Special Feature
Atypical Presentations of Hypoglycemia
By William J. Brady, MD
Hypoglycemia is most often easily diagnosed and rapidly treated with satisfactory patient outcome in the prehospital or emergency department (ED) setting. The classic presentation of hypoglycemia involves a diaphoretic patient with a history of diabetes mellitus who is found with an altered mental status. The patient is subsequently found to have used insulin or oral hypoglycemic agents and taken relatively little oral nutrition. The central nervous system has a small reservoir of glucose, sufficient for only a few minutes of normal function; with a decline in serum sugar, the brain quickly exhausts its reserve supply of carbohydrate, resulting in central nervous system dysfunction and producing the neuroglycopenic findings. Such manifestations most frequently include alterations in consciousness such as lethargy, confusion, unresponsiveness, agitation, and combativeness (82% of cases). Other neuroglycopenic manifestations include convulsive activity (7%) and the development of focal neurologic deficits (2%).1 Other predominant clinical manifestations result from a release of counter-regulatory hormones, primarily the catecholamines epinephrine and norepinephrine. Such signs and symptoms are noted in 8% of ED patients with hypoglycemia, including anxiety, extreme hunger, weakness, tremor, diaphoresis, pallor, tachycardia, and palpitations.1
Alternatively, the hypoglycemic patient’s presentation and history may lead the emergency physician to believe that the condition may be due to some other clinical event such as cerebrovascular accident,2 status epilepticus, sympathomimetic drug ingestion,3 acute psychosis,3 head injury,4 and acute respiratory failure.5 In fact, hypoglycemia may masquerade as any alteration in mentation; the common clinical denominator found among these varied presentations is an alteration in the level of consciousness with or without other neurologic signs.
Illustrative Cases
The following clinical scenarios demonstrate the varied presentations of hypoglycemia as well as their effect on early ED evaluation and patient outcome. Perhaps the most interesting case involves the young female with a history of insulin-dependent diabetes mellitus (IDDM), who was a victim of a high-speed motor vehicle crash. EMS providers found the patient unresponsive and actively convulsing in the over-turned automobile; with spontaneous termination of the seizure, asymmetric pupils were noted. Paralysis-assisted endotracheal intubation at the scene was initiated without difficulty. Following intubation, a "bedside" determination of the patient’s serum glucose revealed a "low" reading. With glucose replacement therapy, the patient’s abnormal mentation normalized. She was extubated and discharged from the ED after additional evaluation and monitoring. This case illustrates the potential for missing the diagnosis in the apparently head-injured patient with seizure.4
The next case involves a patient with a known history of cocaine abuse and unknown history of insulin-dependent diabetes mellitus (IDDM). The patient was found wandering on the street by police; upon contact, the patient became belligerent and was noted to be diaphoretic. He was transported to the ED, requiring significant physical restraint by police officers. Initial ED management included physical and chemical restraint; soon after ED arrival and adequate control of the patient, a medical warning label was found on the patient stating "IDDM." He was treated with intravenous dextrose with prompt normalization of his altered mental status. Toxicology screening did not reveal cocaine. The patient was admitted to the hospital for observation and discharged without incident 24 hours later.3 A similar situation involving police officers involved an adult male who was found driving erratically on interstate roads. After stopping the vehicle, the patient was uncooperative and, when physically confronted, agitated and belligerent. After a considerable use of physical force, the patient was removed from his vehicle and physically restrained. Ultimately, a history of IDDM was uncovered, with normalization of the altered consciousness. Legal proceedings are reportedly pending against the police agency involved.6 These cases illustrate the potential disaster lurking behind a presentation of a theorized sympathomimetic ingestion. While such a diagnostic consideration was quite reasonable, an over-reliance on such a conclusion early in the ED course is dangerous to the patient, the emergency physician, and law enforcement personnel.
The patient with a presumed acutely decompensated psychosis may also lead the emergency physician away from the correct diagnosis of hypoglycemia. Similar to the case of the assumed cocaine abuser, an adult male with a known history of schizophrenia and medical noncompliance was observed with bizarre behavior; unknown to police and ED personnel was a history of IDDM. After considerable use of force and chemical restraint, hypoglycemia was diagnosed and the patient was appropriately treated, with satisfactory outcome.3
Finally, an infant with a history of prolonged fasting presented to the ED with fever, cough, and confusion. Unknown initially to the ED personnel was a physician-ordered fast for a diagnostic study. Upon arrival in the ED, the patient demonstrated unresponsiveness with fever, cyanosis, respiratory distress, unilateral reduced breath sounds, and poor muscular tone—a presumed diagnosis of sepsis with respiratory failure. Stabilization included ventilatory support initially by oxygen mask and subsequently by intubation without chemical paralysis. Vascular access was obtained by intraosseus technique with the infusion of fluids and antibiotic agents; laboratory studies including a bedside glucose determination were obtained which demonstrated hypoglycemia. Glucose replacement therapy normalized the findings. The patient was admitted to the ICU with a hospital course which did not reveal an infectious cause of the presentation.5 This case featured early focus on systemic infection with respiratory compromise as the etiology of the altered mentation. Correction of alterations in the "ABCs" is initially appropriate in the ED; a determination, however, of the serum glucose early in the course is also mandatory in such instances.
Conclusions
It is imperative for emergency physicians to consider hypoglycemia as a potential cause of any alteration in consciousness. These patients must be rapidly screened for hypoglycemia, with a bedside determination of the serum glucose, and treated appropriately, regardless of presumptive diagnoses. In such settings, the emergency physician may focus directly on the presumed cause and, thus, fail to measure the patient’s blood glucose level early in the evaluation. While hypoglycemia is rarely fatal, significant irreversible central nervous system damage may occur if the blood glucose concentration is not rapidly corrected. Further, medical interventions such as neuromuscular blockade-assisted endotracheal intubation may be avoided with prompt normalization of the mental status via dextrose infusion.
References
1. Malouf R, Brust JCM. Hypoglycemia: Causes, neurological manifestations, and outcome. Ann Neurol 1985;17:421-430.
2. Shotliff K, et al. Hypoglycemia masquerading as stroke. Postgrad Med J 1992;68:843-844.
3. Brady WJ, Duncan CW. Hypoglycemia masquerading as acute psychosis and acute cocaine intoxication. Am J Emerg Med 1999;17:318-319.
4. Luber S, et al. Acute hypoglycemia masquerading as head trauma: A report of four cases. Am J Emerg Med 1996;14:543-547.
5. Luber S, et al. Hypoglycemia presenting as acute respiratory failure in an infant. Am J Emerg Med 1998;16:281-284.
6. Shen F. Motorist in diabetic shock arrested in MD; Man’s erratic behavior prompts beating, dog attack, and multiple charges. The Washington Post June 22, 1988:B3.
Hypoglycemia may present as:
a. seizure.
b. diaphoresis.
c. combativeness.
d. acute neurologic deficit.
e. All of the above
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