New model predicts posthysterectomy hematocrit

SCOTTSDALE, ARIZ. – A simple model may help individualize the ordering of blood work after an uncomplicated hysterectomy done for benign indications, according to Dr. Carolyn W. Swenson.

Weight, preoperative hematocrit, and race independently predicted a higher hematocrit on postoperative day 1. Estimated blood loss, volume of intraoperative crystalloid used, preoperative platelet count, and use of intraoperative crystalloid as a dichotomous variable independently predicted a lower hematocrit, she said at the annual meeting of the Society of Gynecologic Surgeons.

Using a mathematical model based on the seven variables accurately predicted hematocrit on postoperative day 1 in 91% of cases, where accuracy was defined as a predicted hematocrit that fell within 4 percentage points of the actual value. "This may support the selective ordering of postoperative labs after hysterectomy, which not only would limit unnecessary lab tests for patients, but also increase the cost effectiveness of our medical care, which could lead to considerable cost savings," Dr. Swenson said at the meeting, jointly sponsored by the American College of Surgeons.

"At this conference, we have heard a lot about the importance of resource utilization in practice and cost-effective medical care," said lead investigator Dr. Swenson of the University of Michigan, Ann Arbor. "So if I told you there was an easy way to have one less thing to follow up on after a hysterectomy, there would be one less procedure for patients to undergo, and this simple thing could potentially save the health care system over $7 million a year, hopefully many of you would be interested."

Dr. Swenson and her colleagues analyzed data from 1,918 women who had hysterectomies in 2012 and validated the model in 366 comparable women operated on in 2013. The data came from the Michigan Surgical Quality Collaborative, which includes 49 community and academic hospitals. The researchers excluded patients with cancer or sepsis, those with obstetric or emergent indications, and patients receiving perioperative blood transfusions. The database included patients who had hysterectomies done for prolapse.

"In order to facilitate the use of this model, we are in the process of developing an iPhone app so that at the end of a case, a surgeon can easily and quickly calculate [the patient’s] predicted postop day 1 hematocrit, and then use that value along with their clinical judgment to decide whether or not to order this lab test," she said. "It’s just seven variables. You don’t need an iPhone app to be able to do it, but it just makes it a lot easier."

A complete blood cell count often is routinely ordered after a hysterectomy, yet "the literature shows that in the absence of any clinical suspicion, routine postoperative labs after gynecologic surgery essentially never affect clinical outcomes."

On average, the women studied were 47 years old and had a body mass index of 31 kg/m², reported Dr. Swenson. More than three-fourths were white, and about one-fourth were smokers. Hysterectomies were done by a variety of routes, with the largest share, roughly 40%, done laparoscopically.

Dr. Swenson disclosed no relevant conflicts of interest.

SCOTTSDALE, ARIZ. – A simple model may help individualize the ordering of blood work after an uncomplicated hysterectomy done for benign indications, according to Dr. Carolyn W. Swenson.

Weight, preoperative hematocrit, and race independently predicted a higher hematocrit on postoperative day 1. Estimated blood loss, volume of intraoperative crystalloid used, preoperative platelet count, and use of intraoperative crystalloid as a dichotomous variable independently predicted a lower hematocrit, she said at the annual meeting of the Society of Gynecologic Surgeons.

Using a mathematical model based on the seven variables accurately predicted hematocrit on postoperative day 1 in 91% of cases, where accuracy was defined as a predicted hematocrit that fell within 4 percentage points of the actual value. "This may support the selective ordering of postoperative labs after hysterectomy, which not only would limit unnecessary lab tests for patients, but also increase the cost effectiveness of our medical care, which could lead to considerable cost savings," Dr. Swenson said at the meeting, jointly sponsored by the American College of Surgeons.

"At this conference, we have heard a lot about the importance of resource utilization in practice and cost-effective medical care," said lead investigator Dr. Swenson of the University of Michigan, Ann Arbor. "So if I told you there was an easy way to have one less thing to follow up on after a hysterectomy, there would be one less procedure for patients to undergo, and this simple thing could potentially save the health care system over $7 million a year, hopefully many of you would be interested."

Dr. Swenson and her colleagues analyzed data from 1,918 women who had hysterectomies in 2012 and validated the model in 366 comparable women operated on in 2013. The data came from the Michigan Surgical Quality Collaborative, which includes 49 community and academic hospitals. The researchers excluded patients with cancer or sepsis, those with obstetric or emergent indications, and patients receiving perioperative blood transfusions. The database included patients who had hysterectomies done for prolapse.

"In order to facilitate the use of this model, we are in the process of developing an iPhone app so that at the end of a case, a surgeon can easily and quickly calculate [the patient’s] predicted postop day 1 hematocrit, and then use that value along with their clinical judgment to decide whether or not to order this lab test," she said. "It’s just seven variables. You don’t need an iPhone app to be able to do it, but it just makes it a lot easier."

A complete blood cell count often is routinely ordered after a hysterectomy, yet "the literature shows that in the absence of any clinical suspicion, routine postoperative labs after gynecologic surgery essentially never affect clinical outcomes."

On average, the women studied were 47 years old and had a body mass index of 31 kg/m², reported Dr. Swenson. More than three-fourths were white, and about one-fourth were smokers. Hysterectomies were done by a variety of routes, with the largest share, roughly 40%, done laparoscopically.

Dr. Swenson disclosed no relevant conflicts of interest.

SCOTTSDALE, ARIZ. – A simple model may help individualize the ordering of blood work after an uncomplicated hysterectomy done for benign indications, according to Dr. Carolyn W. Swenson.

Weight, preoperative hematocrit, and race independently predicted a higher hematocrit on postoperative day 1. Estimated blood loss, volume of intraoperative crystalloid used, preoperative platelet count, and use of intraoperative crystalloid as a dichotomous variable independently predicted a lower hematocrit, she said at the annual meeting of the Society of Gynecologic Surgeons.

Using a mathematical model based on the seven variables accurately predicted hematocrit on postoperative day 1 in 91% of cases, where accuracy was defined as a predicted hematocrit that fell within 4 percentage points of the actual value. "This may support the selective ordering of postoperative labs after hysterectomy, which not only would limit unnecessary lab tests for patients, but also increase the cost effectiveness of our medical care, which could lead to considerable cost savings," Dr. Swenson said at the meeting, jointly sponsored by the American College of Surgeons.

"At this conference, we have heard a lot about the importance of resource utilization in practice and cost-effective medical care," said lead investigator Dr. Swenson of the University of Michigan, Ann Arbor. "So if I told you there was an easy way to have one less thing to follow up on after a hysterectomy, there would be one less procedure for patients to undergo, and this simple thing could potentially save the health care system over $7 million a year, hopefully many of you would be interested."

Dr. Swenson and her colleagues analyzed data from 1,918 women who had hysterectomies in 2012 and validated the model in 366 comparable women operated on in 2013. The data came from the Michigan Surgical Quality Collaborative, which includes 49 community and academic hospitals. The researchers excluded patients with cancer or sepsis, those with obstetric or emergent indications, and patients receiving perioperative blood transfusions. The database included patients who had hysterectomies done for prolapse.

"In order to facilitate the use of this model, we are in the process of developing an iPhone app so that at the end of a case, a surgeon can easily and quickly calculate [the patient’s] predicted postop day 1 hematocrit, and then use that value along with their clinical judgment to decide whether or not to order this lab test," she said. "It’s just seven variables. You don’t need an iPhone app to be able to do it, but it just makes it a lot easier."

A complete blood cell count often is routinely ordered after a hysterectomy, yet "the literature shows that in the absence of any clinical suspicion, routine postoperative labs after gynecologic surgery essentially never affect clinical outcomes."

On average, the women studied were 47 years old and had a body mass index of 31 kg/m², reported Dr. Swenson. More than three-fourths were white, and about one-fourth were smokers. Hysterectomies were done by a variety of routes, with the largest share, roughly 40%, done laparoscopically.

Dr. Swenson disclosed no relevant conflicts of interest.