Conference Notes 8-28-2012

Conference Notes 8-28-2012

Grippo  Ortho Jeopardy

Perilunate Dilocation: Look at the lateral view of the wrist.   The capitate/lunate/radius need to line up.  If the capitates is dorsal to the lunate the dlx is perilunate.   If the lunate is dislocated volarly, it is a lunate dlx.

Supracondylar FX: 60% of peds elbow fxs.   Severe fractures that are not treated properly can develop Volkman’s ischemic contracture.

Femoral neck fractures: Have risk of avascular necrosis.   Older patients will get a arthroplasty.

Scapholunate DLX:  widening of space between scaphoid and lunate.  Terry Thomas sign.  Treat with radial splint.

Montaggia Fx:  Proximal ulnar fx with dislocation of radial head.

Galeazzi Fx:  Distal radius fx with dislocation of radio-ulnar joint.    Mnemonic is MUGR=montaggia/ulnar fx galeazzi/radial fx

Bennet’s Fx: Intra-articular fx at base of thumb. 

Barton’s Fx: Distal radius fx with intra-articular involvement.  Usually fx goes thru volar aspect of radius.  Can have either dorsal or volar angulation.

Bohler’s Angle: Normal is greater than 20 degrees.   If less than 20 degrees that is indicative of a calcaneous fracture.    With calcaneal fractures check for compartment syndrome in foot.  Also look for other joint and spinal injuries in patients who fell from height.

Lis Franc Fx:  tarso-metatarsal FX/DLX.  Look for fx at base of 2nd mt and/or non-allignment of based of second MT and middle cuneiform.

Boxer’s fx: Needs reduction if angulation >40 degrees.  If pt has associated fight bite give antibiotic prophylaxis.    After reduction place in ulnar gutter splint with finger in flexion.

Lovell comment: Frequently fight bite injuries require OR irrigation and debridement.   Harwood added that in the OR it can be determined whether the bite went into the joint space.    Both felt IV antibiotics were indicated and hand consult for either OR or Obs admit or Very close follow up.   This is high risk medico-legal situation.

Jone’s Fx:  Fx of metaphysis/diaphysis junction of 5th MT.  Risk of nonunion.  Non-weight bearing for 6 weeks.   Needs Ortho follow-up.  Psuedo-Jones Fx is basically an avulsion fx of tuberosity of 5th MT.   These heal well and only require cast shoe.

Salter Harris FX:  Type 2 is most common.    Mnemonic is ME: metaphysis involvement is a  2, epiphysis involvement is a 3.  1 is easy to remember because it is just thru the physis and 4 is also easy because it goes thru both the metaphysic and epiphysis.   5 is a compression injury to the physis.  

Pilon Fx: Bad comminuted distal tibial fx due to talus ramming into tibial plafond due to a fall from height. 

Chauffeur’s(Hutchinson’s)  Fx:  Fx of the radial styloid.   Used to occur when turning the crank of early model  cars.  

Barounis     Undifferentiated Shock

Shock: Inadequate O2 delivery to meet tissue demand.

Oxygen delivery=(HR x SV) x 1.34 X HGB X SAO2 X10.    HGB and O2 Sat are the most important factors for O2 delivery.

Shock is bad because it results in anaerobic metabolism and lactate production.   The sodium potassium pump malfunctions.  Lactate is the cry of poorly perfused mitochondria.

Types of shock: 

Obstructive (tamponade/tension pneumo/pe/auto peep/rv infarct) Eval for this is to listen to breath sounds, use ultrasound.  Check EKG for signs of RV infarct; lead III will have more st elevation than lead II. Check for auto-peep on vent.

Distributive shock: (sepsis/cyanide/anaphylaxis)  Bounding pulse with hypotension.

Cardiogenic Shock: cool clammy, altered mentation

Hemorrhagic shock:  the patient is bleeding.

Approach to shock: Assess heart rate (pulse is not the main issue between 60 and 180),  make a volume assessment/obstructive assessment (cvp/U/S of VC /urine output/gingival mucosa),  assess contractility with U/S,  figure out the SVR (check extremities for warmth/bounding pulse/coolness/decrease pulse)

On ultrasound if IVC collapses more than 50% with inspiration the patient is volume responsive.  This assessment is obtained with the subcostal long view of aorta.   You also want to check the abdominal aorta/pericardium/rv /morrison’s pouch.  

History is unreliable in the assessment of shock.   Physical findings are more reliable than history.

PEEP helps push fluid out of the lungs into the right heart.  Also the increased thoracic pressure from PEEP helps move blood to abdominal organs/brain/extremities by pressure gradient.

Jim Jensen  PharmD   Vasopressor Review

Dopamine:  Indications septic shock, hypotension without hypovolemia, symptomatic bradycardia.  Can cause arrhythmias.

Levophed: More potent alpha agonist.   Indicated for septic shock or hypotension due to low svr.  Increases myocardial oxygen demand, may cause arrhythmias. 

Phenylepherine: Soley an alpha agonist with no beta effects.   Last line pressor .  Start high dose and titrate down because it is a relatively weak vasopressor.   Harwood comment: Only use for this agent is  neurogenic shock.     

Epinepherine: Mixed alpha and beta agonist.   Indicated in ACLS, septic shock after dopamine or norepi, anaphylactic shock.

Vasopressin: Smooth muscle vasoconstriction.  Inidcated in ACLS and is an option in septic shock with catecholamine resistance.   

If a vasopressor extravasates out of the vessel, you can use phentolamine locally to counteract the effects of the vasopressor.   Harwood comment: Give the phentolamine through the IV that extravasated so that the antidote goes right to where the  tissue injury has occurred.

Central line is required for Epinepherine drip and norepi drip.   Central line not required for dopamine, phenylephrine, vasopressin.

Dobutamine:Beta agonist that  increases cardiac contractility/cardiac output and vasodiates.   Can cause arrhythmias and hypotension.

Milrinone: Phosphodiesterase inhibitor increasing CAMP.  Increases cardiac output but does cause vasodilation. 

Plavix vs. Ticagrelor (Effient):  Ticagrelor has a stronger antiplatelet effect and has been shown to reduce thrombotic events compared to Plavix.  This comes with the cost of higher rate of  bleeding.  ASA dosing over 81mg decreases the effectiveness of Ticagrelor.

Carlson  Toxicology Antidotes

Antidote: Any treatment that lowers the LD50 of a toxin.  Direct antidotes act right at the site of the toxins action.    Indirect antidotes are supportive such as cooling, oxygenation, folate co-factor replacement etc.

Fomepizole is antidote for toxic alcohols.  Blocks alcohol dehydrogenase.   Pyridoxine is co-factor antidote for ethylene glycol.   Folate is a co-factor indirect antidote for methanol.

Lead poisioning:  Antidotes are succimer, BAL, EDTA.  In severe cases use BAL and EDTA both.   Can’t give BAL to patients with peanut allergy.

Mushroom poisoning with seizure:  Antidote is pyridoxine for gyromitra poisioning.    Gyromitra acts similar to INH and blocks GABA production.  

Clonidine poisoning: Antidote is narcan.  May need higher dose.  Repeated 2mg doses up to 10 mg.  There is controversy about the effectiveness of this antidote.

Hydrogen sulfide poisoning: Antidote is sodium nitrite for the sulfhemoglobinemia.   HBO is a second line direct antidote for this as well.

Calcium channel blocker OD: First line tx for severe OD’s is Insulin 0.5U/kg bolus followed by 0.5U/kg/hr drip and supplemental glucose therapy.

Anticholinergic toxidrome: Antidote is benzodiazepines first line.   Physostigmine is a direct antidote that should only be used with caution.  There is EM literature that shows physostigmine is actually relatively safe in patients with clear cut anticholinergic symptoms without other coingested substances.  The problem is that clear cut isolated anticholinergic OD’s are not very common.   

 Paraquat: Antidotes are Fuller’s earth, bentonite.  Don’t give O2 because it will cause pulmonary fibrosis.  

Coral snake: Red on yellow, Kill a fellow.   Coral snake (elapid) antivenin.    Red on black, venom lack refers to a non-venomous milk snake.   

Sulfonylurea overdose: Antidote is glucose and  octreotide.

Methylene Chloride:  Methylene chloride is broken down to CO in the liver.   Treat with HBO.  Methylene choloride has a long duration of action so patients may need multiple dives.

 Lily of the valley, fox glove,and oleander are plant sources of cardiac glycosides (digoxin): Antidote is digibind.   Atropine can also work by reducing vagal tone.

Rattle snake bite: Antidote for crotalid bites is crotalid antivenin.  Indications for antivenin are local spread,  coagulopathy , abnormal vitals.   Mnemonic: Spread, bled, almost dead.   Give 5 vials minimum.  Be prepared to manage anaphylaxis.

Hydroflouric acid:  Treat with calcium gluconate.   Don’t use calcium chloride because it can cause tissue damage.  Pt will have a lot of pain.  Can give calcium gluconate via topical gel, local injection, and intra-arterial infusion.   Needs hand consult or transfer to burn center.

Methemoglobinemia:  Treat with methylene blue.   HIV patients with G6PD deficiency  on dapsone for PCP can develop methemoglobinemia.

Amanita Phylloides muchroom.  Will cause vomiting more than 6 hours after ingestion.  Amanita acts like amped up apap resulting in centrilobular necrosis of liver.   Antidote is nac.

Organophophates: Treat with atropine and 2-PAM.   If you have tachycardia with cholinergic OD think hypoxia as secondary to pulmonary/airway secretions.   Still need to give atropine. 2-PAM regenerates acetylcholinesterace.

Willison/Carlson   Oral Boards

Case 1. Transverse myelitis.  Critical actions were perform detailed neuro exam, rule out cord impingement with mri, foley decompression of bladder.  Triad of sudden onset back pain, sensory changes (including allodynia) and weakness/sphincter dysfunction.   #1 thing for emergency physician to do is rule out cord compression.   Most references advise steroid treatment.   Can be a harbinger of MS or sarcoid.  

Case2. Depakote(valproic acid)  overdose with severely high ammonia level.  Critical actions were  intubation, check valproic acid and ammonia levels, treat with L-carnitine.  Can dialyze for severe cases.   Metabolism of depakote requires carnitine.  When you use up your carnitine you produce the toxic metabolite ammonia.  Giving l-carnitine allows normal metabolism of depakote.

Case3. Molar Pregnancy.  Critical actions were give iv fluids, get beta hcg, get u/s and identify molar pregnancy, consult ob-gyne.  Molar pregnancies occur 1 in 1200 pregnancies. Increased risk at extremes of age.  Two types genetically 69xxx or 69xxy or 46xx or 46 xy.  There is a chance of malignancy in both types.  Worst outcome is with patients that present with lung mets.  BHCG is usually great than 100,000. Uterus is larger than expected for age.