Main Story

Medical Gas Distribution- Lifeline of a hospital

With increasing number of hospitals going for accreditation, streamlining medical gas systems has become crucial, says Sonal Shukla

Medical gases form the very backbone of a hospital. Without them it would be impossible to run a hospital, as they play an essential role in the functioning of critical care units and key operational areas like OR, ICUs, HDUs and high risk procedural areas.

The Gases We Need

Oxygen is the most vital gas that may be needed by any patient admitted anywhere in the hospital. Nitrous oxide is used as an anaesthetic agent in surgery; mixed with oxygen to help patients relax during dental procedures; and in cryo-surgery (the use of extreme cold to destroy tissue). Nitrogen is used to provide pneumatic pressure in medical equipment; to prevent combustion and other chemical reactions; and as a component of many gas mixtures. Carbon dioxide is used to inflate areas of the body for laparoscopy surgery, mixed with air or oxygen to stimulate breathing.

Medical air is used in administering breathing treatments and as a mixing component for other respiratory gases. Compressed air is used to drive certain medical equipments like drills, saws and ventilators. Although technically not a gas, vacuum exhaust for waste anaesthetic gas disposal (WAGD or scavenging) and surgical suction must also be provided and is considered an integral part of the medical gas system. Current research indicates that noble gases like the xenon, helium, neon and argon produce cardio-protection and may play significant role in certain types of cardiac surgery.

Concerns & Recommendations

Automatic O2 Gas Control panel

Oxygen regulator

With an increasing number of hospitals going for accreditation, streamlining medical gas systems has become even more crucial. If the medical air is not properly treated, it may also lead to acting as a reservoir of nosocomial infections. Size of the pipes supplying medical gases should be adequate as per NFPA 99 standards.

Patients are endangered if medical gas systems, particularly oxygen, malfunction. The main features of such systems are the sources of the gases and the means of their delivery to the OR. It is necessary for an anaesthesiologist to understand both these elements to prevent and detect medical gas depletion or supply line misconnection.

Quality of gas plays important role in recovery too. Medical compressed air should not have any contaminants in the form of particulate matter, odour, oil vapour or other gases. According to experts, it is important that the air intake of medical air compressors should be located outdoors away from main building. "Particles including water and oil aerosol present in breathing air should be, or = 0.1 micron and the oil content, if any must be, 0.01 mg/cu m. The dew point of the air given to patients should be 40 degree centigrade," says Anil Dhamdhere, Manager Engineering, Dr LH Hiranandani Hospital, Mumbai.

Experts emphasise on having dual air dryers, dual air filters and dual line pressure regulators on all systems, and recommend the use of automatic moisture separators and dew point monitors, which should be connected to the master alarm panel.

Quality of supply is achieved by the use of gases purchased from appropriate manufacturer or produced by plant performing to specified standards, by the maintenance of cleanliness throughout the installation of the system, and by the implementation of the various testing and commissioning procedures. Quality certification of gas by supplier for each and every supply is advisable to keep a tab on the quality. "99.9 per cent purity certification of oxygen delivery should be obtained from the vendor," shares Dr Sanjiv Singh, Senior Medical Administrator, AIMS, Kochi.

Bare Essentials

The criticality of medical gas lies in its proper distribution. A medical gas pipeline system is designed to provide a safe and effective method of delivering the required medical gas from the source of supply through a pipeline system to the patient via a terminal unit.

Central bulk medical oxygen storage system

"Each medical gas must be supplied from a separate system, and it is essential that all parts of each system are gas specific to ensure that there is no possibility of cross-connection between any systems," shares Dr Deep Arora, Head - General Anaesthesia and Pain Management, Max Healthcare, New Delhi. The central piped system should be having branch connections in the respective departments, and has to be directed through calculated number of outlets in various zones of the hospital. According to experts, the route of the gas distribution system should be carefully planned since it could lead to an environmental disaster.

"With the proper medical gas system, users should be able to easily access medical gas outlet points. It is necessary to keep the outlet points out of the way. The gas flow and pressure should not exceed beyond some specified limit," states Dr N Tibrewala, Anaesthetist, Breach Candy Hospital, Mumbai. The distribution of O2 and N2O should ideally be in every room, ICUs, HDUs. O2 should be available in portable cylinders on trolleys, and CO2 in OTs.

Piping should be protected against physical damage, corrosion etc. Pipe size, size of manifold is to be decided based on the total consumption of the hospital. "Buried piping should be installed at sufficient depth to prevent piping from excessive stress. Trenches should be excavated so that piping is firm and substantial continuous bearing is on the bottom of the trench," says PK Kishore, Senior Manager in charge of Medical Gases, CSSD, and laundry, SRMC, Chennai.

Piping shall not be installed in kitchen, electrical room, corridors etc. If installed in such areas it should be with protection shields. Correct size piping should be designed for central delivery of medical gas system. Separate housing should be there to have gas control panel and other equipment. "Oil or oil mist and other hazardous material should not contaminate the surrounding. No grease, oil, or naked flame should be used in near area. Separate gauge indicating the line pressure should be an integral part," adds Kishore.

In Safe Hands

"The piped material should be copper seamless tubes with flux less silver brazing" - Anil Dhamdhere Manager Engineering Dr LH Hiranandani hospital Mumbai

"When it comes to choosing medical gas equipment, people start thinking of saving money" - Dr Deep Arora Head - General Anaesthesia & Pain Management Max Healthcare, New Delhi

"Certain amount of redundancy has to be built in at the time of installation itself" - Maj Gen Naresh Vij Director - Projects and Engineering P D Hinduja Hospital Mumbai

The system has to be operational round the clock, with practically zero down time. Failure of system can be fatal and life threatening if not restored. Most of the ventilators are run by medical air in the hospital. In ICU, the patients require oxygen and in OT, gases like nitrous oxide and carbon dioxide are uitilised frequently. "Any breakdown there has to be rectified immediately. Certain amount of redundancy has to be built in at the time of installation itself," opines Maj Gen Naresh Vij, Director - Projects and Engineering, PD Hinduja Hospital, Mumbai.

The probability of errors resulting in serious harm to the patients or to the handlers is very high and is a major area of concern. Incorrect cylinder (connecting wrong cylinder at the inlet), incorrect contents (different gas in a cylinder than what it is marked for), incorrect valve, incorrect cylinder colour, incorrect labelling, inoperable valve, damaged valve, asphyxia (accidently breathing gases other than oxygen), fires, explosions, projectile damage, contaminated cylinder contents, nitrous oxide abuse, overfilled cylinders, thermal injury and malfunctioning flow meters, system leakage, choking of ON line filters, failure of oil free compressors, failure of vacuum pumps, are few of the innumerable challenges that could come across while dealing with medical gas systems. Experts emphasise on installation of gas systems as per guidelines and routine checking of system for leakage. "With the availability of piped gases, users have generally become complacent about checking the availability of alternate oxygen source in emergency situations, indeed a sure shot recipe for disaster. In-built check-in systems should be powered to enforce such basic discipline," shares Dr Anil Karlekar, Cardiac Anesthesia, Fortis Escorts Heart Institute, New Delhi.

Periodical cleaning of suction points with application of reverse air pressure will ensure trouble free vacuum. It is also crucial to check compressor set points to ensure required gas pressure till user end and replacement of piston rings, oil of vacuum pumps consumables like gaskets, suction filters and anti bacterial filters. "It is essential to have safety aesthetics in distribution lines, with easy access for repair," adds Dr Tibrewala. Constant leak testing should also be performed to make the distribution system safe. Having isolation walls takes care of any leakage of gases as they isolate the source of leakage.

The system pipes should be colour-coded as per regulation for easy identification. "There is a colour coding system given according to the BIS standards, so as uniformly standardised the distribution pattern," shares Dr Singh. According to Dhamdhere, the piped material should be copper seamless tubes with flux less silver brazing. The supply of pipes shall accompany with manufacturers test certificates for physical properties and chemical composition. The supply of pipes shall be further substantiated with inspection certificates from third party inspectors.

"Continuity of supply is achieved by the specification of a system which (with the exception of liquid oxygen systems that may include a secondary vessel) have duplicate components, and by the provision of an adequate emergency/reserve supply for all systems; by the provision of alarm systems, and by connection to the emergency power supply system," shares Dr Arora. The system should be thus installed with low pressure alarm system to indicate failure/leakage of gas at appropriate manned locations 24x365 days like nursing station and central plant supply station. The central LMO station should be remotely monitored for level of gas with the help of telemetry system and automatically refilled on sensing low level of reservoir by the supplier.

Staff involved in handling medical gas systems should be well informed and properly trained too. "Hospitals have to follow strict guidelines as far as procurement, storage and utilisation is concerned. All people who handle medical gases should be well versed with those things," says Dr Jitendra Bapat, Consultant Anaesthesiologist, P D Hinduja Hospital, Mumbai. Breakdowns of medical gas machineries are functionally not affordable. Hence, hospitals need to perform preventive maintenance meticulously as per manufacturer's recommendation. "It is mandatory to replace the tear and wear parts at an appropriate time and check lists need to be maintained and monitored," opines Bobby Jose, General Manager-Clinical Engineering, Kokilaben Dhirubhai Ambani Hospital, Mumbai.

Designing it Right

Medical gases need to be made available round the clock, 365 days in a year; uninterrupted, unadulterated either by design or by intent, at all the designated locations, in required volumes and quantity at the desired pressure in a safe manner. The hospital can face sudden increase of gas supply demand at user end. Hence, experts recommend that preset level and three days stock of gases has to be maintained throughout the year. "Adequacy of supply depends on an accurate assessment of demands and the selection of plant appropriate to the clinical/medical demands on the system," says Dr Arora. Estimates of a particular hospital's peak demand determine the type of medical gas supply system required.

"There should be a redundant stand-by supply source to meet breakdown situations--like a dual system for gas supply and alternate bottled gas supply source at hospitals. Hospital designated staff must record the consumption pattern on day to day basis with record for every refill," shares Dhamdhere.

Access to manifold rooms should be from the open air, not from corridors or other rooms. "Normal commercial lorry access is suitable for gas cylinder delivery vehicles, but consideration should be given to the provision of a raised level loading bay when this is justified economically on the basis of cylinder handling costs," says Alok Sharma, Biomedical Engineer, Max Healthcare, New Delhi.

Two doors should preferably be provided in a manifold room. One should be large enough to facilitate cylinder handling and must be in an outside wall. Exits must be free of all obstructions; doors must open outwards and must normally be locked to prevent unauthorised access. The internal walls, including any internal doors of the manifold room, should be suitable non-combustible two-hour fire-resistant material as defined in BS 476 Parts 4 and 8. Internal doors should be avoided where practicable. Heat detectors should be provided.

The manifold room will contain the manifolds as well as cylinder racks holding sufficient spare cylinders to replace one bank of each manifold and the emergency/reserve manifold. Further replacement cylinders should be supplied from the non-flammable medical gas cylinder store. The size of the manifold room should therefore be determined from the size of the equipment, as advised by the manufacturer. Adequate space should also be allowed for cylinder handling

Plant rooms should be designed and constructed to ensure the satisfactory control of noise emission. The effect of two vacuum pumps or compressors running together, in the case of duplex installations, and three or more in the case of multiplex installations, will be to increase the free-field noise level outside the plant room by 5 dBa for each additional pump or compressor operation over and above the specified limits. Consideration should be given to provide acoustic enclosures to reduce the free-field noise levels in noise-sensitive areas adjacent to plant rooms. "Ventilation should be provided at both high and low levels for all manifold rooms, to allow circulation of air. As a guide, well-separated openings equivalent to at least 1.5 per cent of the total area of the walls and room should be provided," adds Sharma.

Tech Updates

When it comes to technological advancements in medical gas systems, the system of transportation and system of usage has become better. Today, automated systems of monitoring and control for maintaining various gas pressures are available. "Motorised/robotic ceiling pendants in OTs that gives flexibility, manipulation, productivity; AGSS-scavenging system to expel hazardous gases exhaled by patient in the OTs; hyperbaric oxygen chambers for burns; moisture measurement devices for med compressed air for the prevention of infection and safety of ventilators; development of screw/rotary compressors and pumps, are few of the other prominent advancements in this field," shares Mathew Verghese, Vice President Projects and Engineering, Manipal Health Systems, Bangaluru.

Network based monitoring system is intended to provide real time information to hospital personnel on the status of all the medical gas devices. It is a computerised network management system which scans every device in a hospital and displays it on the screen of a host PC. In the event an alarm condition occurs, the scanning of all devices stop and the device, which is in an 'alarm condition', is displayed continuously. Further, it can be directly connected to BMS. However, Indian healthcare scenario still has a long way to go when it comes to adopting the technology in this area, feels Dr Arora. "Only few good corporate hosptials are focused on this subject and the numbers are minimal. When it comes to choosing medical gas equipment people start thinking of saving money," says he.

Guidelines & Standards

There is lack of proper guidelines governing the medical gas distribution system in India.

Each hospital has its own policy and guidelines, but there are no strict national guidelines. Hospitals follow any of the international design and safety standards which are followed world wide ie NFPA-99 (USA), HTM-2022 (UK), EN-737 (EU) and DIN-Germany.

Dr Arora says, "Quality of medical gas directly affects the quality patient treatment and indirectly affects the performance of high end equipments. Unless there is any regulation, there will be a compromise on safety." Experts believe that guidelines should become statutory for each healthcare delivery setting, to follow. "A proper body should be formed to formulate the guidelines. NABH can help in formulating, monitoring (auditing) and suggesting mechanism to plan and execute in each of the healthcare organisations, in order to bring standardisation across India," opines Dr Singh.

Dr Bapat agrees, "Of course, there is a need for Indian version and national body has to take it into consideration. We follow international guidelines; however, you cannot replicate their infrastructure here. Therefore, one has to translate them to our scenario and logistics." A level of standardisation is required too. "The equipment compatibility by different manufacturers to gas outlets is a practical problem in Indian hospitals. It might occur that a ventilator used in the hospital may not be compatible to use in an ambulance with out an appropriate adaptation," shares Jose. It is essential for hospitals to give focused attention when it comes to medical gas systems as an important long term investment.

sonal.shukla@expressindia.com