Hyperosmolar hyperglycemic state: Clinical sciences

Chapters:

Watch video only

Introduction0:00–0:53

Hyperosmolar hyperglycemic state, or HHS for short, is a life-threatening complication of type 2 diabetes mellitus. It is usually triggered by a precipitating factor, such as illness or infection, that eventually leads to relative insulin deficiency, hyperglycemia, and elevated serum osmolality.
Keep in mind that there’s a higher risk of HHS in older individuals, especially those with impaired cognitive function or thirst perception, as well as those who do not adhere to their treatment regimen for diabetes.
The diagnosis of HHS requires lab workup that demonstrates an elevated blood glucose and serum osmolality, as well as the absence of metabolic acidosis and ketonuria.Now, if you suspect HHS, you should first perform an ABCDE assessment to determine if your patient is unstable or stable.

Unstable patient0:53–1:30

HHS generally presents as unstable, so stabilize the airway, breathing, and circulation. Next, obtain IV access and give 1-liter bolus of isotonic IV fluid.
Next, put your patient on continuous vital sign monitoring, including heart rate, blood pressure, and pulse oximetry, and provide supplemental oxygen, if needed.Once you stabilize the patient, obtain a focused history and physical exam.

Focused H&P1:30–2:15

Your patient typically reports polyuria, polydipsia, weakness, lethargy, or even seizures. These are commonly associated with a recent precipitating illness or infection.
Additionally, there might be a known history of diabetes with inadequate glycemic control or recent disruption in therapy.
On the other hand, a physical exam might reveal signs of severe dehydration, such as dry mucous membranes, tachycardia, and hypotension.
In severe cases, you might even notice somnolence and focal neurologic deficits, such as visual disturbance. Based on these findings, suspect HHS and order labs, including an ABG or VBG, a serum osmolality, a CMP, and a urinalysis.

Suspect HHS2:15–3:52

Next, review the lab results and assess diagnostic criteria for HHS, which include blood glucose above 600 mg/dL; serum osmolality over 320 mOsm/kg; the absence of metabolic acidosis; and minimal or no ketonuria.
If diagnostic criteria for HHS are not met, you should consider alternative diagnoses. On the other hand, if the lab results show that HHS criteria are met, you can diagnose HHS and begin insulin treatment.
Here’s a clinical pearl! HHS can present with signs and symptoms that are similar to diabetic ketoacidosis, or DKA for short.
Unlike HHS though, in DKA, the distinguishing feature is a ketoacidosis, with a pH under 7.3 and a serum bicarbonate below 15.
Also, the serum glucose in DKA is usually less than 600 mg/dL. Another condition that may masquerade as HHS is diabetes insipidus.
Individuals with diabetes insipidus can also present with extreme thirst, polyuria, lethargy, and increased serum osmolality, but unlike in HHS, hyperglycemia is not a feature of this condition.Ok, now that we’ve diagnosed HHS, let’s turn our attention to management.

Management3:52–6:35

Start with immediate IV fluid resuscitation, as well as a bolus of IV insulin, dosed at 0.1 unit per kilogram, followed by a constant IV insulin infusion at 0.1 units per kilogram per hour.
At the same time, pay attention to the serum potassium level, because insulin and fluid resuscitation can lower serum potassium levels.
If the serum potassium is above reference range, no potassium replacement is needed. On the other hand, if the serum potassium is below reference range or even within reference range, add potassium to the IV fluids.
In fact, if the potassium is below the reference range, it's actually necessary to replace potassium before even starting insulin!
Here’s a high-yield fact to keep in mind! As soon as you give insulin, it will shift potassium from blood right into the cells, dangerously decreasing its blood levels.
So a modestly low potassium of 3 could quickly reach a lethal level of 2.5 if you start the insulin drip before appropriately replacing the potassium.
And now a clinical pearl! Order a CMP every 2 to 4 hours to identify electrolyte imbalance, hold insulin infusion if potassium is low, and initiate replacement as appropriate.
Once you do that, assess the corrected sodium level, as this will guide your choice of IV fluid rehydration therapy. This is important because the elevated glucose increases serum osmolality, causing water to move from the intracellular to the extracellular space, artificially lowering the serum sodium.
The corrected sodium is equal to the measured serum sodium, plus 1.6 times the glucose concentration minus 100, divided by 100.
Now, here’s a clinical pearl to keep in mind! Once you’ve calculated the corrected serum sodium level, you can also determine the effective serum osmolality by multiplying the corrected sodium concentration by 2; then add the glucose concentration divided by 18.
Follow the effective serum osmolality every 2 to 4 hours, to ensure that it’s steadily returning to the normal range.Ok, now if the corrected sodium is below the reference range, start an infusion of 0.9% normal saline, but if the corrected sodium is within or above the reference range, start an infusion of half-normal saline.

Insulin titration6:35–8:16

Now that you are done with the initial management, your next step is to assess your patient’s blood glucose after one hour.
If the blood glucose is falling by more than 50 to 70 milligrams per deciliter per hour, your patient is having an adequate response, so continue the insulin infusion at the current rate.
On the other hand, if it's falling by less than 50 to 70 milligrams per deciliter per hour, your patient is having an inadequate response, so give another bolus of IV insulin and resume the insulin infusion at the previous rate.Next, reassess the blood glucose every hour.
If blood glucose is over 300 mg/dL, continue the insulin infusion and titrate if needed. Continue to monitor blood glucose hourly until it drops below 300 mg/dL.
Here’s a high-yield fact! Rapid fluctuations in serum osmolality can lead to cerebral edema.
So you should be very cautious with fluid management when treating hyperglycemia and electrolyte abnormalities in HHS. While reduction in serum glucose levels is the mainstay of HHS treatment, it is ideally accomplished gradually, as rapid fluctuations in serum osmolality can lead to cerebral edema, a rare but life-threatening complication of HHS.
Be on the lookout for signs and symptoms of cerebral edema, including headache, decreased consciousness, seizures, bradycardia, and hypertension.
If suspected, the recommended treatments include IV mannitol and mechanical ventilation.Once the blood glucose falls below 300 mg/dL, decrease the IV insulin infusion rate, and add 5 percent dextrose to the IV fluids, to prevent hypoglycemia.

IV to subcutaneous insulin8:16–9:18

Then, give a subcutaneous dose of fast-acting insulin along with a meal. Be sure and discontinue the IV insulin infusion 1 to 2 hours after subcutaneous insulin is given.
After transitioning to subcutaneous insulin, continue to monitor blood glucose every hour, with the goal of keeping the blood glucose between 200 and 300, while ensuring that your patient is tolerating oral intake.
HHS is considered to be resolved once your patient has a normal serum osmolality and has reached baseline mental status.
Finally, make sure to manage any precipitating factors, such as infection, illness, or inadequate diabetes treatment, and don’t forget to provide diabetes education if your patient hasn’t received it yet.Alright, as a quick recap… If you suspect HHS, assess criteria to confirm the diagnosis.

Review9:18–10:27

Once you diagnose it, begin insulin treatment, but don’t forget to check potassium and sodium levels, and correct any electrolyte abnormalities.
Next, assess the blood glucose after one hour, and if it’s decreasing by 50 to 70 mg/dL every hour, continue the current insulin infusion rate.
But if it’s decreasing by less than 50 to 70 mg/dL, give another bolus of IV insulin and continue the previous insulin infusion rate.
Keep assessing the blood glucose hourly, and if the values remain over 300, continue insulin infusion and titrate it as needed.
Once the blood glucose falls below 300, decrease the IV insulin infusion rate, add 5% dextrose to the IV fluids, and switch to subcutaneous insulin.
Finally, continue blood glucose monitoring every hour, manage any precipitating factors, and provide diabetes education.
Hyperosmolar hyperglycemic state: Video and Causes | Osmosis