Conference Notes 8-30-2011

Conference Notes  8-30-2011
Jones fracture is a linear fracture at the metaphysis of the the 5th MT.   Treatment is non weight bearing in cast for 6 weeks.    Fracture at the 5th MT tuberosity is called pseudo-jones and does not require casting.
Erythema Chronicum Migrans is target-like rash associated with  Lymes Disease. Treat with  doxycycline, rocephin or amox.  Erythro also acceptable on paper but Harwood says don't use erythro.
RMSF  treat with doxy in kids and adults.   Use choramphenicol in pregnant women.
HSV encephalitis shows bright temporal lobe on MRI
TEN/ Steven Johnson's associated with antibiotics like bactrim.   Transfer to burn unit.  Stop the drug needless to say.
Phlegmasia Cerulean Dolens is a severe dvt compromising venous outfow.  Leg is swollen and Purple
Phlegmasia Alba Dolens is a severe dvt with a white leg.  Arterial inflow is compromises
Pityriasis Rosea starts with a herald patch then becomes generalized.  Not contagious.  Thought to be viral.   Christmas tree pattern of rash on skin is key word for tests.
Colormetric Co2 detectors can falsely stay purple in the cardiac arrest patient.  The detectors need to see 4% co2 in exhaled breath and co2 may be less in the arrest patient.
End tidal   has close to 100% sensitivity for detecting tracheal intubation.
If you are in the trachea you will see a wave form on the capnograph. 
Capnography in the Cardiac Arrest Patient can guage effectiveness of CPR.  Your co2 with good cpr should be around 10.   If you see a sudden rise of 10 on the capnograph suggests ROSC.    Capnography can be used in place of pulse check.   If end tidal co2 is less than 10, 20 minutes out they are effectively dead.  This probably also applies to kids.  
Bicarb iv can falsely elevate entidal co2.
Capnography can demonstrate early apnea during procedural sedation
In copd and bronchospasm  the capnography wave form can demontrate breath stacking early. 
In patients with metabolic acidosis, ETCO2 will be high.   In DKA it will be low. 
Pneumomediastinum due to Macklin Effect in which alveolar air ruptures into interstitium and dissects toward hilum. Examples are asthmatics, scuba divers, smoking crack pipe etc.  If pneumomediastinum is not due to esophogeal rupture or tracheobronchial trauma it is benign.  If it is due to esophogeal rupture or trach-bronch trauma this is an emergency with high risk of mortality.  Requires surgery.
Mach Band can mimick a pneumediastinum.  The Mack band lacks a thin bright white line of the pleura.  This is very common.
Deep sulcus sign is a low/deep diaphragm and cp angle that indicates a pneumothorax.     The deep sulcus sign may be the only indication of a pneumothorax on CXR.  
Most common cause of fatal transfusion reaction is giving the wrong blood to patient and ABO incompatibility is present. 
Only use IV Saline with PRBC transfusion.  D5 can cause hemolysis. LR has CA which can cause clotting. 
O-pos blood can be used a an uncrossmatched resucitative transfusion instead of  O-neg in males and females over 50.
Blood transfusion requires a filter in the iv line. 
Transfuse as fast as tolerated.  If chf run it in slowly.   Gotta transfuse under 4 hours.   There may be some bacteria in the unit of blood or plasma and it is felt that transfusion under 4 hours limits the chance of increasing bacteria in blood. 
1 unit of PRBC's should raise hgb by 1.
1 unit of aphoresis platelets increases the platelet count by 20-40,000.
Criteria to transfuse for adults is hgb <8 or hgb 8-10 with symptoms or COPD/CAD/Other CV disease.  There is debate about the 8 hgb cut off.  Pt's with heart disease do better with blood.   Also transfuse pt's with acute blood loss >2% blood volume.
If pt has history of allerigic reaction to prbc/platelet transfusion, ask for washed or twice washed      
In patients with severe immunosuppression needs irradiated blood to prevent graft vs. host disease. 
Tissue damage is mostly related to velocity based on the equation KE=1/2mass x (velocity squared)
Cavitation is movement of soft tissue as missile passes and severity is based on velocity.     
Handgun accuracy is low.  11% of perps and 25% of cops hit their intended target. 
High velocity is >2000 ft per second.
Wound care: irrigation, tetanus update, cover with gauze.   GSW's are not sterile but infection is rare.  If infection develops it is usually due to gram positives from skin flora.   Routine abx prophylaxis is not indicated. 
Indication for bullet removal: superficial and irritating, cosmetic reasons, joint space, globe of eye, in vessel lumen, nerve impingement, abscess, forensic investigation, elevated lead levels.
Do bullets set off metal detectors?  Yes
Missiles in joint spaces are most prone to cause lead poisoning.  Also bullets in bone are at risk. 
Desmoteplase for strokes.  It is a plasminogen activator.  70% similar to TPA.
You can give up to 4.5-9 hours out. No neuro toxicity. More fibrin specific than TPA.  Half life is 4.5 hours.  Found naturally in the saliva of a vampire bat.  
Clinical equipose:  Genuine uncertainty as whether treatment in one arm of a clinical study has  benefit over treatment in the other arm. 
Intra-arterial thrombolysis (neurointerventional stuff) can be used 4-6 hours out from onset of stroke.
Studies have also looked at surgical recanulization out to 8 hours after onset of stroke. Clinical outcome data on these neurointerventional techniques are limited.
If you have a patient more than 3 hours out from onset of stroke, get a CTA in addition to CT.   Neuro will decide whether pt gets  Desmoteplase vs. Neurointervention.  No one knows if either helps patients.  
In afib,  F waves can look like p waves but have variable morphology. 
Aflutter should have very consistently symmetric flutter waves.  If they have differing morphology, then you have afib. 
Adenosine dosing thru central line is only 1-3 mg.   You might want to give sedation prior to giving Adenosine to lessen the feeling of impending doom/chest discomfort.
Heart rates 140-160 is usually aflutter with 2:1 conduction.
Retrograde P Waves should make you think AVNRT
You can't identify WPW in a narrow complex svt.   Orthodromic WPW SVT looks like any other narrow complex SVT.    Narrow complex tachycardia adenosine is ok.  Wide complex use procainamide.