Monthly Archives: July 2010

“Bread and Butta” Fires

This is the first fire related case study. Hope you enjoy.

Scenario

You are assigned to an engine company in a mid to low income area of your city. Your engine is staffed with four personnel, a dedicated driver, an officer, and another firefighter in addition to yourself. Around midnight, you are dispatched to a house on fire. The address isn’t specific. Typically, nonspecific address calls mean either the caller was passing by wasn’t sure what they saw or are false calls (calls that originate but the occupants or neighbors didn’t call). However, the CAD printer rolls a 2nd time dispatching your station’s ambulance to the call (when this happens before the first engine arrives it means that multiple calls have been received. Multiple calls lend more legitimacy).

You don’t notice a smoke plume, but it is dark outside and the passing street lights don’t offer much illumination. As you come down the street, the ambulance (which was out of the house) arrives first and informs your officer that there is fire showing in the rear of the farthest window from the street they are positioned on. As you arrive a few seconds later the fire is visible, shooting from the window. The structure is a single story apartment building with four separate units, wood framed with brick veneer. From the exterior it is estimated that the structure is 10% involved

You pull a 150′ 1-3/4″ attack line from the bed and advance the line to the door closest the street. A member of another company forces the door while you put on your SCBA facepiece. They inform you and your officer that the door is blocked and go around the other side of the structure. You see the smoke coming out of the door and push the door in, then shove a table from behind the door out of the way. As you look in, you are informed that another entrance on the side is open and clear (the arrow in the exterior diagram). You reposition and wait for your line to charge before advancing. Another firefighter is ahead of you searching as he advances.

You locate the fire in the the rear of the structure in the bedroom, the approximate location of the window you observed when you turned on to the street. A window A/C unit is involved in fire and the flames have worked up over the room into the attic space. You extinguish this fire and the fire extending to the eves over the bedroom. The truck company on the exterior has placed a PPV fan at the first entrance and powers the smoke and heat out of the room. You can see that the bed has been burned up and a power cable to the A/C unit is partially burned. The truck company pulls ceiling around the point of origin and locates additional fire burning up the roof joists. This is extinguished and the fire is placed under control.

Discussion

This is a classic example of common household fires. They do not usually get big enough to destroy a house when they are detected quickly but between ignition and suppression they generate a lot of smoke and heat. The initial report from the ambulance crew gave us a quick summary of what we would be facing, and from the exterior it appeared that there would be a lot of fire to deal with. The decision was made to attack with a 200 gpm nozzle due to the potential for structural involvement, and during overhaul it was discovered that the structure was minimally involved. This is a textbook operation as well as the standard procedure when the structure is involved. It is procedure to under pressurize the attack line at 90 psi until a water source can be established. Due to the proximity of a water source to the attack engine the line was brought to the full pressure of 100 psi while a connection using soft sleeve 5″ hose was made.

Forcible entry was required due the security doors and bars on access points. This area is considered a high crime area, so it is not uncommon for additional hard security features to be installed. This can delay access to both the fire and trapped occupants, and as the fire grows the environment becomes more and more untenable for occupants who may be trapped inside. Visual examination of the wood around the point of ignition and other contents in the room suggest that the fire was never able to reach flashover (approx 1000 degrees F) but was hot enough to ignite the window frame, the eves of the roof directly over the window, and burn the roof rafters and roof sheeting. No insulation was present in the roof structure.

Lessons Learned and Conclusion

Be wary of exterior doors, especially when there are multiple entrance points. Occupants will block them to use the space (in this case, a kitchen table. The fire may appear larger on the exterior than the interior, but it is always a good idea to use a larger handline if it is believed that the structural components are involved. In this case, no rescue was necessary as the occupants were not at home, but it would have been difficult to access them if there were due to the security doors and bars. PPV proceeded quickly due to the point of origin being a window itself, no hole was cut in the roof as the fire was controlled rapidly.

The point of origin was determined to be the window A/C unit. No investigator was needed and the fire was ruled accidental.

Vacation

I’ve been on vacation for the past week or so, and had a lot of time to reflect on some things in the industry. I’ve been mainly BS’ing with the information superhighway, including putting my wife and toddler to sleep with EMS Garage and EMSEducast podcasts (both of which are not boring in the slightest and are very worthwhile programs when you have the time to listen) and I came across a few topics that kept me interested and thinking. I’m thinking that I’ll hopefully present a little information about soon. I’ll do it either another anecdote/case study type deal or just plain outright summarize it, I haven’t decided yet.

Either way, here’s a summary of my vacation. Rented car, drove, picked up dude in Kentucky, played two days of paintball in Indiana, drove back, woke up early, slept, drove some more, slept, went to COSI in Columbus, OH, got my wallet stolen, drove, researched disposable CPAP systems, drove some more. Tomorrow the family and I are going to Cedar Point (yay) then the long drive back to Memphis.

Things on my agenda on my return: clean, mow lawn, clean, plan kitchen remodel, play with baby, write some blog posts while baby is sleeping, play with baby some more. I’m booked until the weekend.

Case study 1 – “she talkin’ out her head…”

Since very little happened during my last rotation, I am going to present something from a long time ago, so bear with me as some of the facts may be a bit fuzzy. The names, times, and locations have been changed to protect the innocent and guilty alike…

History

You are responding to the report of 68 y/o F with an altered LOC. As usual, dispatch information is vague at best. When you arrive you find two confused family members and the patient sitting on a bedside commode moaning and babbling incoherently. The family states that the patient has been constipated for several days and they have been force feeding her magnesium citrate for the past several hours. You notice 2 empty bottles and one half empty, all three bottles are 10 oz bottles. They further state that the patient has been on the commode for several hours and has been “talkin’ out her head cause she gone crazy.”

The assessment reveals pale, cool, diaphoretic skin, extreme weakness and above noted altered LOC. BP is 60/P. Pulse is rapid, weak, and thready at a rate of approximately 130, respirations are rapid and shallow at a rate of 10, lungs are clear, abdomen is non-tender to palpation, hips and pelvis are stable with no signs of outward trauma. The contents of the bedside commode are brown and extremely watery with no signs of solid fecal matter or blood.

Discussion

This is a very clear cut and simple case of hypovolemic shock caused by dehydration. The magnesium citrate is a very powerful laxative and when used too much or too often can cause dehydration through osmosis. Osmosis, as you remember from high school science, is the process by where water is drawn out of cell into a space.

As the water is drawn into the intestines, the hypothalamus detects the rise is osmolarity, or the increase in the concentration of electrolytes and acids in the blood plasma. The hypothalamus causes the posterior pituitary gland to release antidiuretic hormone (ADH), which tells the kidneys the retain water in order to dilute the electrolytes in the blood plasma down to a normal level. In this case, the body responded as it should have, retaining water to hold the blood plasma osmolarity at a normal level. However, the overdose of magnesium citrate caused the body to shunt the water it was holding to maintain homeostasis was forcibly drawn into the intestines to cause diarrhea. The result was a drop in available water and the resulting dehydration.

Metabolic alkalosis ensues at this point, where the pH level is above 7.35. The respiratory rate drops and CO2 is retained. This complicates matters as the CO2 causes further CNS depression. Worst case, had the call for EMS come much later, the patient could possibly have been in cardiac arrest or close to it. ECG findings would show a prolongation of the QT interval, which could (and would possibly would due to compounding issues with respiration and hypovolemia) cause cardiac arrest. Consideration of H’s and T’s (here hydrogen ion and hypovolemia) would give treatment option of fluid resuscitation, bringing the fluid level back to normal and correct the acid-base derangement by lowering the amount of bicarbonate in the blood plasma.

The maximum dose of magnesium citrate for an adult patient is 360mg. The bottles were 10 ozs, so if the patient had received only one bottle it would have been sufficient. However, ignorance on the caregivers part led them to give this patient well over that dose, about 1.5 times over! And without proper fluid replacement the situation went from a simple case of constipation to near death from shock.

Treatment

You rapidly move the patient out of the home in the shock position and to the ambulance. Warming is started and the patient is placed on the monitor. Venous access is established in the left antecubital and right external jugular with large bore catheters and rapid fluid replacement is started using normal saline and two pressure infusers. The patient’s mental status improves dramatically and the blood pressure rises to 98/76. The patient receives 2 liters of fluid in transit and high flow oxygen per standard shock treatment guideline.

On arrival at the hospital, ABG reveals the acid-base problem and electrolyte dilution is continued. The patient is admitted for observation and recovery then discharged to assisted living.

Conclusion

In this case, we examined how a simple case of dehydration can not be so simple, and how deviation of the acid-base relationship can cause severe acute changes that can lead to cardiac arrest if not corrected quickly. Keep these things in mind when you are treating your next patient who calls at 3am for constant diarrhea or vomiting.

References (all accessed on 7/13/2010)

Dehydration

Magnesium citrate

Metabolic alkalosis