Predicting postoperative day 1 hematocrit levels after hysterectomy.

BACKGROUND: The Swenson model was developed as a linear regression model to estimate postoperative day 1 hematocrit levels after benign hysterectomy. Predictive variables included preoperative hematocrit level, patient weight, estimated blood loss, intraoperative crystalloid volume, preoperative platelet count, and hysterectomy route that predicted postoperative day 1 hematocrit level at ±5% for 100% of patients who used an internal validation set. OBJECTIVE: We aimed to validate externally the Swenson model using our hysterectomy population and to further validate the model in a cohort that included robotic-assisted cases. STUDY DESIGN: In a retrospective cohort, data were collected from benign hysterectomies from April 2014 through May 2016. Predicted postoperative day 1 hematocrit level was calculated with the use of the Swenson equation and compared with measured hematocrit values. We compared our results to the Swenson model results using chi-square or Fisher's exact test. We then restricted our analysis to those with actual postoperative day 1 hematocrit level of ≤30%, to determine whether the model performed accurately in this subgroup that may need intervention. We generated a receiver-operating characteristic curve with Louden Index to determine the best cut-point from the Swenson hematocrit level projections for the prediction of an actual hematocrit level of ≤30%. Furthermore, we stratified the Swenson model predicted hematocrit level into 4 ranges: <32%, 32-35%, 35-38%, and >38%. This stratification allowed us to assess the differential accuracy of the Swenson model across hematocrit level ranges. RESULTS: Of 602 hysterectomies, 478 patients had all the variables that were needed for the Swenson model and postoperative day 1 hematocrit level for comparison. The Swenson model was significantly less accurate in our data compared with their validation set with fewer patients whose predicted hematocrit level was accurate at different thresholds from ±1% through ±5% of actual hematocrit level (all P<.001). Only 76.8% of the predicted hematocrits were accurate within ±5%. Analysis of variance showed accuracy that was similar among different surgical routes (P=.193). A quadratic best-fit curve showed accuracy was maximized when hematocrit level of 36.2%. Projected hematocrit level was ±2.5% of actual but deteriorated at higher and lower hematocrit level values. When the analysis was restricted to those patients with postoperative day 1 hematocrit levels of ≤30%, accuracy was worse, with only 55.3% of predicted hematocrit level values within ±5%. In this subset, the Swenson equation was more likely to overestimate hematocrit level and give false reassurance. A receiver-operating characteristic curve analysis showed that the best Swenson cut-point for the prediction of an actual hematocrit level of ≤30% was 31.9% (sensitivity, 75.5%; specificity, 64.0%). Finally, predicted hematocrit level was divided into 4 groups: <32%, 32-35%, 35-38%, and >38%. When predicted hematocrit level was <32% (n=164), the model was more likely to under-predict hematocrit level and was least accurate in the subset of patients who were most likely to need intervention. When predicted hematocrit level was 32-35% (n=192), 17.2% of the patients (approximately 1 in 6) had an actual postoperative day 1 hematocrit level of ≤30%. When a predicted hematocrit level of ≥35% was used as a cut-off point, the percentage of patients who had an actual postoperative day 1 hematocrit level of ≤30% dropped to 8.2%. No patients had an actual hematocrit level of <24%, which makes this a reasonable choice for screening for anemia. CONCLUSION: Although the Swenson model was reliable for the prediction of postoperative day 1 hematocrit level in their internal validation set, it did not perform as well in our hysterectomy population. It may have utility as a screening tool if the projected hematocrit level was ≥35%. Further research is needed to create a model for the prediction of postoperative day 1 hematocrit level that can be incorporated into standard practice.

Kidney Stones as an Underrecognized Clinical Sign in Pediatric Cushing Disease.

OBJECTIVE: To investigate the prevalence of kidney stones in a population of children with Cushing disease (CD) and to compare it with the prevalence of kidney stones in healthy children. STUDY DESIGN: Clinical and biochemical data from 139 pediatric patients with CD (68 females, 71 males) were analyzed retrospectively. Computed tomography scans were reviewed for kidney stones. RESULTS: Among 139 patients, 27 with CD (19.4%) had either radiographic evidence and/or a history of kidney stones. Those with kidney stones had higher urine free cortisol (P = .008) and transsphenoidal surgery at an older age (P = .007). The average urinary calcium/creatinine ratio was elevated in patients with CD (0.22 ± 0.11). The prevalence of kidney stones was higher in children with CD than in normal children (19.42% vs 1.0%; P < .001). CONCLUSION: Our results illustrate that kidney stones are an underestimated complication of pediatric CD, especially when compared with the prevalence of nephrolithiasis in the general pediatric population. Long-term consequences for kidney function are not known and need to be studied.

Delayed Diagnosis of Cushing's Disease in a Pediatric Patient due to Apparent Remission from Spontaneous Apoplexy.

We report here a pediatric patient whose Cushing's Disease was diagnosed late because of her cyclical presentation, presumably due to subclinical pituitary apoplexy. Starting at age 8, she presented with observable signs of Cushing's but was not clinically assessed for Cushing's Syndrome until the age of 15. Initial tests at age 15 were consistent with Cushing's Disease, however, the patient presented with spontaneous remission of hypercortisolemia just a few short months later. Her cushingoid features never subsided, and at age 17, her MRI showed a partially empty sella; this finding of an empty sella contributed evidence to our suspicion of asymptomatic apoplexy, especially since the patient never reported an episode of acute headache. Pituitary apoplexy in corticotroph adenomas is very uncommon, but even more rare in microadenomas, making this case very unusual. Lost to follow-up, she was not reevaluated for Cushing's Disease until age 25, and her laboratory tests were consistent with an adrenocorticotrophic-dependent pituitary tumor; Pituitary magnetic resonance imaging revealed a 9 mm X 6 mm X 8 mm mass projecting on the superior aspect of pituitary and abutting the wall of the right cavernous sinus. The patient had a transsphenoidal surgery to remove the microadenoma and is planned to undergo radiation therapy. To the best of our knowledge, this is the first report of subclinical apoplexy of a microadenoma in a pediatric patient with Cushing's Disease. It brings to light the importance of long term follow up for pediatric patients presenting with clinical symptoms of Cushing's Syndrome.