dx.doi.org/10.1016/j.rcae.2014.02.004

Scientific and Technological Research

Dietary supplements and the anesthesiologist: Research results and state of the art

Los suplementos dietéticos y el anestesiólogo: resultados de investigación y estado del arte

Silvana Franco Ruiza,^b,*, Patricia González Maldonado^b,c

^a Surgeon, Universidad de Caldas, Specialist in Epimediology Universidad del Rosario
^b Member of the Anestecoop Education Committee, Medellín, Antioquia, Colombia
^c Surgeon, Universidad Nacional de Colombia, Specialist in Anesthesiology and Resuscitation, Universidad Nuestra Señora del Rosario, Pediatric Anesthesia Visiting Staff, Hospital Federico Gómez, Universidad Nacional Autónoma de México, Specialist in Service Anesthesiologist, Universidad de La Sabana Clinic, Anesthesiologist, National Police Hospital, Anesthesiologist, Clínica Palermo, Bogotá, Colombia

Please cite this article as: Franco Ruiz S, González Maldonado P. Los suplementos dietéticos y el anestesiólogo: resultados de investigación y estado del arte. Rev Colomb Anestesiol. 2014;42:90–99.

Corresponding author at: Calle 121 # 15^a-14, Bogotá, Colombia. E-mail address: silvanafrancor@gmail.com (S. Franco Ruiz).

ARTICLE INFO

Article history: Received 15 January 2013 Accepted 10 January 2014 Available online 13 March 2014

ABSTRACT

Background: There is a growing worldwide trend towards the consumption of nutritional supplements. Patients scheduled for surgery who are users of dietary supplements run the risk of interactions between these substances and drugs used in the perioperative period. Objectives: To conduct a socio-demographic characterization, and determine the prevalence of nutritional supplement use in people taken to surgery; to offer a reference guideline for use during pre-anesthetic consultation.
Methods: The research team conducted an observational descriptive and cross-sectional study of patients presenting to the pre-anesthetic consultation in thirteen cities; 1130 patients were asked about the use of these substances.
Results: The prevalence of use was 20.7%, higher among females at 62.8%, compared to males; consumption in people over 41 years was 63.2%; self-medication in 72.8%; increased consumption with age; in middle and high socioeconomic brackets, consumption was 63%; the higher the education, the higher the consumption; 36.6% plan to continue consumption despite the surgical procedure.
Conclusions: The high rate of consumption of nutritional supplements in patients about to undergo surgery, possible drug interactions, and adverse effects of perioperative consumption of some herbs should trigger an alarm in the anesthesiologist performing the pre-anesthetic consultation; it is necessary to include this in the interview and act accordingly. We recommend always asking to see product packaging.

Keywords: Prevalence, Anesthesia, Diet, Therapy, Patients, Surgical, Procedures, Operative.

RESUMEN

Introducción: Hay una creciente tendencia mundial hacia el consumo de suplementos nutricionales. Los pacientes que consumen dichas sustancias y que van a ser llevados a cirugía tienen un riesgo potencial de presentar interacciones medicamentosas entre estas sustancias y los medicamentos del período perioperatorio.
Objetivos: Realizar una caracterización sociodemográfica y determinar la prevalencia del consumo de suplementos nutricionales en personas que van a ser llevadas a cirugía; además, servir como guía de consulta para tomar conductas en la consulta preanestésica.
Metodología: Se llevó a cabo un estudio observacional descriptivo de corte transversal, con pacientes que se presentaban a la consulta preanestésica, en 13 ciudades del país. A 1.130 pacientes se les interrogó acerca del consumo de estas sustancias.
Resultados: La prevalencia de consumo fue de un 20,7%, siendo mayor en el sexo femenino, con un 62,8%, frente al sexo masculino; el consumo en personas mayores de 41 años fue del 63,2%; se automedicaron un 72,8%; a mayor edad, mayor consumo; entre los estratos medio y alto el consumo fue del 63%; a mayor nivel educativo, más consumo; el 36,6% piensan seguir consumiendo a pesar del procedimiento.
Conclusiones: El alto índice de consumo de suplementos nutricionales en pacientes que van a someterse a una cirugía, las posibles interacciones con los medicamentos del perioperatorio y los efectos adversos de algunas hierbas medicinales deben poner en alerta el anestesiólogo que realiza la consulta preanestésica; es necesario incluir este tema en el interrogatorio y tomar conductas al respecto. Es aconsejable solicitar los empaques de los productos que consume.

Palabras clave: Prevalencia, Anestesia, Dietoterapia, Pacientes, Procedimientos, Quirúrgicos, Operativos.

Introduction

Technological developments in medicine at the present time occur at dizzying speed and research brings about amazing breakthroughs year after year regarding new therapies for a broad range of diseases.

Notwithstanding, a growing number of people resort to alternative, non-conventional practices such as acupuncture, homeopathy, herbal therapies and dietary supplements used as nutritional add-ons to their normal diets.¹

This has come about because people want to have better control over their health. In contrast with medications, dietary supplements are not subject to rigorous evaluations before they reach the market.² One out of every six patients takes some type of dietary supplement concomitantly with medications prescribed by their physicians. All kinds of supplements are found in drugstores, supermarkets, local stores, etc., and patients are now able to find abundant information on the web. However, most of them fail to mention the use of these substances to their physicians, placing their life at risk as a result of potential interactions. It is estimated that 70% of patients fail to inform their physician³ and many of them even take mixes of drugs and nutritional supplements containing substances with unknown side effects that might interact with perioperative medications and result in adverse events.⁴

Many companies promote herbal medications as dietary supplements. It is estimated that this is a 19 billion-dollar industry and that almost half of the Americans take daily supplements, only some of which have proven efficacy.⁵ According to a report published in 2009 in the United States regarding consumer trust in dietary supplements, 84% of people trust the quality, safety and efficacy claims of these products.⁶ Table 1 shows the common uses of various substances.

TABLE 1

In 1994, the US Congress passed a law defining dietary supplements as substances mainly for oral intake containing, as their main characteristic, a “dietary ingredient” designed to supplement the diet. Some examples of dietary supplements are vitamins, minerals, herbs (alone or in a mix), aminoacids, and food components such as enzymes and gland extracts. They come in different presentations including tablets, soft gels, liquids and powders. They are not presented as food substitutes or as meal replacements, and they are labeled as dietary supplements.⁷ On the other hand, nutraceuticals are dietary supplements containing a concentrated form of a bioactive substance originally derived from a food source but now present in a non-food matrix, used as health enhancers at higher doses than those found in normal foods.⁸

Tsen et al.⁹ Showed that up to 32% of patients assessed during the pre-operative phase used dietary supplements, herbal products, or both. Effects associated with plant-derived products include pharmacokinetic alterations (alteration of absorption, distribution, metabolism, and clearance of conventional medications; pharmacodynamic alterations; and direct interactions with drugs.¹⁰

Dickinson et al.³ Surveyed cardiologist, dermatologists and orthopedic surgeons in order to determine if they used dietary supplements and recommended them to their patients. They found that up to 75% of them used supplements and up to 91% recommended their use in situations related to their specialties, for example, lowering cholesterol, reducing joint pain, anxiety, etc. They recommended substances such as omega3 oil, calcium, vitamins and glucosamine. Noteworthy is the concern of these professionals for the absence of continuing education courses on this subject. Table 1 shows a list of the most common uses of some dietary supplements.

The objective of this work was to perform a sociodemographic characterization, determine the prevalence of the use of dietary supplements in patients who are going to be taken to surgery and receive a pre-anesthesia assessment, and to offer a consultation guideline to help anesthesiologists take action during the pre-anesthesia assessment.

Materials and methods

Design

A descriptive cross-sectional study was proposed in order to determine the prevalence of dietary supplement use.

Population and sample

A sample was taken at the investigator’s convenience in those cities where the cooperative (ANESTECOOP) operates.

Procedure

Data were collected through interviews conducted by anesthesiologists during the pre-anesthesia consultation, and recorded in a format designed for that purpose. The interviews were conducted in 13 cities of the country (Pereira, Valledupar, Apartadó, Cartago, Sincelejo, Armenia, Bogotá, Montería, Buga, Manizales, Riohacha, Cali, La Dorada), totaling 1248 patients interviewed in the pre-anesthesia assessment. Of that total, 1130 were taken into account for analysis and the remaining 118 were excluded for different reasons (incomplete or illegible surveys, etc.).

Variables

They correspond to the questions in the survey, which in turn match each of the specific objectives.

Inclusion criteria

Patients over 18 years of age scheduled for elective surgery of any type attending the preoperative consultation.

Statistical analysis

Frequencies were performed for the qualitative variables together with a bivariate analysis using chi², with a statistical significance value of 0.05. The only quantitative variable (age) was analyzed using means and standard deviations and then recoded in ranges. Prevalence was determined and results were contrasted with the data of the NHANES 2002 and 2008 surveys.

Ethical considerations

This is a descriptive observational study based on interviews for which a verbal consent was obtained from the patients. A form was used to record data pertaining to the study and there was no experimentation with the patients at any time; there were no physical examination or biochemical measurements; hence, the Helsinki declaration does not apply.

Results and analysis

It was determined that the prevalence of dietary supplement use was 20.7%, with a higher consumption among females (62.8%) compared to males. By age group, the higher consumption was found between 41 and 60 years (39.8%); in patients over 60 years of age, the rate was 23.4%, for an overall consumption of 63.2% in adults over 41. Table 2 Shows the socio-demographic characteristics of the surveyed population.

Consumption prevalence according to level of education was distributed as follows: complete primary education, 24.2%; complete secondary education, 36.7%; and 39% among patients with technical, university or graduate education.

Consumption prevalence in income brackets 1 and 2 (lower) was 34.5%, 60.1% in income brackets 3 and 4 (middle), and 5.4% in income brackets 5 and 6 (upper); of the patients surveyed, 88.3% came from the urban area.

To the question of how they had started using these products, 72.8% reported self-medication and the remaining 27.2% reported medical recommendation; 51.9% had started using supplements on a recommendation from a friend or relative.

When asked about the reasons for using nutritional supplements, 44.5% of the respondents reported that they were healthy but wanted to supplement their diets, and 33.7% reported illness and the desire to improve their health. Another reason, given by 8.6% was the feeling of fatigue.

To the question of how long they had been using supplements, 50.5% reported between three and six months, 30% reported 7–12 months, and the remaining 19.5% reported more than one year.

Bearing in mind that patients in the pre-anesthesia consultation are going to undergo surgery, to the question of whether they were planning to stop using the product, or interrupt its use temporarily, or if they were planning to continue to use it despite the procedure, 22.6%, 40.8% and 36.6%, respectively, gave a positive response.

In the bivariate analysis, a statistically significant association was found between consumption and age, income bracket, gender and level of education. It was found that, the older the age the higher the consumption, the higher the income bracket the higher the consumption (63% among people in middle and upper income brackets); there was higher consumption among females, and higher consumption also among people with a higher level of education.

As far as the different substances used as dietary supplements, a wide range of products were reported with close to 200 different responses including Green tea, multivitamins, folic acid, omega-3, glycerine, beta carotene, guarana, gingko biloba, valerian, duck embryos, artichokes, soy, spirulina, transfer factors, shark cartilage, ginseng, plus a whole variety of brand names.

Discussion

Adverse reactions to herbal medicines and supplements are not well recognized and, what is even worse, not reported. Most of the people using dietary supplements do not stop using conventional medications prescribed by their physicians.¹¹ Even more difficult than detecting adverse reactions to medications, is detecting adverse reactions to dietary supplements. It is important to set up a system of reporting and follow-up of potential interactions and adverse reactions caused by these substances in order to be able to evaluate these products and create policies regarding their use.⁷ Table 3 summarizes the main reasons why the general population uses these products, as determined by three independent studies; it shows that the reasons are similar to those found in this research, and points to the fact that most people hope to improve their health and start using these substances without thinking about potential interactions with medications they may be taking at the same time.

Two studies conducted in 2000¹² in pre-surgical patients reported that almost half of those patients used dietary supplements. The biggest source of concern though, is that patients rarely offer this information and, worse still, anesthesiologists rarely ask about it. Later on, in 2004, MacKichan et al. asked about the reasons why patients do not discuss the use of these substances with their physicians, and found the following answers: products are labeled as natural and therefore they assume that they are safe; a medical prescription is not required; they are not considered medications. This study found that 72.8% of people using supplements simply self-medicate, and perhaps the argument for not asking their physicians, as was found in the previous studies, is that the products are labeled as natural and they assume they are safe.¹⁰

Some statistics show that close to 50% of the patients undergoing surgery discontinue the use of dietary supplements on their own. Consequently, the obvious conclusion is that the other 50% continues to use them.² In our case, the result is somewhat different, as we found that only 22.6% of the people who use these products think about interrupting their use before the surgery. This reinforces the idea of the sense of trust regarding dietary supplements.

There is an association between use and age over 41, female gender, upper socio-economic bracket, and higher level of education. This may be due to the fact that, the higher the level of education, the higher the purchasing power and the higher the income bracket. Leung et al., reported similar results in 2000, in a study similar to ours: 39.2% used some form of supplement; 56.4% did not mention the use of these products to their treating physician; 53% planned to discontinue their use before surgery. The authors report the following variables as associated with the use of dietary supplements: female gender, high income, high education level, and age range between 39 and 45 years.²

NHANES, The National Health and Nutrition Examination Survey is a representative survey conducted nationwide in the United States. It comprises medical exams and tests, as well as detailed questions about respondent health, lifestyle and diet, and also the use of dietary supplements. The results of this survey in 2002 showed an association between the use of dietary supplements and a high level of education and age over 60. Of the respondents, 16.8% used four or more types of supplements,¹³ with results similar to ours.

The NHANES 2008 survey¹⁶ estimated the use of complementary and alternative medicine among American adults and children. They used data from prior surveys conducted by the CDC and also compared the data with the 2002 survey. They found that 4 out of every 10 adults and 1 out of every 9 children used this type of medicine.

Hogg et al. used a survey in United Kingdom hospitals to ask whether they had specific policies or protocols for managing patients who were taking herbal medicines during the perioperative period, and they found that 90% of the participating institutions had none.⁴ The situation may be the same in the hospitals in our country. Table 4 shows adverse reactions and interactions of the most commonly used dietary supplements.

TABLE 4

Conclusions

We submit this paper not only as the product of a research process but also as study material and guideline for the country’s anesthesiologists. It is important to ask these questions of our patients and try to determine, as accurately as possible, what substances they are consuming, how these can affect the planned procedure, and how to act, not only for the benefit of the patients but also for our own peace of mind. There are reports in the literature about serious adverse events when these substances are associated with anesthetic agents. This is one of the few studies conducted in Colombia in relation to the intake of nutritional supplements prior to a surgical intervention.

The lack of sound studies plus the absence of knowledge regarding the effectiveness of these products, creates a false sense of reassurance. The use of these products becomes a challenge for healthcare providers, in particular with patients going to surgery, considering that interactions between some supplements and anesthetic drugs may be fatal.¹⁰ Education to the public is required in order to avoid abuse of these substances, self-medication and the false belief that natural products are free from adverse effects.

The following is a list of general recommendations for anesthesiologists^{8,15,16,18,19}:

1. Always ask about the use of supplements and herbal medicine and turn this into a habit as part of the routine patient interview.
2. Always document patient use of supplements in the clinical record.
3. Discontinue supplements in cases of pregnancy and breastfeeding.
4. Ask patients to bring (physically) all medications and supplements that they are using.
5. Evaluate the components in the supplements used by the patient at the time, and consider potential adverse reactions and drug interactions.
6. The American Society of Anesthesiologists recommends discontinuation of these substances two weeks before elective surgery.

Table 5 shows evidence-based recommendations for the use of some dietary supplements.⁸

Funding

None.

Conflicts of interest

The authors have no conflicts of interest to declare.

REFERENCES