Ultrasound-guided paramedian approach: A novel technique for lumbar puncture in the Emergency Department.

Lumbar puncture is performed to evaluate for multiple neurologic conditions, including meningitis and subarachnoid hemorrhage. However, success rates with the landmark-based technique are limited. Ultrasound is most commonly used for pre-marking without dynamic guidance, which presents several limitations, including absence of real-time guidance and lack of reliability if any patient movement occurs after skin marking. We describe a novel, ultrasound-guided paramedian approach which was successfully performed in the Emergency Department setting for lumbar puncture. Physicians should consider this technique as an alternate model using real-time guidance to reduce needle passes in those with difficult anatomy.

Ontogenetic variation in human nasal morphology.

Internal nasal cavity morphology has long been thought to reflect respiratory pressures related to heating and humidifying inspired air. Yet, despite the widely recognized importance of ontogeny in understanding climatic and thermoregulatory adaptations, most research on nasal variation in modern and fossil humans focuses on static adult morphology. This study utilizes cross-sectional CT data of three morphologically distinct samples (African, European, Arctic) spanning from infancy to adulthood (total n = 321). Eighteen landmarks capturing external and internal regions of the face and nose were subjected to generalized Procrustes and form-space principal component analyses (separately conducted on global and individual samples) to ascertain when adult-specific nasal morphology emerges during ontogeny. Across the global sample, PC1 (67.18% of the variation) tracks age-related size changes regardless of ancestry, while PC2 (6.86%) differentiates between the ancestral groups irrespective of age. Growth curves tracking morphological changes by age-in-years indicate comparable growth trajectories across all three samples, with the majority of nasal size and shape established early in ontogeny (<5 years of age). Sex-based trends are also evident, with females exhibiting a more truncated growth period than males, particularly for nasal height dimensions. Differences are also evident between the anterior and posterior nose, with the height and breadth dimensions of the anterior nasal aperture and nasal cavity showing differential ontogenetic patterns compared to the choanae. Cumulatively, these results suggest that multiple selective pressures influence human nasal morphology through ontogenetic processes, including metabolic demands for sufficient oxygen intake and climatic demands for adequate intranasal air conditioning.