Case Presentation: We present a case of a 52 year old female with acutely altered mental status who was misdiagnosed of severe hypoglycemia due to a failure to recognize an incorrect common lab result.  This is a Caucasian female with a past medical history of end stage renal disease on hemodialysis, scleroderma, and Raynaud’s, who was found acutely altered by her family members. En route to the hospital, the emergency personal checked finger stick blood glucose to investigate the cause of her acute encephalopathy and found the patient to be severely hypoglycemic with blood glucose on point of care testing (POCT) of 20mg/dL. She was given 0.5 amp of D50, however, patient’s mentation did not improve. Her finger stick glucose was rechecked and remained 20mg/dL. She was given another 0.5 amp of D50 and this cycle was repeated three times, without any notable improvement in patient’s condition. Once she arrived to the hospital, her repeat finger stick blood glucose was 43mg/dL. She was started on an infusion of D5 in an attempt to improve her hypoglycemia and ultimately her mentation. A peripheral blood draw from her antecubital fossa was concurrently performed to look for other metabolic causes of her acute encephalopathy. Her basic metabolic panel revealed that her blood glucose from her peripheral blood was actually 660mg/dL. There was noted to be a clear discord between the finger stick blood glucose POCT and blood sugar from a peripheral blood draw.  Eventually, a computed tomography of her head was performed which showed an acute subdural hemorrhage with mass effect which was determined to be the actual cause of her encephalopathy.   

Discussion: While the initial hypoglycemia that was detected on finger stick could have been true, each subsequent finger stick POCT continued to demonstrate severe hypoglycemia with sugars of 20mg/dL, despite receiving 3 amps of D50. It was hypothesized that the patient likely had pseudohypoglycemia in setting of Raynaud’s and Scleroderma as well as cool extremities which can give inadequate blood sugar readings on POCT. This was confirmed when the blood glucose on the basic metabolic panel drawn from blood in a relatively larger brachial vein was disproportionately high as compared to the finger prick. As per literature search, there have been case reports of patients with scleroderma with Raynaud’s phenomenon having pseudohypoglycemia when using blood from a finger prick to test for sugar levels due to the impaired microcirculation in the periphery. This indicates that in patients with circulatory compromise, cool extremities or vasospastic diseases such as Raynaud’s, finger stick blood is an unreliable way of measuring point of care tests such as glucose.

Conclusions:  It is important to recognize this discrepancy as misdiagnosis can lead to a delay in proper intervention and can add to patient’s morbidity and mortality.