Pediatric Case of the Week 17: Spring Cleaning

13-year-old boy is brought in by EMS after he was found in bed with confusion, headache, and nausea.  According to his parents' he had slept in his “new man-cave bedroom” which they had just created in the basement of their old house. The room also happens to be adjacent to the “mechanicals” which include a hot water heater and a hot water boiler.

EMS noted initial hypoxemia with sats in the low 90’s and placed him on non-rebreather.

No significant past medical history, he is otherwise healthy and doing well in school.  Parents do not suspect drug use and he has no history of depression.

VS:  Temp 97.4, HR 112, BP 95/60, RR 30, Sat 99% on 10L

Primary survey: Airway: is patent.  Breathing: rate is slightly increased.  Circulation: skin is pale and pulse is slightly increased.  Deficits: he appears confused, oriented to person only, GCS 12, without additional focal neurologic deficits.

Secondary Survey: No signs of head trauma.  He is moderately confused (as noted on primary), PERRLA. CV RRR, no murmurs. Lungs are notable for faint crackles at the bases. Abdomen NT/ND and normal bowel sounds.  Skin warm, axilla normal sweating.

IStat: pH 7.3, PaCO₂ 31.8, HCO₃ 16, SaO₂ 99%, Na 141 mEq/L, K 3.8 mEq/L, BUN 12, Cr 0.9, glucose 198 mg/dL, Hb 16.3 g/dL.

EKG shows sinus tachycardia with no additional abnormalities. 

Portable CXR shows subtle pulmonary edema.

If his respiratory status were to diminish, which chemical agents would you use to paralyze/sedate?

If he were to become hypotensive, which pressor(s) would you initiate?

What additional labs would you like to order?

Assuming his status remains unchanged in the ED, where would you likely admit this patient: ICU, Telemetry, Floor?



----------------------------WEEKEND UPDATE------------------------------------

Carbon Monoxide toxicity is most frequently associated with smoke inhalation. But it should be considered in less obvious scenarios in which patients present with symptoms ranging from severe altered mental status to mild headache and “flu-like” symptoms. 

Toxicity ranges from asphyxia, myocardial dysfunction, and a full spectrum of neurological dysfunction.  It can be very difficult to diagnose and is commonly misdiagnosed as Headache or Viral Syndrome. Unfortunately, CO has the quality of being both odorless and tasteless (Similar to a certain colleague of mine just after a he’s taken a rare but much needed shower.)

The CDC reports that in 2001-2002 about 15000 people were treated for unintentional non-fire-related CO exposure.  Most of these exposures occurred during the winter months and were related to faulty enclosed heating systems. The same report noted that children younger than 4 had the highest incident of unintentional CO exposure, but fortunately the lowest rate of death.

The differential for altered mental status is VERY LONG.  In this case you would definitely want to consider other toxidromes, seizure, neurologic, and cardiac etiologies.

Some key points regarding CO toxicity:

-Patients may not appear cyanotic, because Hgb takes on a red hue when bound to both O2 and CO.

-GET AN EKG, (you would want get an EKG in all Altered Mental Status patients regardless) however, CO can specifically cause cardiac toxicity.

-Standard pulse oximetry will not differentiate oxyhemoglobin from carboxyhemoglobin.  O2 Sats will often be falsely elevated.

-Carboxyhemoglobin levels can be directly measured by arterial or venous blood samples.

-For anyone taking the Boards soon: CO shifts the oxyhemoglobin dissociation curve to the left; which inhibits the release of oxygen to the tissues.  (It decreases both O2 loading in the lungs AND unloading of in the tissues.)

 (This image was intentionally left small and insignificant because, personally, I loathe it and think it should be obliterated from all medical texts. I have learned it 15 times and can never remember it.) 

-If the patient is maintaining his/her airway, the treatment is 100% O2.  If not, have a low threshold for intubation. 

-I think, as long as the potassium comes back normal, you could intubate using etomidate and Succinylcholine or Rocuronium.  If the K comes back elevated, or you don’t have it but are worried about seizure or prolonged down time, you may want to consider Rocuronium (a non-depolarizing paralytic and less likely to drive up K precipitously.)

-Hyperbaric O2: The magic number for CO level is >25 (>20 if pregnant).  Other high risk situations include: pregnancy with signs of fetal distress, LOC, pH <7 .="">

-Additional interesting facts/thoughts:

-Smokers walk around with a baseline CO as high as %10.  They are MORE susceptible to the toxic effects of CO (as if they needed another reason to quit.)

-After hurricane Katrina there were 78 cases of non-fatal CO exposure and 10 deaths.  Nearly all the cases were related to gasoline powered back up generators being run outside but near the home’s air-conditioner blower unit.

-In winter (Minnesota): Ice houses

 

-In summer (Minnesota): Napping in the back of a motorized boat

-All Season: riding in the back of an old truck (I might have been a neurosurgeon had I not made a trip "up north" in one of these bad boys at age 12...)