Edited by Trisha Dunning AM, RN, MEd, PhD, CDE, FRCNA and Glenn Ward MBBS, BSc, DPhil (Oxon), FRACP, FRCPath
This week, we continue with our special series of case discussions.
Mrs. TZ was referred by a podiatrist: Mrs. TZ is a 50-year-old woman with Type 1 (she assures me this is a correct diagnosis) and she has been diagnosed for some years. She is currently on 12 units NPH and 6 units TDS NovoLog (NovoRapid). She has recently been experiencing hypos or more hypo unawareness. Around lunchtime, her blood glucose is usually between 54-108mg/dL (3 and 6 mmol/L) and her postprandial test is no higher than 95mg/dL (8.2 mmol/L). She recently increased her morning dose of NovoLog….
Her hypos are happening at about 35-25mg/dL (1.8–1.4 mmol). She sometimes gets blurred vision and sweating. Mrs. TZ works full-time in an office, and although her colleagues know she has diabetes, during her last episode her boss left her alone (a little scary for both I think) but her main concern is she may hypo when she is driving. I wonder whether she is Type 2 late onset? I would appreciate your advice, thanks.
My immediate response would be to address the hypoglycemia. Because the hypoglycemia occurs before lunch I would reduce her breakfast NovoLog by 2 units, initially bearing in mind that is approximately 30% of her dose. People are taught to adjust their insulin in 1- to 2-unit increments up to 4 units. I would review her hypoglycemia management to ensure that she takes simple (fast acting) carbohydrate, for example 5-7 jellybeans or 100 ml of lemonade at the first sign of a hypo and follows with some complex (slow-acting) carbohydrate. In Mrs. TZ’s case, this could be her lunch, ensuring that it includes complex carbohydrate. She should be advised to retest her blood glucose after 30 minutes to make sure her blood glucose is rising. If the symptoms of hypoglycemia have not resolved after 10 minutes, she should eat another 15 g of fast-acting carbohydrate.
Blurred vision and sweating are common hypoglycemic symptoms. Other symptoms include trembling, weakness, hunger and nervousness. These symptoms vary among people with diabetes. Most people recognize their symptoms, but Mrs. TZ is experiencing hypoglycemic unawareness, which can be exacerbated by the frequent episodes of hypoglycemia and the duration of diabetes. Hypoglycemic unawareness means that people do not recognize the early symptoms so they progress and the brain does not get enough glucose. Confusion, drowsiness and changes in behavior followed by coma and possibly seizure occur. This is a very serious situation. It requires another party to manage the hypoglycemia and assist with resuscitation. This includes protecting the airway and injecting glucagon if it is available or calling an ambulance. Educating and supporting the family is very important.
Mrs. TZ should be referred to her general practitioner to determine whether she has Type 1 or Type 2 diabetes. (See case discussion “Mrs. TP.”) [Put Link Here to Last Week’s Case]
Meanwhile, the diabetes educator should assess Mrs. TZ’s diabetes self-management, the accuracy of her blood glucose meter through quality control testing, ensuring the blood glucose strips are in date, checking her testing technique, testing and recording frequency and accuracy by downloading the blood glucose test record stored in the meter memory. All of these steps help eliminate user error, which is often unintentional.
Review insulin administration by checking:
- the insulin delivery device;
- Mrs. TZ’s technique;
- injection sites;
- that she is not injecting into the same area all the time, which can cause hypertrophy and interfere with insulin absorption; and
- the dosing accuracy of her insulin pen (dial up 20 units and deliver the dose into the plastic pen needle cap. If the level of insulin in the cap is to the bottom of the flange, the dose is accurate).
Asking Mrs. TZ how she adjusts her insulin will help determine whether she adjusts her dose correctly. I suggest she needs more education about insulin action because she increased her insulin dose at breakfast despite becoming hypoglycemic around lunchtime, which suggests the pre-breakfast dose should be reduced. I would refer her to a dietitian for a dietary review and to ensure she has adequate carbohydrate with her breakfast. She may in fact omit breakfast. I would also discuss exercise with her, because it could be another cause of her hypoglycemia. Some people can experience hypoglycemia many hours after exercise.
Mrs. TZ’s boss knows she has diabetes and expects her to be responsible for her diabetes care at work. He and other employees need to be able to manage hypoglycemia, but her employment may be jeopardized if she does not appropriately monitor her diabetes and have regular medical reviews. People with diabetes cannot be (nor do they want to be) in the company of another person 24 hours a day.
Sensible blood glucose monitoring and adherence to her diet will reduce the risk of hypoglycemia and improve her safety at work as well as when she is driving. It is essential she tests her blood glucose before driving to ensure it is at a safe level (for example > 90mg/dL.[5.0 mmol/L]) and has simple carbohydrate with her at all times. Mrs. TZ is on insulin and is required to have an annual fitness to drive assessment by the Motor Traffic Authority before her driver’s license is renewed. The review includes a medical check-up, history of hypoglycemia, vision check and diabetes assessment to ensure she is safe to drive and does not put herself or others on the road at risk.
Many patients inform the GP that they have Type 1 and are usually correct if they use that term. However, many people often describe their diagnosis as insulin-requiring when the diagnosis may be less straightforward. A good history will often give the diagnosis. Mrs. TZ has had her diabetes for many years, and her particular pattern of insulin use with relatively small doses suggests Type 1 but other findings such as body mass index (BMI), duration of diabetes before commencing insulin, and initial presentation would help establish the diagnosis.
Late onset Type 1 refers to a situation where people develop Type 1 diabetes at a much older age than usually expected. These patients often have a normal BMI; the so-called lean diabetic. A significant proportion of older people develop late onset Type 1 diabetes (LADA), possibly approximately 20% of patients diagnosed with Type 2 diabetes. Patients with a normal BMI or those who require increasing doses of medication very quickly should be tested for anti-GAD antibodies. It is important to identify this group of patients, because they will require insulin much earlier than patients with Type 2. They are also at risk of ketoacidosis. Late-onset Type 2 diabetes may be confused with the older term ‘mature onset diabetes,’ which is now called Type 2 diabetes.
Hypoglycemic events can be very frightening, more so when symptoms suddenly occur due to hypoglycemic unawareness. Patients may become confused or collapse due to the lack of warning and be unable to treat the hypoglycemia. Unfortunately, as patients are treated more aggressively to prevent complications, the number of hypoglycemic reactions patients endure is also likely to increase. Hypos in the workplace can be an issue. Regular glucose monitoring during the day, ready access to a quick source of glucose, and regular meal times are important. It is useful for fellow workers to be aware of the risk of hypos so they can help if a severe hypo should occur.
Mrs. TZ has also identified a major issue of safety when driving, which is especially important since she has hypo unawareness. Mrs. TZ should always check her blood glucose before driving and have ready access to quick-acting glucose in the car.
Current recommendations from the Rules of The Road driver guidelines in most states ask if you have diabetes and usually require a note from the doctor indicating that you are safe to drive. If a hypoglycemic episode occurs while driving and is the cause of a car accident the driver licensing authority should be notified. A ‘defined’ hypoglycemic event relevant to driving is one of sufficient severity to impair perception or motor skills, cause abnormal behavior or impair consciousness. It is different from mild hypoglycemic symptoms such as sweating, trembling, hunger, and tingling around the mouth, which are common occurrences in the life of a person with diabetes treated with insulin and some oral hypoglycemic agents.
The pattern of glucose control is important when adjusting the insulin dose to avoid hypos and to retain good control. There is evidence that the newer long-acting insulins such as Lantus can give the same level of control but with fewer hypos. Education about appropriate insulin self-adjustment during changes in meals or exercise is important for all patients with diabetes. The doses of NovoLog insulin were not specified, but reduction of the breakfast dose would be critical in this patient, aiming to eliminate the lunchtime hypoglycemia. Her target glucose should be 90-144mg/dL (5–8 mmol/L) before meals and any glucose level under 4 more than occasionally would trigger an insulin dose readjustment.
The driving issues are serious in patients having major or ‘defined’ hypoglycemic episodes and the Rules of the Road guidelines for individual states are important to understand and follow.
Other countries have similar initiatives and it is important to note that the legal implications vary significantly in different countries and indeed different states. While the guidelines are very useful, it is critical to be aware of the specific legal requirements in the particular practice location. For example, the requirement for health professionals to notify the relevant driving authorities of concerns varies considerably. The legal protection given to the health professional who might notify authorities or fill in reports also varies within states and countries internationally. The other complication is that, even if there is indemnification, the civil legal system might still allow a health professional to be joined in legal actions with a defendant when damages are sought. In summary, it is critical to be informed, not only about the specific regulations in a practice location, but also the non-regulatory civil legal implications.
The aims of the book are to: (1) address commonly encountered diabetes management problems; (2) develop comprehensive responses from a range of relevant health professionals who suggest management approaches relevant to their area of practice. The speciﬁc health professionals who provide comments about each case depend on the speciﬁc clinical issue; and (3) stimulate thought and discussion.
The target readership is health professionals from a range of professional backgrounds and general as well as specialist professionals such as general practitioners, nurses, dietitians, and podiatrists. The book will be particularly useful for beginner practitioners specializing in diabetes. In addition, it will provide suggestions or food for thought for more experienced practitioners. The cases will be excerpts from the book are all real and are presented exactly as the information was received from the person making the referral. General practitioners, diabetes educators and people with diabetes referred most of the cases; some were self-referrals by people with diabetes. They represent referrals to various diabetic health professionals and concern commonly encountered clinical issues.
Next Week: Another Case Discussion
For more information on the book, just follow this link to Amazon.com, Managing Clinical Problems in Diabetes
Copyright © 2008 by Blackwell Publishing Ltd, UK
Edited by Trisha Dunning AM, RN, MEd, PhD, CDE, FRCNA and Glenn Ward MBBS, BSc, DPhil (Oxon), FRACP, FRCPath