Retained foreign body: a fingernail fragment?

A 19-year-old female presented four and one-half months after an occupational injury from a punch-type machine. Exploration revealed a large fragment of her fingernail embedded in the fingerpad. Foreign bodies are commonly encountered in the practice of emergency medicine and failure to localize and remove them can result in significant morbidity. We present a case of a fingernail as a foreign body. Foreign bodies may be difficult to detect despite sophisticated imaging techniques. Although not visualized often, a radiolucent foreign body may be inferred from boney changes. A thorough history regarding mechanism of injury and resultant wound exploration are required. When an adequate wound examination using digital tourniquet control and proper precautions is performed, the majority of foreign bodies will be detected.

Control and optimization of apheresis procedures in a COBE 2997 cell separator.

To obtain more efficient operation of a COBE Model 2997 clinical cell separator using either a Single Stage II (SS II) or a Dual Stage separation chamber, modifications were made to allow complete computer control. Product cell density was detected using an optical sensor and controlled by automatic feedback through a microcomputer interface. Control was accomplished by automatically adjusting the red blood cell (RBC) and plasma product flow rates using a proportional-integral (PI) algorithm. Results show that, using either chamber, the product cell density can be maintained at a preselected value for extended periods of time without operator intervention. This system allowed investigation of optimal operating regions for plateletpheresis and leukapheresis procedures. The effects of centrifuge rpm and controller set point on centrifuge operation were investigated using a second order factorial experimental design. Theoretical significance of model parameters was assessed with the aid of a hindered settling model and simple reasoning about the interface position relative to the collection port. The results suggest that, in either chamber, the optimum operating region for plateletpheresis procedures occurs at moderate controller set points and high centrifuge rpm. The resultant operating efficiency and product purity values are approximately 63 percent and 0.65 respectively in the SS II chamber and approximately 70 percent and 0.70 respectively in the Dual Chamber. In the SS II, the optimum operating region for leukapheresis procedures occurred at high controller set point values for any centrifuge rpm above 1200 with an operating efficiency near 100 percent. However, in the Dual Chamber, the optimum operating region for leukapheresis procedures occurred at high controller set points and high centrifuge rpm's, again providing an operating efficiency near 100 percent.

Interface dynamics in a centrifugal cell separator.

Experiments were performed with bovine blood to study the response of the plasma/cell interface position to pumping rate adjustments in two single-stage (SS I and SS II) cell separation chambers. Standard clinical instrumentation and equipment and on-line computer interfacing were used to monitor and control the interface position. The data provided a quantitative description of its dynamics in the SS I and the SS II chambers. In the SS I chamber, adjustments in the flow rate caused the interface to move very slowly and in a complex manner from one steady-state operation position to another. Such behavior made both manual and computer-controlled operation very difficult. By contrast, the SS II chamber was inherently unstable for most operating conditions. We demonstrated, however, that a feedback controller could be used easily to adjust or maintain the interface position, and this system moved from one steady-state operating condition to another 10 times as fast as the system using the SS I chamber. Also, the manner in which the controller allowed the system to respond to operator requests was much simplier than that for the SS I system.

Closed tendon injuries of the hand in athletics.

Closed tendon injuries in the hand are common in the athlete. Neglect of such injuries may result in irreparable damage to the hand. Even seemingly minor injuries must be carefully evaluated and treated by a physician. Early diagnosis, accurate and precise treatment, and proper rehabilitation are extremely important to regain optimal function after these injuries. Most of the injuries can be controlled by conservative means. However, when surgical repair is indicated, it is important for the surgeon to be trained and familiar with the anatomy and techniques of surgery of the hand.

Iliacus hematoma and subsequent femoral nerve palsy after penetration of the medical acetabular wall during total hip arthroplasty. Report of a case.

Intrapelvic perforation of the medial acetabular wall during total hip arthroplasty is not uncommon but has been associated only rarely with adverse effects. A postoperative iliacus hematoma with secondary femoral nerve palsy occurred in a 61-year-old woman. The patient had been on Coumadin prophylaxis against deep venous thrombosis, but bleeding times were never excessively prolonged. Diagnosis was made by computerized tomographic (CT) scan. Conservative therapy produced resolution of the nerve deficit within eight months. Careful attention to the placement of anchoring drill holes in the acetabulum could have prevented this complication. Iliacus hematoma should be considered in the differential diagnosis of a femoral nerve palsy in the postoperative total hip patient, particularly if anticoagulation is employed.