Ventilation and perfusion scanning in children

Defining information needs in neonatal resuscitation with work domain analysis

OBJECTIVE

To gain a deeper understanding of the information requirements of clinicians conducting neonatal resuscitation in the first 10 min after birth.

BACKGROUND

During the resuscitation of a newborn infant in the first minutes after birth, clinicians must monitor crucial physiological adjustments that are relatively unobservable, unpredictable, and highly variable. Clinicians' access to information regarding the physiological status of the infant is also crucial to determining which interventions are most appropriate. To design displays to support clinicians during newborn resuscitation, we must first carefully consider the information requirements.

METHODS

We conducted a work domain analysis (WDA) for the neonatal transition in the first 10 min after birth. We split the work domain into two 'subdomains'; the physiology of the neonatal transition, and the clinical resources supporting the neonatal transition. A WDA can reveal information requirements that are not yet supported by resources.

RESULTS

The physiological WDA acted as a conceptual tool to model the exact processes and functions that clinicians must monitor and potentially support during the neonatal transition. Importantly, the clinical resources WDA revealed several capabilities and limitations of the physical objects in the work domain-ultimately revealing which physiological functions currently have no existing sensor to provide clinicians with information regarding their status.

CONCLUSION

We propose two potential approaches to improving the clinician's information environment: (1) developing new sensors for the information we lack, and (2) employing principles of ecological interface design to present currently available information to the clinician in a more effective way.

Pulmonary perfusion scans following transcatheter patent ductus arteriosus closure using the Amplatzer devices

INTRODUCTION

Obstruction to flow in the left pulmonary artery (LPA) is a well-known complication after transcatheter device closure of patent ductus arteriosus (PDA). This complication has been studied for different devices using lung perfusion radionuclide scintigraphy (LPRS), but not for Amplatzer devices. This study was performed to evaluate the effect of such devices on lung perfusion using LPRS.

METHODS

This is a retrospective study that looked at all patients who had PDA closure using different Amplatzer devices at our center between July 1999 and January 2007. All patients underwent LPRS within 24 hr of the procedure. We compared LPRS with other hemodynamic data obtained by cardiac catheterization and echocardiography. Results are presented as mean ± SD or median and ranges.

RESULTS

A total of 70 patients had PDA closure using an Amplatzer device; median age was 1.8 years (4 months to 75 years) and median weight was 12 kg (5-112 Kg). Nine patients had associated cardiac anomalies. Sixty eight patients had available LPRS. The mean percent of left lung perfusion (LLP) was 42.7% (± 6.7%). Excluding patients with pre-existing LPA stenosis, 17% had abnormally decreased LLP. On hemodynamic measurements, 62 patients had available direct pressure measurements following PDA closure. None had significant increase. No correlation was found with echocardiographic data.

CONCLUSION

PDA closure with Amplatzer family of devices is associated with a relatively significant risk of decreased perfusion to the left lung, mostly mild abnormalities. Comparison with catheterization and echocardiographic measurements showed lack of correlation with LPRS findings.

Guidelines for lung scintigraphy in children

The purpose of this set of guidelines is to help the nuclear medicine practitioner perform a good quality lung isotope scan. The indications for the test are summarised. The different radiopharmaceuticals used for the ventilation and the perfusion studies, the technique for their administration, the dosimetry, the acquisition of the images, the processing and the display of the images are discussed in detail. The issue of whether a perfusion-only lung scan is sufficient or whether a full ventilation-perfusion study is necessary is also addressed. The document contains a comprehensive list of references and some web site addresses which may be of further assistance.