Perioperative specific management of blood volume loss in craniosynostosis surgery

Accurate assessment and replacement of blood loss and fluid–electrolyte deficit during craniosynostosis repair is difficult owing to patient size and the diversity of surgical technique. Forty-three patients undergoing primary craniosynostosis repair over a 10-year period were studied retrospectively to determine blood loss and fluid deficit and to assess blood transfusion practices during both intraoperative and postoperative periods. Blood loss was calculated on the basis of estimated red cell mass (ERCM) and fluid-electrolyte imbalance was investigated with blood samplings. Blood transfusion was considered appropriate if the postoperative or posttransfusion ERCM was within 12% of the preoperative value. Estimated fluid requirement (EFR) was used in 4 ml kg^–1 h^–1 except for neonates. Intraoperatively, 80% of all patients were appropriately managed with respect to blood transfusion and EFR. Postoperatively only 20% of the patients receiving transfusions were transfused appropriately. In 23.3% of these patients (10/43) unexpected respiratory distress developed immediately after their recovery from the anesthesia. With the measurement of estimated blood volume and allowable blood loss, appropriate transfusion could be achieved for the successful treatment of the primary craniosynostosis. Received: 16 February 1998     

Ischemic necrosis of the entire femoral head and rapidly destructive hip disease: potential causative relationship

 Objective. Rapidly destructive hip disease (RDHD) is an uncommon disorder of the hip that has been considered a disease of unknown cause and distinct from ischemic necrosis of the femoral head. The objective of this study was to investigate ischemic necrosis of the femoral head as one potential cause of RDHD. Design and patients. In 600 patients who underwent MR imaging of the hip, 20 cases of ischemic necrosis involving the entire femoral head in 18 patients (3%) were retrospectively studied with routine radiography and MR imaging. All patients had surgically confirmed ischemic necrosis of the femoral head. Results and conclusions. All patients showed rapid destruction of the femoral head on routine radiography and MR imaging as compared with the gradual onset of clinical symptoms. Plain radiographs showed several bone fragments at the inferomedial aspect of the femoral head (75%), acetabular erosions (55%), eccentric depression at the lateral articular surface of the femoral head conforming to the adjacent acetabulum (35%), and mild osteoarthritis (15%). Bone sclerosis was often present at sites of impaction between the femoral head and the acetabulum. MR imaging showed marked distention of the joint capsule in all cases. In 14 of 20 cases, the contents of the joint space showed predominantly low or intermediate signal intensity on T1- and T2-weighted images. Ischemic necrosis involving the entire femoral head may represent one of the causes of RDHD.     

Substance P augments a persistent slow inward calcium-sensitive current in voltage-clamped spinal dorsal horn neurons of the rat

Rat spinal dorsal horn neurons in slice preparations perfused with Ringer solution containing 0.5-1 microM TTX and/or 10-20 mM tetraethylammonium at 29 degrees C, were studied by using a single microelectrode voltage-clamp technique. Slow persistent inward currents were recorded during depolarizing voltage commands to membrane potentials positive to about -40 mV. The inward current was depressed by removing external Ca, or by adding 0.1-0.2 mM Cd, 5 mM Co or 0.1 mM verapamil, and was increased by adding Ba or Bay-K 8644. Substance P (SP) augmented a persistent slow inward Ca-sensitive current in a dose-dependent manner. It is suggested that this effect may be instrumental in generating the SP-evoked slow depolarization, increase in membrane excitability, and the 'bursting' behavior in the immature rat dorsal horn neurons. In addition, in some neurons SP reduced the M-like current, which effect may contribute to, but not explain, generation of the SP-induced slow depolarization.