Practice trends in the management of low hematocrit in the acute rehabilitation setting.

OBJECTIVE: To examine current clinical practice regarding the management of anemic patients in the acute rehabilitation setting. DESIGN: Ninety-four medical directors of inpatient rehabilitation units were surveyed on their use of transfusion thresholds and human recombinant erythropoietin. Factors affecting their clinical decision making were assessed. RESULTS: The majority of physicians responded that they recommend red cell transfusion in patients with a hematocrit <25%. When a history of cardiovascular disease and advanced age was present, more physicians were likely to transfuse at higher hematocrit levels. Forty-six percent of physicians reported recommending the use of human recombinant erythropoietin in anemic patients. Only 30% of respondents classified their clinical management of anemia as evidence based. CONCLUSIONS: Clinical practice guidelines should be developed to aid the rehabilitation medicine specialist in the management of anemic patients in the acute rehabilitation setting. Further study of the relationship between hematocrit level, tolerance for therapeutic exercise, and long-term functional outcome is indicated.

Progressive hypoglycemia's impact on driving simulation performance. Occurrence, awareness and correction.

OBJECTIVE: Progressive hypoglycemia leads to cognitive-motor and driving impairments. This study evaluated the blood glucose (BG) levels at which driving was impaired, impairment was detected, and corrective action was taken by subjects, along with the mechanisms underlying these three issues. RESEARCH DESIGN AND METHODS: There were 37 adults with type 1 diabetes who drove a simulator during continuous euglycemia and progressive hypoglycemia. During testing, driving performance, EEG, and corrective behaviors (drinking a soda or discontinuing driving) were continually monitored, and BG, symptom perception, and judgement concerning impairment were assessed every 5 min. Mean +/- SD euglycemia performance was used to quantify z scores for performance in three hypoglycemic ranges (4.0-3.4, 3.3-2.8, and <2.8 mmol/l). RESULTS: During all three hypoglycemic BG ranges, driving was significantly impaired, and subjects were aware of their impaired driving. However, corrective actions did not occur until BG was <2.8 mmol/l. Driving impairment was related to increased neurogenic symptoms and increased theta-wave activity. Awareness of impaired driving was associated with neuroglycopenic symptoms. increased beta-wave activity, and awareness of hypoglycemia. High beta and low theta activity and awareness of both hypoglycemia and the need to treat low BG influenced corrective behavior. CONCLUSIONS: Driving performance is significantly disrupted at relatively mild hypoglycemia, yet subjects demonstrated a hesitation to take corrective action. The longer treatment is delayed, the greater the neuroglycopenia (increased theta), which precludes corrective behaviors. Patients should treat themselves while driving as soon as low BG and/or impaired driving is suspected and should not begin driving when their BG is in the 5.0-4.0 mmol/l range without prophylactic treatment.

Biopsychobehavioral model of severe hypoglycemia. II. Understanding the risk of severe hypoglycemia.

OBJECTIVE: To evaluate the clinical/research utility of the biopsycho-behavioral model of severe hypoglycemia in differentiating patients with and without a history of severe hypoglycemia and in predicting occurrence of future severe hypoglycemia. RESEARCH DESIGN AND METHODS: A total of 93 adults with type 1 diabetes (mean age 35.8 years, duration of diabetes 16 +/- 10 years, HbA1 8.6 +/- 1.8%), 42 of whom had a recent history of recurrent severe hypoglycemia (SH) and 51 who did not (NoSH), used a handheld computer for 70 trials during 1 month recording cognitive-motor functioning, symptoms, blood glucose (BG) estimates, judgments concerning self-treatment of BG, actual BG readings, and actual treatment of low BG. For the next 6 months, patients recorded occurrence of severe hypoglycemia. RESULTS: SH patients demonstrated significantly more frequent and extreme low BG readings (low BG index), greater cognitive-motor impairments during hypoglycemia, fewer perceived symptoms of hypoglycemia, and poorer detection of hypoglycemia. SH patients were also less likely to treat their hypoglycemia with glucose and more likely to treat with general foods. Low BG index, magnitude of hypoglycemia-impaired ability to do mental subtraction, and awareness of neuroglycopenia, neurogenic symptoms, and hypoglycemia correlated separately with number of SH episodes in the subsequent 6 months. However, only low BG index, hypoglycemia-impaired ability to do mental subtraction, and awareness of hypoglycemia entered into a regression model predicting future severe hypoglycemia (R2 = 0.25, P < 0.001). CONCLUSIONS: Patients with a history of severe hypoglycemia differed on five of the seven steps of the biopsychobehavioral model of severe hypoglycemia. Helping patients with a recent history of severe hypoglycemia to reduce the frequency of their low-BG events, become more sensitive to early signs of neuroglycopenia and neurogenic symptoms, better recognize occurrence of low BG, and use fast-acting glucose more frequently in the treatment of low BG, may reduce occurrence of future severe hypoglycemia.

Frequency of severe hypoglycemia in insulin-dependent diabetes mellitus can be predicted from self-monitoring blood glucose data.

Severe hypoglycemia is associated with insulin-dependent diabetes mellitus and may occur more frequently as metabolic control approaches normal. The goal of this study was to determine whether the frequency of severe hypoglycemia could be predicted by the following predictor variables: 1) frequency and degree of low blood glucose (BG) readings, 2) degree of BG variability during routine self-monitoring blood glucose (SMBG) readings, and 3) level of glycemic control measured by glycosylated hemoglobin-A1 (HbA1). Seventy-eight insulin-dependent diabetes mellitus subjects from 3 different sites had their glycosylated HbA1 assayed and then performed 50 SMBG recordings during the next 2-3 weeks. Over the following 6 months, subjects recorded their severe hypoglycemic episodes (stupor or unconsciousness). There was no difference in the number of severe hypoglycemic episodes between subjects in good vs. poor metabolic control. A higher frequency of severe hypoglycemia during the subsequent 6 months was predicted by frequent and extreme low SMBG readings and variability in day to day SMBG readings. Regression analysis indicated that 44% of the variance in severe hypoglycemic episodes could be accounted for by initial measures of BG variance and the extent of low BG readings. Patients who recorded variable and frequent very low BG readings during routine SMBG were at higher risk for subsequent severe hypoglycemia. Individuals who had lower glycosylated Hb levels were not at higher risk of severe hypoglycemic episodes.

Long-term follow-up evaluation of blood glucose awareness training.

OBJECTIVE: Blood glucose awareness training (BGAT) has been found effective in teaching individuals with insulin-requiring diabetes to improve their ability to better recognize blood glucose (BG) fluctuations. This study investigated whether subjects who underwent BGAT a mean of 4.9 years previously were superior to past control subjects in terms of their ability to recognize BG fluctuations, and whether past BGAT subjects had fewer automobile crashes and lost work days and better glycosylated hemoglobin than control subjects. Additionally, the beneficial effects of providing booster training to past BGAT subjects also was evaluated. RESEARCH DESIGN AND METHODS: This study followed up 28 past BGAT subjects. Half of these subjects (n = 14) received a simple booster-training program. Twelve previous control subjects also were evaluated. Booster subjects were given a BGAT diary to complete for 2 weeks before evaluation. Evaluation for all subjects included completion of a retrospective questionnaire on work and driving history, blood drawing for a glycosylated hemoglobin analysis, and having subjects estimate and measure their BG levels 50-80 times during a 3- to 4-week period during their daily routine. RESULTS: At long-term follow-up, BGAT subjects had significantly fewer automobile crashes than control subjects. BGAT subjects receiving booster training were significantly more accurate at estimating their BG levels and were more aware of hypoglycemia. Post hoc analyses indicated that the ability to accurately estimate BG fluctuations correlated positively with follow-up glycosylated hemoglobin and the number of hypoglycemic and hyperglycemic symptoms participants demonstrated. Both BGAT and control subjects demonstrated significantly improved glycosylated hemoglobin relative to baseline measures. CONCLUSIONS: These data suggest that BGAT has long-term benefits, which can be enhanced with booster training. Specifically, BGAT and simple booster training may result in reduction of severe hypoglycemic episodes and automobile crashes in the long term.

Effects and correlates of blood glucose awareness training among patients with IDDM.

Whereas self-monitoring of blood glucose (SMBG) is the recommended source of information on which to make self-care decisions, patients frequently use estimates of their own blood glucose (BG). This study evaluated whether patients with insulin-dependent diabetes mellitus (IDDM) could learn to improve accuracy of BG estimations and whether this would lead to improved metabolic control. Subjects in BG awareness training improved both their BG-estimation accuracy and glycosylated hemoglobin (HbA1) compared with the control group. Initial BG-estimation accuracy was marginally associated with pretreatment HbA1 and months of previous SMBG experience. Posttreatment improvement was associated with pretreatment BG-estimation accuracy and the ability to counterregulate to insulin-induced hypoglycemia.

Self-measurement of blood glucose. Accuracy of self-reported data and adherence to recommended regimen.

Reflectance meters containing memory chips were used in a study that addressed several questions concerning routine use of self-monitoring of blood glucose (SMBG), including accuracy of patient blood glucose (BG) diaries, reliability of self-reported frequency of SMBG, and adherence to recommended SMBG regimen. Thirty adults with insulin-dependent diabetes used memory meters and recorded test results in diaries for 2 wk while performing their normal SMBG regimen. Analysis of glucose diaries showed that only 23% of the subjects had no diary errors and 47% had clinically accurate diaries (less than 10% error rate). The most common types of errors were omissions of values contained in meter memory and additions of values not contained in meter memory, with significantly more omissions than additions. Alterations of test values (e.g., changing a 300-mg/dl reading to 200 mg/dl) were extremely rare. There was no difference in the rate of errors that resulted in a more positive clinical profile (omitting unacceptable values and adding acceptable values) or a more negative clinical profile (omitting acceptable values and adding unacceptable values). Examination of the actual frequency of SMBG showed that most subjects (56.6%) measured their BG an average of two to three times each day. Self-report of SMBG frequency correlated with both actual frequency and HbA1. Although actual frequency of SMBG was not related to physicians' recommendations, the majority (64%) of subjects were self-testing as often or more often than they had been instructed.