Competent in the Use of SCBA
Training to live
Be mindful not to create “training scars,” which can be fatal. For example, how many times have you been told “Don’t worry about the alarm, this is training” or “If you run out of air, just unplug.” Although the premise itself is meant to complete the training evolution, each time that these comments are made, a total disregard for your safety and for available air supply versus consumption rates is reinforced. The fact is, waiting for the alarm to sound isn’t an effective way to manage air supply, and it’s the result of a training scar that was developed by lack of enforcement when enforcement was needed the most.
Confidence should be built while reinforcing the importance of performance under pressure, particularly when heart rate is elevated and all rationale is lost. This is what’s referred to as “condition black.” This is pure survival instinct, and it occurs when the heart rate generally exceeds 175 bpm.
Training to operate as well as control breathing during condition black is a must. During an evolution, if the participant runs out of air, this should signal the end of the evolution, and improvement should be sought from that point forward. Although advanced methods on what to do when you run out of air are being taught, training officers don’t want to instill a false sense of security that the consequences of poor air management aren’t severe.
Fireground effectiveness/safety
The size of the firefighter, stress levels, physical fitness and how intensely the individual is working all play a role in how long that it takes to exhaust a cylinder. Assuming that a 30- or 45-minute bottle rating equates to the same amount of working time on air is not only ignorant but extremely dangerous. While working on air there’s about a 33 percent increase in energy expenditure, and the additional weight that’s carried on the back increases cardiorespiratory function. So, the user’s physical condition coupled with the individual’s level of training and amount of experience ultimately enhances the duration of one’s air supply.
In emergency situations, each additional breath that a person who is on SCBA takes can cost that person greatly when it comes to time for escape or rescue.
Under normal working conditions, the average time that it takes to deplete a 30-minute, 4,500-psi bottle is 12–16 minutes. Every 100 psi in that same bottle equates to approximately 8–10 breaths. This is why it’s critical to have a plan in place to conserve air that’s in the bottle and to give you the greatest chance of surviving the fireground. The aim should be to reduce the difference between air that’s required and air that’s consumed. The amount of time that the air supply will last is unique to each firefighter, so be sure to thoroughly evaluate different breathing techniques.
One thing that’s certain: The better shape that you are in, the more efficient that you will be while using SCBA.
Conclusions
The present study showed that when compared to controls, firefighters’ hypoventilate during a maximal test and GXT. The hypoventilation resulted in increased ETCO2, and presumably increased arterial CO2, during exertion. It is proposed that firefighters have altered CO2 sensitivity due to voluntary hypoventilation during training and work. Confirmation of low CO2 sensitivity and the consequence of this on performance and long-term health remain to be determined.
Fig. 1
The end-tidal CO2, respiratory rate, and heart rate cycle exercise at 25%, 50%, and 70% of V.O2max. (A) End-tidal CO2. (B) Respiratory rate. (C) Heart rate cycle exercise. Control (nonfirefighter) participants are represented by solid lines and firefighter participants by dashed lines. Circles = control participants-facemask condition, squares = control participants-SCBA condition, upright triangles = firefighter participants-facemask condition, upside-down triangles = firefighter participants-SCBA condition.
SCBA, self-contained breathing apparatus; V.O2max, maximal oxygen consumption.