most often jointly, all of them contributing to the quality of treatment: 1. picking up/freeing/immobilizing the injured person, 2. controlling the hypovolemic collapse and the traumatic shock, 3. dealing with the associated distresses, 4. suppressing pain. The techniques used to pick up, free and immobilize the injured person require a close co-operation with the rescuing staff (stretcher bearers, fire department, first-aid workers). The hypovolemic shock is treated by volume replacement, mainly with colloids. Local hemostasis may sometimes be necessary. Anti-shock trousers should be widely used in cases of multiple trauma. Dealing with the associated distresses gives priority to ventilation. The indications of ventilatory support must be very wide whenever coma or signs of respiratory distress are noted, more so with an associated shock. The indications of aspiration of a gaseous or fluid pleural effusion must also be discussed. Maximal suppression of pain must be kept in mind throughout all these operations.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesia↗
PubMed1989

[Clinical examination of the comatose patient].

The clinical examination of a comatose patient may be divided into neurological ang general. The neurological examination aims at determining all that is proper to the state of coma, its complication, whatever they origin (mostly cerebral oedema and herniation) and its focal signs. As for the coma itself, one may distinguish between disorders of consciousness or perceptivity and disorders of wakefulness. Specific reactivity and reactivity to pain. This must be combined with a study of muscle tone (reactions in flexion and extension, reflexes). Reflexes of the brain stem, nowadays better known, provide for a better assessment of severity and a better evaluation of tiered suffering. Vegetative symptoms, including respiration, cardiovascular system, temperature, trophicity, sphincteral function, must be studies in all comas. The classification of comas into stages of severety and the relevant scores (Glasgow, Liège) must be known with their advantages and limitations. The general clinical evaluation, including past history and associated signs, may suggest an aetiological diagnosis and point to the necessary paraclinical explorations.

Coma↗
PubMed1989

[Treatment of severe hyponatremia by restricted water intake].

The outcomes of 23 patients admitted to a medical intensive care unit for severe hyponatraemia (less than 120 mEq/l) associated with neurological disorders were reviewed. All patients had restricted water intake combined with a sodium intake adjusted to the natriuresis, and some received a loop diuretic. The mean correction rate during the first 48 hours was slow (greater than 12 mmol/l.24 h) in 16 cases and fast (less than or equal to 12 mmol/l.24 h) in 7 cases. Following biochemical cure, 2 patients in the fast correction group had an unfavourable outcome: one died for an unknown reason, the other developed pontine myelinosis. A review of the literature did not provide evidence that a certain rate of correction was better than the other, but it showed that an excessive rise in natraemia or an overcorrection of hyponatraemia was dangerous. Slow correction of hyponatraemia, usually obtained with water intake restriction, may be recommended.

Adult↗
PubMed1989

Phosphorus nuclear magnetic resonance evidence of abnormal skeletal muscle metabolism in chronic alcoholics.

Pathophysiologic events leading to rhabdomyolysis in alcoholics are not clearly understood. We examined 18 alcoholic patients (10 with and 8 without a recent history of rhabdomyolysis) and 15 healthy non-alcoholic volunteers by phosphorus nuclear magnetic resonance spectroscopy of thenar eminence muscle. At rest, phosphocreatine, ATP, and pH levels were similar in patients and control subjects. During aerobic exercise, phosphocreatine utilization was greater, pH fell more slowly, and maximum acidosis was less in alcoholics with previous rhabdomyolysis than in control subjects. During ischemic exercise, both patient groups exhibited a significantly slower and smaller decrease in pH than did control subjects. These findings are consistent with impaired muscular glycolysis or glycogenolysis in both alcoholic groups. This metabolic myopathy may contribute to the onset of acute rhabdomyolsis.

Adult↗
PubMed1989

[Thrombectomy or thrombolysis in the treatment of proximal phlebitis. Functional long term results].

MATERIALS AND METHODS Between 1981 and 1985, 78 iliocaval thrombi were treated by aggressive therapy: 52 surgical thrombectomies were performed by a femoral approach associated, depending on the case, with a caval approach; and 26 iliofemoral thrombi were lysed according to a protocol in which urokinase and plasminogen were used over a 48-h period. Subsequent functional evaluation was based on clinical scoring (0 to 9 points) taking into account functional impairment, edema and trophic disorders. Patency of trunks and the deep valvular state were assessed by Doppler examination and plethysmography. RESULTS In the surgical group, 3 early deaths occurred, only one of which could be attributed to an embolic course. Six weeks after surgery the rate of recurrence of iliac thrombosis was 50% (25% postoperative + 25% secondary). Beyond this period, there were no recurrences of thrombosis. There was a direct, statistically significant relation between the degree of iliac patency and the realization of an ideal thrombectomy on a nonadherent fresh clot. The functional results, assessed after four and a half years of follow-up, are satisfactory (score less than 3) in 80% of patients. The poor results with venous claudication or varicose ulcer all occurred in the case of massive persistent thrombi of the femoral confluence. Valve lesions were signaled in 46% of patients by a massive backflow in orthostatism. In the medical group, a major hemorrhagic complication occurred under urokinase therapy in 11% of patients, including one for whom it was fatal. Sixty percent of patients showed immediate radiological improvement allowing partial or total freeing of a venous confluence. The functional results after 4 years of follow-up were nondisabling in 85% of patients. No leg ulcers were detected. Late iliac patency was low (26%), whereas at the femoral level almost all of the thrombi which remained after lysis became patent again spontaneously. Valve failure was found in 37% of patients. Both groups had very similar late functional results despite rather different anatomical conditions. The iliac patency rate was higher in the surgical group (50% vs 26%), but plethysmographic study showed that in case of therapeutic failure devalvulation was greater after surgery (46% vs 37%).

Femoral Vein↗
PubMed1989

[Hemorheology, hemodynamics and microcirculation. 1].

The microcirculation constitutes an ubiquitous vascular network presenting a mesh pattern, and comprising different types of vessels, arterioles, small veins, capillaries, arteriovenous shunts or similar structures, and lymphatics. Many dimensions have to be recognized, or simply mentioned, if one is to understand the hemodynamic and hemorheological particulars of this territory, which differ, in many aspects, from those specific to the macrocirculation (number and length of the vessels, diameter and cross section, intercapillary distance, geometric characteristics, intravascular pressure, pressure gradient, pressure-volume relationship, flow rate, mean velocity of plasma and RBC, velocity profile, local hematocrit, in situ viscosity, kinematic viscosity, wall shearing conditions, local oxygen transport, aggregation and deformability of RBC, leukocyte properties, etc.). The flow rate in capillary tubes and capillary vessels of the living organism varies with many factors, such as proximal hemodynamics, hemorheological characteristics of blood (fibrinogen, macro- and micro-hematocrit), some known effects (Farheus, Farheus Lindqvist), local diameter, the plasma layer which plays the role of the limiting layer, the endothelial film, the wall effect, and so forth. Models of the circulation have been propounded, none of which takes into account the whole of these phenomena due to their great complexity. Hemodynamic and hemorheological interactions provide for a better understanding of certain concepts, such as vascular resistance, hindrance, capacitance, local flow rates, real capillary opening and closing, development of two-directional functional shunts, autoregulation, pressure-volume relationship, critical closing pressure, circulatory current slowing effect, sequelae of intravascular aggregation of formed blood elements.

Hemodynamics↗
PubMed1989

[Rheologic particulars of venous flow. Physiopathologic consequences].

Hemorheological parameters must be taken into account for a better knowledge of venous flow properties. The postcapillary venules are the region of lowest shear rates and therefore the region of highest whole blood viscosity. Red cell aggregation plays a major role in blood viscosity, especially at low shear rate. This microrheological parameter can be increased in pathological circumstances, including a low capillary flow, venular insufficiency, elevated hematocrit, high levels of acute phase proteins. At the level of the capillaries, microcirculatory stasis leads to a low oxygen supply and consequently to poor metabolic state lowering local ATP levels. As a result, both platelet and white blood cell functions are compromised. Hemorheological studies have shown that both deep venous thrombosis and chronic venous insufficiency are associated with high blood viscosity mainly due to an increased red cell aggregation. This hemorheological vicious circle--stasis promoting hyperviscosity leading to further stasis--could be broken up by therapeutic intervention including hemodilution, fibrinolytic drugs or other specific agents.

Blood Circulation↗