Biofeedback – A Promising Non Pharmacological Tool of Stress – Related Disorders

Biofeedback is a therapeutic method of obtaining better awareness of physiological functions based on principles of operant conditioning and learning in general. While patient observes changes in physiological parameters in real-time (e.g. blood pressure, heart rate variability, temperature, electrodermal activity, etc.), he/she learns how to manipulate them at will. By means of this technique, individuals can improve their mental, emotional, and physical health. Clinical biofeedback training becomes popular for treating a variety of medical conditions, manage ment of disease symptoms, and improvement of overall health through training of stress management. There is no center or group to systematically deal with biofeedback methods in Slovakia, except the Slovak Institute of CBT (cognitive-behavioral therapy) that teaches biofeedback as a therapeutic method. However, biofeedback and its opportunities have a relatively long history of exploration and practice, which is the best precondition for positive changes in this area. The review article aims to provide an insight to biofeedback training as a non-pharmacological therapeutic tool in stress management and stress-related diseases and disorders. The article also describes biofeedback modalities and efficacy on various medical conditions.

Barbosa RT, Valenti VE, Oliveira FR, Roque AL, Júnior HMFES, Garner DM, Raimundo RD, de Abreu LC. The effects of cataract surgery on autonomic heart rate control: a prospective cross-sectional and analytical study

OBJECTIVES

We aimed to evaluate the effects of cataract surgery on cardiac autonomic modulation.

METHODS

A cross-sectional and analytical study was conducted at the Hospital Maria Braido in the city of São Caetano do Sul, São Paulo, between 2015 and 2016. We investigated 19 patients of both sexes who were all over 50 years old; all patients had a diagnosis of senile or bilateral cataracts and were recommended to undergo implantation of the intraocular lens. Heart rate variability (HRV) was evaluated before, during and after cataract surgery.

RESULTS

There were no significant changes in the time and geometric domains of HRV before, during or after surgery. The high-frequency (HF) band in normalized units (nu) on the spectral analysis significantly increased (p=0.02, Cohen's d=0.9, large effect size). However, the low-frequency (LF) band in nu significantly decreased during surgery (p=0.02, Cohen's d=0.9, large effect size).

CONCLUSION

Throughout the intraocular lens implantation cataract surgery, there was an increase in parasympathetic modulation and a decrease in the sympathetic component of the heart rate (HR). We propose that this result is attributable to the supine position of the patients during surgery and the trigeminal reflex.