A seventeen-year-old girl who had adolescent idiopathic scoliosis had a posterior spinal arthrodesis for the treatment of a double major curve (58 degrees to the right from the fourth to the tenth thoracic vertebra, with correction to 40 degrees on side-bending, and 56 degrees to the left from the eleventh thoracic to the third lumbar vertebra, with correction to 24 degrees on side-bending). Previous treatment had consisted of two years of surface electrical stimulation with an electrospinal orthosis (Medtronic, Minneapolis, Minnesota), which was worn while the patient was sleeping. The curve progressed despite this treatment, and the patient did not have additional follow-up until she was seen by us.
The patient was healthy but of slight build: she was 145 centimeters tall and weighed thirty-eight kilograms. She donated three units of autologous blood before the procedure. Preoperatively, the hemoglobin level was 108 grams per liter (normal, 115 to 165 grams per liter), the platelet count was 400 x 109 per liter (normal, 150 to 400 x 109 per liter), the activated partial thromboplastin time was twenty-nine seconds (normal, twenty-one to thirty-two seconds), and the prothrombin time was 11.6 seconds (normal, 10.5 to 12.7 seconds).
General anesthesia was maintained with nitrous oxide and isoflurane, and the systolic blood pressure was kept between eighty and ninety millimeters of mercury (10.66 and 12.00 kilopascals) with nitroprusside. The patient was under anesthesia for a total of nine hours; the duration of the operation was six hours and fifteen minutes. A routine posterior approach was used, and an arthrodesis was performed from the third thoracic to the second lumbar vertebra with use of Cotrel-Dubousset instrumentation.
There was slightly more bleeding than usual during the dissection, so thrombin-soaked Gelfoam sponges were used to aid hemostasis. Shed blood was salvaged with the Cell Saver 3 (Haemonetics), and heparin (30,000 units per liter of normal saline solution) was used as the anticoagulant. The heparinized saline solution was dripped in at fifteen milliliters per 100 milliliters of whole-blood loss. In this instance, three units of salvaged cells were infused, with the anticoagulant volume totaling 650 milliliters (a total of 650/1000 x 30,000 x 19,500 units of heparin).
A standard wake-up test to determine the function of the spinal cord was performed four and one-half hours after the induction of anesthesia, when the instrumentation was in place and correction had been achieved. The patient moved the feet well and was put back under anesthesia. At that time, the estimated blood loss was 1400 milliliters, the pulse rate was eighty beats per minute, the blood pressure was 70/40 millimeters of mercury (9.33/5.33 kilopascals), and the urinary output was 400 milliliters (average, eighty milliliters per hour). By that time, the patient had received 7000 milliliters of normal saline solution, the hemoglobin level was fifty grams per liter, and the hematocrit was 15 per cent. Bone graft was taken from the posterior iliac crest while decortication of the site of the arthrodesis was completed.
The first unit of predonated autologous blood was to be transfused approximately fifteen minutes before the wake-up test was performed, but transfusion was delayed by half an hour because the identification number on the blood did not match that on the patient's wristband. While the issue of blood identification was being resolved at the blood bank, the patient received 500 milliliters of 5 per cent albumin followed by the first unit from the Cell Saver. After matching had been confirmed, the first unit of predonated autologous blood was transfused with another 500 milliliters of 5 per cent albumin. During this delay, the patient remained stable, with a systolic blood pressure of sixty-five to seventy millimeters of mercury (8.66 to 9.33 kilopascals) and a pulse rate of ninety-five to 100 beats per minute.
Thirty minutes after initiation of the transfusion of the first unit of washed salvaged cells, both wounds began to fill rapidly with blood while the incisions were being closed. There was no indication of a transfusion reaction, so the second unit of predonated autologous blood, the second unit from the Cell Saver, 500 milliliters of 5 per cent albumin, and 1500 milliliters of normal saline solution were infused. Fifteen minutes later, the systolic blood pressure dropped to fifty millimeters of mercury (6.67 kilopascals), and the pulse rate, to forty beats per minute; ST-segment depression was seen on the electrocardiogram. Atropine, epinephrine, and bicarbonate were administered along with the third unit of predonated autologous blood and the third unit from the Cell Saver while wound closure was completed expeditiously. Despite the administration of another 1500 milliliters of normal saline solution (which brought the total fluid replacement to 10,000 milliliters of normal saline solution, 1500 milliliters of 5 per cent albumin, three units of predonated autologous blood, and three units of washed salvaged blood), the patient remained hypotensive with a systolic blood pressure of fifty millimeters of mercury (6.67 kilopascals) for another twenty minutes until the systolic blood pressure returned to 120 millimeters of mercury (16.00 kilopascals). The patient was rolled to the supine position and was noted to have a grossly distended abdomen, generalized edema (especially about the face), and hematuria. Fifteen minutes after wound closure and during the following two hours, she received two units of homologous blood, three units of fresh-frozen plasma, another 4000 milliliters of normal saline solution, and ten units of platelets. Thus, the total fluid replacement included 14,000 milliliters of normal saline solution, 1500 milliliters of 5 per cent albumin, three units of predonated autologous blood, three units of washed salvaged blood, two units of banked blood, ten units of platelets, and three units of fresh-frozen plasma.
A radiograph of the chest showed bilateral pulmonary infiltrates consistent with either adult respiratory distress syndrome or transfusion-related acute lung injury. A computed tomography scan, made on an emergency basis, showed marked amounts of ascites (with a density ranging from approximately one to twenty Hounsfield units) within the abdomen but no evidence of retroperitoneal hematoma.
Forty minutes after the hemodynamic collapse, the prothrombin time was 17.4 seconds, the activated partial thromboplastin time was 150 seconds, the fibrinogen level was 0.8 gram per liter (normal, 1.48 to 4.22 grams per liter), the level of fibrin degradation products was more than forty milligrams per liter (normal, less than ten milligrams per liter), and the hemoglobin level was ninety-seven grams per liter. There had been no rash or evidence of a transfusion reaction intraoperatively, and subsequent Coombs' tests and repeat blood-typing of returned blood-unit bags showed no incompatibility.
The patient required five days of mechanical ventilation in the intensive-care unit and received four additional units of packed red blood cells, eight units of fresh-frozen plasma, and one unit of cryoprecipitate. The coagulation profile returned to almost normal on the first postoperative day, but the clinical course was further complicated by acute pancreatitis that necessitated parenteral nutrition for ten days. She was discharged to home in good condition thirteen days after the operation with satisfactory correction of the scoliosis.
Six months after the operation, the patient had a thoracic curve of 20 degrees, a lumbar curve of 32 degrees, and intact neurological function. The hardware had not migrated but it was somewhat prominent and was palpable under the skin, with the stabilization rod on the right causing minor irritation. The patient was able to begin physical therapy and physical-education class but was not permitted to participate in contact sports.