DKA Optic Ultrasound
DKA Optic Ultrasound
Diabetic ketoacidosis (DKA) is a complication of type 1, or "insulin-dependent," diabetes
 (T1DM) and is defined by a high blood glucose level (over 200 mg/dL) coupled with severe
 acidosis. In this state the body breaks down fat tissue for adequate energy production. This
 results in ketone and acid production, and ultimately DKA. Cerebral edema (CE), or "brain
 swelling," can also occur with severe DKA. Current evaluation for DKA-related CE necessitates
 a high index of clinical suspicion and often times such patients receive advanced brain
 imaging such as computed tomography (CT) scans.Ocular sonography (ultrasound) is an
 alternative imaging technique that can provide immediate diagnostic capability at the bedside
 and minimize radiation exposure. This technique has been used to rapidly and accurately
 detect increased brain swelling through measurement of the optic nerve sheath diameter (ONSD)
 in a number of clinical situations including pediatric head trauma, hydrocephalus and
 ventriculoperitoneal shunt malfunctions, and altitude sickness in adults. Investigators plan
 to conduct a prospective study including children aged 7-18 years. The objective of this
 study is to assess the utility of sonographic measurements of the ONSD as a tool for
 identification of DKA-related CE.
Diabetic ketoacidosis (DKA) is a complication of type 1, or "insulin-dependent," diabetes
 (T1DM) and is defined by a high blood glucose level (over 200 mg/dL) coupled with severe
 acidosis. Children with T1DM lack adequate insulin production. Without insulin, glucose
 cannot be used by cells to produce energy and blood glucose levels increase. As a result, the
 body breaks down fat tissue for adequate energy production. This results in ketone and acid
 production, and ultimately DKA. Often times DKA is present at the time of diabetes diagnosis.
 Recent estimates suggest that nearly 30% of children that present with DKA are newly
 diagnosed with diabetes. DKA can also occur as a result of poorly controlled T1DM or poor
 adherence to insulin therapy. It is common for such patients to have recurrent episodes of
 DKA, which may lead to permanent brain injury.

 Cerebral edema (CE), or "brain swelling," can also occur with severe DKA. It is unclear what
 causes CE in children with DKA. Proposed mechanisms include changes in blood flow to the
 brain, inflammatory mediation, and alteration in the intracellular and extracellular fluid
 composition in the brain. CE can be "clinically apparent" or "subclinical" in terms of
 symptomatology. Children with clinically apparent DKA-related CE present with neurologic
 deficits and altered mental status. These children are at risk for herniation of the brain
 stem due to elevated pressures in and around the brain, and ultimately death. The neurologic
 manifestations of clinically apparent DKA-related CE typically occur 4-12 hours after the
 initiation of medical therapy. However, cases have been reported to occur prior to initiation
 of therapy. Although clinically apparent DKA-related CE is rare, occurring in 0.5-1% of
 children with DKA, subclinical DKA-related CE is much more common with estimates suggesting
 that up to 54% of children with DKA have underlying CE that goes clinically undetected. Early
 identification of both clinically apparent and subclinical DKA-related CE is critical as the
 time between initial neurologic symptoms and clinical deterioration can be as little as 3
 hours. Moreover, early identification of subclinical DKA-related CE may lead to differences
 in medical therapy.

 Current evaluation for DKA-related CE necessitates a high index of clinical suspicion and
 often times such patients receive advanced brain imaging such as computed tomography (CT)
 scans. While CT scans can identify CE, this imaging modality exposes patients to ionizing
 radiation, is expensive, and may take considerable time in some instances. Moreover, CE can
 occur in the absence of acute change on CT and some patients with subclinical CE may go
 unidentified. Magnetic resonance imaging (MRI) has been used to identify subclinical
 DKA-related CE, however this is often time-consuming, expensive, requires sedation, or may be
 unavailable at some centers. Ocular sonography (ultrasound) is an alternative imaging
 technique that can provide immediate diagnostic capability at the bedside and minimize
 radiation exposure. This technique has been used to rapidly and accurately detect increased
 brain swelling through measurement of the optic nerve sheath diameter (ONSD) in a number of
 clinical situations including pediatric head trauma, hydrocephalus and ventriculoperitoneal
 shunt malfunctions, and altitude sickness in adults.

 It is believed, no study has used ocular ultrasound to examine the ONSD in the setting of
 diabetes or DKA for identification of clinically apparent or subclinical CE. It is unclear if
 patients with T1DM have a fundamentally different baseline ONSD measurement compared to
 described normal values. It is also unclear how the ONSD varies during times of
 diabetes-related illness, such as high blood glucose levels without criteria for DKA compared
 to unequivocal DKA.

 Investigators plan to conduct a prospective study including children aged 7-18 years that
 present to the Children's Endocrinology Clinic and Children's Emergency Department. The
 objective of this study is to assess the utility of sonographic measurements of the ONSD as a
 tool for identification of DKA-related CE. Specifically, the primary aim of this study is to
 measure and compare the mean ONSD in children with well-controlled T1DM to those presenting
 to the Emergency Department (ED) with DKA and to those presenting to the ED with T1DM and
 hyperglycemia without criteria for DKA. Investigators hypothesize that the mean ONSD
 measurement is smaller in children with well-controlled T1DM compared to children presenting
 to the ED with DKA and compared to children with T1DM and hyperglycemia without criteria for
 DKA. Secondarily, investigators aim to compare the mean ONSD in children presenting to the ED
 with DKA to those presenting to the ED with T1DM and hyperglycemia without criteria for DKA.
 The study team hypothesizes that the mean ONSD measurement is larger in children presenting
 to the ED with DKA compared children presenting with T1DM and hyperglycemia without criteria
 for DKA.
Inclusion Criteria:

 Ages 7-18 years English speaking

 DKA group recruited from Children's ED. Criteria for DKA:

 1. Hyperglycemia >200 mg/dL AND

 2. Venous pH <7.30 AND/OR

 3. Bicarbonate level <15 AND

 4. Either positive urine or serum ketones

 T1DM and hyperglycemia without criteria for DKA (recruited from Children's ED). Criteria
 for inclusion:

 1. Hyperglycemia (>200 mg/dL) not meeting above criteria for DKA

 Well-controlled T1DM control group (recruited from Children's Endocrinology Clinic).
 Criteria for inclusion:

 1. Hemoglobin A1c <8% at time of clinic visit

 2. No previous episodes of DKA other than at the time of diagnosis

 3. Has never had a documented hemoglobin A1c >10%

 Exclusion Criteria:

 DKA and patients with T1DM and hyperglycemia without criteria for DKA

 1. Treatment with more than 10 mL/kg IV fluids prior to transfer from outside hospital

 2. Treatment with insulin prior to transfer from outside hospital

 3. Patients with type 2 DM

 4. Patients with Hyperosmolar Hyperglycemic Nonketotic State

 5. Underlying neurologic condition predisposing to changes in ICP (hydrocephalus,
 ventriculoperitoneal shunt, Chiari I malformation, Chiari II malformation, pseudotumor
 cerebri, brain tumor)

 6. Underlying condition predisposing to changes in intraocular pressure (glaucoma, eye
 trauma)

 Well-controlled T1DM group with poorly controlled disease, defined as:

 1. Hemoglobin A1c >8% OR

 2. >1 previous episode of DKA, including DKA at time of diagnosis OR

 3. Hemoglobin A1c documented >10% any time in the past