coma + narrow pupil = opioid toxicity
coma + dilated pupil = tca toxicity
coma + lateralization = stroke or hemorrhage
coma + no lateralization = poisoning , post ictal , hepatic failure , brainstem stroke
coma + ocular nerve palsy and divergent squint = wernicke's encephalopathy
coma + bells phenomenon = psychogenic coma
approach to patient with coma:
there is two important ddx you should put in mind
1-brainstem lesion (ischemia , hemorrhage , tumor , etc...)
2-metabolic coma (hypoglycemia , hyperglycemia , excessive alcohol intake , medication overdose , illicit drug use , uremic or hepatic encephalopathy , etc..)
[bi-hemispheric lesion can cause coma but this is rare ]
hx :
take rapid history while performing ABC(ضغط سكر كحول كيف فقد الوعي حركات لااراديه فجاة فقد الوعي وعي مشوش قبل ان يفقد الوعي )(hx of htn , dm , alcohol , involuntary movement , sudden loss of conscious , decrease level of conscious before complete loss of conscious )
examination :
determine severity
conscious = awake
drowsy = respond to simple stimulus
stupor = respond to painful stimulus
coma = don't respond to painful stimulus
eye examination
pupils if reactive and symmetric think of metabolic coma , if asymmetric think of brainstem lesion
doll's head maneuver , if eye movement symmetrical - metabolic , asymmetrical -brainstem
exam sign of basal skull fracture (racon eye ,battle sign , csf leak , hemotympanum)
exam meningeal sign , if positive think of cns infection or subarachnoid hemorrhage (but remember they usually don't cause coma , patient come drowsy or conscious)
investigations:
RBS
ECG
treatment :
give dextrose , thiamin blindly ,(*references advice to give nalxone , flumazenil before thiamin)
this approach shouldn't take more than 2 minutes
then send for brain imaging or metabolic screen accordingly
approach to patient with depressed consciousness :
ABC , DIAGNOSIS , TREATMENT , EXAMINATION , IMAGING , DISPOSITION
ABC :airway , breathing , circulation
DIAGNOSIS : RBS , obtain IV line , maintain spo2 94-97% , initiate cardiac monitoring , ECG , portable x-ray , POC labs
TREATMENT : administer : dextrose if hypoglycemia , naloxone if opioid toxicity suspected , thiamine if malnourished
EXAMINATION: complete physical-neurological examination
if improved - treat and observe
not improved ?
secure airway if not improved , administer antibiotics if infection suspected
if there brainstem signs : CT , CTA
if no brainstem signs : CT
IF no structural cause : ddx
1-toxic - labs , antidote /dialysis
2-seizure - EEG , anticonvulsant
3-PRES - MRI , antihypertensive
4-infection- LP , antibiotics
5-nutrition - thiamine,glucose
6-endocrine = thyroid studies , steroids
IF structural cause :
consult specialist , treat cause , provide neuroprotective care , admit to ICU
