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Biomedical subjects

J Lacroix

Publications and source records attributed to J Lacroix.

At least 73 records · Page 4Linked to original sources

[Left ventricular decompression and neuropsychiatric disorders in coronary surgery].

The marked decrease in neuropsychiatric morbidity (NPM) following coronary artery bypass (CAB) over a period of four years led us to carry out a retrospective study in order to identify the cause. Two hundred fifty-eight consecutive CAB procedures were performed between 1983 and 1986. For 133 patients (group A), the CAB procedure was performed with left ventricular vent (LVV) and for 125 patients (group B) without LVV. In group A, 93 patients (group A1) had cardiopulmonary bypass (CPB) with a bubble oxygenator and 40 patients (group A2) had CPB with a membrane oxygenator. In group B, 30 patients (group B1) had CPB with a membrane oxygenator without filter in the arterial line and 95 patients (group B2) had CPB with a membrane oxygenator and filter in the arterial line. The reduction in NPM arose from the removal of the LVV, as the incidence of NMP was in group A 24.6% versus 12.3% in group B (p < 0.05). The substitution of the bubble oxygenator by a membrane oxygenator does not alter the incidence of NPM: 23.3% in group A1 versus 27.5% in group A2 (p > 0.05) nor did incorporation of a filter in the arterial line: 10% in group B1 versus 13.1% in group B2 (p > 0.05). Introduction of air in the left ventricle via an LVV catheter opening and coronary arteriotomy therefore causes gaseous microembolic events responsible for NPM following CAB.

Coronary Artery Bypass↗

Uvulitis and supraglottitis: early manifestations of Kawasaki disease.

Two children with Kawasaki disease initially had upper respiratory tract manifestations. The first was admitted with a diagnosis of uvulitis; in the second the clinical picture was characterized by supraglottic involvement, confirmed by direct laryngoscopic examination.

Child, Preschool↗

Frequency of upper gastrointestinal bleeding in a pediatric intensive care unit.

OBJECTIVE: To determine the frequency of upper gastrointestinal (GI) bleeding in pediatric ICUs. DESIGN: Prospective, descriptive study. SETTING: Pediatric ICU in a university hospital. PATIENTS: All children admitted to a pediatric ICU over a 55-wk period. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Upper GI bleeding was considered to be present if there was an episode of hematemesis or if any amount of blood was seen in drainage from a nasogastric tube. Sixty-three (6.4%) upper GI bleeds were detected among 984 patients: 5.2% in 698 patients who did not receive upper GI bleeding prophylaxis, and 9.4% in 286 patients who did receive some prophylaxis. Density was defined as the number of events/1000 days.patient. The mean density was 10.8 GI bleeding episodes/1000 days.patient in a pediatric ICU. A multivariate analysis detected four independent risk factors or risk markers for upper GI bleeding: high Pediatric Risk of Mortality score, coagulopathy, pneumonia, and multitrauma. Age, sex, hepatic and respiratory failures were identified as confounding variables. An upper GI bleeding episode was defined as being clinically important if hypotension, death, or transfusion occurred within 24 hrs after the bleeding. There were four clinically important GI bleeding episodes. All were caused, at least in part, by a coagulopathy. The GI bleeding was associated with a need for transfusion in four children, and with hypotension in two. CONCLUSIONS: The frequency of upper GI bleeding is substantial, but the rate of occurrence of clinically important upper GI bleeding is low, even in a pediatric ICU where most patients do not receive any prophylaxis.

Adolescent↗

[Structural typology assay of principal anticancer agents on the basis of molecular fragmentation].

The developed formula of 58 anticancer agents used in therapeutic or still in clinical essays were treated by molecular connectivity matrix method. This technic allows the search and the automatically count of structural fragments of the different studied molecules. Then it has been possible to build a spanning tree (Prim's arborescent skeleton) which gathers the different molecules and permits to put a priori new structures.

Antineoplastic Agents↗

[Overall analysis of structural factors responsible for the activity and toxicity of antiparasitic agents used in therapy].

A mini-data bank was constituted from the 73 french antiparasitic patent medicines and was implanted in microcomputer. A maximum of chemical, pharmaceutical, therapeutical and toxicological data were collected and treated by multivariate analysis. Exploitation of these informations processing allows to take out correlations between chemical structure toxicity, and specificity.

Anthelmintics↗

Arterial catheter-related infections in children. A 1-year cohort analysis.

To determine the incidence of infection secondary to arterial catheterization in children as well as the risk markers, we prospectively evaluated, during a 1-year period, all arterial catheters installed in children admitted to the pediatric intensive care unit. A total of 340 cannulas were placed in 310 children aged 80 +/- 4 months (mean +/- SEM) for a period of 64 +/- 4 hours. Most catheters were inserted percutaneously (99%) in the radial artery (86.5%). Ninety-two percent (313/340) of the catheters were sterile (group 1), 5% (17/340) were contaminated (less than 10 colony-forming units on semiquantitative culture) (group 2), and 3% (10/340) were considered either locally infected (ie, greater than or equal to 10 colony-forming units) (eight of 10) or associated with a possible catheter-related sepsis (two of 10) (group 3, or infected group). The incidence of local inflammation at the insertion site was higher in group 2 than in group 1 (18% vs 2.9%) but not statistically different between groups 3 and 1 (10% vs 2.9%). The duration of arterial catheterization was longer in group 3 than in group 1 (125 +/- 31 vs 61 +/- 4 hours). The risk of infection was nonexistent in the first 48 hours of catheterization. Thereafter it was calculated as being 6.2% (10/161), but it correlated poorly with the duration of arterial catheterization. These results confirm the very low incidence of infection related to arterial catheterization in children. Thus, routine catheter reinsertion is, in our opinion, unjustified.

Adolescent↗

[Prophylaxis of gastroduodenal hemorrhage caused by stress during pediatric intensive care].

Patients admitted to intensive care units frequently develop stress ulcers, erosive gastritis and complications such as upper gastrointestinal bleeding. Stress-related upper gastrointestinal bleeding (UGIB) has been of particular concern to many practitioners working in intensive care units and has led to the treatment of most if not all patients admitted to these units with antacids, H2 receptor antagonists or sucralfate in order to protect the gastric mucosa. It is considered that the 3 aforementioned medications are effective in decreasing the overall incidence of UGIB, but it has not been demonstrated that they are efficacious in reducing the incidence of clinically significant UGIB, ie cases that are complicated by anemia, hemorrhagic shock, or death. In addition, the cost and complications resulting from prophylaxis should be taken into consideration, which raises further questions about the systematic use of these agents. This article reviews the current literature on this subject; the authors propose a conservative use of prophylaxis, and that these agents be prescribed in a selective manner to the patients at the greatest risk of developing UGIB.

Child↗

Neurologic crises in hereditary tyrosinemia.

Hereditary tyrosinemia results from an inborn error in the final step of tyrosine metabolism. The disease is known to cause acute and chronic liver failure, renal Fanconi's syndrome, and hepatocellular carcinoma. Neurologic manifestations have been reported but not emphasized as a common problem. In this paper, we describe neurologic crises that occurred among children identified as having tyrosinemia on neonatal screening since 1970. Of the 48 children with tyrosinemia, 20 (42 percent) had neurologic crises that began at a mean age of one year and led to 104 hospital admissions. These abrupt episodes of peripheral neuropathy were characterized by severe pain with extensor hypertonia (in 75 percent), vomiting or paralytic ileus (69 percent), muscle weakness (29 percent), and self-mutilation (8 percent). Eight children required mechanical ventilation because of paralysis, and 14 of the 20 children have died. Between crises, most survivors regained normal function. We found no reliable biochemical marker for the crises (those we evaluated included blood levels of tyrosine, succinylacetone, and hepatic aminotransferases). Urinary excretion of delta-aminolevulinic acid, a neurotoxic intermediate of porphyrin biosynthesis, was elevated during crises but also during the asymptomatic periods. Electrophysiologic studies in seven patients and neuromuscular biopsies in three patients showed axonal degeneration and secondary demyelination. We conclude that episodes of acute, severe peripheral neuropathy are common in hereditary tyrosinemia and resemble the crises of the neuropathic porphyrias.

Acute Disease↗

Pediatric liver transplantation: the Montreal experience.

The introduction of cyclosporine A in 1980 greatly improved the survival of children with end-stage liver disease undergoing orthotopic liver transplantation. The average 1-year survival rate following hepatic transplantation increased from 30% in 1963 to 70% in 1980. This report summarizes the initial experience of two pediatric hospitals in Montreal--Hôpital Ste-Justine and Montreal Children's Hospital. Since December 1985, 13 orthotopic liver transplantations have been performed in 11 patients: six females and five males. The median age was 18 months (range, 13 months to 17 years) and the median weight was 10 kg (range, 8.5 to 38 kg). The indications for transplantation were biliary atresia (5 patients), tyrosinemia (2 patients), biliary hypoplasia (1 patient), Amerindian cirrhosis (1 patient), Crigler-Najjar syndrome, type I (1 patient), and fulminant non-A, non-B hepatitis with grade IV encephalopathy (1 patient). Immunosuppression was ensured by cyclosporine A, azathioprine, and steroids. The function of 11 grafts was immediate following revascularization of the grafts. One graft had delayed function due to preservation injury, and one had primary nonfunction. Surgical complications included bile peritonitis (1), ruptured aneurysm of an aortic conduit (1), and thrombosis of the hepatic artery necessitating retransplantation (2). Three of our patients died, one from postoperative cerebral edema, one of primary nonfunction of the graft, and one of ruptured aneurysm of an aortic conduit. Our overall survival rate was 72% with a follow-up of 3 to 32 months. Pediatric liver transplantation can now provide successful treatment and cure of liver diseases considered, until recently, dismal and hopeless.

Adolescent↗

Admission to a pediatric intensive care unit for poisoning: a review of 105 cases.

We reviewed all patients treated for intoxication in the pediatric ICU (PICU) of the Sainte-Justine Hospital over a 3-yr period. Poisoning (105 patients) constituted 3.1% of PICU admissions. Most involved children less than 3 (42%) yr or greater than 12 (33%) yr. Products most commonly ingested included tricyclic antidepressants (22%), benzodiazepines (15%), theophylline (10%), ethanol (10%), hallucinogens (8%), salicylates (8%), narcotics (8%), antihistamines (7%), and carbamazepine (5%). Three children became comatose after ingesting about 1 g of hashish. Multiple drug ingestions were frequent (22%), particularly in suicide attempts (11/23). Treatment was, in general, interventionist and nonspecific; aggressive measures for poisoning were required in only two patients who were hemodialyzed. Two patients stayed in the PICU greater than 2 days. All patients survived with no sequelae, except for one patient who required an intestinal resection. Poisoning in children is a common occurrence leading to PICU admission; however, the medical prognosis is usually excellent.

Adolescent↗

Prophylaxis of upper gastrointestinal bleeding in intensive care units: a meta-analysis.

A meta-analysis was performed of 15 randomized studies on the prophylaxis with cimetidine and/or ant-acids of upper GI bleeding acquired in the ICU. There were eight comparisons of a group receiving cimetidine with a control group, nine comparisons of a group receiving antacids with a control group, and ten comparisons of a group receiving cimetidine with a group receiving antacids. The incidence of upper GI bleeding ranged from 3.4% to 52.7% among 866 control patients who received either a placebo or no prophylaxis. In five of eight comparisons, cimetidine was significantly more effective than no treatment or a placebo to prevent occult and overt upper GI bleeding; the typical odds ratio was 0.32 (95% confidence interval 0.21 to 0.49). In six of nine comparisons, antacids were significantly more effective than no treatment or a placebo; the typical odds ratio was 0.12 (0.08 to 0.19). Finally, antacids were significantly more effective than cimetidine in two of ten comparisons; the typical odds ratio was 1.61 (0.97 to 2.65). However, weaknesses in the study designs, heterogeneity of treatment effects, the lack of strength of the accumulated evidence, and the fact that no utility has been shown in terms of reducing morbidity (shock, need for transfusion) or mortality, prevent any definitive conclusion in regard to compulsory use of upper GI bleeding prophylaxis for ICU patients.

Antacids↗

Respiratory failure and mechanical ventilation in severe bronchiolitis.

A retrospective review of children who needed mechanical ventilation for severe bronchiolitis identified 62 cases over a 10 year period. The mean age at initiation of ventilation was 73 days (range: 14-201). Compared with a group of 150 children in hospital for bronchiolitis but not transferred to the intensive care unit, these 62 cases were significantly younger (73.0 compared with 166.3 days), and smaller (4.5 compared with 6.8 kg), and significantly more had been born prematurely (40% compared with 16%). Taken independently, age, weight, and prematurity were significantly associated with the need for artificial ventilation, weight being the most important factor. Using stepwise logistic regression, prematurity in itself added to the quality of the prediction but age did not. The mean duration of mechanical ventilation was 105 hours (range 2-381). Duration of ventilation was significantly longer in children with a low gestational age at birth and a positive familial history of atopy. There were no deaths, and no patient developed pneumothorax or pneumomediastinum. Mechanical ventilation is well tolerated and safe in acute bronchiolitis.

Age Factors↗

[Multiparameter analysis approach of antiparasitic structure-activity relationships in function of the parasite taxonomy].

In this paper the authors have studied the structure-parasitic activity relationships through the Chemical Abstracts data base which groups together the works published in this field for the last twenty years. With mathematical methods of multidimensional data reduction using a computer it has been possible to validate the classification of human parasites on the base of their sensitivity to chemical families. The specificity of the pharmacochemical relationships was described through two factorial maps. This work shows that it is possible to find new chemical series with potential parasitic activity.

Animals↗

Reye's syndrome. A reappraisal of diagnosis in 49 presumptive cases.

We retrospectively studied 49 patients who were discharged from Sainte-Justine Hospital, Montreal, Canada, or who died between 1970 and 1987 with a presumptive diagnosis of Reye's syndrome. Reye's syndrome was defined as certain, probable, unlikely, or excluded according to clinical, biological, and histologic criteria agreed on a priori by a panel of experts. Patient charts were reviewed blindly by three clinicians. Assessments were similar in 42 cases (86%) (weighted K = 0.78 to 0.85, which suggested substantial agreement); for the remainder, agreement was reached after discussion. Reye's syndrome was considered certain in 1 case (2%), probable in 11 (22%), unlikely in 21 (43%), and excluded in 15 (31%). Four children in the study group did not undergo biopsy or autopsy; in three of these, Reye's syndrome was unlikely according to clinical and biological criteria, and in one, the diagnosis was unclassifiable. The incidence of certain or probable Reye's syndrome was low in our institution during the study period. Our results suggest that the apparent disappearance of Reye's syndrome should be reassessed.

Adolescent↗