Variability in the diagnostic and management practices of post-hemorrhagic ventricular dilatation in very preterm infants across Canadian centers and comparison with European practices.

OBJECTIVES: To investigate the variability in diagnostic and therapeutic approaches to posthemorrhagic ventricular dilatation (PHVD) among Canadian neonatal centers, and secondary exploration of differences in approaches between Canadian and European practices. METHODS: We conducted a survey among Canadian tertiary neonatal centers on their local practices for managing very preterm infants with PHVD. The survey covered questions on the diagnostic criteria, timing and type of interventions and resources utilization (transfer to neurosurgical sites and neurodevelopmental follow-up). In a secondary exploration, Canadian responses were compared with responses to the same survey from European centers. RESULTS: 23/30 Canadian centers (77%) completed the survey. There was no consensus among Canadian centers on the criteria used for diagnosing PHVD or to initiate intervention. The therapeutic interventions also vary, both for temporizing procedures or permanent shunting. Compared to European practices, the Canadian approach relied less on the sole use of ultrasound criteria for diagnosing PHVD (43 vs 94%, p < 0.0001) or timing intervention (26 vs 63%, p = 0.007). Majority of European centers intervened early in the development of PHVD based on ultrasound parameters, whereas Canadian centers intervened based on clinical hydrocephalus, with fewer centers performing serial lumbar punctures prior to neurosurgical procedures (40 vs 81%, p = 0.003). CONCLUSION: Considerable variability exists in diagnosis and management of PHVD in preterm infants among Canadian tertiary centers and between Canadian and European practices. Given the potential implications of the inter-center practice variability on the short- and long-term outcomes of preterm infants with PHVD, efforts towards evidence-based Canada-wide practice standardization are underway.

Beta-adrenergic blockade in the dentate gyrus in vivo prevents high frequency-induced long-term potentiation of EPSP slope, but not long-term potentiation of population spike amplitude.

High frequency (HF)-induced and norepinephrine (NE)-induced long-term potentiation have been hypothesized to utilize common mechanisms of induction and expression in the dentate gyrus. In vitro data tend to support this hypothesis, but few studies have been done in vivo. The present study records perforant path-evoked potentials simultaneously on two micropipettes, one filled with saline and the other with the beta-antagonist, timolol. Stimulation of the paragigantocellularis nucleus (PGi) was used as a method of producing NE release in the dentate gyrus, and thus, to assess the efficacy of beta-receptor blockade on the timolol pipette. Beta-blockade by timolol attenuated PGi-induced spike potentiation. HF-induced potentiation of the excitatory post-synaptic potential (EPSP) slope was also blocked by timolol, but HF-induced spike amplitude potentiation was unaffected. These results are consistent with an earlier report examining HF-long-term potentiation (LTP) following 6-OHDA-induced NE depletion, which showed that the EPSP slope LTP depended, for its full expression, on NE, but potentiation of the population spike amplitude component of HF-induced LTP did not. In the present study, PGi-induced potentiation of spike amplitude on the saline pipette was normal after HF-induced saturation of spike amplitude potentiation, suggesting that the mechanisms for expression of spike potentiation, as well as induction of spike potentiation, are separate for HF and NE stimulation.

Prevention of neoplastic seeding during surgery: an investigation into OR. Protocols and practice in Canada.

A review in the Medical Post (Wysong, 1996) discussed the merit of glove and instrument changes during cancer surgery with a view to reducing the incidence of neoplastic seeding. This review stimulated the author to investigate current practices in this regard adopted by surgical staff across Canada. The author believes that a valid comparison exists between practices utilized in infection control and those which can be used to limit the problem of neoplastic seeding at the time of surgery. Results indicated a considerable interest in adopting a protocol utilizing glove and instrument changes at critical points during surgery, such as reconstruction and closure.

Acute hydrocephalus following aneurysmal subarachnoid hemorrhage.

BACKGROUND: Acute hydrocephalus is a potentially treatable cause of early neurological deterioration after aneurysmal subarachnoid hemorrhage (SAH). METHODS: A retrospective study of 105 consecutive cases of aneurysmal SAH was undertaken to determine those factors significantly related to the development of acute hydrocephalus. Acute hydrocephalus was diagnosed when the bicaudate index was greater than the 95th percentile for age on a CT scan within 72 hours of the ictus. RESULTS: Thirty-one percent of the patients developed acute hydrocephalus. Grade of SAH was a significant factor for the development of acute hydrocephalus on univariate analysis as 87% of patients with acute hydrocephalus (29/32) presented with at least grade 3 (Hunt-Hess) SAH (P < 0.05). In addition, posterior circulation aneurysms on univariate analysis were associated with acute hydrocephalus (p < 0.05). Both premorbid hypertension and intraventricular blood (p < 0.05) were predictors for acute hydrocephalus, whereas intracisternal blood, age and sex were not. On multivariate linear regression analysis, factors found to be significantly associated with acute hydrocephalus were premorbid hypertension, intraventricular blood, CSF diversion and definitive shunt procedures. External ventricular drainage was not associated with any instances of rebleeding. Thirty-seven percent (10/27) of patients with acute hydrocephalus who survived were improved by pre-operative external ventricular drainage. CONCLUSIONS: Patients with acute hydrocephalus following SAH can be safely treated with external ventricular drainage. Multiple factors can be identified to predict those patients who will develop acute hydrocephalus post aneurysmal rupture. Approximately 30% of those patients with acute hydrocephalus will require definitive shunt placement. Acute hydrocephalus occurred in 31% of aneurysmal SAH patients in this series.

A prospective study of burn scar maturation in pediatrics: does age matter?

A prospective study was performed to determine whether patterns of burn scar maturation varied among different pediatric age groups. Patients were divided into three groups according to age at the time of burn injury: birth to 3 years, 4 to 11 years, and 12 to 18 years. Scarring of sheet grafts on an extremity was assessed throughout the maturation process in three areas: vascularity, pliability, and height. A 1-inch square was selected on the graft edge adjacent to unburned skin. Two experienced therapists independently evaluated the test area and averaged their scores. There were no significant differences in rate of scar maturation between age groups. Burn scar maturation of sheet skin grafts in the pediatric patient with burns demonstrated a rapid peak of scarring (1 to 2 months) and scar maturation (9 to 13 months).