|Year : 2021 | Volume
| Issue : 1 | Page : 82-84
Meeting oxygen requirements of rural India: A self-contained solution
Nirupam Madaan1, Biraj Chandra Paul2, Randeep Guleria3
1 Additional Professor, Department of Hospital Administration, AIIMS, New Delhi, India
2 Senior Resident, Department of Hospital Administration, AIIMS, New Delhi, India
3 Director, AIIMS, New Delhi, India
|Date of Submission||17-Dec-2020|
|Date of Decision||23-Dec-2020|
|Date of Acceptance||24-Feb-2021|
|Date of Web Publication||20-Mar-2021|
Room No. 4A, Ground Floor, Old Private Ward, AIIMS, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Addressing oxygen requirements of rural India should aim at using a safe, low-cost, easily available, and replenishable source of oxygen of moderate purity. This may be possible with the provision of a self-sustaining oxygen concentrator (pressure swing adsorption with multiple molecular sieve technology) capable of delivering oxygen at high-flow rates, through a centralized distribution system to 100 or more bedded rural hospitals, with back up from an oxygen bank of 10 × 10 cylinders. This will provide a 24 × 7 supply of oxygen of acceptable purity (~93%) for the treatment of hypoxemic conditions and will enable hospitals to specifically provide for high-flow oxygen in at least 15% of the beds. It may also serve as a facility for a local refill of oxygen cylinders for emergency use within the hospital as well as to subsidiary primary health centers, subcenters, and ambulances, thereby nudging our health-care system toward self-sufficiency in oxygen generation and utilization.
Keywords: COVID-19, hypoxemia, multiple molecular sieve technology, oxygen concentrator, pressure swing adsorption
|How to cite this article:|
Madaan N, Paul BC, Guleria R. Meeting oxygen requirements of rural India: A self-contained solution. Indian J Public Health 2021;65:82-4
|How to cite this URL:|
Madaan N, Paul BC, Guleria R. Meeting oxygen requirements of rural India: A self-contained solution. Indian J Public Health [serial online] 2021 [cited 2021 Jul 31];65:82-4. Available from: https://www.ijph.in/text.asp?2021/65/1/82/311514
| Introduction|| |
Hypoxemia, or low blood oxygen saturation, and its management is a critical component of the WHO guidelines for neonatal resuscitation anesthesia, emergency care, and triage. In neonates, common conditions requiring oxygen therapy include respiratory distress syndrome, birth asphyxia, and transient tachypnea. Prematurity, sepsis, seizures, or hypoglycemia may also require adjunct oxygen therapy. Chronic obstructive airway disease, asthma, and pneumonia require frequent oxygen. Any health-care facility providing emergency, surgical, trauma, and obstetric care needs a robust backup of oxygen supplies. For this purpose, oxygen has been listed foremost in the WHO list of essential medicines.,
India fought to avert a shortage of medical oxygen cylinders particularly in rural hospitals during the COVID-19 pandemic when, according to a recent BBC report, hospitals and care centers were consuming up to 1300 tons of oxygen every day, compared to 900 tons/day before the pandemic. Many states depended upon production units outside the state to meet their oxygen demands. Some states tried to prevent oxygen from being moved outside their borders as part of their efforts to meet their domestic needs. As a consequence, there was a huge escalation of medical oxygen price although the ceiling price of oxygen was fixed by the National Pharmaceutical Pricing Authority last year at ₹17/m3.
| Overview of Technologies Available for Delivering Medical Grade Oxygen|| |
Liquid oxygen cylinder
LOCs are double-walled liquid storage tanks made up of high-quality insulating material which holds cryogenic liquid oxygen under vacuum to prevent evaporation losses. The medical liquid oxygen (minimum 99.5% purity) must first be vaporized to a compressed gas and then warmed at ambient (room) temperature inside the equipment before the patient can receive the oxygen through tubing into the nostrils via a nasal cannula. When 1 L of liquid oxygen is evaporated, it expands to ~ 860 L of gaseous oxygen.
Oxygen cylinder is a metal container filled with compressed gas held under high pressure. When fully filled with oxygen, cylinders range from small portable cylinders for ambulatory use (53 cm height, 3 kg weight, 430 L of oxygen) to large static cylinders (71 cm height, 18 kg weight, 2122 L of oxygen). Conversely, a central bank of oxygen cylinders may be created by placing them in series to supply piped gas within a hospital, with adequate backup.
Oxygen concentrator concentrates oxygen from a gas supply (typically ambient air) by selectively removing nitrogen to supply oxygen-enriched air. Typically, oxygen concentrators have been made using three different technologies.
- Vacuum swing adsorption which generates oxygen from air at high pressure and flow for industrial use by passing air through a single low-pressure blower and reversing its flow by using a valve
- Membrane gas separation concentrators use synthetic membranes made from polymers such a polyamide or cellulose acetate, or from ceramic or even nanomaterial to separate a gas mixture to get oxygen. These technologies are sustainable, with relatively low environmental impact and compact space requirements, but come at a higher cost
- Pressure swing adsorption (PSA) concentrators utilize a molecular sieve to adsorb gases and operate on the principle of rapid PSA of atmosphere nitrogen onto zeolite minerals, thereby venting nitrogen. PSA is reliable and economical for small- to mid-scale oxygen generation and can provide oxygen at the rate of 10 l/min at the terminal end; with the introduction of multiple molecular sieve technology, flow rates as high as 900 l/min can be realized, and redundancy reduced.
| Meeting Indigenous Requirements for Rural India|| |
Developed as first referral units for offering secondary-level curative services to the sick, most community health centers and district hospitals have been traditionally dependent upon prefilled oxygen cylinders of the large “D” type variant (50 L) used singly or in the form of a bank of cylinders to meet oxygen requirements for inpatient care. The smaller B-type cylinders (volume 10 L) and single-person oxygen concentrators are used for ambulatory oxygen therapy. Large multispecialty hospitals and a few smaller hospitals have graduated to using liquid medical oxygen as a source of oxygen supply.
Oxygen concentrators using PSA have been used in low-resource settings across the world with great success. A prospective study across five hospitals in Papua, New Guinea, observed a 35% reduction in the risk of child mortality from pneumonia 27 months after oxygen concentrators were installed. Similar endeavors in Malawi, Eritrea, Egypt, and Mongolia have shown good operational success, as long as they are backed by a reliable electric supply. India can harness the technology of PSA to evolve self-sustaining, robust, and renewable models of oxygen delivery to hospitals having 100 or more beds, with the provision to fill adequate D-type cylinders which can supply the primary health centers and ambulances in the vicinity of that hospital, and also act as a fall back oxygen bank for the hospital itself.
The best solution
Many states of India have a traditional rural heartland with a slow pace of development and adoption of modern technology which makes the daily transportation and filling of oxygen cylinders very onerous. The northern and northeastern states have terrain which is difficult to negotiate. Liquid oxygen-generating plants are not available in many states, and each state is wont to look after its own requirements before agreeing to supply liquid oxygen to other states. The vagaries of supply and demand also add to the uncertainty of supply of this essential commodity to hospitals. This is compounded with wastage in transportation and losses due to evaporation and the inherent risk of fire in storing and transporting oxygen in any form. PSA type of oxygen extractors, on the other hand, has various advantages [Figure 1] over the LOC in the rural setting, the greatest of which is that they provide a self-sustaining and replenishable source of oxygen. These oxygen extractors can be used to fill B- and D-types of cylinders to keep emergency supplies for use in primary health centers and ambulances within a health-care segment.
|Figure 1: Advantages of using oxygen extraction systems with pressure swing adsorption technology.|
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| Requirements for a 100-Bedded Hospital with 15% Intensive Care Unit Beds and 3 Operating Suites|| |
The capacity of an oxygen generator plant is calculated using the formula:
Total LPM = (No. of beds x 0.75 LPM) + (No. of beds in OT × 7 LPM) + (No. of beds in intensive care unit [ICU] × 30 LPM).
Total flow rate (Nm3) = Total LPM × 0.06.
For a 100-bedded hospital with 15% ICU beds, 3 odds ratio, and 4 pre/postoperative beds:
Total LPM = 63.75 + 21 + 570 = 654.75 LPM
Total flow rate required = 654.75 × 0.06 = 39.28 Nm3
A rural hospital of the said denomination will require an oxygen concentrator of specifications as mentioned, feeding directly into the manifold system to provide oxygen at the terminal outlets, with another outlet leading to the oxygen cylinder bank of a 10 × 10 denomination, which will be fed through the concentrator to keep a backup supply in case of exigency. Both will feed into the hospital manifold system for distribution, as represented in [Figure 2].
|Figure 2: Schematic representation of oxygen generation and delivery system in a rural hospital.|
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| System Requirements|| |
Fully automatic microprocessor-based oxygen concentrator
Fully automatic microprocessor-based oxygen concentrator with 2 kVA online UPS with at least 30 min backup for of the concentrator plant is required. The onsite oxygen generator module should be multiple zeolite molecular sieves based, employing PSA technology, and should comply with ISO 10083 standards, ISO 7396-I, HTM 02-01, NFA99C. Oxygen supply system with fully automatic oxygen control panel must comply with HTM 0201/NFPA 99 and should be US UL/ETL/ATL listed/European CE certified.
Oxygen manifold supply system
The oxygen manifold should be of size 10 + 10 bulk cylinders, compatible with Class-D type bulk cylinders, with an emergency backup of 5 × 5 cylinders with flowmeters, and distribution piping of copper as per standard BS: EN 13348:2008/ASTM B819 standards, with outlets in user areas
The use of PSA technology gives oxygen of lesser purity (87%–96%) than a liquid oxygen cylinder (99%). It also necessitates the availability of certain prerequisites, namely
- Continuous electric supply of 300–600 W
- Backup generator, battery bank, and UPS of suitable capacity in case of electric failure.
- Voltage stabilizer and surge protector
- Regular preventive maintenance and change of filters
- Availability of spare parts and accessories (nasal prongs, bubble bi-PAP, nebulizers, pulse oximeters, Y-piece, tubing, sieve-beds, valves, printed circuit boards, etc.)
- Availability of technically trained staff.
The provision of a PSA comes at a much lesser total cost than a liquid oxygen tank, at U$$ 2–8/KL as against U$$ 10–30/KL2. Different components of the PSA and the distribution system, at current market rates, would cost approximately one crore rupees if all the components of the PSA, booster, UPS, generator, and distribution system with accessories and maintenance cost for 10 years are taken into account, and would make small and medium hospitals self-sufficient in the provision of oxygen at a sustainable cost.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
McCoy RW. Options for home oxygen therapy equipment: Storage and metering of oxygen in the home. Respir Care 2013;58:65-85.
Duke T, Wandi F, Jonathan M, Matai S, Kaupa M, Saavu M, et al
. Improved oxygen systems for childhood pneumonia: A multihospital effectiveness study in Papua New Guinea. Lancet 2008;372:1328-33.
[Figure 1], [Figure 2]