Backdraft Postscript

post·script

1 – a paragraph added to a letter after it is concluded and signed by the writer; or any addition made to a book or composition after it had been supposed to be finished, containing something omitted, or something new occurring to the writer

As it turned out, Missy was a WUS. That’s not a disparaging comment about her intestinal fortitude – it’s a classification of stroke known as a “Wake Up Stroke.” According to a recent article in the American Heart Association / American Stroke Association entitled Thrombolytic Therapy for Patients Who Wake-Up With Stroke, approximately 25% of all strokes are WUS. Given that people may sleep 25%-30% of their life it can only be expected that a stroke will happen during that time in a proportionate number. EMS currently deals with a short (4-hour) window of time to rush a patient to a stroke center for thrombolytic therapy – if a stroke has a known onset of four hours or less, the patient is eligible for thrombolytic therapy. Outside of that window it is considered a “cold stroke” and thus ineligible. If the onset time of the stroke cannot be verified, such as in the case of a WUS, the patient is automatically ineligible for thrombolytic therapy. This latest article, however, states that the therapy may be safe in longer periods of time from onset of symptoms. Further studies are being conducted to explore the possibility of an extended time period for this treatment.

I recently attended a lecture series by a panel of neurologists on strokes and the latest trends in therapy. During the session the extension to the thrombolytic window was explained in greater detail. To paraphrase four hours of lecture, in the event of an ischemic stroke there is a proportion between necrotic (dead) brain tissue and the surrounding ischemic (under-perfused) brain tissue which can be visualized with a Functional MRI. With a proportion of 80/20 thrombolytic treatment would have very little effect. With a proportion of 25/75 thrombolytic treatment may have a greater effect and the potential benefits of extending the window would then outweigh the possible risks. The ramifications of this line of research is that every patient has their own personal window of opportunity for thrombolytic therapy which can only be viewed once that patient reaches a stroke center. This same research is showing that an extension of the window to as long as sixteen hours may be safe in some situations.

In the case of Missy I took her into the hospital running Code-3 because of the smoke inhalation and potential for an airway that may be in the process of closing. Yet I transported her to a stroke center, bypassing a regular ED with no specialties, to ensure that neurologists would be on hand to quickly evaluate her recent stroke symptoms. Unfortunately the extension to the thrombolytic window is still in the research phase and has not progressed to cover the WUS scenario at the local hospitals. The deficits from Missy’s stroke did not immediately resolve and she was not a candidate for thrombolytic therapy. She will undergo extensive physical therapy in an attempt to regain some of her left-side functionality.

Meanwhile, Stacy, the fire medic/RN who got caught up in the excitement of the fire to the point that she missed an obvious stroke in her patient, has since been promoted to Lieutenant…

 

 

Backdraft

back·draft

1 – a reverse movement of air, gas, or liquid

2 – an explosion that occurs when air reaches a fire that has used up all the available oxygen, often occurring when a door is opened to the room containing the fire

Missy woke up a little early and from the start she knew something was wrong. She just didn’t feel right and the world seemed just a little more confusing than usual. She tries to get up out of the bed but the weakness is just a little more pronounced than usual and she never makes it all the way out of bed. Thinking maybe it would help to bring the world into perspective Missy reaches for a morning cigarette with her left hand, but finding she can’t quite make that work she finally reaches across her body with her right arm, grabs the cigarette, puts it between her lips, and lights it while laying in bed. With the smoke inhaled deep into her lungs she starts to relax again and nod off.

There’s shouting from outside the house – someone is yelling at her. She opens her eyes and sees the flames overhead – gently rolling across the ceiling with the smoke starting to burn her lungs on every breath. She tries to get up but again the weakness is stopping her from getting out of bed. Suddenly there is light in her bedroom, as the door opens, this is quickly followed by intense heat as the flames erupt as if seeking the oxygen from the open door. Strong arms grab Missy and start to drag her out of the house. Once on the front lawn she can see the flames well above the roof as firefighters are breaking windows and drenching her house with water.

As we roll into the neighborhood my partner and I stop following street signs and just follow the smoke to the location of the medical call. We have to park a block away as the small residential street is full of fire apparatus and supply lines. We roll the gurney closer to the house, avoiding the standing water and six inch fire hoses that snake across the road. Sitting in front of a burned-out house is my patient, leaning forward in a tripod position, sucking hard on an oxygen mask, with both arms being held out to either side.

Stacy, the fire medic, is supervising two Explorers who are simultaneously taking blood pressures, one on each arm. Our county has a Fire Explorers program for youth who someday want to be firefighters – it gives them the opportunity to volunteer with a local fire unit and learn the basics of the job. Both of the Explorers seem distracted by the commotion of the fire; they glance repeatedly from the blood pressure dial to the flames. It’s obvious they would rather be squirting water than taking care of this woman.

Finally, Tracy has had enough and asks each of them for their findings – she knows I’m not going to hang out here all day waiting for kids to check a vital sign that I’m going to recheck regardless of their findings. The kid on the left gives us a report of 90 over 60, the kid on the right tells us it’s 180 over 110. I have a dead pan stare on my face as I wait for Stacy to give me a report.

Stacy is writing the two sets of blood pressures on the patient care form and handing it to me. “Yeah, I know, you’ll have to check the BP again. Basically she was smoking a cigarette in bed and fell asleep. The blinds caught fire and the whole house went up. She got caught in a backdraft when they went in to get her. She had moderate smoke inhalation without any visible burns. That’s about it. Are you good?” Am I good? Hell no I’m not good. But I’m absolutely ready to leave.

Having moved Missy onto the gurney we start the long trek back to the ambulance. We have to double back a few times because of standing water creating small lakes in the street and fire hoses blocking our way. Throughout the ordeal I’m grumbling to myself about the poor treatment of Missy. Yeah, great, they got her out of the fire, but her treatment stopped there. Stacy knows better, she’s also an RN at a local Emergency Department, yet she released her helpers to let them fight the beast while the Explorers tried in vain to take vital signs. She didn’t have a history and knows almost nothing about this patient except she was in a fire.

Once we’re back in the rig I can start over and give Missy a proper check-out prior to going to the ED. Looking her over I can’t see any obvious burns but I’m more concerned with her breathing and airway at the moment. I slip the oxygen mask off and shine a flashlight in her mouth and nose and find singed nose hairs with soot extending the visible length of the nares – not good. Soot in the mouth and on the lips – not good. Oxygen saturation of 86% on room air – not good. Wheezing in the apex of each lung with a stridorous noise starting to come from the throat – really, really not good!

As my partner prepares the Albuterol and Atrovent nebulizer to affix to the mask I put an end tidal carbon dioxide nasal cannula on her nose so I can keep a good record of her respiration trends and quality of breathing, but looking at her face something just isn’t right.

“Missy, we’re going to give you a breathing treatment to help you breathe a little better but I have to ask about your medical problems. First off, have you ever had a stroke?” I’m seeing the telltale facial droop on the left side with an eyelid that looks like it’s being pulled down in the corner.

“Yeah, I had me a mini-stroke a while ago. They said it’s because of the A-fibs. But I all better now.” Now that I hear her speak I can tell there’s a bit of a slur to her speech.

“So you’re saying you didn’t have any lasting deficits from the stroke; like facial droop or weakness on one side?” My partner just finished setting up the nebulizer but I need to finish this line of questioning before putting it on and obscuring her face with a mask. He moves up to the front and starts getting us out of the neighborhood; I haven’t given him a destination yet – we both know that destination will be critical with this woman – yet we need to get moving.

“You know, now that you say it, it feel kinda like that mini stroke right now. I could’t get out of bed and my arm jus’ seem like it don’t want to move like it should.” That’s enough for me. I run Missy through a series of stroke tests; facial droop, slurred speech, left side weakness, change in sensory appreciation from left to right side and minor cognitive disassociations (how many wheels on a tricycle, what color is an orange, that kind of thing).

I glance out the front window as I place the mask over Missy’s head and see that we’re just exiting the neighborhood. Rechecking her blood pressure I discover that the Explorer on the left was closest – she’s 84 over 48. I start to set up the Sodium Thiosulfate drip for the IV.  “Okay, you ready for this?” I yell up to my partner.

“Yeah, go ahead, where we headed?” He yells over his shoulder as he lights up, turns on the siren, and heads for the freeway.

“Well, you already guessed we’re going Code-3. We’re going to Hilltop ED; 44 year old female, moderate smoke inhalation, hypotensive, tachycardia, tachypnea, Albuterol/Atrovent/Sodium Thiosulfate running. She’s also got a cold stroke, unknown onset time, left side weakness, with a history of.”

“Seriously?”

“Yeah, seriously, that’s what started the fire.”

 

 

Dead Space Postscript

post·script

1 – an extra piece of information about an event that is added after it has happened

The patient in question did in fact have a massive pulmonary embolus known as a Saddle PE. Because the embolus lodged in the pulmonary artery at the bifurcation between the left and right branch, much of his lung capacity was not actively engaging in gas exchange. He was not able to offload the EtCO2 or fully oxygenate the blood. His altered state was actually a hypoxic event even though his lungs were clear and had perfect tidal volume. The EtCO2 reading was the only finding, other than skin signs and oxygen hunger, that pointed me in the right direction.

Upon turning him over to the MD at the ED I concluded my report with my findings and a differential diagnosis of PE. This bought me a raised eyebrow from the MD as a PE is a very difficult thing to diagnose without the help of a CT. That same MD seemed a little more on board with my findings when the patient flat lined ten minutes later and subsequently three more times before they pushed thrombolytics to dissolve the clot.

Later that night he was moved to the ICU and extubated the next day. He recovered with no lasting deficits yet he remained in the hospital for two more weeks as they continued to administer blood thinners and observe for any reoccurring emboli.

The bifurcation of the cherry tree is a beautiful analog for the inner vasculature of the lungs. Nutrients are carried along the trunk to the blossoms where gas exchange occurs and photosynthesis creates energy that is then carried back along the trunk. When a branch is injured the blossoms die and create a dead space. The cherry tree has the advantage of many bifurcated branches to continue the cycle – we only have one.

Dead Space

A decrease in perfusion relative to ventilation (as occurs in pulmonary embolism, for example) is an example of increased dead space.[3] Dead space is a space at which gas exchange does not take place, such as the trachea. It is ventilation without perfusion.

Saddle Pulmonary Embolus

A large thrombus lodged at an arterial bifurcation, where blood flows from a large-bore vessel to a smaller one. The ‘classic’ saddle embolus—which occurs at the bifurcation of the pulmonary arteries in fatal pulmonary embolism secondary to a centrally migrating venous embolus—is distinctly uncommon.

Segen’s Medical Dictionary. © 2011

Massive pulmonary embolism

As a cause of sudden death, massive pulmonary embolism is second only to sudden cardiac death. Massive pulmonary embolism is defined as presenting with a systolic arterial pressure less than 90 mm Hg. The mortality for patients with massive pulmonary embolism is between 30% and 60%, depending on the study cited. Autopsy studies of patients who died unexpectedly in a hospital setting have shown approximately 80% of these patients died from massive pulmonary embolism.

The majority of deaths from massive pulmonary embolism occur in the first 1-2 hours of care, so it is important for the initial treating physician to have a systemized, aggressive evaluation and treatment plan for patients presenting with pulmonary embolism.

 

 

Dead Space

dead

1 – having lost life, no longer alive

2 – having the physical appearance of death; a dead pallor

3 – not circulating or running; stagnant: dead water; dead air

 

space

1 – the infinite extension of the three-dimensional region in which all matter exists

2 – an empty area which is available to be used

dead space – a calculated expression of the anatomical dead space plus whatever degree of overventilation or underperfusion is present; it is alleged to reflect the relationship of ventilation to pulmonary capillary perfusion

Walking back into the ED room to get a signature from the nurse I’m momentarily surprised at the level of commotion surrounding the man that was my patient just a few minutes ago. I look up to the overhead monitor that displays his vitals and see the obvious cause for excitement – asystole, the most stable heart rhythm in the world, is marching across the screen and slowly erasing the beautiful complexes of normal heart beats as it fills the screen with the flat line of death. The Paramedic Intern pulls a short step stool out from the corner just as the attending MD makes the call for him to begin CPR. Well, I guess my differential diagnosis was correct, small comfort considering he’s dead now.

There’s a question in paramedicine that is useful to the Paramedic in deciding a course of action on any given call – is this person big sick or little sick? The speed at which we can determine the acuity level of any given patient helps us in determining how fast we move through the call. On occasion the first look at a patient can tell you everything you need to know in terms of acuity. As I walked into the bedroom I could see that this is one of those times. My new patient looked up at me from the bed and it’s obvious that this is big sick and I’ll be moving fast today.

The firefighters arrived just a few seconds before us so they’re still attaching the monitor  leads and trying to get a blood pressure. I know what they’ll find based on the patient’s skin signs alone. The term – pale/cool/diaphoretic – gets overused in our business but it still surprises me when I see these skin signs manifest on a patient. A man of his ethnic background would be hard pressed to look pale so the fact that he looks ashen tells me all I need to know. My first thoughts on a call like this are about extrication. I want to get this guy out of here, into my ambulance, and start driving. Everything else can be figured out on the way to the hospital but the main priority is getting him from the bedroom to the ambulance. The problem is that he’s over two hundred pounds and there are three flights of stairs between me and my ambulance.

I send my partner back to the rig for a stair chair as I start to take in the vital signs and patient history to see if I can paint a picture of the last few hours that led to this big sick presentation. It seems that he and his wife were out running some errands and he started feeling sick about an hour ago. He vomited once and now he’s presenting with an altered mental status, very low blood pressure (72/48), fast heart rate (118 bpm), clear lung sounds, and skin signs that are screaming “heart attack” at me. Of course that was until I ran the 12-lead for the second and third time. The results keep showing nothing even remotely concerning in the cardiac department. In his altered state the only intelligible uttering I can make out from him is, “I…can’t…breathe…”

I put a non-rebreather oxygen mask on him and start the trek of three flights of stairs to the ground floor and the relative comfort of my ambulance where I can start to figure this thing out. The new stair chairs with the revolving treads make quick work of the stairs while preserving our backs in the process. It seems we’re on the ground floor in just a minute or two and headed towards the ambulance.

Finally inside the ambulance, I have decent light and all of my tools at hand so I can try to analyze his condition while driving to the closest hospital. I’ve already ruled out the possibility of a STEMI (S-T elevation myocardial infarction – a.k.a. heart attack), which would require a cath-lab, so I am free to head to the nearest hospital. As I check his 12-lead a fourth time – on the right side this time, still looking for the elusive STEMI – the firefighters decide it’s a good opportunity to leave. Figures. Looks like I’m on my own on this one.

With lights flashing and the siren singing a duet with the air horn I bounce down the road while starting two IVs in my quickly fading patient. Once that’s done I set up two bags of warm saline flowing wide open to drop as much fluid on him as possible and try to keep that blood pressure out of the double digits.

I slip the non-rebreather off of his face and put on a nasal cannula that has a receptacle for reading the exhaled breath and measuring the end tidal carbon dioxide (EtCO2). I actually do a double take as the reading comes back as 8 when the normal reading should be between 35 and 45. Hell, I’ve stopped CPR and pronounced people dead with higher EtCO2 readings!

A number this low just doesn’t make sense. I listen to lung sounds again and they are still coming up clear. I check his blood sugar to rule out a DKA (diabetic ketoacidosis)  presentation and it comes up perfect. Sepsis could possibly take the reading this low and explain the presentation but not with an onset of just one hour. There’s only one other differential diagnosis that is making sense to me right now and when that flashes into my head I’m more relieved than I can admit to see the bright lights of the ED out of the back window as my partner backs us into a spot by the double doors and I prepare to give my findings to  the doctors on the other side.

In these days when science is clearly in the saddle and when our knowledge of disease is advancing at a breathless pace, we are apt to forget that not all can ride and that he also serves who waits and who applies what the horseman discovers. 

Dr. Harvey Cushing