Hyperbaric oxygen therapy (HBOT) is a medical treatment for wound healing that involves intermittent inhalation of 100% oxygen at higher than normal atmospheric pressure, inside a special treatment chamber. Normal atmospheric pressure is 1 Bar, which is equivalent to 76 cm of Hg pressure at sea level. So any pressure greater than this can be called hyperbar. This oxygen at high pressure is called Hyperbaric Oxygen or HBO, said Dr Tarun Sahni, Senior Consultant, Apollo Indraprastha Hospital, New Delhi, during a conference on 'High Risk Diabetic Foot' in Kanpur, India, jointly organized by the Indian Podiatry Association, UP Chapter of Association of Surgeons of India (ASI), and Hyperbaric Society of India.
HBOT increases dissolved oxygen in the plasma which is responsible for its effects. Blood normally carries 19ml of oxygen with Haemoglobin (Hb) and 0.3ml of it is dissolved in plasma. If a person breathes 100% oxygen, then its level in Hb increases to 20ml and that in plasma to 1.5ml. But with HBO, Hb is saturated with oxygen and the amount of oxygen carried in the plasma increases to 6ml. It is this increase in the dissolved oxygen which is good for the body, said Dr Tarun Sahini.
HBOT for wound care is based upon sound physiological principles. Without adequate oxygenation, normal healing process cannot take place. Wound healing has been found to improve at increased ambient pressures, as has been seen in the case of divers. Oxygen plays a pivotal role in almost every major component of wound healing. Increasing the wound oxygen tension/pressure enhances the healing process, said Dr Tarun Sahini.
Thus adequate tissue oxygen is an essential factor in wound healing. A significant increase in tissue oxygen promotes wound healing by directly enhancing fibroplast replication and neovascularisation; increasing leukocyte/bacterial activity; helping in bone formation and stem cell stimulation. During HBO, due to higher pressure, the oxygen dissolves more in the liquid part of the blood and its level increases 10 to 20 times the normal value. This oxygen reaches all areas of the body - even those places where it was not reaching earlier due to inadequate blood supply or less haemoglobin, said Dr Tarun Sahini.
Conditions benefitting from HBOT are:
(i) wounds - in diabetic patients, arterial and venous ulcers, accident wounds, burns, gangrene, bone infection or osteomyelitis and other non/ slow healing wounds
(ii) Oncology - radiation tissue damage
(iii) Primary treatment of carbon monoxide poisoning, smoke inhalation
(iv) Sudden deafness, vertigo, tinnitus
(v) Neuro rehabilitation - head/spinal injury, stroke, cerebral palsy, Bells palsy.
Patients with diabetes, peripheral vascular disease, traumatic injury and infections are more susceptible to problem wounds. Wounds may not heal due to many reasons, the major one being poor supply of oxygen. Lack of oxygen results in swelling of tissues; which increases the distance for oxygen to travel; which further reduces oxygen supply; finally resulting in tissue destruction. According to specialists, when the tissue oxygen tension drops to less than 30mm of Hg pressure, healing by cellular division is significantly reduced and may even stop. In such an environment, fibroplasts and leucocytes are not capable of functioning, said Dr Tarun Sahini.
This therapy has proved to be very good in the treatment of severe ischemic diabetic foot ulcers and soft tissue infections. All diabetic wounds in lower extremity benefit from hyperbaric oxygen.
HBO can be administered in Mono Place Treatment Chamber, wherein a single patient is placed in the chamber pressurized with 100% oxygen. Or it can be given in Multi Place Treatment Chamber where many patients can be treated at the same time. These chambers are pressurized with compressed air, and the patient breathes 100% oxygen at that pressure, through special masks or oxygen hoods. Apollo hospital in Delhi uses the latter type. It is perhaps the only hospital in India, apart from one other at Ahmadabad, which boasts of an HBO Clinic, said Dr Tarun Sahini.
As it takes approximately one hour to saturate the tissues, most treatments are set at 90 minutes of oxygen breathing. Thus a single treatment session lasts for two hours, giving 30 minutes for preparation before and observation after the therapy. An average of 30 sessions (one per day) is required, though it may go up to 100 sessions in some acute cases, said Dr Tarun Sahini.
HBOT is a relatively new concept in India though very popular in countries like China (it has more than 2500 HBO clinics) ,Russia (2000 clinics), USA (400 clinics) and UK (200 clinics). But it is gaining acceptance as it not only saves and preserves the quality of life, but also reduces high cost of disability arising out of amputation, shortens the healing time and reduces costs of repeated surgery, said Dr Tarun Sahini. When combined judiciously with standard orthopaedic and vascular treatments, it would go a long way in reducing morbidity and mortality (CNS).
Contributed by: Bobby Ramakant