Jean-Louis Jacob

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.

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.

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.

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.

Serum gastrin and blood glucose levels during halothane-nitrous oxide anaesthesia and strabismus surgery in children

The purpose of this study was to determine whether serum gastrin levels are increased by reflexogenic stimuli applied to the extrinsic muscles of the eye. Serum gastrin and blood glucose concentrations were measured in ten normal children aged between 5 and 12 yr during general anaesthesia with halothane and nitrous oxide and during strabismus surgery. Fasting basal concentrations of gastrin (33.6 ± 14.8 pg · ml−1) and of glucose (4.43 ± 0.72 mmol · L−1) were in the normal range of values for children. Intravenous atropine (0.01 mg · kg−1), general anaesthesia with halothane in nitrous oxide and oxygen by mask for three minutes, tracheal intubation, extraocular muscle stimulation and surgical stress did not cause any variation in the mean serum gastrin concentration. On the contrary, tracheal intubation and surgical stress increased blood glucose concentrations (P < 0.05). There was no difference in the serum gastrin levels after extraocular muscle stimulation between children with positive or negative oculocardiac reflexes (44.5 ± 16.7 pg · ml−1 vs 38 ± 14.7 pg · ml−1, respectively). The incidence of vomiting predischarge was 60 per cent. Serum gastrin levels did not differ between children who vomited and children who did not (44.3 ± 18.5 pg · ml−1 vs 47.1 ± 16.9 pg · ml−1, respectively). Vomiting after strabismus surgery cannot be attributed to high gastrin serum levels. Consequently, it is unlikely that vomiting after strabismus surgery is linked to an “culogastric reflex” with the vagus nerve as the efferent pathway.RésuméCette étude a été conçue dans le but de vérifier si les concentrations sériques de gastrine se trouvent augmentées après la stimulation des muscles extrinsèques de l’œil. Les concentrations sériques de gastrine, de même que les concentrations sanguines de glucose, furent mesurées, chez dix enfants normaux, âgés de 5 à 12 ans, durant l’anesthésie générale à l’halothane et au protoxyde d’azote et durant la chirurgie pour correction de strabisme. La gastrinémie basale et à jeun (33,6 ± 14,8 pg ° ml−1 ) et la glycémie basale et à jeun (4,43 ± 0,72 mmol ·−1) étaient dans les limites des valeurs normales pour ce groupe d’âge. L’administration d’atropine IV (0,01 mg · kg−1), l’anesthésie générale à l’halothane et au protoxyde d’azote par masque pendant trois minutes, l’intubation trachéale, la stimulation des muscles extraoculaires et le stress chirurgical n ’ ont pas causé de variations significatives dans les concentrations sériques de gastrine. Par contre, l’intubation trachéale et le stress chirurgical ont causé des augmentations significatives des concentrations de glucose dans le sang (P < 0,05). Il n’y a pas eu de différence significative, après la stimulation des muscles extrinsèques de l’œil, entre la gaslrinémie moyenne des enfants qui ont présenté un réflexe oculocardiaque positif et la gastrinémie moyenne des enfants dont le même réflexe était négatif (44,5 ± 16,7pg · ml−1 et 38 ± 14,7pg · ml−1, respectivement). L’incidence de vomissements post-opératoires, avant le congédiement de l’hôpital, était égale à 60 pour cent. La gastrinémie n’était pas signiflcativement différente entre les enfants qui ont vomi et ceux qui n’ ont pas vomi (44,3 ± 18,5pg · ml−1 et47,1 ±16,9 pg · ml−1, respectivement). Les vomissements postcorrection de strabisme ne peuvent pas être attribués aux variations de la gastrine sérique. Par conséquent, il est fort improbable que les vomissements post-correction de strabisme soient dûs à un réflexe « oculogastrique » dont le vague serait la voie éfférente.

Combined horizontal and oblique muscle surgery to treat synergistic divergence

CAN J OPHTHALMOL—VOL. 44, NO. 5, 2009 611 malities have been associated with chromosome 9 inversion, including dysmorphic features (short stature, depressed nasal bridge, down-slanting eyes, low-set ears, hypertelorism), microcephaly, deafness, ectodermal dysplasia (absent sweat glands, hypotrichosis, hypodontia), repeated spontaneous abortion, infertility (absence of ovaries, hypoplastic uterus, oligozoospermia), developmental and psychomotor delay, as well as psychiatric disorders. Congenital cataract and blindness have rarely been reported. Optic nerve hypoplasia is the most common congenital disc anomaly, occurring in 6.3 out of 100 000 children, and is a leading cause of blindness in infants and toddlers. It is often associated with midline cerebral defects, including absent septum pellucidum and agenesis of corpus callosum, constituting the De Morsier syndrome or septo-optic dysplasia.5 Many prenatal insults have been linked to the development of optic nerve hypoplasia, including maternal smoking and ingestion of anticonvulsant medications, alcohol, quinine, and antidepressants, as well as maternal diabetes and congenital cytomegalovirus or hepatitis B infection. Genetic disorders known to be associated with optic nerve hypoplasia are trisomy 18, Cri-du-chat syndrome (5p deletion), PAX6, HESX1, SOX2, and SOX3 gene mutations. To the best of our knowledge, this is the first report of optic nerve hypoplasia associated with chromosome 9 inversion. Whether there is a true association between these 2 conditions or whether they are coincidental findings in our patient remains to be elucidated.

Detection by electron microscopy of a small subband 13q14.11 deletion in an hereditary retinoblastoma.

High-resolution banding, specific for electron microscopy, was applied to chromosomes of synchronized blood lymphocytes obtained from a child with bilateral retinoblastoma. Ultrastructural analysis of the subbands in region q14.1, after synchronization and immunochemical banding, showed that the deletion in the abnormal chromosome 13 corresponds to subband 14.11, thus evidencing that the retinoblastoma gene is located within subband q14.11. This first application to a diagnostic problem of immunochemical banding suggests that, coupled with electron microscopy, this banding provides a higher resolution than that obtained with light microscopy and should be useful to pinpoint important localizations.