[Central venous catheters in pediatric patients]. / Le cathétérisme veineux central chez l'enfant.

Central venous catheterizations are often used in pediatric intensive care units or for long-term intravenous treatment. It consists in positioning the catheter extremity in the venous cava-right atrium junction. Adapted material and techniques are necessary for young children because of particularities in anatomy and the size of the different venous trunks. The aim of this paper is to present the different material and techniques and to show the indications, complications and follow-up in central venous catheterization for young children.

[Umbilical and peripherally inserted venous central catheterization of the newborn]. / Le cathétérisme veineux ombilical et épicutanéocave chez le nouveau-né

Umbilical venous and peripherally inserted venous central catheters are widely used to perfuse low-weight preterm and term newborns in intensive care units. This catheter must be inserted carefully and monitored rigorously to prevent complications. This paper develops today's knowledge on the use and complications in the newborn population.

Response of atrial natriuretic factor to surgical pericardial drainage in patients with chronic pericardial effusion.

Previous studies have demonstrated the importance of atrial transmural pressure in the secretion of atrial natriuretic peptide. These studies have been performed in patients with pericardial effusion and hemodynamic compromise. The response of atrial natriuretic peptide to the drainage of chronic pericardial effusion without clinical evidence of tamponade is unknown. We studied 13 patients with chronic abundant pericardial effusion but without hemodynamic compromise. Blood samples for hormonal determinations were drawn before and after surgical pericardiocentesis. Right atrial pressure was measured during the procedure. Drainage induced a significant increase of atrial natriuretic peptide (from 12 +/- 3.9 to 105 +/- 22.8 pmol/l, P < 0.001, mean +/- S.E.M.), correlated with the fall in right atrial pressure (from 7.65 +/- 1.18 to 4.31 +/- 1.46 mmHg, P < 0.05, r = 0.68, P = 0.01). This increase was inversely correlated with the rise of mean blood pressure after surgery (from 84 +/- 2.37 to 100 +/- 5.3 mmHg, P < 0.05, r = 0.65, P < 0.02). Plasma renin activity decreased after drainage (from 8.12 +/- 2.57 to 3.27 +/- 0.65 ng/ml/h, P < 0.05). Surgery induced an increase of plasma levels of aldosterone (from 811 +/- 241 to 1199 +/- 249 pmol/l, P < 0.05), which were reduced after pericardiocentesis (371 +/- 102 pmol/l, P < 0.02). In patients with chronic abundant pericardial effusion, surgical pericardiocentesis induced a significant increase of atrial natriuretic peptide, correlated with a fall in right atrial pressure. The increase of atrial natriuretic peptide was similar than in patients with tamponade, despite a moderate fall in right atrial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

An IBM PC-based system for experimental haemodynamic studies.

An IBM PC-based real-time data acquisition, monitoring and analysis system for experimental haemodynamic studies was developed. Comprehensive haemodynamic signals, such as aortic and left ventricular pressures, aortic and coronary blood flows, two segmental lengths, two segmental thicknesses, electrocardiogram and airway pressure, were acquired and monitored to assess cardiac function. The system performs computer-aided analysis and derivations on a number of haemodynamic parameters and cardiac function indices. The system has been tested and validated extensively over a number of series of experimental haemodynamic studies to investigate the effects of anaesthetic agents, cardiovascular drugs, and changes in loading on normal and critically ischaemic myocardium of anaesthetised laboratory subjects. Without this specialised and automated system, the analysis of the data acquired from the haemodynamic studies would be too time-consuming and could not be fully performed.

[Resection and reconstruction of the carina with separate two-lung high-frequency jet ventilation]. / Résection et reconstruction de la bifurcation trachéale sous jet ventilation à haute fréquence, séparée sur les deux poumons.

Carinal resection and reconstruction via a right transpleural approach in an hypoxemic patient provides difficult maintenance of satisfactory gas exchange when one lung ventilation is inadequate. The present case report concerns a 62-year-old patient with chronic obstructive airways disease and a carinal squamous cell carcinoma. He underwent tracheobronchial reconstruction surgery by Barclay's procedure through a right postero-lateral thoracotomy. During resection and reconstruction phases, the gas exchange was maintained by a new technic: high-frequency-jet-ventilation (HFJV) with two small-bore catheters through the endotracheal tube and JVHF ventilators adjusted to the compliance of each lung (high for the right lung, low for the left one). No circulatory changes were observed during the sutures lines phase (90'). The oximeter and the arterial blood gas values show an adequate procedure. The immediate post operative period was unremarkable and uncomplicated. The histological diagnosis was squamous cell carcinoma involving the carina with one metastatic pretracheal lymph node and microscopic infiltration of the left main bronchus resection margin. Sixteen grays postoperative radiotherapy was required. Ten months after the patient is alive, without tumor recurrence. HFJV greatly facilitates surgery by avoiding endobronchial intubation with large cuffed tubes into the surgical field. In patients with low pulmonary reserve, bilateral lung HFJV is required: two JVHF ventilators with different ranges delivering separate ventilation to the right and left lungs avoid left hypoventilation and right surgical emphysema and insure good surgical conditions.

[Pediatric emergency department policy. Implementation and management of the resuscitation room]. / Recommandations concernant la mise en place, la gestion, l'utilisation et l'évaluation d'une salle d'accueil des urgences vitales pédiatriques.

The pediatric resuscitation room is the place where children suffering from vital distress are cared for in the emergency unit. Recommendations for its organization, functioning and evaluation have been ruled on by experts from six medical societies involved in these emergencies. They concern all the hospital's physicians, nurses and administrative directors.

[Nociceptive flexion reflex. Principles and applications of the threshold determination]. / Réflexe nociceptif de flexion. Principes et applications de la mesure du seuil.

The threshold for the pain flexion reflex in the lower limb can be used to determine the potency in man of analgesic drugs acting centrally. A new apparatus is, the "algometre", described. Bipolar electrical stimulation (5 stimuli of 1 ms over a period of 10 ms) is applied to the saphenous nerve just behind the external malleolus. An amplifier detects the muscle response (electromyogramme; EMG) at the muscle-tendon junction in the popliteal space; this occurs about 70-130 ms after the painful stimulus. The whole system is linked to a microcomputer. The EMG and EMG/intensity curves are displayed on a colour screen, and can be copied by a colour tracing table. The whole machine is mobile and can be moved from bed to bed. An increase in the threshold during inhalation of 50% nitrous oxide in oxygen was shown. However, the usefulness of the "algometre" in clinical practice remains to be assessed by further studies.

[Cryoanesthesia by freon spray for venepuncture in children]. / Cryoanesthésie par pulvérisation de fréon pour ponction veineuse chez l'enfant.

This prospective study was designed to assess the quality of skin analgesia provided by cryoanesthesia induced by a spray of freon (dichloro-tetrafluoro-ethane) for venous cannulation (22 or 24 Gauge cannulas). Eighty children between the ages of 5 and 15 years were allocated to two groups: 40 children had a conventional venepuncture, 40 others had a venepuncture under cryoanesthesia. The spray of freon was applied for ten seconds on the area of skin to be anaesthetised. The venous cannulation was carried out by an anaesthetist of the paediatric surgical unit. The intensity of pain at venepuncture was quantified with a visual analogic scale (range 0 to 100). The median values of the pain scores were 11.5 (0 to 50) in the cryoanesthesia group and 48 (11 to 75) in the control group respectively. It is concluded that freon spray provides a convenient analgesia for venepuncture in children aged 5-15 years.

[A study of blood loss during surgery for scoliosis. Posterior approach in 319 adolescents]. / Etude du saignement dans la chirurgie de la scoliose. Interventions par voie postérieure chez 319 adolescents.

A retrospective study including 319 patients was realized from 1984 to 1993 in order to evaluate during scoliosis surgery the incidence on bleeding of the type of scoliosis and the anesthetic procedure. Blood losses were below one litre thus reducing the homologous blood transfusions. The patient was in prone position on a modified Wilson frame which facilitates venous return from the dorsal region. A moderate controlled hypotension was realized by combination of halothane, intravenous nitroglycerin (NG) and beta-blocking drugs (when required). Somatosensory evoked potentials were continuously monitored during surgery. A compression of the dorsal region was realized postoperatively in order to reduce blood loss. The blood losses were compared using Student's t-test. The mean perioperative bleeding was 9.8 ml.kg-1 for idiopathic scoliosis (no transfusion required), 14.1 ml.kg-1 for secondary scoliosis (p < 0.05 vs idiopathic) and 29.3 ml.kg-1 for neuromyopathic scoliosis (p < 0.05 vs idiopathic), indicating a major influence of muscle atonia on bleeding. The moderate controlled hypotension by iterative injection of NG and beta-adrenergic blocking drugs provided a safe and reversible hypotension.

Total spinal anesthesia during combined general-epidural anesthesia in a 7-year-old child.

Total spinal anesthesia (TSA) is a rare complication of lumbar epidural anesthesia through inadvertent spinal injection of local anesthetics following an undiagnosed dural breach or spinal placement of the catheter. TSA has rarely been reported in children. TSA occurred during epidural anesthesia in a 7-year-old child undergoing abdominal surgery. Recent previous lumbar punctures and intrathecal chemotherapy for Burkitt's lymphoma at the same level may have facilitated dural breach. Epidural anesthesia should not be attempted at the same intervertebral level as prior recent lumbar punctures.

Interregional differences in the systolic and diastolic response of nonischemic myocardium to remote coronary occlusion.

BACKGROUND: Previous work showed a twofold increase in stiffness of nonischemic myocardium at the base during ischemia of the left anterior wall. Whether the diastolic response of nonischemic myocardium to remote ischemia depends on the localization of the ischemic or the nonischemic area is unknown. METHODS: In dogs with open chests, regional function in ischemic and nonischemic myocardium was assessed (sonomicrometry) before and 5 min after occlusion of the left anterior descending coronary artery (LAD; n = 7) or the left circumflex coronary artery (LCX; n = 7). RESULTS: In nonischemic myocardium at the base, left anterior descending and left circumflex coronary artery occlusion both resulted in a twofold increase in chamber stiffness, whereas contractility and peak lengthening rate remained unchanged. In nonischemic myocardium of the posterior wall, left anterior descending coronary artery occlusion resulted in a significant (P<0.05 vs. control, P<0.05 vs. base) increase (mean+/-SD) in chamber stiffness (25+/-6%), contractility (17+/-5%), and peak lengthening rate (28+/-6%). In nonischemic myocardium at the apex, left circumflex coronary artery occlusion resulted in a significant (P<0.05 vs. control, P<0.05 vs. base) increase in chamber stiffness (15+/-5%), contractility (16+/-4%), and peak lengthening rate (19+/-6%). CONCLUSIONS: Stiffening of remote nonischemic myocardium occurs regardless of the localization of the ischemic and nonischemic area. The systolic and diastolic responses of nonischemic myocardium are not necessarily homogenous but may vary among different regions.

Myocardial ischemia and reperfusion are associated with an increased stiffness of remote nonischemic myocardium.

During and after an ischemic injury, maintenance and recovery of cardiac function may critically depend on remote nonischemic myocardium. Graded myocardial ischemia is associated with an approximately 50% increase in stiffness of nonischemic myocardium. We determined whether this increase in stiffness is unique to the ischemic period or persists during reperfusion. Ten anesthetized (isoflurane 1.0% vol/vol) open-chest dogs were instrumented to measure left ventricular pressure and dimensions (sonomicrometry) in ischemic and nonischemic myocardium. Regional chamber stiffness and myocardial stiffness were assessed using the end-diastolic pressure-length relationship which was modified by stepwise infusion and withdrawal of 200 mL of the animals' own blood during baseline, 45 min low flow ischemia (systolic bulge), and 60 min after the onset of reperfusion. In remote nonischemic myocardium, regional myocardial ischemia was associated with a significant (P < 0.05) increase in chamber stiffness (+44%) and myocardial stiffness (+48%). Sixty minutes after the onset of reperfusion, chamber stiffness (+54%, P < 0.05 versus baseline) and myocardial stiffness (+55%, P < 0.05 versus baseline) remained increased. Thus, the ischemia-induced increase in stiffness of remote nonischemic myocardium persists for at least 60 min after reperfusion.

The influence of preload on post-systolic shortening in ischaemic myocardium.

Post-systolic shortening is a wall motion abnormality defined as shortening of cardiac muscle after the end of ejection and usually regarded as a manifestation of ischaemia. This study was designed to determine whether changes in preload may alter the magnitude of ischaemia-induced post-systolic shortening. Eleven beagles were anaesthetized (halothane 0.8%) and instrumented for measurement of pressures, flows and dimensions in the apical subendocardium supplied by the left anterior descending coronary artery. Myocardial ischaemia was obtained by tightening a micrometer-controlled snare around the left anterior descending coronary artery. Post-systolic shortening, calculated as end-systolic length minus minimum length divided by end-systolic length, was measured at different levels of preload. Increasing the preload from 4 to 17 mmHg caused a significant reduction in post-systolic shortening (8.9% vs. 12.9%, P < 0.05, Student's paired t-test); post-systolic shortening was negatively correlated with coronary perfusion pressure (r = 0.35, P < 0.01) and positively correlated with systolic bulging. This study demonstrates that the amount of post-systolic shortening depends on the volume status, which therefore has to be taken into account in interpreting regional wall motion abnormalities, such as those detected by echocardiography.