Monosegmental liver transplantation from an adult to an infant.

A shortage of small pediatric organ donors has led to the development of reduced size liver transplantation in children. However, the discrepancy between donor and recipient weight can limit the use of this procedure despite transplantation of the left lobe only. Monosegmental liver transplantation using segment III only was recently described. We report here the case of an 11 month old, 6.9 kg boy who received another monosegmental graft (segment II) from a 78 kg donor on an urgent basis. Because of the lack of parenchymal landmarks between segments II and III, sterile methylene blue solution was injected into the portal vein of segment III: parenchyma of this segment colored immediately and was resected accordingly. Three and a half years later, the growth, development, and nutrition of this child were normal. This procedure seems to be helpful when the left lobe of the graft is obviously too large.

Effects of cardiac surgery on renal function in children.

In order to determine whether cardiac surgery with cardiopulmonary bypass (CPB) affects renal function in children, glomerular filtration rate (GFR and renal plasma flow (RPF) were determined preoperatively and on the second postoperative day by a single-injection, urineless technique in a randomly selected group of 10 children. The GFR was 126.7 +/- 6.8 ml. per minute per 1.73 sq. M. (mean +/- S.E.M.) before the operation and 127.4 +/- 16.2 on the second postoperative day (p = 0.95). The RPF was 541.7 +/- 80.6 ml. per minute per 1.73 sq. M. preoperatively and 536.0 +/- 82.1 on the second postoperative day (p = 0.8 to 0.9). The results in this group of 10 children indicate that renal function is not markedly altered 2 days after cardiac surgery with CPB and deep hypothermia with circulatory arrest. The study also revealed a falsely decreased creatinine clearance. This was due to an increase in postoperative plasma creatinine values, probably related to an increase in plasma noncreatinine chromogens.

Chronotropic and inotropic supports are both required to increase cardiac output early after corrective operations for tetralogy of Fallot.

To assess the respective roles of chonotropism, inotropism, and afterload reduction in increasing cardiac index early after corrective operations for tetralogy of Fallot, we measured vascular pressures and cardiac output and evaluated left ventricular dimension changes before and after a 35% rise in heart rate over baseline. This rise was induced by atrial pacing with intact atrioventricular conduction, isoproterenol, or atrial pacing together with dobutamine. With atrial pacing, left ventricular end-diastolic diameter decreased (38.7 +/- 4.3 to 34.2 +/- 5.6 mm, p less than 0.05), the shortening fraction (ratio of the difference between left ventricular end-diastolic and end-systolic diameters to left ventricular end-diastolic diameter) remained constant, and stroke volume index was reduced (28.8 +/- 4.5 to 19.7 +/- 4.6 ml/m2, p less than 0.05). As a result, cardiac index was left unchanged. When dobutamine was added as supplemental inotropic support, left ventricular end-diastolic diameter remained constant, shortening fraction increased (30% +/- 5.4% to 36% +/- 3.3%, p less than 0.05), and cardiac index rose significantly (3.04 +/- 0.61 to 4.18 +/- 0.85 L/min/m2, p less than 0.05). Heart rate acceleration with isoproterenol, combining chronotropism, positive inotropic support, and afterload reduction, slightly increased left ventricular end-diastolic diameter, significantly raised shortening fraction, and markedly enhanced cardiac index (3.03 +/- 0.55 to 4.9 +/- 1.09 L/min/m2). Atrial pacing with intact atrioventricular conduction, as an isolated chronotropic stimulus, is not suited to increase cardiac index early after operations for tetralogy of Fallot unless additional inotropic support is simultaneously provided.

Hemodynamic effect of isoprenaline and dobutamine immediately after correction of tetralogy of Fallot. Relative importance of inotropic and chronotropic action in supporting cardiac output.

In order to compare the effect of isoprenaline and dobutamine immediately after correction of tetralogy of Fallot, 12 randomly selected patients were studied postoperatively. Left ventricular end-diastolic volume, measured preoperatively by means of left ventricular angiograms in eight patients, was decreased to a mean value of 58.6 +/- 5.5 ml/m2 (mean +/- standard error of the mean). Postoperatively, cardiac output was measured by thermodilution before, during, and after infusion of increasing doses of isoprenaline (0.05, 0.1, and 0.2 micrograms/kg/min) and dobutamine (2.5, 5, and 10 micrograms/kg/min) successively given in each patient. Simultaneously, central venous, left atrial, pulmonary arterial, and systemic arterial pressures were recorded. Cardiac index increased significantly in response to all three doses of isoprenaline. Dobutamine produced only a small increase which was not statistically significant. Stroke volume index did not vary significantly with either drug. Consequently, cardiac index was directly related to heart rate. Preload of the left ventricle as well as afterload was significantly reduced (p less than 0.01 and p less than 0.05, respectively) by isoprenaline but not by dobutamine. An increase in left ventricular work index per minute was found with both drugs; however, only with isoprenaline was the increased work accompanied by a significant increase in cardiac index. We conclude that patients with tetralogy of Fallot usually have a small left ventricle which, immediately after correction, reacts to catecholamines by only an insignificant increase in stroke volume index. Consequently, isoprenaline is more effective than dobutamine in raising cardiac index due to the increase in heart rate. Moreover, it decreases systemic vascular resistances and obviates the need for administration of a vasodilator.

Use of Gianturco Z stents in the treatment of vascular compression of the tracheobronchial tree in childhood. A feasible solution when surgery fails.

Severe tracheomalacia secondary to extrinsic vascular compression following a switch operation for transposition is reported. Two attempts at surgical correction failed but successful treatment has been achieved by implantation of two endobronchial Gianturco Z stents. Nonabsorbable stenting in children should be used only in severe obstruction as a last resource, but this technique proved to be feasible in a child weighing 6.2 kg.

Prosthetic heart valve replacement in children. Results and follow-up of 273 patients.

We report the results and long-term follow up in 273 children (aged 2 to 16 years) who underwent prosthetic valve replacement. Mechanical valves (mostly Starr-Edwards) were used in almost all, and in 62 children more than one valve was replaced. Operative mortality was 4.7%. Actuarial survival curves (including hospital mortality) indicate a 86% survival rate at 5 years and 75% at 10 years. For isolated mitral valve prostheses (the largest subgroup), the figures are 87% at 5 years and 82% at 10 and 15 years. The main complication was thromboembolism, which occurred at a linearized rate of 2.7 per 100 patient-years. Actuarial curves indicate that 88% of patients are embolus free at 5 years, and 77% at 10 years. No patient with aortic valve replacement only had an embolism. Five of eight tricuspid prostheses thrombosed. Patients given aspirin and dipyridamole only did not have a higher rate of thromboembolic events than those given warfarin. There were five cases of endocarditis (two fatal) and four of dehiscence. No patient so far has needed replacement of a prosthesis because of somatic growth. Thus valve replacement can be performed with low mortality in children, and with satisfactory long-term survival. Thromboembolism remains a significant problem, although it appears to be less common than in adults. In this study, treatment with antiplatelet drugs only did not carry a higher rate of thromboembolic events than did treatment with warfarin.

Atrial natriuretic factor after heart operations in children. Relation to hemodynamic and renal parameters.

The purpose of this study was to measure changes in serum atrial natriuretic factor concentrations immediately after heart operations in children under baseline conditions and in response to continuous infusion of dopamine (2.5 and 5.0 micrograms/kg/min). During control periods, levels of atrial natriuretic factor were elevated at 190 +/- 24 and 199 +/- 36 pg/ml. The cardiac index was 2.6 L/min/m2 and the renal plasma flow was decreased to 269 +/- 41 ml/min/1.73 m2, indicating a state of renal vasoconstriction (mean renal fraction of cardiac index of 10.0% +/- 1.0%). The mean sodium fractional reabsorption was 99.0% +/- 0.2%. During dopamine infusion, atrial natriuretic factor concentrations increased to 259 +/- 57 pg/ml and to 280 +/- 56 pg/ml, with dopamine 2.5 and 5.0 micrograms/kg/min, respectively (p = not significant), whereas left atrial pressure decreased from 11.7 +/- 0.9 mm Hg during the control period to 10.1 +/- 0.9 and to 9.9 +/- 1.0 mm Hg (p less than 0.05). No correlation was found between changes in left atrial pressure and atrial natriuretic factor levels. Dopamine at 5 micrograms/kg/min increased the cardiac index to 3.0 +/- 0.2 L/min/m2 (p less than 0.001) and the renal plasma flow to 406 +/- 61 ml/min 1.73 m2 (p less than 0.001), alleviating the renal vasoconstriction. The mean urinary sodium excretion increased to 0.33 +/- 0.08 mmol/kg/hr (p less than 0.01). The atrial natriuretic factor plasma concentrations were not related to the urinary sodium excretion, renal plasma flow, or glomerular filtration rate during the control period or during dopamine treatment. These data indicate that after heart operations in children, low urinary sodium excretion occurs despite high circulating atrial natriuretic factor levels. Atrial natriuretic factor concentrations were related neither to left atrial pressures nor to the renal changes induced by dopamine.

Combined high-frequency ventilation in children with severe adult respiratory distress syndrome.

Six children conventionally ventilated for acute pulmonary parenchymal failure developed severe hypoxemia (mean PaO2 48 +/- 7 mmHg at an FiO2 of 0.95 +/- 0.08) persisting for more than 6 h despite a progressive increase in positive end expiratory pressure (PEEP) to 14.7 +/- 1.5 cmH2O. Combined high-frequency jet ventilation (HFJV, mean rate 225 b/min superimposed on small tidal volume conventional ventilation) resulted in a sustained increase in PaO2 to 93 +/- 21 mmHg, p less than 0.05 while peak inspiratory pressure decreased from 47 +/- 8 to 35 +/- 6 cmH2O and positive end expiratory pressure could be reduced to 5.8 +/- 4.5 cmH2O, p less than 0.05 and FiO2 to 0.88 +/- 0.10. This improvement occurred without new barotrauma nor deleterious effects on hemodynamic function or diuresis. After a mean of 62 h of combined function or diuresis. After a mean of 62 h of combined HFJV, persistent improvement in gas exchange allowed us to resume conventional mechanical ventilation at lower airway pressures in 4 children who continued to improve and survived. The 2 other children maintained satisfactory gas exchange on combined HFJV, but ultimately died from multiple organ failure. We conclude that combined HFJV might prove helpful to relieve profound hypoxemia and possibly decrease the risk of barotrauma in children with catastrophic pulmonary failure.

Hemodynamic effects of amrinone in children after cardiac surgery.

The hemodynamic effects of amrinone were assessed in seven children following cardiac surgery. Amrinone was administered as a bolus of 1 mg kg-1 body wt., followed by continuous infusion at 10 micrograms kg-1 min-1 for 1 h and two stepwise increases to 20 and 40 micrograms kg-1 min-1 for 30 min each. Hemodynamic data were obtained and plasma concentrations of amrinone measured 1 h after the bolus dose and immediately before each increment of the infusion rate. Amrinone levels ranged from 0.7 to 2.3 mg l-1. Administration of amrinone lowered systemic vascular resistance from 20.0 +/- 4.3 to 16.5 +/- 4.6 mmHg l-1 min-1 m-2 (p less than 0.05) and reduced mean arterial pressure from 71.7 +/- 9.5 to 62.6 +/- 13.5 mmHg (p less than 0.05) at the highest infusion rate, confirming the known vasodilative effect of the drug. However, these effects did not result in a statistically significant increase in stroke volume (35.0 +/- 7.5 to 35.5 +/- 7.0 ml m-2, NS) or cardiac index (3.10 +/- 0.50 to 3.20 +/- 0.40 l min-1 m-2). One additional patient, in whom a higher loading dose was tried in order to achieve a higher plasma concentration, developed systemic hypotension. A correlation was established between the plasma concentrations of amrinone and the percentage decrease in systemic resistance (r = 0.70, p less than 0.05). These results suggest that in children after open heart surgery, amrinone acts primarily as a systemic vasodilator, with questionable inotropic effect. Accordingly, its use should be restricted to children with severe cardiac failure and documented highly elevated afterload.

Relief of severe pulmonary hypertension after closure of a large ventricular septal defect using low dose inhaled nitric oxide.

A 16-month-old girl developed severe pulmonary hypertension after closure of a large ventricular septal defect. All conventional therapeutic measures failed; an attempt to add nitric oxide at a continuous low dose to the inspired gas allowed resolution of pulmonary hypertension and low cardiac output. This report documents that continuous inhalation of low dose nitric oxide is capable of selective resolution of pulmonary hypertension following cardiac surgery for a large septal defect in a child. This suggests that a transient dysfunction in the release of nitric oxide by the pulmonary endothelial cell is responsible for the vasoconstriction.

The hemodynamic effect of phentolamine and dobutamine after open-heart operations in children: influence of the underlying heart defect.

The hemodynamic effects of phentolamine alone and in combination with dobutamine were studied in the immediate postoperative period in two groups of children. Group 1 (N = 6; mean age, 152 months) had open-heart operation for acquired mitral valve disease. Group 2 (N = 6; mean age, 60 months) had intracardiac repair for tetralogy of Fallot. Before drug administration, cardiac index did not differ between groups, but patients with tetralogy of Fallot had a higher heart rate and smaller stroke volume index; systemic vascular resistance was high in both groups. With phentolamine (10 micrograms/kg/min), cardiac index and stroke volume index increased similarly in both groups (+ 13% for cardiac index in Group 1, +9% in Group 2), while systemic vascular resistance, pulmonary vascular resistance, and pulmonary wedge pressure decreased. When dobutamine (5 micrograms/kg/min) was added, there was a further increase in cardiac index in both groups, but it was greater in Group 1 (+17% vs +12%, p less than 0.01, compared with phentolamine alone; +33% vs +22%, p less than 0.01, compared with control). Systemic vascular resistance remained unchanged and heart rate increased in both groups, so that the left ventricular stroke work index increased. Although stroke volume index increased significantly with dobutamine in Group 1 (+11%, p less than 0.01), it remained unchanged in Group 2 (+3%, not significant). Thus in Group 2, dobutamine increased cardiac index only by increasing heart rate. This suggests that the relatively small, noncompliant left ventricle in patients with tetralogy of Fallot cannot further respond to inotropic drugs by increasing stroke volume index.

[Is the progesterone test a generalizable method of screening for neoplastic and preneoplastic lesions of the endometrium?]. / Le "test à la progestérone" est-il la méthode généralisable de dépistage des lésions néoplasiques et prénéoplasiques de l'endomètre?

A "progesterone test" has recently been proposed as a tentative method to detect early neoplastic and pre-neoplastic lesions of the uterus endometrium. At the time progesterone is stopped, a "deprivation" metrorragia demonstrates a remanent hyperoestrogenism, which represents a well-known risk factor for this type of lesion. The method has been evaluated in private practice; 389 patients were offered the test: 87% accepted. Metrorragias were observed in 28% of the cases; however, no neoplastic nor pre-neoplastic lesions could be detected in this group of patients. Moreover, one patient presented with an advanced endometrial cancer one year after a negative test. The reliability of such a test clearly needs further evaluation.

Pharmacokinetics of pipecuronium in infants, children and adults.

In order to explain the reported shorter clinical duration of action of cumulative ED95 of pipecuronium in infants as compared to children or adults, the pharmacokinetic profiles of pipecuronium were compared in infants (n = 6; mean age 6.8 months; mean weight 7.3 kg) in children (n = 6; mean age 4.6 years; mean weight 19.2 kg) and in adults (n = 7; mean age 42 years; mean weight 58.2 kg). Equipotent doses (2 x ED95) of pipecuronium were injected i.v. as single bolus and arterial blood was sampled for 4-5 h. Pipecuronium was quantified by complex formation with [125I]-labelled rose bengal. Pharmacokinetic parameters were calculated using a two-compartment open model. The median for the distribution half-life of pipecuronium was 2.54 min (interquartile range: 1.0-2.5 min) in infants and 2.04 min (0.26-2.04 min) in children; both were significantly shorter than in adults (5.75 [3.7-9.7] min). The plasma clearance of pipecuronium was significantly decreased in infants (1.50 [0.6-1.5] ml.min-1.kg-1; P < 0.05) as compared to children and adults (2.27 [0.88-2.27] and 2.45 [1.7-3.2] ml.min-1.kg-1, respectively). The total volume of distribution was similar in all three groups. We conclude that the pharmacokinetic features of pipecuronium are age-dependent: differences as compared to adults consisted of a faster distribution in both infants and children and a slower elimination in infants. The pharmacokinetic profile of pipecuronium does not explain the faster recovery from neuromuscular blockade in infants as compared to children. Because of the low total plasma clearance in infants, pipecuronium dosage should be carefully monitored to avoid accumulation and prolonged paralysis.

[Medical responsibility and nosocomial infections]. / Responsabilité médicale et infections nosocomiales.

Modifications of the civil and administrative jurisprudence regarding nosocomial infections reflect the will to pay the patient for compensation for injury. The June 29, 1999 decree of the French Court of Cessation shows the transition from presumption of malpractice to obligation of safety. The authors describe those modifications, including the physician's and hospital liabilities, and assess their consequences, as proof of an external cause is now mandatory while proof of absence of malpractice is no longer sufficient.

[Verification of bacteriological safety of PCM 40 air conditioner]. / Vérification de l'inocuité bactériologique du climatiseur PCM 40.

This study assessed the bacteriological safety of the bedside air conditioner PCM 40 (Howorth Airtech), used for prevention of intraoperative hypothermia, by blowing filtered warm air through a special mattress. The 3 microns bacterial filter of the device released 2,968 +/- 5,618 particles of diameter less than 3 microns per m3 of room air, containing 78,798 +/- 37,243 of such particles per m3. The amount of bacteries in the air pulsed from the mattress was 30 +/- 41 cfu/m3 vs 120 cfu/m3 in the ambient air and in the hot air supply tubing it reached 6 +/- 5 cfu/m3 vs 175 +/- 77 cfu/m3. It is concluded that bacteriological data do not contra-indicate the use of this air conditioner in the operating theater. The only limitations for use are the position (prone or lateral position) and type of surgery (neurosurgery).