Western Canada Mine Rescue Manual Chapter 9 Oxygen Therapy PDF

Western Canada Mine Rescue Manual Chapter 9 Oxygen Therapy 9-1 OBJECTIVES Oxygen therapy is administered to assist a casualty’s breathing. Mine rescuers must know when and how to use it. In some jurisdictions, oxygen therapy is included as part of first aid training. Upon completion of this chapter,...

Western Canada Mine Rescue Manual Chapter 9 Oxygen Therapy 9-1 OBJECTIVES Oxygen therapy is administered to assist a casualty’s breathing. Mine rescuers must know when and how to use it. In some jurisdictions, oxygen therapy is included as part of first aid training. Upon completion of this chapter, the trainee shall be able to demonstrate competency in:  Safe practices for oxygen storage, transport, and use  Recognizing when to use oxygen therapy  The benefits of oxygen therapy  The components and assembly of oxygen-therapy equipment  Administering oxygen therapy  Calculating duration based on flow from an oxygen cylinder Oxygen under high pressure can dangerously lower the flash points and ignition temperatures of petroleum products. SAFE STORAGE, TRANPSORT, AND USE Following these guidelines for medical oxygen cylinders will help prevent incidents. Storage  Ensure the equipment is clean and in good working order. Check that connections are tight and that controls operate freely.  Keep cylinders secure at all times.  The valve protection cap must be in place to protect it from damage whenever large-capacity cylinders are in storage.  Store all cylinders in a cool, well ventilated, specifically designated place.  Keep oxidizers, corrosives, and combustibles well separated.  All cylinders are subject to hydrostatic testing as per manufacturer’s specifications. Transport  Cylinders must be secured and capped when being transported.  Never use a cylinder as a roller or support. Use      Strictly enforce no smoking or open flame when in use. Post signage when practicable, such as in first aid rooms. When changing cylinders, open valves slowly and check for leaks. While in use, always keep cylinders secure and well away from heat and flame. If a leaking cylinder cannot be corrected by tightening the valve, it must be clearly tagged and taken outside to a safe location away from ignition sources, open flame, and petroleum. Secure the cylinder and allow the pressure to bleed completely. The clearly labelled cylinder must be returned to the supplier for repair. Never ship a leaking cylinder. All cylinders must be refilled by a qualified person. 9-2 WHEN TO USE OXYGEN THERAPY Oxygen is essential to normal cell function and life itself. Any condition that affects the supply, exchange or transport of oxygen between the atmosphere and the body’s cells results in hypoxia, a condition defined as inadequate oxygenation of the body tissues. Supplementary oxygen given during pre‑hospital treatment of injuries may significantly improve a casualty’s recovery and even the chances of survival. Oxygen therapy is not a substitute for clearing the airway. More extensive training is required to use advanced techniques. The body needs a continuous supply of oxygen but is unable to store it. Any casualty with the following history, signs, and symptoms will be suffering from hypoxia:  Pale, cool, clammy skin (shock)  Spinal cord injuries  Cyanosis (blue lips, earlobes or fingernails)  Allergic reactions  Shortness of breath (dyspnea) or absence  History of serious trauma, even if there are of breath no obvious injuries  Problems with heart function  Nausea and vomiting  Blood loss (internal or external)  Headache  Loss of consciousness  Agitation, irritability or confusion  Extensive burns  Drowsiness  Crush injuries  Pregnant casualties BENEFITS OF OXYGEN THERAPY The benefits of oxygen therapy include:  Increased oxygen supply to the brain, reducing loss of the central nervous system and maintaining control of vital body functions  Increased oxygen supply to the heart  Reduced work load on the heart by enriching the oxygen load in the blood, thus reducing the volume of blood that must be pumped  Stabilized rate and depth of breathing  Reduced movement of an injured chest will reduce the pain associated with attempts to breathe  Enriched oxygen content of the air reaching the lungs in the event of partial airway obstruction  Improved gaseous exchange within lungs congested with fluid (oedema or pneumonia) or particulate by providing more oxygen in the limited volume  Improved gaseous exchange at the tissue level  Improved muscle tone, particularly within artery walls  Generally reduced pain and anxiety Improvement in the casualty’s condition may be indicated by:  Improved skin colour, temperature, and condition  Reduced breathing effort  Stabilized pulse rate  Reduced pain  Reduced anxiety, apprehension and restlessness  Improved level of consciousness 9-3 Casualties with Chronic Breathing Problems People with ongoing or chronic obstructive pulmonary disease (COPD) are chronically short of breath and have difficulty breathing. People at the severe stages of this condition are rarely found in a working environment. If providing first aid and oxygen therapy is needed, administer as one would to any other casualty but monitor breathing very closely. If required, reduce flow rate but do not stop oxygen therapy once it has been started. OXYGEN THERAPY EQUIPMENT The Oxygen Therapy Unit An oxygen therapy unit has three main components: an oxygen cylinder, a regulator, and a delivery tube with a facemask. Portable units also require a carrying case designed to protect the unit. Oxygen cylinders Medical-grade oxygen (approximately 99% oxygen) is supplied as a compressed gas at 2,000 psi in a variety of standard cylinder sizes. The sizes of cylinders are:  D (412 L)  E (682 L)  M (3,540 L)  K (6,900 L) Note: A “+” sign stamped at the top of the cylinder indicates that pressure can be increased by 10% to 2,200 psi. Whatever the size of the cylinder used, they are subject to the requirements of hydrostatic testing. The hydrostatic test date is stamped on the cylinder. A five-pointed star stamped at the top of the cylinder indicates that the hydrostatic test date has been extended an additional five years, and then must be tested every 10 years afterward. Cylinder markings D and E cylinders have a pin-indexed medical post outlet with a valve operated by a purpose-specific wrench. Others have a special CGA-540 oxygen threaded outlet and a hand valve. Both connections are designed to be unique and prevent inadvertent connection to any gas other than oxygen. Pin-indexed medical post outlet (L), threaded outlet (R) 9-4 Pressure Regulators The regulator assembly has two purposes:  Reduces the pressure of oxygen delivered from the cylinder to between 40 and 70 psi.  Regulates the rate of flow (in litres per minute or Lpm) of the delivered oxygen. The regulator assembly attaches to the cylinder with a yoke containing corresponding pins that fit the medical post and a screw-clamping device. Cylinders with a threaded connection are attached via a corresponding female thread on the regulator assembly. Adaptors are available to attach threaded and yoke-type connections together. The adaptor used to fit a yoke-type regulator assembly onto a threaded cylinder can be particularly valuable in a major emergency situation. Using these adaptors will prevent gases other than oxygen from being connected. Oxygen Mask and Delivery Tube There are several models of delivery masks available. Delivery tubes are included with the masks. All but the one-time-use simple mask require more extensive training. 9-5 CAREvent To use this device for oxygen therapy, follow the same steps as one would for the normal oxygen therapy unit. The only difference is that a 3,000-psi Drager BG4 cylinder can be used. The delivery hose and mask used with the normal oxygen therapy unit will work on this regulator. The handheld resuscitator can also be used for oxygen therapy on a breathing casualty. The device will act in the “on demand” mode much like a self-contained breathing apparatus (SCBA). As the casualty inhales, a valve opens allowing the oxygen to flow into the face piece or nose cup. Follow these steps to prepare the handheld resuscitator for use: 1. Ensure oxygen flow adjustment is set at zero 2. Connect the supply cylinder to the regulator 3. Connect the resuscitator delivery hose to the regulator 4. Connect the delivery hose to the resuscitator 5. Attach the resuscitator to the face piece or nose cup 6. Turn oxygen supply cylinder on 7. Place face piece or nose cup on casualty (Adjust straps accordingly) Note: All connections should be “finger” tightened only This manual will not describe the functions the CAREvent® DRA handheld rescuer can provide for a non-breathing casualty. Please refer to site specific training and always follow the manufacturer’s recommendations. Oxygen delivery hose and mask connected to regulator with BG4 oxygen cylinder. (Ready for “normal” oxygen therapy delivery) Oxygen delivery hose, CAREvent® resuscitator and face piece connected to a DSS outlet on regulator with oxygen cylinder Oxygen regulator for use for use with a CAREvent® resuscitator 9-6 INSPECTING CYLINDERS AND ASSEMBLING COMPONENTS Inspecting  All components must be visually inspected for damage and contamination before use. If there are any deficiencies noted, tag the component and remove it from service.  Look for an in-service tag or markings denoting cylinder status.  Check hydrostatic testing stamp on the cylinder as per manufacturer’s guidelines. Assembling  Certain types of cylinders come with a plastic breakaway strap over the new gasket. There is also a metal version with a rubber centre that can be used more than once. Ensure that the gasket does not get doubled by removing the old gasket. If it is not removed, alignment problems can arise.  Secure the cylinder in an upright position.  Point the aperture in a safe direction away from people or ignition hazards.  The cylinder must be quickly opened and closed, or “cracked” to ensure there are no contaminants in the aperture.  As the yoke is positioned on the medical post, check that the gasket is in place and that the pins on the yoke are aligned with the holes in the post (pin indexing).  Tighten the screw clamp to secure the regulator, hand-tightened only.  Check that the regulator flow control is fully off before opening the cylinder. (In some models, this requires turning counter-clockwise.)  Open the cylinder valve slowly to stabilize the gauge and then continue to open one full turn.  Conduct leak test: o Close the cylinder valve o Observe the gauge for drops in pressure for five minutes o Open the cylinder valve o Observe for gauge movement o If there is any drop in the pressure reading, re-tighten the regulator to the cylinder and repeat the test o If there is no drop in pressure, close the cylinder, bleed off the pressure in the regulator using the flow control  Unit is now field-ready and should be securely stored in a designated area. ADMINISTERING OXYGEN Observe the following steps and precautions when administering oxygen:  No smoking or open flame must be strictly enforced.  Ensure face mask and tubing are attached to the regulator assembly. Open the cylinder valve gently and slowly.  Turn the flow control on the regulator to the desired flow rate.  Allow the oxygen to flow for several seconds to clear any foreign material from the hose and mask.  Ask the casualty if they have had oxygen therapy while reassuring the casualty about the use and benefits of oxygen therapy prior to administering. 9-7    If the casualty is apprehensive, have the casualty hold the mask near their face if possible until they are comfortable with it. Once comfortable, the elastic strap can be placed behind the casualty’s head. All casualties requiring oxygen therapy should receive oxygen a constant flow rate of 10 litres per minute unless travel time will deplete the supply. Document the start time, flow rates, and any effects on the casualty. Never leave a casualty who is not fully alert alone with an oxygen mask secured to their face, even if the casualty is in the lateral or recovery positions. If they vomit, the airway may not clear itself. SHUT DOWN PROCEDURE When oxygen therapy is complete, follow these steps:  Shut off the flow on the regulator.  Note the remaining cylinder pressure. Change the cylinder as per on-site operating procedures. Note: 200 psi is commonly considered empty.  Close the main cylinder valve.  Re-open the flow valve and bleed off pressure in the regulator until the gauge(s) read zero.  Close the flow valve.  Replace the face mask and delivery tube with a new unit and ensure all components are ready for use.  If changing a cylinder or removing a regulator, bleed off the residual pressure in the regulator and dis-assemble. OXYGEN CYLINDER DURATION The rescuer administering the oxygen must ensure the oxygen supply will last for the duration of casualty care. For example, to quickly approximate the duration for a D cylinder (400 L) based on the flow rate used: 1. Divide cylinder pressure (psi) by 100 2. Multiply by:  3.0 for 6 litres per minute (Lpm)  2.5 for 8 litres per minute (Lpm)  2.0 for 10 litres per minute (Lpm) CYLINDER PRESSURE (psi) 2000 1500 750 Oxygen Cylinder Duration – Rule of Thumb Calculations “D” Cylinder 400 L of Oxygen Divided by 100 FLOW (Lpm) 6 FLOW (Lpm) 8 (x3) (x2.5) 20 60 minutes 50 minutes 15 45 minutes 37.5 minutes 7.5 22.5 minutes 18.75 minutes FLOW (Lpm) 10 (x2) 40 minutes 30 minutes 15 minutes 9-8 Using The Cylinder Factor Method Note: Safety factor minus (-) 500 psi CYLINDER SIZE D E M H-K FACTOR 0.16 0.28 1.56 3.14 Calculation: Example: Cylinder pressure times (x) factor Divided by flow (Lpm) = minutes D size Cylinder with pressure of 2000 psi x Factor 0.16 = 320 Divided by flow 6 litres per minute = 53.33 minutes The charts below show the durations for various pressures and flow rates for E, M, and K cylinders. PSI 2000 1500 1000 500 Oxygen Cylinder Duration “E” Cylinder 682 L of Oxygen 6 Lpm 8 Lpm 1 hr, 53 minutes 1 hr, 23 minutes 1 hr, 25 minutes 1 hr, 3 minutes 56 minutes 42 minutes 28 minutes 21 minutes 10 Lpm 1 hr, 8 minutes 51 minutes 34 minutes 17 minutes PSI 2000 1500 1000 500 Oxygen Cylinder Duration “M” Cylinder 3,540 L of Oxygen 6 Lpm 8 Lpm 8 hr, 40 minutes 5 hr, 51 minutes 6 hr, 30 minutes 4 hr, 14 minutes 4 hr, 20 minutes 2 hr, 36 minutes 2 hr, 10 minutes 59 minutes 10 Lpm 4 hr, 40 minutes 3 hr, 23 minutes 2 hr, 15 minutes 47 minutes PSI 2000 1500 1000 500 Oxygen Cylinder Duration “K” Cylinder 6,900 L of Oxygen 6 Lpm 8 Lpm 17 hr, 30 minutes 13 hr, 0 minutes 13 hr, 0 minutes 9 hr, 50 minutes 8 hr, 45 minutes 6 hr, 30 minutes 4 hr, 20 minutes 3 hr, 15 minutes 10 Lpm 10 hr, 30 minutes 7 hr, 50 minutes 5 hr, 15 minutes 2 hr, 35 minutes 9-9