Jean Milot

The oculocardiac reflex: a graphic and statistical analysis in infants and children.

A new method for the detection and recording of the oculocardiac reflex (OCR) is described and applied to 49 healthy infants and children (six months to nine years old) undergoing strabismus surgery under halothane anaesthesia with spontaneous ventilation. Eighty-one extraocular muscles were studied. Square wave stimuli (abrupt and sustained tractions) were definitely more reflexogenic than slow slope stimuli (very gradual, progressive and gentle tractions). Vagai escape, as well as fatigue of the OCR, are graphically documented and analysed. In this series, using well-defined and controlled tractions, the medial reclus was not more reflexogenic than the other extraocular muscles. Hypercapnia was an important adjuvant factor of the OCR. Controlled ventilation is recommended. The routine use of intravenous amicholinergic drugs is briefly discussed. Prevention of the OCR, and prophylaxis of cardiac arrhythmias during strabismus surgery, now seem to be placed on a more rational basis.RésuméLes auteurs décrivent une nouvelle méthode d’enregistrement graphique pour l’étude du réflexe oculocardiaque (ROC) et l’emploient chez 49 enfants (six mois à neuf ans; état physique l de la classification ASA) soumis à des corrections de strabisme et anesthésiés à l’halothane en respiration spontanée. Les stimulations brusques et soutenues étaient définitivement plus réfiexogènes que les stimulations progressives et délicates (P = 0.03). L’échappement vagai et la fatigue du ROC sont graphiquement documentés et analysés. L’emploi de stimulations d forme et à intensité bien définies révéla que le droit interne n’était pas plus réfiexogène que les autres muscles extrinsèques de l’il. L’hypercapnie était un facteur adjuvant important dans le déclenchement du ROC. La respiration contrôlée est recommandée, au moins lors des tractions musculaires. L’usage routinier d’agents anticholinergiques par voie intraveineuse est brièvement discuté. La prophylaxie du ROC et la prophylaxie des arythmies cardiaques survenant au cours des corrections de strabisme, sont ainsi placées sur des bases plus rationnelles.

Recombinant interferon alfa-2b in the treatment of vision-threatening capillary hemangiomas in childhood☆

INTRODUCTION Hemangiomas of the orbit and eyelids may cause serious ocular problems usually related to amblyopia and astigmatism. Steroids have become the accepted treatment. However, some hemangiomas are resistant to steroids or require prolonged use,with unacceptable side effects. Interferon alfa-2b, an antiangiogenic protein, was used in this prospective study to treat visually threatening hemangiomas that were unresponsive to oral or intralesional steroid treatment. METHODS Forty patients aged 2 to 36 months with life- or organ-threatening hemangiomas were prospectively enrolled to evaluate the efficacy and safety of interferon alfa treatment for hemangiomas. Sixteen of these 40 patients had hemangiomas causing serious ocular dysfunction. The patients were treated with 3 x 10(6) U/m2 interferon alfa-2b subcutaneously daily for 3 months; treatment was then tapered or retreated according to response and protocol. Therapeutic responses were documented. RESULTS Fifteen patients with ocular hemangiomas have finished treatment. The pretreatment volume measured by computed axial tomographywas an average of 22.3 cm3. Clinical response with eye opening was observed at an average of 6 weeks. There was a significant regression of the hemangioma in all patients, with an average 82% reduction in volume. Patients were treated with glasses and occlusion therapy as appropriate. Final visual acuities with a follow-up averaging 14 months after cessation of interferon treatment were normal, except that five of 15 patients had amblyopia; one of these patients had 20/40, two had 20/60, and two had 20/70. There were no major illnesses or serious adverse side effects. CONCLUSION Interferon alfa-2b treatment resulted in good to excellent regression of all the hemangiomas. This regression was clinically significant,with patients able to open the affected eye an average of 6 weeks into treatment. Visual results were good, with moderate amblyopia occurring only in patients treated at a later age. Interferon alfa-2b was well tolerated by these young patients, and no significant illness or side effect has occurred.

On- and off-responses in the photopic electroretinogram in complete-type congenital stationary night blindness.

We examined the on- and off-responses of the photopic electroretinogram in patients with complete congenital stationary night blindness. Standard flash electroretinograms as well as those produced in a ganzfeld modified for long-duration light stimuli (500 msec) permitted the separation of on- and off-responses in four patients and four normal subjects. The amplitude and latency of the electroretinogram on- response (a- and b-waves) and off-response (d-wave) in addition to the oscillatory potentials of the off-response in normal subjects and patients were compared. The abnormal on-response was demonstrated in all the patients, and the offresponse with its oscillatory potentials were preserved. We showed that the second portion of the off-response (of inner retinal origin) is normal. If congenital stationary night blindness is a defect of depolarizing bipolar cells, these results preclude input of the depolarizing bipolar cells and support the hyperpolarizing bipolar cells as the cellular origin of the off-response electroretinogram.

Antiemetic prophylaxis with promethazine or droperidol in paediatric outpatient strabismus surgery

This randomized, double-blind study evaluated the antiemetic efficacy and the side-effects of promethazine pretreatment (0.5 mg · kg−1 IV + 0.5 mg · kg−1 IM) versus droperidol + placebo pretreatment (droperidol. 0.075 mg kg−1 IV + physiological saline, 0.02 ml · kg−1 IM). One hundred unpremeditated ASA physical status I children ranging from two to ten years, and undergoing outpatient strabismus surgery were studied. All children received inhalational anaesthesia with halothane, nitrous oxide and oxygen. Neither opioids nor muscle relaxants were used. The incidence of vomiting and/or retching and the incidence of side-effects were determined in the post-anaesthesia recovery room (PARR), in the short-stay surgical unit (SSSU), and after discharge from the hospital (including the journey and the stay at home during the first postoperative day). Promethazine and droperidol were equally effective in reducing the incidence of vomiting before discharge to two and eight per cent respectively. On the contrary, the incidences of vomiting after discharge and overall were significantly less with promethazine (ten and ten per cent) than with droperidol pretreatment (54 and 56 per cent) (P < 0.0001). Promethazine permitted the time to discharge from the hospital to be reduced to an average of three hours, without increasing the incidence of vomiting postdischarge. Promethazine pretreatment is much less expensive than droperidol pretreatment. The incidence of restlessness was significantly less with droperidol (eight per cent) than with promethazine (36 per cent) (P < 0.001). Promethazine pretreatment demands the use of an analgesic like acetaminophen in order to reduce the incidence of postoperative pain and restlessness. With the exception of restlessness, the overall incidence of side-effects was not statistically different between the two groups.RésuméCette étude randomisée et à double insu a été réalisée dans le but d’évaluer et l’efficacité antiémétique et les effets indésirables du prétraitement à la prométhazine (0,5 mg · kg−1 IV + 0,5 mg · kg−1 IM) versus le prétraitement au droperidol + placebo (droperidol, 0,075 mg · kg−1 IV + sérum physiologique, 0.02 ml · kg−1 IM). Cent enfants non prémédiqués, à l’état physique I de la classification ASA, dont l’âge variait entre deux et dix ans et devant subir une correction de strabisme en courtséjour ont été étudiés. Tous ces enfants ont été anestliésiés à l’aide d’halothane, de protoxyde d’azote et d’oxygène. Aucun opiacé et aucun curarisant n’a été employé. L incidence de vomissements et l’incidence d’effets indésirables fûrent déterminées à la salle de réveil, à l’unité de courtséjour postopératoire, et après le congédiement de l’hôpital (transport vers la maison et séjour à domicile pendant la première journée postopératoire). Le prétraitement à la prométhazine a réduit l’incidence de vomissements pré-congédiement de l’hôpital (deux pour cent) autant que le prétraitement au droperidol (huit pour cent). Par contre, l’incidence de vomissements post-congédiement de l’hôpital et l’incidence globale de vomissements postopératoires fûrent significativement plus faibles chez le groupe d’enfants prétraités avec de la prométhazine (dix; dix pour cent) que chez le groupe prétraité avec du droperidol (54: 56 pour cent) (P < 0.0001). Le prétraitement à la prométhazine a permis de raccourcir la moyenne du temps de congédiement de l’hôpital aux alentours de trois heures sans augmenter l’incidence de vomissements post-congediement. Le prétraitement à la prométhazine coûte beaucoup moins cher que le prétraitement au droperidol. L’incidence d’agitation postopératoire fût significativement plus élevée avec la prométhazine (36 pour cent qu’avec le droperidol (huit pour cent) (P < 0,001). Les enfants prétraités à la prométhazine doivent recevoir un analgésique du type acétaminophène, dans le but de réduire l’incidence de douleurs et d’agitation postopératoires. Mise à part l’agitation, l’incidence globale d’effets indésirables n’a pas été statistiquement différente entre les deux types de prétraitement. Les auteurs discutent l’étiopathogénie des vomissements et la pharmacologie des antiémétiques chez les enfants exposés aux corrections de strabisme.

Ophthalmic Manifestations of Aarskog (Facial-Digital-Genital) Syndrome

Four boys with facial-digital-genital or Aarskog syndrome were whort with triangular faces, characteristic deformities of the hands and feet, and anomalies of the external genitalia. The syndrome appears to be inherited in an X-chromosomes-limked recessive manner. Previous reports emphasized the presence of hypertelorism but careful measurements of the interorbital dimensions revealed primary telecanthus in addition to hypertelorism. The palpebral fissures had a marked antimongoloid obliquity and in half the reported cases, there was unilateral or bilateral congenital blepharoptosis. Strabismus, hyperopic astigmatism, and large corneas may be additional features.

The oculorespiratory reflex revisited

Continuous measurement of the intratracheal pressure and capnography are very simple and accessible methods for the detection and recording of the oculorespiratory reflex (ORR). Eight healthy children (five to 14 years old) undergoing strabismus surgery under halothane-nitrous oxide anaesthesia with spontaneous ventilation were studied. The ORR was evoked by traction on the extrinsic muscles of the eye (four medial recti and four lateral recti). Slowing of the respiratory rate and/or shallow respiratory movements were observed in each patient. One patient developed apnoea of 20 seconds duration which forced the use of manually controlled ventilation. Intravenous atropine (0.01 mgçkg-1) reduced the incidence of positive OCR (to 37.5 per cent) but did not diminish the incidence of the ORR (100 per cent). Since the ORR may lead to hypercapnia and hypoxaemia, controlled ventilation is recommended for patients undergoing strabismus surgery at least immediately before and during the muscular traction. It is now clear that the ORR may be evoked by traction on the extrinsic muscles of the eye, may produce hypercapnia and hypoxaemia and so, may aggravate the consequences of the OCR.RésuméCette étude a été conçue afin de savoir si le réflexe oculorespiratoire (ROR) peut être déclenché par ľétirement des muscules extrinsèques de ľoeil et ainsi pouvoir présumer de son importance face au réflexe oculocardiaque (ROC) lors des corrections de strabisme. Ľenregistrement graphique de la pression intratrachéale et la capnographie se sont avérées des méthodes simples et fiables pour la détection et pour ľétude du ROR. Huit enfants (de cinq à 14 ans; état physique I de la classification ASA) opérés pour des corrections de strabisme, anesthésiés à ľhalothane et au protoxyde ďazote, en respiration spontanée, fûrent étudiés. Nousavons employédes tractions musculaires de 200-250 grammes durant 10-15 secondes. Malgré ľemploi ďatropine par voie intraveineuse (0.01 mg·kg-1), le ROR (bradypnée, arythmie respiratoire) a été positif dans 100 pour cent des cas, alors que le ROC n’a été positif que dans 37,5 pour cent des cas. Un enfant (fille de 14 ans) a présenté une apnée de 20 secondes, après la stimulation de son droit interne. En conclusion, le ROR est une entité assez fréquente, lors des corrections de strabisme, pouvant amener de ľhypercapnie et de ľhypoxie et, par conséquent, pouvant aggraver le ROC et faciliter ľapparition ďarythmies cardiaques. La ventilation contrôlée est donc à recommander lors des corrections de strabisme, au moins immédiatement avant et pendant les tractions musculaires.

Clinical evaluation of aminocaproic acid for managing traumatic hyphema in children.

PURPOSE The purpose of this study is to determine the incidence of secondary hemorrhage after traumatic hyphema in children and to evaluate the efficacy of epsilon aminocaproic acid in reducing this incidence. METHODS In a prospective, randomized, double-blind study performed between November 1987 and February 1994, 94 children admitted for traumatic hyphema were assigned to receive either aminocaproic acid (n = 48) (100 mg/kg every 4 hours; maximum, 30 g daily) or placebo (n = 46) for 5 days. Patients who had ingested aspirin in the week preceding admission were excluded from the study. RESULTS Mean age of the patients was 9.4 years. Black patients comprised 4% of the study population. Secondary hemorrhage occurred in only three patients (3.2%), two from the placebo group and one from the aminocaproic acid group, none of whom had any complications. The duration of hospital stay and the clot resorption times were increased significantly in the aminocaproic acid group (P < 0.001). CONCLUSIONS The authors report a very low incidence of secondary hemorrhage compared with most previous studies. This difference is likely related to the small proportion of black patients in our study and to the exclusion of patients having ingested aspirin, two factors that seem to be associated with higher rates of rebleeding. The efficacy of aminocaproic acid could not be determined due to the low incidence of hemorrhage. The results of this study, however, suggest that the incidence of secondary hemorrhage in white patients without prior ingestion of aspirin is insufficient to justify routine use of aminocaproic acid in managing traumatic hyphema. Rather, an individualized decision based on the risk factors of each patient would seem more appropriate to avoid a slower clot resorption time and possible side effects of this medication.

First cytogenetic evidence of homozygosity for the retinoblastoma deletion in chromosome 13.

Retinoblastoma (Rb) provided the first model in which both normal alleles of a recessive gene had to be lost as a prerequisite for tumorigenicity. However, region q14 of chromosome 13 appears cytogenetically normal in the majority of Rb tumors, and no homozygotic deletion had previously been observed. High-resolution cytogenetics of an Rb tumor revealed a homozygotic deletion in bands q13.3-14.2 of chromosomes 13 in 35% of the cells and a heterozygotic deletion, involving the same region, in 17%. In one third of the cells, although random chromosome loss occasionally occurred, no specific anomaly was detected. The remaining cells showed either monosomy 13, tetraploidy, or an i(1p). Revealing a homozygotic deletion in subbands 14.1 and 14.2 of chromosomes 13 provides the first cytogenetic evidence of the two somatic mutations considered essential to inactivate the Rb gene. These results allow insight into the succession of events necessary for tumor development.

Cataracts and ketotic hypoglycemia.

Of 40 patients with ketotic hypoglycemia, 15 (nine boys and six girls) developed cataracts. The mean age at onset of the first hypoglycemic attack was 20 months, and the average age at the time the cataracts were discovered was 3 1/4 years. The average birth weight of 14 children was 2060 g. The cataracts were bilateral in all but one case. Seven patients (11 eyes, bilateral in four patients) developed complete cataracts. Despite aphakic correction and occlusion therapy, the major cause of visual loss after cataract surgery was stimulus deprivation amblyopia. Other ocular abnormalities included strabismus and jerky horizontal nystagmus. Neurologic impairment--epilepsy, psychomotor retardation, and/or electroencephalographic abnormalities--was present in over one half of the patients. All children with ketotic hypoglycemia should be referred promptly for an ophthalmic examination so that appropriate therapy can be implemented early.

Ondansetron for the prevention and treatment of nausea and vomiting following pediatric strabismus surgery

BACKGROUND Neither droperidol nor ondansetron has been proven completely effective, and there are conflicting data comparing the efficacy of the two agents. The purpose of this study was to compare the efficacy, safety and cost of a combination of ondansetron administered intravenously in the operating room followed by oral ondansetron treatment at home with the more commonly used treatment of intravenous droperidol therapy and oral dimenhydrinate therapy, for the prevention and treatment of postoperative nausea and vomiting in children undergoing strabismus surgery. METHODS Double-blind randomized clinical trial with parallel comparison groups. All patients aged 6 months to 18 years who underwent strabismus surgery at a pediatric hospital in Montreal between Nov. 13, 2000, and June 12, 2001, were included. The exclusion criteria were nausea or vomiting, or use of antiemetics or narcotics in the 24 hours preceding surgery, and past history of hepatic, gastric or renal disease. The outcome measures were frequency of nausea and vomiting, severity of nausea and adverse effects in hospital, during transportation home and during the first 24 hours at home. Data were obtained through nursing notes and through a telephone interview conducted 24 to 48 hours after discharge. RESULTS Of the 208 eligible patients, 172 were randomly assigned to the study groups (88 to the ondansetron group and 84 to the droperidol/dimenhydrinate group). We found no statistically significant difference in the incidence of nausea and vomiting in hospital or at home between the two groups (25.3% vs. 31.6%, p = 0.371). There was a significant difference between the two groups in the rate of vomiting during transportation home (3.6% vs. 12.6%, p = 0.044). The incidence of severe nausea was 14.4% with ondansetron and 15.4% with droperidol, a nonsignificant difference (p = 1.00). No significant difference was observed between the two groups in the incidence of any nausea (p = 0.434) or adverse effects (p = 0.220). We calculated that the combination of droperidol and dimenhydrinate was seven times less costly than the ondansetron regimen. INTERPRETATION In this study, the efficacy and safety of intravenous administration of droperidol followed by oral use of dimenhydrinate did not differ from that of intravenous followed by oral use of ondansetron in children undergoing strabismus surgery. Since treatment with ondansetron is much more costly than the combination of droperidol and dimenhydrinate, at this time the use of ondansetron in the prevention and treatment of vomiting and nausea in this population may not be beneficial on a cost basis if all other variables are considered.