Hypoglycemia is a well-known potential adverse event for individuals on insulin and oral diabetic medications. Risk factors for medication-related hypoglycemia include age > 65, renal insufficiency, cardiovascular disease, and congestive heart failure [7]. While the majority of hypoglycemia episodes are relatively benign and rapidly reversible with oral or intravenous glucose, there remains the risk of hypoglycemia-induced seizures, traumatic injuries, cardiovascular disease, cardiac arrhythmia, coma, and even death if treatment is delayed [8,9,10]. For those who have returned to their normal state, an impaired counter-regulatory physiologic response to low serum glucose may occur in leading to increased susceptibility to severe hypoglycemia in the period shortly following their initial event [11].
Treatment of symptomatic hypoglycemia by EMS providers or ED staff with oral or parenteral glucose is typically followed by a variable time of observation to allow patients to demonstrate their ability to maintain euglycemia. For those who do not return rapidly to their baseline mental status further investigation is clearly warranted [5]. In the prehospital setting, up to 68–72% of patients who have returned back to baseline refuse hospital transport following a return to their normal state [12, 13]. Among those declining hospital transport by EMS providers, a rate of recurrent symptomatic hypoglycemia requiring additional evaluation has been shown to occur in 4.8–9.0% of cases [12,13,14]. To our knowledge, the frequency of return visits for patient’s discharged directly from the ED after an observation period has not been previously described prior to our report.
Specific insulin preparations and oral diabetic medications are variable in time of onset, duration of action, and time to peak effect. Current recommendations are for hospital observation for individuals taking either long-acting insulin or oral diabetic agents given their duration of action [3,4,5]. Although there is a paucity of literature to support these guidelines, an understanding of the duration of drug action provides a rationale for this treatment approach and heightened concern for hypoglycemia recurrence. The benefit of early discharge and reducing both the burden on hospital resources and ED length of stay, avoiding the risk of iatrogenic injury and hospital acquired infections must be weighed against the potential dangers of discharging individuals who are at risk of recurrent hypoglycemia. Those individuals of an advanced age and those who live without adults to monitor their blood sugars and mental status may be at greatest risk.
Our study provides support for the discharge of patients that physicians believe to be at low risk who have maintenance of euglycemia and are not taking oral diabetic agents or long-acting insulin. We identified no patients among the 68 patients who were discharged taking only short-acting insulin who had return ED visits in the subsequent 48 h for hypoglycemia. The significance of a 15.8% overall rate of recurrent hypoglycemia among those on oral diabetic agents alone among individuals ED physicians initially felt were appropriate for discharge is not trivial. For those individuals taking long-acting insulin with or without short-acting insulin, a 5.4% rate of recurrent hypoglycemia leading to return ED visits would also be considered a frequency in which disposition decisions should be considered on a case-by-case basis.
Should the decision be made by clinicians to discharge patients from the ED where there remains a concern with recurrent hypoglycemia, this should occur in a standardized manner to ensure patient safety. These individuals should be in the presence of and frequently monitored by family or other caregivers, frequent assessments of blood sugar should be performed, and dietary changes and medication adjustments may be necessary if these were a factor in the initial hypoglycemia episode. A pattern of recurrent hypoglycemia in this higher risk population may be expected among individuals refusing initial EMS hospital transport and similar precautions and education would be strongly recommended.
There are several study limitations that should be noted. Efforts were made to identify any patients that may have returned to other nearby care facilities. Two major health systems whose medical records were reviewed make up nearly all facilities that provide emergency care to area residents within a 20-mile radius of the study hospital. There does remain the possibility that individuals may have returned to health care facilities outside of the area hospital’s typical catchment area that would lead to an underestimation of recurrent ED visits. A review was performed to identify any contact made with EMS providers and subsequent refusal of care; however, the complexities of area EMS services may have led to additional missed cases of recurrent hypoglycemia. The potential for symptomatic hypoglycemia that individuals may have managed at home without contacting a health care provider may additionally lead to an underestimation of our risk of hypoglycemia recurrence. Our single site review of hypoglycemia cases over 2 years involved a small total number of total return visits leading to uncertainty in the true rate of return visits.
And additional limitation of this study is that the true rate of recurrent hypoglycemia was not identified and should not be extrapolated from our findings. Lin et al. [15] performed an evaluation of 244 patients who had been admitted to the hospital with hypoglycemia episodes and found 31.8% of this group had recurrence of hypoglycemia. Our study is descriptive in nature and looked solely at patient’s presumed to be at low clinical suspicion of recurrent hypoglycemia who were discharged home. There were no clear criteria as to who was considered “low risk” and it was assumed that physician’s discharging patients to home had risk stratified these individuals as being low risk of hypoglycemia recurrence. Given the nature of the study design, efforts to establish what factors constitute true low-risk criteria and how long to observe patients prior to discharge were not performed. Future studies assessing specific risk factors for those taking long-acting insulins and oral agents who are at greatest risk of hypoglycemia recurrence would be of benefit to determine appropriate disposition.