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Dilemmas in diabetes

New drugs and insulin pumps add to the challenge of inpatient diabetes care.

Inpatient diabetes care is getting ever more complicated, thanks to an expanding array of drugs and wider usage of insulin pumps. Limited availability of endocrinologists also means that hospitalists can be on their own when dealing with these challenges.

“We are now getting these huge number of new drugs, new classes of drugs—and this includes new insulins,” said Irl Hirsch, MD, MACP. “Nobody, when these drugs were being tested, in my mind, really thought about, ‘Well, what happens when these patients get sick and have to come into the hospital?’”

Outpatient use of long-acting insulin, for example, can complicate inpatient prescribing, said Dr. Hirsch, professor of medicine in the division of metabolism, endocrinology, and nutrition and diabetes teaching and treatment chair at the University of Washington School of Medicine in Seattle

Other challenges to maintaining glycemic control during an admission of a diabetes patient (many of which are for reasons unrelated to diabetes, the experts noted) include the perioperative pathways and “meals on demand” approaches that many hospitals have adopted.

Meanwhile, new diabetes drugs and discoveries continue to flow through the development pipeline, complicating decisions about oral medication management. In September, the FDA approved the first oral formulation of a glucagon-like peptide (GLP-1) receptor agonist, semaglutide, and in October, dapagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, got a new indication to reduce risk of heart failure hospitalization.

Those rapidly evolving treatment options are difficult for hospital physicians to keep up with, particularly at smaller facilities where there might not be an endocrinologist onsite, said Archana Sadhu, MD, who directs the system diabetes program at Houston Methodist Hospital in Texas and is an assistant professor of clinical medicine at Weill Cornell Medical College in New York City.

One analysis, published in 2014 in the Journal of Clinical Endocrinology & Metabolism, identified a shortage of 1,500 adult endocrinologists nationally. Based on existing patterns, the researchers projected that this access situation would stay the same or worsen over the next decade as more people are diagnosed with diabetes and other endocrine conditions.

For hospital care, that ongoing shortage is further aggravated by practice patterns, Dr. Sadhu said. “Outside of the big academic centers, most endocrinologists don't do inpatient medicine,” she said, and thus some hospital physicians “are absolutely flying solo.”

Insulin in the hospital

To help ease the confusion, hospitalists should work with their pharmacies and hospital administration to develop charts that present all of the medications available on the formulary in one place, including such details as the drugs' duration of action, recommended Doron Schneider, MD, FACP.

“Even within the insulin category itself, there are now different insulins, there are different concentrations of insulins, there are different formulations,” said Dr. Schneider, chief patient safety and quality officer at Abington-Jefferson Health in Abington, Pa. “And it is not hard to make a mistake.”

For example, a potential treatment pitfall involves the long-acting insulin degludec injection, which has a half-life of 24 hours and can remain in the body as long as 42 hours, Dr. Hirsch said. He's not aware of any hospital formulary that carries it but said it's starting to be used more frequently on the outpatient side.

Dr. Hirsch described a scenario in which a patient with type 2 diabetes is admitted in the evening with deep venous thrombosis. The patient has his diabetes under control with an HbA1c level of 6.5% and usually takes 40 units of degludec every morning. But the hospital only has glargine available. So the hospitalist prescribes 40 units of glargine (which has a half-life of 12 hours) for the next morning at 8 a.m.

Twelve hours after that first dose of glargine, the patient still has half of the glargine units, roughly 20, on board, Dr. Hirsch said. Those units combined with the remaining 30 units or so of degludec result in a total of 50 units of circulating basal insulin by that evening.

“This is what we call insulin stacking,” Dr. Hirsch said. “You have all of this extra insulin on board stacked on top of each other. And these patients are going to crash, and we see it.”

Dr. Hirsch said that he asks his patients to bring their degludec with them if they know they're going to the hospital. If the hospitalization is unexpected, he asks a family member to get it, assuming the patient doesn't require IV insulin. “Because switching them to glargine is always ugly,” he said.

The increasing use of insulin pumps and related technology creates a new set of considerations. At the University of Washington's diabetes clinic, a quarter of the patients with type 2 diabetes who rely on insulin are using sensors, according to Dr. Hirsch. Among type 1 patients, roughly 70% are wearing sensors and 60% are using pumps, he said.

The American Diabetes Association's Standards of Diabetes Care supports select patients continuing to self-manage their insulin needs after hospital admission, either by shots or a pump, as long as they're cognitively and physically able, among other criteria. That approach should be pursued only if the patient, nursing staff, and physician agree that it's appropriate, the authors wrote.

But a hospital should establish a formalized procedure or approach for this practice, Dr. Schneider said. Some elements could include mandating an endocrinologist consult, he said, as well as bringing in a pharmacist or diabetes educator with the expertise to verify that the pump works properly. The hospital also might want to ask patients to sign off on their self-management, he said.

Smaller hospitals may not have access to the skills of an inpatient glycemic team or an on-site endocrinologist. Without those resources, patients with the necessary cognitive and other skills—or in some cases a savvy family member—should still be allowed to continue using their pumps, Dr. Hirsch said. (A review article on diabetes technology, published in August 2018 in Diabetes Care, makes a similar point; it also outlines treatment scenarios or imaging tests in which the pump should be managed differently.)

If the patient does self-manage insulin, Dr. Hirsch stressed, all insulin dosing needs to be documented in the medical record. If a patient becomes unable to self-manage while in the hospital, she should be switched to basal-bolus insulin, he said.

Oral meds and operations

For patients taking oral diabetes medications, traditional practice has been to switch them to insulin when they are hospitalized. The American Diabetes Association's Standards of Diabetes Care call for this and recommend resuming oral drugs one to two days before discharge. But there may be “certain circumstances,” the authors added, when a patient's home oral regimen should be continued.

Those circumstances may depend on the reason for admission and the specific drug or class, the experts said. For instance, if a patient was on metformin and a glipizide with an HbA1c of 6.9% before admission for hip surgery, there may be no reason to switch him to insulin for a two-day hospital stay, Dr. Hirsch said. However, if the same patient was instead admitted for an exacerbation of chronic obstructive pulmonary disease and treated with steroids, he would require insulin.

Major surgery, such as a coronary artery bypass graft, may also require a switch to insulin, Dr. Hirsch noted. “These patients are often difficult due to severe insulin resistance during and after the procedure, and then it takes a day or two to get onto a regular diet,” he said.

Some classes of diabetes drugs are particularly problematic if patients aren't eating, noted Robert Rushakoff, MD, FACP, an endocrinologist and director for inpatient diabetes at University of California, San Francisco (UCSF). For example, sulfonylureas carry high risk of hypoglycemia, he noted.

Newer drug classes like SGLT2 inhibitors can make for particularly challenging decisions. Dr. Rushakoff highlighted the risk of euglycemic diabetic ketoacidosis as a reason to halt these drugs in the hospital, while on the other hand, Dr. Hirsch pointed out their beneficial effects on heart failure.

“If someone [with diabetes] is admitted to the hospital [for heart failure], and they are already on the drug, should you continue with the drug if that's why they are admitted?” asked Dr. Hirsch. More research is needed to answer that question, he said.

Another consideration is that the newer, more expensive drug classes are often not available on hospital formularies, Dr. Hirsch noted.

In the perioperative setting, there are a few additional speed bumps. One involves a perioperative pathway called ERAS (enhanced recovery after surgery), which Dr. Rushakoff said has been increasingly adopted at facilities across the country and is designed to speed patients' return to function. Steps include minimizing fasting and encouraging earlier mobility, but one component is to give patients a high-carbohydrate drink shortly before surgery, said Dr. Rushakoff, lead author on an opinion piece in the March 2019 Annals of Surgery that criticized this practice.

The drink can potentially boost the patient's glucose levels, Dr. Rushakoff said. But since the drink is such a routine part of the pathway, hospitalists might not realize that it could be contributing to elevated blood sugar, Dr. Rushakoff said. “Hospitals do this everywhere in the United States now without knowing what they're doing to patients,” he said.

Another perioperative step—administering dexamethasone to reduce nausea and vomiting after surgery—also can result in hyperglycemia for the first postsurgical day, Dr. Rushakoff said. So if postoperative patients' glucose readings are elevated, it's worth checking the chart to see if they got the antinausea medication or a carb-loaded beverage, he said.

Otherwise, he said, “If you start writing insulin orders that are just based then on the postoperative numbers, you could end up giving too much insulin, because the effect of the dexamethasone will be gone in a day.”

Keeping up with basics

One hospital care challenge that was cited by all is the struggle to keep blood glucose stable when patients can order meals whenever they're hungry rather than on a set schedule. At UCSF, patients with diabetes can order meals on demand with some guideposts, such as a time interval of at least three hours, Dr. Rushakoff said. There's also tight coordination with the nursing staff, so they know when a meal has been delivered and can check blood glucose levels and adjust insulin if needed, he said.

At Houston Methodist, meals on demand are also available, typically in non-ICU areas. Procedures have been established to alert nurses that the meal is arriving and patients are educated to tell their nurse before they start eating so that their glucose can be tested, Dr. Sadhu said.

Even with the best efforts, though, patients who have already gotten their insulin and eaten a few bites of their meal can be pulled away by another department, such as imaging taking them for a scan, Dr. Sadhu said. “They haven't eaten enough to cover the insulin that they got,” she said. “And next thing you know they are in a CT scan getting hypoglycemic.”

Amid all of a patient's other medical issues, it's also easy for a hospitalist to lose sight of diabetes, particularly if it seems disconnected to the primary reason for admission, Dr. Sadhu said. But glucose readings should be checked daily, if not more often, and the drug regimen adjusted accordingly, similar to any other vital sign, she said.

“We know that their glycemic control is going to affect all those other diagnoses directly,” she said. “If they're repeatedly low or they're repeatedly high, their infection is not going to improve, their postoperative complications are going to go up.”

Dr. Sadhu also encouraged smaller hospitals to consider creating their own inpatient glycemic team to assist with insulin dosing, pump logistics, and other complexities. At Houston Methodist, the team manages 70 to 80 patients typically, with Dr. Sadhu rounding and providing oversight. But the bulk of the front-line work is done by nurse practitioners, she said.

A smaller hospital could create a similar team led by a general internist or a hospitalist with special training in diabetes, Dr. Sadhu said. “There are not enough endocrinologists, that's a plain fact,” she said. “So we have to figure out other models of delivery.”