Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Input: Consider Input: Context: We have previously shown that blood transfusion in the first 24 hours is an independent predictor of mortality, intensive care unit (ICU) admission, and increased ICU length of stay in the acute trauma setting when controlling for Injury Severity Score, Glasgow Coma Scale score, and age. Indices of shock such as base deficit, serum lactate level, and admission hemodynamic status (systolic blood pressure, heart rate) and admission hematocrit were considered potential confounding variables in that study. The objectives of this study were to evaluate admission anemia and blood transfusion within the first 24 hours as independent predictors of mortality, ICU admission, ICU length of stay (LOS), and hospital LOS, with serum lactate level, base deficit, and shock index (heart rate/systolic blood pressure) as covariates.', 'Prospective data were collected on 15,534 patients admitted to a Level I trauma center over a 3-year period (1998-2000) and stratified by age, gender, race, Glasgow Coma Scale score, and Injury Severity Score. Admission anemia and blood transfusion were assessed as independent predictors of mortality, ICU admission, ICU LOS, and hospital LOS by logistic regression analysis, with base deficit, serum lactate, and shock index as covariates.', 'Blood transfusion was a strong independent predictor of mortality (odds ratio [OR], 2.83; 95% confidence interval [CI], 1.82-4.40; p < 0.001), ICU admission (OR, 3.27; 95% CI, 2.69-3.99; p < 0.001), ICU LOS (p < 0.001), and hospital LOS (Coef, 4.37; 95% CI, 2.79-5.94; p < 0.001) when stratified by indices of shock (base deficit, serum lactate, shock index, and anemia). Patients who underwent blood transfusion were almost three times more likely to die and greater than three times more likely to be admitted to the ICU. Admission anemia (hematocrit < 36%) was an independent predictor of ICU admission (p = 0.008), ICU LOS (p = 0.012), and hospital LOS (p < 0.001).
Answer: Blood transfusion is confirmed as an independent predictor of mortality, ICU admission, ICU LOS, and hospital LOS in trauma after controlling for severity of shock by admission base deficit, lactate, shock index, and anemia. The use of other hemoglobin-based oxygen-carrying resuscitation fluids (such as human or bovine hemoglobin substitutes) in the acute postinjury period warrants further investigation.

Output: Is blood transfusion , independent of shock severity , associated with worse outcome in trauma?


Input: Consider Input: Context: Spinal anesthesia can be challenging in patients undergoing total joint arthroplasty because of poorly palpable surface landmarks and age-related changes in the lumbar spine. We hypothesized that pre-procedural ultrasound imaging would be effective in identifying the lumbar intervertebral spaces and would provide an accurate measure of the depth to the intrathecal space.', "Fifty patients undergoing elective total joint arthroplasty were recruited in this prospective descriptive study. Using a curved-array 2-5 MHz transducer, the lumbar spine was imaged in two views, i.e., longitudinal parasagittal (LP) and transverse midline (TM). The intervertebral levels were identified by counting upwards from the sacrum. The locations of the interlaminar spaces were identified by visualizing the ligamentum flavum-dura mater complex and the posterior aspect of the vertebral body. The needle insertion point for a midline approach was determined from the ultrasound examination and was marked on the skin of the patient's back.", 'The mean patient age was 67 +/- 10 yr, and 46% of the patients had a body mass index >30 kg . m(-2). Surface landmarks were difficult or impossible to palpate in 38% of the patients. The scan quality on the LP and TM views was adequate or better in 100 and 98% of the patients, respectively. Dural puncture was achieved with one needle insertion attempt and within two needle insertion attempts in 84% and 98% of the patients, respectively. The ultrasound-measured depth to the intrathecal space correlated well with the actual needle insertion depth (concordance correlation coefficient = 0.82, accuracy 0.95, precision 0.86), with a tendency to overestimate the depth by just 2.1 +/- 5.4 mm.
Answer: Ultrasound imaging of the lumbar spine provides clinically useful information that can facilitate spinal anesthesia in the older orthopedic patient population.

Output: Does an ultrasound-assisted approach facilitate spinal anesthesia for total joint arthroplasty?


Input: Consider Input: Context: The incidence of ureteral stenosis in kidney transplant recipients is 3%-8%. The treatment of ureteral stenosis has been traditionally operative reconstruction, although such intervention is associated with high rates of serious complications, including graft loss and even perioperative mortality. More recently, endourological treatment has been proposed due to its low morbidity.', 'The objective of this study was to assess the usefulness of balloon percutaneous dilatation as a treatment technique for ureteral stenosis in kidney transplant recipients.', 'Among 1000 kidney transplantations performed between 1980 and 2004, the coexistence of high creatinine values and urinary tract dilatation in the postoperative period, after discarding concomitant causes, was managed with a percutaneous nephrostomy. Once renal function recovered, antegrade pyelography was performed to confirm the presence and determine the location of ureteral stenosis. Ureteral dilatation was performed using a 5-French balloon-fitted angioplasty catheter.', 'Fifty-six patients were diagnosed with ureteral stenosis during follow-up, an incidence of 5.6%. Transluminal balloon dilatation was the first therapeutic option in 45 cases, whereas surgery was performed directly on 11 patients. Disappearance of the stenosis as well as maintenance of an improved creatinine level was verified in 45% of cases (20 patients). Two patients experienced graft loss. Both a short time to diagnosis after transplantation (P = .06) and the presence of a previous acute rejection episode (P < .05) were good prognosis factors for the endourologic solution of a ureteral stricture.
Answer: Balloon dilatation may be considered the definitive procedure for treatment of ureteral stenosis in selected cases. Percutaneous nephrostomy should be used for initial diagnosis and improvement in the renal function before attempting an open procedure.


Output: Is endourological management better in early-onset ureteral stenosis in kidney transplantation?