Conference Notes 10-2-2012

Gottesman/Anderson   Oral Boards

Case 1: CO poisoning

Case2: AKA:  Treat with IV fluids and glucose

Case3: Morbidly Obese Patient with respiratory failure:  

Harwood comment: The lesson of these 3 cases is getting the ABG. It will help you solve all 3 cases.  VBG can be used frequently in place of ABG.  If you want a CO level on the VBG, make sure to tell the respiratory therapist. They may not run the CO.    The caloric content of a bag of D5 is 200 calories, so you may need to give D10 or food or Amps of glucose to correct marked hypoglycemia.

Girzadas comment: For the SuperObese patient be sure to use RAMP positioning and call for back up from anesthesia or other EM physician

Kulstad Study Guide CV Disease

Aortic insufficiency murmur is heard in 32% of patients with aortic dissection.

Best work up for iliac dvt in a pregnant patient is MRI.

Work up for ischemic limb is Vascular consult and CT angio of limb.  Heparin is usually indicated.  Definitive therapy is thrombectomy and embolectomy.  Harwood comment: Just give heparin and consult vascular surgery.  Ct angio may be a time waster.

Signs of Aortic dissection: wide mediastinum, tracheal deviation, and aortic shadow beyond calcified wall.   Harwood comment: there is a difference between traumatically torn aorta and aortic dissection.  Xray findings are not all common to both.

Phlegmasia cerulea dolens: Severe ileo femoral dvt with venous engorgement.  Can lead to compartment syndrome and gangrene.   Treat with heparin and IR thrombolytics.   Phlegmasia alba dolens is called the milk leg.  Much less common and is a dvt resulting in decreased arterial perfusion.

High risk patients with concern for dvt who have a negative U/S, they need f/u U/s in 7 days.  2 negative U/S makes risk of PE or DVT less than 1% in 3 monts

Wells criteria and modified Wells criteria: clinical assessment for pulmonary embolism

Clinical symptoms of DVT (leg swelling, pain with palpation)	3.0
Other diagnosis less likely than pulmonary embolism	3.0
Heart rate >100	1.5
Immobilization (≥3 days) or surgery in the previous four weeks	1.5
Previous DVT/PE	1.5
Hemoptysis	1.0
Malignancy	1.0
Probability	Score
Traditional clinical probability assessment (Wells criteria)
High	>6.0
Moderate	2.0 to 6.0
Low	<2.0
Simplified clinical probability assessment (Modified Wells criteria)
PE likely	>4.0
PE unlikely	≤4.0

Data from van Belle, A, et al. JAMA 2006; 295:172.

 

Most common extremity aneurysm is  popliteal .  Often bilateral and rarely rupture.

Treatment of aortic dissection: reduce shear force with esmolol and drop MAP to 60.  Can add nitroprusside or other agent if needed to get map to 60.  Start though with esmolol.    Labetalol would be another option.

Be very cautious managing asymptomatic htn.   There is a risk of causing stroke with rapid lowering of BP.  Restart their medications.  If they are untreated you can start a low dose diuretic.

Thrombotic cause is more common than embolic cause of limb ischemia.   This is due to good anticoagulation management of patients with Afib and valve replacements.

There is no distinct number that identifies a hypertensive emergency.   Emergency is defined by end organ damage.   Harwood comment: pre-ecclampsia  is a hypertensive emergency with a relatively low bp cutoff.  Usually 140/90.

The following eight factors constitute the PE rule-out criteria

• §  Age less than 50 years
• §  Heart rate less than 100 bpm
• §  Oxyhemoglobin saturation ≥95 percent
• §  No hemoptysis
• §  No estrogen use
• §  No prior DVT or PE
• §  No unilateral leg swelling
• §  No surgery or trauma requiring hospitalization within the past four weeks

Coghlan comment: Why not include cancer in the PERC rules.  Barounis response that when Jeff Kline discussed on previous podcast he said cancer did not change the probability in his study.  

Harwood and Barounis felt that if a cancer patient has neg perc/neg dimer/neg trop then they likely don’t have a PE.   Elise and Barounis disagreed on whether CT would be indicated in this situation.  There was some heated discussion between Harwood/Elise/Christine/Barounis on this topic.  There was not consensus on whether a CT was absolutely necessary in the cancer patient who has a neg perc/neg dimer/neg trop.

Best treatment for  patient with asymptomatic htn who is not on meds currently:   HCTZ, Lisinopril .  Pharmacy student comment: Lisinopril may be less effective in African American patients.  Harwood comment: Chlorthaladone is a thiazide diuretic that is more potent than HCTZ.  Consensus was that you don’t need to start potassium therapy with low dose HCTZ or Chlorthaladone.  Hypokalemia is not a big problem with HCTZ 25mg or less.

Maslar  Dive Medicine

Humans can’t breathe under water through a long snorkel tube because there is water pressure pressing on our chest and increasing the air pressure in our bodies.  Our diaphragms cannot overcome this pressure.

Dybarism: most common source of diving problems. Ear squeeze is usually a problem of descent. Ear pain can develop.  TM can rupture.   Valsalva is treatment for ear squeeze but If you overdo it you can cause round window rupture resulting in hearing loss/vertigo/tinnitus.   Sinus pain is usually a problem of ascent resulting in sinus pain.  Pulmonary barotraumas can also occur on ascent in a diver breathing pressurized air.  The diver  needs to exhale as you ascend or the expanding air can cause alveolar rupture.  Patients can have pneumomediastinum.   Worst case scenario of dysbarism is air embolism.  Arterial gas embolism will occur almost immediately upon surfacing.  Of all dysbarism injuries, only the air embolism requires hyperbaric treatment.

Diver descending: ear squeeze.   Diver ascending:sinus pain, pulmonary barotraumas, arterial gas embolism

Decompression sickness (Bends): Usually involves nitrogen which is most prevalent atmospheric gas and is inert.  Joe used the can of coke metaphor to describe decompression sickness.  If you open a can of coke real fast you get a lot of bubbles. If a diver surfaces too fast relative to the time they were underwater you get bubbles in the blood/tissues/joint.  Interestingly, we don’t really know where bubbles come from or how they hurt us.   Gasses coming out of solution with decompression sickness usually affect the spine rather than the brain. Acute stroke symptoms should point more to arterial gas embolism than decompression sickness. Treatment is hyperbaric oxygen to push bubbles back into solution.

Who needs hyperbaric recompression tx: decompression sickness, arterial gas embolism, CO toxicity

Christine comment: If you have to treat a patient with a diving related malady and have questions or need guidance you can call the Diver’s Alert Network (DAN).

Lovell    Targeted Temperature Management Post-Cardiac Arrest

Post cardiac arrest syndrome: precipitating disorder, tissue ischemia,

Therapuetic hypothermia: mechanism of action is to slow down brain/heart/overall metabolism and slowing the inflammatory cascades that are negatively impacting brain.

Ice packs have been shown to effectively cool patients.  So low tech cooling means have been shown to be just as effective as the hi tech options.  We have cold IV saline in the ER to use to start cooling patients early.

Hypothermia therapy either results in patients with good neurologic outcomes or they die.  Hypothermia treatment does not result in more patients with a persistent vegetative state.

Number needed to treat for therapeutic hypothermia: good neuro outcome=6,  lower mortality=7.  These are great numbers!

 AHA guidelines: Class 1 recommendation for comatose patients with ROSC after V-Fib arrest. Should also consider with patients resuscitated from other types of arrests.

Complications to be expected: infection and coagulopathy, bradycardia, electrolyte abnormalities, 5-20% rate of seizures, labile BP, hyperglycemia, avoid hyperthermia with re-warming.  Keep patients below 37.5C.

Can use therapeutic hypothermia even if prolonged resuscitation and/or unwitnessed arrest or prolonged down time prior to resuscitation or cancer.  Elise made a strong point that in all decisions to initiate hypothermia treatment to consider their pre-arrest health status and pre-arrest prognosis. Can even use therapeutic hypothermia when given lytics for PE.  Don’t use it for patients who arrested from bleeding because hypothermia will result in coagulopathy.   In patients on Coumadin, you don’t need to reverse or correct their inr’s.  Plavix does not preclude therapeutic hypothermia.  Elise would also cool patients with hemophilia who were not actively bleeding.  Patients with risk for head bleed due to trauma need head ct prior to cooling.

PICIS has algorithm for hypothermia.  We will have to find out where algorithm will be stored in FIRST NET system.

There is some data to suggest that delay to cooling increases risk of death.  Minnesota study shows 20% increase in death with each hour of delay to starting cooling.

New study coming down the pike: Do we need to actually cool pt’s down to 33C or is 36C good enough? European study of 875 patients is looking at this question.

Post-arrest prognostication: You have to wait until 72 hours when using therapeutic hypothermia.  Cooling and associated meds can decrease brain function for 72 hours after ROSC.

Harwood question: what is the definition of coma in the post arrest patient?  Elise answer: If you give a verbal command with no response or GCS <8.

Can also use hypothermia in neonatal hypoxic ischemic encephalopathy. NNT=7 to reduce death or major neurodevelopmental disability. Can use in Pediatric Cardiac Arrest.

New research to use therapeutic hypothermia for traumatic brain injury.

Remember that there is usually a culprit coronary lesion with cardiac arrest. So patients should go to cath lab after resuscitated V-Fib arrest.

Use left femoral vein for cool guard catheter.

Sam Lam Question: What about patients that re-arrest? Elise answer: if patients re-arrest or require hi dose or multiple pressors then stop cooling.  Outcome is dismal.

SEE THE ACMC PROTOCOL ON THE NEXT PAGE

 

Levato   Febrile Neutropenia

Absolute neutrophil count less than 500 is neutropenia.  Temp>38 is a fever

ABx choices are Cefipime or Primaxin.   Vanco is limited to specific categories listed on form (shock, skin,foreign device infection, mucositis).  For beta lactam allergy: aztreonam/cipro/tobramycin. Pick 2 of these three.

Main concern in these patients is on gram neg infections.