Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge.

A preload challenge (PC) is a clinical maneuver that, first, increases the cardiac filling (i.e., preload) and, second, calculates the change in cardiac output. Fundamentally, a PC is a bedside approach for testing the Frank-Starling-Sarnoff (i.e., "cardiac function") curve. Normally, this curve has a steep slope such that a small change in the cardiac preload generates a large change in the stroke volume (SV) or cardiac output. However, in various disease states, the slope of this relationship flattens such that increasing the volume into the heart leads to little rise in the SV. In this pathological scenario, additional cardiac preload (e.g., intravenous fluid) is unlikely to be physiologically effective and could lead to harm if organ congestion evolves. Therefore, inferring both the cardiac preload and output is clinically useful as it may guide intravenous (IV) fluid resuscitation. Accordingly, the goal of this protocol is to describe a method for contemporaneously tracking the surrogates of cardiac preload and output using a novel, wireless, wearable ultrasound during a well-validated preload challenge.

Intra-articular dysplasia of the femoral head in developmental dysplasia of the hip.

Central to the current treatment of dysplasia of the hip (DDH) is the concept of congruent reduction of the hip. If the femoral head is aspherical in DDH, this concept needs reconsideration. MRI scans are used to examine the femoral head in children. Diameters of 14 DDH and 12 normal hips were measured in three planes by eight observers on two occasions. Femoral head sphericity was determined using the mathematical concept of eccentricity. In DDH, the femoral head was less spherical, most marked in the coronal plane, yielding a 'rugby ball'-shaped femoral head. Accordingly, concentric reduction of the femoral head in DDH is impossible.