Introduction: Dyspnea (shortness of breath) is defined as a subjective experience of breathing discomfort, and is of varying intensity. The occurrence of dyspnea in subjects with chronic disorders is from the interactions among multiple factors which include physiological, psychological, social and environmental factors. Dyspnea may or may not be associated with hypoxemia, tachypnea or orthopnea. Literature states that almost all of the COPD patients, 80 % of advanced cancer patients and almost75% of patients with chronic disease of any cause experiences dyspnea . The objective of this paper is to discuss the pathophysiology and physiotherapy management of Dyspnea in subjects with chronic diseases.

What causes dyspnea in patients with chronic disease?: Dyspnea is not only caused due to abnormal gaseous exchange; it has been observed that breathlessness reduces if the tidal volume is normal though PCO2 is high and PO2 is low. This shows that perception of breathlessness is due to the imbalance need and ability. Mechano and chemo receptors presents in the respiratory tract detect the changes in the tidal volume and increases the sense of breathing. Increased load over the respiratory muscles are sensed by the brain and perceived as dyspnea .

Assessment of Dyspnea: The aim of dyspnea assessment is to determine the cause, effectiveness of the management strategies and its impact over daily activities. Self reported symptoms are given more importance in dyspnea assessment since it is totally subjective experience. Numerical dyspnea rating scale or Visual analogue scales are the commonly used tools to measure dyspnea.(Refer Table 1)

Dyspnea Assessment using Acronym O, P, Q, R, S, T, U and V ( Adapted from reference 3)

Management

Positioning: Positioning reduces dyspnea by reducing the work of breathing by keeping the respiratory muscles especially the accessory muscle sin mechanically advantageous position.If the subject has dyspnea in lying down position semi fowlers is usually preferred. High side lying with adequate supports are proved to reduce breathlessness in most of the patients with exertional dyspnea, by improving the expansion of the affected side of the lung in case of   unilateral lung pathologies .Upright lean sitting is considered to be one of the best positions to relive dyspnea since it opens up the upper chest and support the shoulder girdle muscles. Leaning forward on a support board or pillows is the most common position used to relieve dyspnea caused due to chronic respiratory illness.

Breathing Exercises: Breathing exercises are the most common techniques used to alleviate dyspnea in subjects with chronic diseases. BE are aimed to retrain the breathing pattern so as to enable the person to maintain the normal tidal volume. It also reduces the work of breathing by improving the efficiency of the respiratory muscles.

Some of the principles to be followed while teaching breathing exercises

• Comfortable sitting with back well supported 
• Hip flexion to create posterior pelvic tilt
• Relaxed shoulder girdle
• External rotation of the shoulders (Palms facing up)
• Gentle auditory clues (breathe in .............. Breath out.................)
• Expiration should be prolonged
•  Tactile stimulus by using the hand
• Breath in through nose and breath out through the mouth
• Pursed lip when ever needed

 BE requires high concentration and patients with severe dyspnea may not be able to follow up the instructions. At time teaching normal patterns of breathing may be distressing to the patients with chronic disorders.

Exercises: Physical activities are proven to be the best way to alleviate dyspnea in people with chronic diseases. Progressive exercises reduce the breathlessness by improving the feeling of well being and improved oxygen utilisation by the skeletal muscles. It has been reported regular physical activities improves the quality of sleep in subjects with chronic diseases. Group exercises are preferred over the individual exercise training as it brings the fun component in. In our study we explored the effect of group exercise in reducing breathlessness in cancer population. The results are very promising and the group exercises are seems to be very effective in reducing the breathless in various stages of cancer survivors.

Fan therapy: It alleviates dyspnea by cooling the nasal pathways and by stimulating trigeminal nerves. Studies have shown fan therapy reduced breathlessness of 29% of the subjects with cancer. The advantages of fan therapy are it is cheap, easy to administer and has no side effects

Pain management: Pain in and around the chess wall is one of the common cause for dyspnea since it reduces the tidal inspiration. Reduction in the tidal volume will lead to reduced lung volumes and capacities and this will produce lung collapse. Pain relieving by means of physical agents has shown to reduce breathlessness in patients with chronic disorders which produces pain. Application of Trans Cutaneous Electrical Stimulation (TENS) is considered as the primary choice in reducing dyspnea though the research evidence is limited ^.

Acupuncture:  Acupuncture is the most popular method to reduce the breathlessness among the patients though it has less research evidence. It was observed that sternum and Li 4 points stimulation are more effective in reducing breathlessness in people with chronic disorders.  There are no side effects because of acupuncture and it is found to be cost effective.

Conclusion: Physiotherapy could be very useful in alleviating dyspnea in subjects with various chronic diseases. Appropriate selection of techniques along with proper education will help the patients to continue their activities of daily living with reduced breathlessness. Therapists working with these patients should be familiar with these techniques, which will enable them to help the patients to get rid of their dyspnea.