Angiographic factors associated with haemorrhagic presentation of brain arteriovenous malformation in a Chinese paediatric population

OBJECTIVE

To identify specific angiographic factors associated with haemorrhagic presentation of brain arteriovenous malformation in Chinese paediatric patients.

DESIGN

Retrospective cross-sectional observational study.

SETTING

Four locoregional tertiary neurosurgical centres in Hong Kong: Queen Elizabeth Hospital, Tuen Mun Hospital, Kwong Wah Hospital, and Pamela Youde Nethersole Eastern Hospital.

PATIENTS

Patients aged 18 years or younger who underwent pretreatment digital subtraction angiography for brain arteriovenous malformation between 1 January 2005 and 31 July 2013 were included. Patients were divided into haemorrhagic and non-haemorrhagic groups based on the initial presentation. Pretreatment digital subtraction angiographies were independently reviewed by two experienced neuroradiologists.

MAIN OUTCOME MEASURES

The following parameters were evaluated for their association with haemorrhagic presentation by univariate and multivariate analyses: nidus location, nidus size, nidus morphology (diffuse or compact); origin and number of arterial feeders; venous drainage; number of draining veins; presence of aneurysms, venous varices, and venous stenosis.

RESULTS

A total of 67 children and adolescents (28 male, 39 female) with a mean age of 12 years were included. Of them, 52 (78%) presented with haemorrhage. Arteriovenous malformation size (P=0.004) and morphology (P=0.05) were found to be associated with haemorrhagic presentation by univariate analysis. Small arteriovenous malformation nidus size and diffuse nidal morphology were identified as independent risk factors for haemorrhage by multivariate analysis.

CONCLUSION

Smaller arteriovenous malformation size and diffuse nidal morphology are angiographic factors independently associated with haemorrhagic presentation. Bleeding risk is important in determining the therapeutic approach (aggressive vs conservative) and timeframe, particularly in paediatric patients.

Hybrid expert-system approach to nurse scheduling

The objective of this research was to develop a hybrid expert system entitled NURSE-HELP to achieve flexible and effective scheduling for nurses. NURSE-HELP was developed with the emphasis on following the ergonomics guidelines, which will improve the performance of nurses. Moreover, the combination of linear zero-one goal programming and an expert system program reduces the program run time while maintaining the quality of the schedule. The system was evaluated by comparing 18 sets of 4-week schedules generated by the head nurses manually and by NURSE-HELP. Concerning the amount of time required to generate the schedules, NURSE-HELP averaged less than 20 minutes, whereas head nurses spent from 2 to 4 hours. The quality of the schedules was measured using the following four criteria: 1) minimum staff level not satisfied, 2) day off request not granted, 3) backward rotation, and 4) maximum consecutive work periods on the night shift. NURSE-HELP was superior in all these aspects.