Autologous blood donation with recombinant human erythropoietin in cardiac surgery: the Japanese experience.

Four units of predonated autologous blood (AB) is considered sufficient to cover the blood requirements of 95% of patients undergoing elective cardiac surgery, thus avoiding the risks associated with allogeneic blood transfusion. A review of six Japanese studies was undertaken to summarize the potential for recombinant human erythropoietin (rHuEPO) to facilitate donation of AB by patients scheduled for cardiac surgery. Intravenous (i.v.) administration of rHuEPO improved the anemia associated with AB donation, an effect that was further enhanced by i.v. iron supplementation. Once weekly subcutaneous (s.c.) administration of rHuEPO facilitated the donation of AB and reduced allogeneic blood requirements in patients scheduled for cardiac surgery, suggesting that rHuEPO could be administered on an outpatient basis. rHuEPO was of particular benefit in anemic patients, eliminating exposure to allogeneic blood in the majority of patients. In conclusion, rHuEPO facilitates the donation of AB and reduces allogeneic blood requirements of patients scheduled for cardiac surgery.

A study of platelet functions with a new analyzer using high shear stress (PFA 100) in patients undergoing coronary artery bypass graft.

Platelet dysfunction can be a major factor in excessive bleeding following cardiopulmonary bypass (CBP). A rapid, specific and sensitive method to identify platelet dysfunction would be a useful tool for identifying patients at an increased risk of bleeding. The ability of PFA100, an in vitro bleeding test, to predict increased bleeding risk linked to platelet dysfunction was tested in 146 patients undergoing primary coronary artery bypass graft. Blood samples were taken the day before surgery, and 15 min and 5 h after heparin neutralization. The preoperative closure times (CT), i.e. the time required for platelets in citrated whole blood to occlude an aperture cut into a membrane coated with collagen plus either epinephrine (CTEPI) or adenosine diphosphate (CTADP) were longer in blood-group-O patients than in patients with other groups. The 15 min postoperative values were significantly longer from preoperative values essentially owing to CBP-induced hemodilution. Interestingly, 5 h after CBP, a significant reduction in CT values probably reflected platelet hyperaggregability. No correlation was found between calculated blood loss (CBL) and either preoperative or postoperative PFA values.

Influence of caloric intake on the respiratory mode during mandatory minute volume ventilation.

Mandatory minute volume ventilation has been proposed as a method for weaning patients from ventilators. The purpose of this study was to delineate the influence of caloric intake on spontaneous ventilation in patients receiving mandatory minute volume ventilation. While the value of such ventilation remained unchanged, eight patients were studied at the following three different levels of daily caloric intake: (1) level A, mean of 223 kcal/sq m; (2) level B, mean of 1,380 kcal/sq m; and (3) level C, mean of 2,100 kcal/sq m. We performed gas exchange measurements and a 24-hour recording of ventilation with a monitoring system providing distinction between spontaneous and mechanical cycles. We found that the ventilatory mode was markedly dependent upon the nutritional intake; the percentage of spontaneous ventilation over 24 hours increased from 11 +/- 7 percent (+/- SE) during diet A to 50 +/- 9 percent during diet B and 79 +/- 8 percent during diet C. This increment paralleled the increase in production of carbon dioxide with caloric intake. We suggest therefore that the patient's ability to breathe spontaneously when receiving mandatory minute volume ventilation should be interpreted according to caloric intake.

An international view of hydroxyethyl starches.

Hydroxyethyl starch (HES) is one of the most frequently used plasma substitutes. A variety of different HES solutions exist worldwide, which differ greatly in their pharmacological properties. HES is classified according to its manufactured or in vitro molecular weight (MW) into high MW (450-480 kDa), medium MW (200 kDa), and low MW (70 kDa) starch preparations. However, this is not sufficient, because as HES is metabolized in vivo, its MW changes, and it is the in vivo MW which is responsible for the therapeutic and adverse effects of each HES. The rate of metabolization depends mainly on the degree of hydroxyethyl substitution (ranging from 0.4 to 0.7), and the C2/C6 ratio of hydroxyethylation. A high degree of substitution and a high C2/C6 ratio lead to a slow metabolization of HES, resulting in a large in vivo MW. Slowly degradable high MW HES 450/0.7 and medium MW HES 200/0.62 have a high in vivo MW and are eliminated slowly via the kidneys. As a result, these starches have a relatively long-lasting volume effect. When infusing higher volumes (>1500 ml) are infused, large molecules accumulate in the plasma. This can result in bleeding complications due to decreased factor VIII/von Willebrand factor, platelet function defects, incorporation into fibrin clots, and an unfavorable effect on rheological parameters. Rapidly degradable medium MW HES 200/0.5 or low MW HES 70/0.5 are quickly split in vivo into smaller, more favorable molecule sizes, resulting in faster renal elimination, shorter volume effect, and fewer adverse effects on coagulation and rheological parameters. For historical and marketing reasons, only slowly degradable, high MW HES (480/0.7) is available in the United States. In Europe, a large variety of HES solutions are available, dominated by medium MW, easily degradable HES (200/0.5). Because of increasing international competition and the availability of newly developed starches, it is important to be aware of the pharmacological properties of HES and the advantages and disadvantages of the individual preparations.

Mechanisms of postoperative prolonged plasma volume expansion with low molecular weight hydroxethy starch (HES 200/0.62, 6%).

OBJECTIVE: To define the mechanisms of the stable and prolonged post-operative plasma volume expansion observed with Hydroxyethyl Starches (HES) and to determine whether a partial intravascular hydrolysis of large molecules contribute to reinforce the colloid-osmotic effect. DESIGN: Prospective, pharmacologic study using single dose of drug. SETTING: University-based, post-anesthesia care unit. PATIENTS: The protocol was performed during the post-operative period, in 10 patients after stable recovery from general anesthesia for carotid endarterectomy. INTERVENTIONS: HES 200/0.62 (500 ml) was infused over 30 min. Standard hemodynamic and biological variables, HES concentration and colloid osmotic pressure were obtained at each measurement. Plasma volume was calculated using 51Cr-labelled RBCs. Patterns of changes in number average molecular weight (MWn) and weight average MW (MWw) were measured using gel permeation chromatography. Measurements were obtained at control, end of infusion, 1 h, 3 h, 6 h and 24 h after infusion. MEASUREMENTS AND MAIN RESULTS: Plasma volume increased by 693 ml (+21%) after the infusion of HES and remained constant over 24 h. HES concentration progressively decreased to reach a value of 35% of the peak at 24 h. MWn and MWw, initially decreased when compared with the dose solution and changed little in the 24 h study period. Diuresis significantly decreased at 3 h up to 24 h. Plasma albumin decreased after infusion and then progressively increased to reach a significantly higher value at 24 h than after infusion. CONCLUSION: Initial plasma volume expansion and decrease in HES concentration agree with previously-published data. Maintenance of plasma volume expansion over 24 h was not related to a partial intravascular hydrolysis. Low elimination rate of HES, extravascular mobilization of albumin and post-operative renal adaptations were possibly the 3 main mechanisms to explain a prolonged plasma volume expansion with HES 200/0.62, 6%.

Low molecular weight hydroxyethyl starch 6% compared to albumin 4% during intentional hemodilution.

Intentional normovolemic hemodilution was chosen as the model to compare a 6% low molecular weight hydroxyethyl starch (LMW HES) to 4% albumin. The study ran over the plasma exchange period for 24 h. Nine patients, scheduled for abdominal aortic surgery, were included in each group. After basal measurements, blood was withdrawn and simultaneously replaced by either 4% albumin (Group 1) or 6% LMW HES (Group 2) to achieve a final hematocrit of approximately 30%. Hemodynamic blood oxygen gas and hormonal plasma levels were determined before hemodilution then at 30 min, 1, 2, 3, and 24 h after the end of hemodilution. Basal value for total blood volume was 4377 +/- 162 ml in group 1 and 4138 +/- 315 ml in group 2. As in both groups the decrease in blood cell volume was exactly compensated by the increase in plasma volume, no significant change in total blood volume (respectively 4432 +/- 159 and 4305 +/- 267 ml) was observed. Throughout the study, in both groups, no significant change in mean arterial and right atrial pressures was observed. In group 2 (LMW HES), a significant increase of pulmonary capillary wedge pressure was noted 120 min after hemodilution. After hemodilution, despite a significant decrease in arterial oxygen O2 content, systemic oxygen transport did not significantly vary until 24 h in relation to the increased cardiac index. An increase in O2 extraction was observed after the exchange but no further increase was observed until the 24 h. No significant changes either in global O2 consumption or in lactate concentration were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of high-frequency jet ventilation on arterial baroreflex regulation of heart rate.

Fifteen anesthetized mechanically ventilated patients recovering from multiple trauma were studied to compare the effects of high-frequency jet ventilation (HFJV) and continuous positive-pressure ventilation (CPPV) on arterial baroreflex regulation of heart rate. Systolic arterial pressure and right atrial pressure were measured using indwelling catheters. Electrocardiogram (ECG) and mean airway pressure were continuously monitored. Lung volumes were measured using two linear differential transformers mounted on thoracic and abdominal belts. Baroreflex testing was performed by sequential intravenous bolus injections of phenylephrine (200 micrograms) and nitroglycerin (200 micrograms) to raise or lower systolic arterial pressure by 20-30 Torr. Baroreflex regulation of heart rate was expressed as the slope of the regression line between R-R interval of the ECG and systolic arterial pressure. In each mode of ventilation the ventilatory settings were chosen to control mean airway pressure and arterial PCO2 (PaCO2). In HFJV a tidal volume of 159 +/- 61 ml was administered at a frequency of 320 +/- 104 breaths/min, whereas in CPPV a tidal volume of 702 +/- 201 ml was administered at a frequency of 13 +/- 2 breaths/min. Control values of systolic arterial pressure, R-R interval, mean pulmonary volume above apneic functional residual capacity, end-expiratory pulmonary volume, right atrial pressure, mean airway pressure, PaCO2, pH, PaO2, and temperature before injection of phenylephrine or nitroglycerin were comparable in HFJV and CPPV. Baroreflex regulation of heart rate after nitroglycerin injection was significantly higher in HFJV (4.1 +/- 2.8 ms/Torr) than in CPPV (1.96 +/- 1.23 ms/Torr).(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence of myocardial ischemia during carotid endarterectomy.

Since patients undergoing carotid endarterectomy often suffer from coronary artery disease, the detection, adequate treatment and prevention of intra and postoperative myocardial ischemia are a major concern. Effectively, the deleterious effects of intraoperative ischemic episodes have been largely documented. They may lead to arrhythmia, left ventricular dysfunction lasting several hours or myocardial infarction. Anesthesia induced by fentanyl, flunitrazepam and pancuronium and maintained with N20 and volatile anesthetics when warranted, has the advantage of preventing cardiovascular stimulation during endotracheal intubation and surgery, and of significantly decreasing the incidence of intraoperative myocardial ischemia in patients suffering from mild angina pectoris. However, with this approach, the incidence of intraoperative ischemic episodes remains high in patients suffering from disabling angina pectoris. In such cases, prophylactic i.v. nitroglycerin, administered continuously at the dose of 0.7 microgram/kg-1/min-1, optimizes myocardial oxygenation during surgery and minimizes the risk of intraoperative myocardial ischemia.

[Postoperative cardiac insufficiency. The value of enoximone]. / Insuffisance cardiaque postopératoire. Intérêt de l'énoximone.

The authors discuss the physiopathological mechanisms of intra and postoperative cardiac failure and the different means of treatment. A distinction is made between the intra and postoperative periods: the factors which predispose to cardiac failure are different and the immediate postoperative period would seem to be the most dangerous in patients with reduced coronary or contractile reserves. Enoximone is a valuable and effective inotropic agent in this situation.

[Pre- and intraoperative management of heparin cross hypersensitivity. Apropos of a case]. / Prise en charge pré- et peropératoire d'une allergie croisée à l'héparine. A propos d'un cas.

A patient with a Starr prosthetic heart valve for 13 years developed chronic idiopathic thrombocytopaenic purpura and a highly probable crossed allergy to heparin. As the valve needed to be replaced, cardiopulmonary bypass surgery was undertaken associating heparin with lioprost and Aprotinine. In this type of situation, aggregation of control platelets by the patient's plasma in the presence of unfractionated heparin and of low molecular weight heparin justifies the use of powerful antiplatelet agents such as lioprost which was associated with Aprotinine for its platelet protective effects. This original combination allowed successful cardiopulmonary bypass surgery under unfractionated heparin under excellent conditions with minimal blood loss. This case underlines the value of this approach for cardiopulmonary bypass surgery in patients with heparin-induced thrombocytopaenia.

[Mid-term results of cardiomyoplasty]. / Résultats à moyen terme de la cardiomyoplastie.

Cardiomyoplasty (CMP) is a technique of circulatory assistance using a pediculated latissimus dorsi muscle wrapped around the heart and electrically stimulated during systole. Sixty-four patients, aged 15 to 69 years (average 50.8 +/- 13 years) with cardiac failure underwent CMP between January 1985 and July 1993. The causes of cardiac failure were : ischaemic heart disease (39 cases), dilated cardiomyopathy (18 cases), cardiomyopathy following valvular heart disease (2 cases), cardiac tumours (4 cases) and congenital heart disease (1 case). Twenty-four patients underwent an associated surgical procedure. Intra and postoperative intra-aortic balloon pumping was required in 27 cases. Hospital mortality (before latissimus dorsi stimulation) was 20.3% (13/64 cases). Evaluation of the survivors 12 months after surgery showed an improvement in functional class (1.,5 versus 3.3 before CMP ; p < 0.05), in isotopic ejection fraction (27 +/- 3% versus 17 +/- 6%, p < 0.05) and cardiac index (2.87 +/- 0.63 l/min/m2 versus 2.38 +/- 0.41 l/min/m2, p < 0.05). There was no significant change in cardiac filling pressures. The number of hospital admissions for congestive cardiac failure in operated patients was 0.4 per patient per year, compared with 2.5 per patient per year (p < 0.05) before CMP. The preoperative predictive factors for late mortality were: permanent functional Class IV (NYHA), severe cardiac dilatation (cardio-thoracic ratio greater than 0.60; left ventricular end diastolic dimension > 75 mm), an isotopic left ventricular ejection fraction < 15%, severe biventricular cardiac failure and irreversible pulmonary hypertension. The actuarial 4 year survival rate was 68.3%.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pharmacology of low molecular weight hydroxyethyl starch]. / Pharmacologie des hydroxyéthylamidons de bas poids moléculaire.

In the last ten years, the practice of plasma volume expansion has changed significantly. Most clinicians have put a stop to the use of fresh frozen plasma because of growing concerns about hepatitis and AIDS transmission. Today, natural and synthetic colloids and crystalloids are used to a great extent. Although clinical practice varies from one institution to another, the most widely observed change was a major increase in the administration of human serum albumin (HSA). As a result, the cost of plasma volume expansion became so high that it justified finding safe and cheaper alternatives to HSA. Low molecular weight, hydroxyethylstarch (HES) are the synthetic colloids which are closest to HSA. HES are modified natural polymers whose physico-chemical properties are defined by their molecular weight and molar substitution ratio. Average molecular weights of these poly-dispersed solutions are approximately 200 to 250 kd (in weight) and 60 kd (in number). Hydroxyethylation, which slows down hydrolysis by alpha-amylase, is best quantified by the molar substitution ratio between the proportions of hydroxyethyl-ether and glucose. HES have pharmacokinetic properties which are independent of molecular weight and directly related to the molar substitution ratio. The two HES available in France are Elohes and Lomol, Elohes, at a concentration of 6%, has a colloid-osmotic effect close to that of plasma. It induces an initial plasma volume expansion greater than that of the infused volume, and has a long lasting effect (24 h) related to its molar substitution ratio (0.62). Lomol, at a concentration of 10%, is hyperoncotic.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hydroxethyl starch: effects on hemostasis]. / Hydroxyéthylamidons: effets sur l'hémostase.

HES are high-polymeric glucose compounds obtained via hydrolysis and subsequent hydroxyethylation from the highly-branched amylopectin contained in maize. Initially, the HES were only characterized by their in vitro molecular weight (Mw), without consideration of the in vivo hydrolysis by alpha-amylase. The degree of substitution and the molar substitution ratio quantify the hydroxyethylation. The glucose units can be substituted at carbon 2, 3 and 6 leading to various substitution patterns. This pattern is described with the C2/C6 hydroxyethylation ratio. The higher the degree of substitution and the C2/C6 ratio, the less the starch is metabolized. The in vitro Mw, the degree of substitution and the C2/C6 ratio are the main determinants of the in vivo Mw which is clinically relevant. Haemorrhagic complications that occur after infusing larger volumes of HES can be avoided with a starch of low in vivo Mw. This is not only due to a lesser effect on the coagulation system which prevents an acquired type I von Willebrand syndrome, but also to a smaller decrease in platelet volume, since platelet volume and platelet function are positively correlated. In addition, HES with low in vivo Mw has significantly better rheological effects than HES with a high in vivo Mw, as high Mw macromolecules affect plasma viscosity negatively. Furthermore high Mw HES macromolecules lead to a distinctive decrease in fibronectin concentration that reflects saturation of the reticuloendothelial system. Another advantage of low in vivo Mw HES is its rather short half-life. Patients with an increased bleeding risk, microcirculatory disturbance or affected RES should receive HES with low in vivo Mw. In the future, HES should be mainly characterized by the in vivo and not the in vitro Mw.

[Threshold values of colloid-osmotic pressure, serum albumin or protein during perioperative period]. / Valeur seuil de pression colloïdo-osmotique, d'albuminémie ou de protidémie pendant la période périopératoire.

The water flux across the capillary membrane is directly related to a gradient of hydrostatic and colloid osmotic forces. The membrane is not an absolute barrier to proteins. Any change in the capillary permeability tends to decrease the plasmatic colloid osmotic pressure. The interstitial space includes a perimicrovascular space and a compliant connective tissue space, where oedema accumulates. The lymphatics may easily drain excess filtration, but cannot clear constituted oedema. Primarily, the risk of pulmonary oedema determines the lower limit of the colloid osmotic pressure. During the perioperative period, any extrapolation of the colloid, osmotic pressure from protidaemia or albuminaemia would be approximate. Two major conclusions can be drawn from the results of Guyton and Lindsey. First, in the absence of left ventricular failure, a 50% decrease in colloid osmotic pressure does not increase extravascular lung water. Second, in the case of left ventricular failure, when the left atrial pressure exceeds 10 mmHg, a 50% decrease in colloid osmotic pressure significantly increases the risk of pulmonary oedema. In these experiments, an impairment in capillary membrane permeability is likely. As a result, the threshold at which extravascular water starts to accumulate cannot be precisely defined. However, in the perioperative period, capillary membrane permeability is frequently altered by the acute phase reaction. Finally, in most perioperative clinical situations, a 50% decrease in colloid osmotic pressure may not require any treatment.

[Ischemia, myocardial infarction and epidural anesthesia in patients with coronary disease]. / Ischémie, infarctus myocardique et anesthésie péridurale chez le coronarien.

In patients with coronary artery disease, the beneficial effects of epidural anesthesia are well known and often emphasized. Thus, several studies have shown a decrease in the determinants of myocardial oxygen consumption, and an improvement in regional and global left ventricular performance. The disadvantages of epidural anesthesia in patients with coronary artery disease are also well known, however, rarely reported. These detrimental effects are dominated by a decrease in arterial pressure which in turn may compromise the coronary perfusion pressure and induce myocardial ischemia. These 2 case reports illustrate the occurrence of myocardial complications in relation to epidural anesthesia. These case reports contrast with data from the literature showing a beneficial influence of epidural anesthesia on the myocardium. However, the severity of the coronary artery disease in these 2 reported patients may explain this discrepancy. These case reports pointed out that the decrease in arterial pressure is not the exclusive mechanism by which myocardial ischemia may be observed during epidural anesthesia since an hemodynamically-unrelated ischemic episode is described. The treatment of myocardial ischemia during epidural anesthesia is illustrated by these 2 case reports. A relationship between myocardial ischemia and myocardial infarction is discussed from these observations.

[Hyperchloremic acidosis druing plasma volume replacement]. / Acidose hyperchlorémique lors du remplissage vasculaire.

OBJECTIVES: Review of the physiological and clinical consequences of hyperchloraemic acidosis observed during plasma volume replacement using crystalloids and colloids. DATA SOURCES: Data were searched in the Medline database after 1990 using the following key words: metabolic acidosis, crystalloids, colloids, albumin, gelatin, hydroxyethyl starch. DATA EXTRACTION: Publications before 1990 were selected for their historical value. Most of articles published after 1990 and all types including case report were accepted. DATA SYNTHESIS: Large volume infusion of isotonic solution can cause hyperchloraemic acidosis. Colloid plasma substitutes using saline solvent may be responsible for the same kind of acidosis with acidaemia. The anion gap is not modified in this case because of chloride increase. Physiological mechanism may be described using the Henderson-Hasselbach equation or the strong ion difference decrease (Stewart concept). Excessive chloride infusion is a major factor in this acid-base disorder and the term hyperchloraemic acidosis should be preferred to dilutional acidosis. When perioperative acidosis occurs, careful and complete analysis of acid-base disturbance should be made. The association of a normal anion gap, normal lactatemia, hyperchloraemia and acidaemia does not need specific treatment. Acidosis corrects spontaneously and slowly following chloride normalization. But any factor that may increase acidosis should be avoided. CONCLUSION: The use of balanced solution like lactated-Ringer solution instead of isotonic saline solution for fluid resuscitation, except for specific contra-indication as intracranial hypertension, may avoid hyperchloraemic acidosis. Potential risk of this acidosis led to the conception of a new colloid using balanced crystalloids solution as the solvent (Hextend).

[Value of thallium-dipyridamole myocardial scintigraphy in coronary patients in non cardiac surgery]. / Intérêt de la scintigraphie myocardique au thallium-dipyridamole chez le coronarien en chirurgie non cardiaque.

Cardiac assessment is of particular importance in patients with documented or suspected coronary artery disease (CAD) as well as in all those patients undergoing vascular surgery. Use of dipyridamole thallium scintigraphy (DTS) in this population could help to detect significant coronary artery narrowing, together with the location and quantification of the areas of myocardium in jeopardy. Such information might lead to changing the surgical procedure, or to starting other treatment, such as coronary angioplasty or bypass graft surgery, thereby diminishing the morbidity and mortality associated with surgery in these high-risk patients. The ability of DTS to predict acute postoperative ischaemic events has been suggested by several studies. Various shortcomings of DTS used as a preoperative screening test have been pointed out in some recent papers. Therefore it is concluded that: 1) DTS should not be used as a routine preoperative test in vascular surgical patients. DTS is not accurate enough when used in patients without any clinical findings suggestive of CAD, 2) DTS may prove more useful in stratifying patients with an intermediate probability of developing cardiac complications. In such patients, the test will not provide a linear "all or nothing" result, but, when taken together with the clinical findings and the nature of the surgical procedure, a complex stratification, 3) Because of progress in the perioperative management of high-risk patients, positive findings on preoperative DTS may not correlate perfectly with perioperative cardiac events, 4) As several factors influence thallium uptake after dipyridamole, DTS does not have a perfect specificity, thus leading to order an excessive number of coronary angiographies. Some patients will be seen as having a false-positive DTS, 5) Preoperative screening DTS leads to cardiac catheterization and hence to revascularisation, independently of symtomatology. Further studies must be undertaken to determine whether this approach will improve short and long term patient survival.

[Contamination of an oxygen delivery circuit by compressed air]. / Contamination d'un circuit d'oxygène par de l'air comprimé.

Routine checking of the FIO2 of a mixture delivered by a ventilator revealed large discrepancies between the FIO2 assigned and that effectively delivered, the latter being low. Measurements of FIO2 at the wall outlets showed the O2 delivery pipeline to be contaminated by compressed air. By disconnecting all the ventilators supplied by this pipeline one after the other, one ventilator, or rather its blender, was found responsible.

[Effects of platelet-rich plasma on hemostasis and transfusion requirement in vascular surgery]. / Effets du plasma riche en plaquettes sur l'hémostase et le besoin transfusionnel en chirurgie vasculaire.

OBJECTIVE: To assess the effect of intraoperative autologous platelet-rich plasma (PRP) transfusion on haemostasis, blood loss and blood requirements during vascular surgery. STUDY DESIGN: Randomized clinical trial. PATIENTS: Twenty patients undergoing elective abdominal infrarenal aortic aneurysmectomy, using autologous transfusion techniques (predonation programme and/or preoperative normovolaemic haemodilution and/or intraoperative use of a cell-saver), were randomly allocated either into the PRP group (n = 10) or the Control group (n = 10). METHOD: In patients of PRP group, 10 mL.kg-1 of PRP were obtained over 40 to 50 min, prior to induction of anaesthesia, and compensated simultaneously with an equivalent amount of hydroxyethyl starch. Each PRP unit was transfused to its donor after aortic declamping. Blood samples were obtained before induction, before incision, at wound closing and at the end of PRP unit transfusion for determination of biological variables. RESULTS: The PRP units transfused in the patients of PRP group contained 755 +/- 117 mL of plasma with a platelet count of 62 +/- 31 G.L-1. The intra and postoperative blood losses were similar in both groups (1622 +/- 758 and 233 +/- 322 mL respectively in PRP group vs 1890 +/- 1331 and 291 +/- 303 mL respectively in Control group). In both groups, three patients required an additional transfusion of homologous blood. The results of biological tests (haematocrit, platelet and white cell counts, prothrombin time, aPTT, thrombin time, fibrinogen, D-dimers, proteins, calcium) were also similar between groups at the various times of sampling. The reinfusion of the PRP unit did not increase the platelet count. CONCLUSIONS: This study demonstrates that intraoperative infusion of autologous PRP does not decrease blood loss and homologous transfusion requirements in patients undergoing elective abdominal infrarenal aortic aneurysmectomy. This result can be related to the relatively moderate enrichment in platelets obtained with the centrifugation speed used in this study.

[Dynamic left intraventricular obstruction after reconstructive mitral valve surgery]. / Obstruction dynamique intraventriculaire gauche après chirurgie réparatrice valvulaire mitrale.

A 71-years-old patient, undergoing mitral valve repair for degenerative valvulopathy and correction of pectus excavatus experienced a cardiogenic shock after weaning from cardiopulmonary bypass. The shock occurred after calcium chloride administration and was unresponsive to inotropic drugs. Transoesophageal echocardiography showed left ventricular outflow tract obstruction due to systolic anterior motion (SAM) of the mitral valve. Discontinuation of inotropic drugs and volume expansion restored the haemodynamic status. By its haemodynamic effects calcium chloride can cause left ventricular outflow tract obstruction, recognized by transoesophageal echocardiography.