Underlying—Disease Risk for Antispasmodic Premedication in Older Patients Undergoing Investigations of the Gastrointestinal Tract

Introduction

Generally, anticholinergic agents or glucagon preparations are administered prior to GI investigations in order to suppress peristalsis and secretions for easier observation of the target area. The parasympatholytic actions of anticholinergic agents contraindicate their use in patients with glaucoma, prostatic hypertrophy and cardiovascular conditions such as arrhythmia and heart disease. Glucagon, a peptide hormone secreted by the pancreas, is contraindicated in patients with phaeochromocytoma, although serious adverse reactions are considered uncommon, other than in patients with marked hyperglycemia.

The importance of clinical risk management (i.e. detecting and reducing the risk associated with medical procedures) has increased in current medical practice. In endoscopy in particular, recent advances and wider application have led to increased use in high-risk cases and according to a nationwide survey in Japan, 74% of deaths associated with endoscopic premedication were in patients aged 60 years or over. ¹ We present the risk management initiatives we have introduced to overcome this problem.

We surveyed patients undergoing investigations of the gastrointestinal (GI) tract from the viewpoint of the influence of the underlying disease on selection of antispasmodic agent. We also investigated associations with age, in order to identify the high-risk group and assist in risk management. For the purpose of this study, elderly subjects were defined as those aged 65 years or over, as per the Japanese Welfare Law for the Elderly.

Methods

Results

The numbers and proportions of subjects with underlying diseases that influenced the selection of antispasmodic agent are shown in Table 1. Circulatory diseases, benign prostatic hypertrophy and diabetes mellitus were relatively common.

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Table 1

Numbers and proportions of the underlying diseases.

	n(%)
Circulatory diseases	100 (26.92)
Hypertension	51 (12.26)
Arrhythmia	29 (6.97)
Angina pectoris	14 (3.37)
Myocardial infarction	6 (1.44)
Glaucoma	12 (2.88)
Benign prostatic hypertrophy	38 (9.13)
Phaeochromocytoma	4 (0.96)
Diabetes mellitus	32 (7.69)

We also collated the proportion of subjects in whom antispasmodic agents (anticholinergic agents/ glucagon preparations) were contraindicated because of underlying diseases (Fig. 3). Of the younger subjects, aged less than 40 years of age, 10-20% has a risk associated with anticholinergic agents. The prevalence of risk-associated underlying diseases increased with age, with anticholinergic agents contraindicated in 53% of subjects aged 65 years and over. Glucagon preparations were contraindicated in 4-15% of subjects aged 40 years and over. To confirm the risk associated with antispasmodic agents in elderly subjects, we divided all patients into two group, aged under 65 years or 65 years and over, and compared the risk between groups (Table 2). Anticholinergic agents were contraindicated in 53% of subjects aged 65 years and over, significantly higher than the 21% of subjects aged under 65 years (χ ² test, P = 0.0014). Glucagon was contraindicated in 11% of subjects aged 65 years and over, significantly higher than the 5% of subjects aged under 65 years (χ ² test, P = 0.033). OPEN IN VIEWER

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Table 2

Risk of antispasmodic agents.

Contraindication	Under 65 years	Over 65 years	generation total
Anticholinergic agents	21%	53%	35%
Glucagon preparations	5%	11%	7%

Discussion

The number of investigations of the GI tract performed in Japan has risen markedly in recent years, with expansion of the system of regular health checks and with increasing consumer demand for early detection and treatment. At the same time the ageing of Japanese society has increased the proportion of patients considered as high risk, in particular elderly patients with unrelated underlying diseases. The Accident Prevention Committee of the Japan Gastroenterological Endoscopy Society has conducted, and published in detail, nationwide surveys of investigation-related accidents at 5-yearly intervals since 1983.^2–4 The third survey comprised 1,200,000 investigations, yielding 2600 accidents for an incidence of 0.22%. Patients aged 60 years or more accounted for 74% of deaths associated with premedication, and 82% of all investigation-related deaths, emphasising the need for risk management in elderly patients undergoing GI investigations.

Harada et al. examined the hemodynamic effects of anticholinergic agents and glucagon preparations administered as premedication for upper GI tract endoscopy, finding that the heart rate and pressure product rose significantly more with anticholinergic agents than with glucagon.^5–16 In other words, the cardiac load is greater following the administration of anticholinergic agents than of glucagon.

The risk of hypoglycaemia should be worried also in non-diabetic patients following glucagon administration, in particular after 90-120 min, we give glucose tablets to the patients after endoscopy.

Collation of the present survey results revealed that anticholinergic agents were contraindicated in 35% of all subjects and that proportion rose with age. In particular, anticholinergic agents should be avoided in more than 50% of subjects aged 65 years and over. On the other hand, glucagon preparations were contraindicated in 7% of all subjects, and 11% of subjects aged 65 years and over, suggesting that, when choosing an antispasmodic agent for an elderly patient, from the viewpoint of preventing adverse events it is better to opt for glucagon rather than an anticholinergic agent.

In conjunction with the conducting of this study, we changed from our previous method of oral interview to using a patient questionnaire to assist with the choice of antispasmodic agent. As a result, in 2001 there was a change in the proportions of the different antispasmodic agents administered prior to endoscopy or barium contrast radiography of the GI tract, from 87% anticholinergics and 11% glucagon prior to introduction of the questionnaire to 79% and 21%, respectively, after its introduction. We considered the questionnaire useful in accurately identifying underlying diseases in the respondents, and assisting in the selection of the appropriate antispasmodic agent. In conducting this study, we were also reminded of the unavoidable fact that unpredictable adverse events will occur in a certain proportion of investigations, and that it is important from the risk management aspect to take a careful history and obtain informed consent in advance of the procedure.

Conclusions

The most prevalent underlying diseases requiring consideration in the selection of premedication for GI investigations are cardiovascular diseases, prostatic hypertrophy and diabetes mellitus. Anti-cholinergic agents were contraindicated in more than 50% of subjects aged 65 years and over, which was a significantly greater proportion than for subjects aged under 65 years. Using a written questionnaire facilitates the identification of underlying diseases and selection of the appropriate premedication. Overall, risk analysis has enabled better identification of factors that are useful in the fields of informed consent and risk management.

Key Points

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The prevalence of risk-associated underlying diseases increased with age, with anticholinergic agents contraindicated in approximately 50% of subjects aged 65 years and over.