Questions of the Week for 5/16/2023

Author: Christian Gerhart

1.     A 35 male presents with acute low back pain that sounds musculoskeletal. List 5 things you should address on your history to ensure no “red flags” are present. 

• Answer

  Some key historical factors to ask about include history of cancer, immunocompromised state, IV drug use, B symptoms, presence of neurologic symptoms, bowel/bladder incontinence, recent fever, recent trauma

2.     A 70-year-old male who smokes daily and has not seen a doctor for decades presents with acute right sided low back pain. What life threatening diagnoses must be considered in this patient? 

• Answer

  A: Vascular emergencies such as AAA rupture, RP hematoma, aortic dissection

3.     When should we consider dual sequential defibrillation in CPR? 

• Answer

  In refractory Vfib arrest. In the DOSE VF study this was defined as 3 shocks with standard pad placement (anterolateral). Repositioning pads to anteroposterior from anterolateral trended towards benefit while adding an anteroposterior set of pads to the anterolateral seemed to have a significant survival benefit. This is still under investigation but seems to have a low risk profile. Consider this in your next refractory VF arrest.

4.     When should we consider VA ECMO activation for cardiac arrest (ECPR)? 

• Answer

  Arrest from acute MI with refractory VF/VT, arrest from massive PE, hypothermic arrest and cardiac arrest due to another reversible cause (tox, acute cardiomyopathy) are common indications. Though this remains controversial there is some evidence suggesting good outcomes for physiologically young patients with VT/VF arrest.

5.     You have a 75 yo patient on Warfarin for Afib who presents with a large spontaneous intracerebral hemorrhage and GCS of 10. What medications would you use to reverse their anticoagulation? 

• Answer

  A: Prothrombin complex concentrate (generally weight/INR based dosing) and Vitamin K (10mg IV) with a goal to reduce INR<1.3. Fresh frozen plasma is an option as well though this generally requires large volumes and is not as effective at rapid reversal. It is very difficult to reduce INR below 1.7 with FFP.

  https://www.ahajournals.org/doi/full/10.1161/STR.0000000000000407

6.     You have a patient with a history of Heparin-induced thrombocytopenia (HIT) and atrial fibrillation on Warfarin who presents with a large intracerebral hemorrhage. Their GCS is 12. How would you reverse their anticoagulation? 

• Answer

  FFP or Factor IX complex concentrate. PCC is usually avoided in patients with a history of HIT since PCC has heparin products in it.

7.     You again have a 75 yo patient who this time is on Apixaban for atrial fibrillation who presents with a large spontaneous ICH and a GCS of 10. What are your options for reversal? 

• Answer

  Either PCC or Andexanet Alfa (NOT BOTH) are acceptable reversal agents for Factor Xa inhibitors. This is a bit controversial. Our institution generally seems to favor Andexxa for this indication but either is probably acceptable. The AHA guidelines slightly favor Andexxa (2a rec) over PCC (2b rec) for ICH. .

8.     You have a 67 yo patient who presents with RIGHT sided weakness (face/upper/lower extremity) and dysarthria. His non contrast head CT is negative for acute blood but shows a dense MCA sign in the L MCA territory (Image on the left). He undergoes thrombolysis with Tenecteplase. Shortly afterwards he becomes altered. A repeat HCT shows a large intraparenchymal hemorrhage. How would you attempt to reverse the Tenecteplase? 

• Answer

  This seems to be an areas with limited evidence however most authors suggest Cryoprecipitate (10 units) + TXA 1g IV +/- FFP and platelets. Thrombolytics have a short half-life but have longer lasting effects on coagulation. We should target a fibrinogen >200 mg/dL, probably shoot for plt >100, and try to keep INR<1.4. This would probably be a good time to use TEG/ROTEM if you know how to interpret it.

9.     You are taking care of a 27 yo male who presents to the ED with altered mental status after running sprints on a hot day. His rectal temperature is 41C. What method should you use to cool this patient? 

• Answer

  Remove clothing (“trauma naked”), place ice bags everywhere and use water + mist + evaporative cooling with fans. ICY line is generally not indicated for rapid cooling (it takes too long). Chilled fluids generally are not helpful. Anti-pyretics should be avoided as they can be harmful in heat stroke.

10. You rapidly cool the above patient. What temperature should you target when cooling him? 

• Answer

  101-103F (approx 38-39 C). We should stop cooling when in 38-39 C range to prevent overshooting our target. We would want to monitor closely with a temp sensing foley, or esophageal temperature probe (if intubated).

11. Your patient becomes increasingly altered to the point where he is unable to protect his airway and requires intubation. What agents should you use for this procedure? 

• Answer

  AVOID SUCCINYLCHOLINE. Sux can raise potassium and these patients are already at high risk for hyperkalemia. Use rocuronium as your paralytic. Select a sedative as you usually would based on the patient in front of you. There do not seem to be any major contraindications to our typical sedative agents.

12. You intubate a patient is respiratory distress who appears to have a severe pneumonia. In order to maintain a lung protective ventilation strategy, what plateau pressure should you target and how do you measure this on the ventilator? 

• Answer

  Perform an inspiratory hold to measure the plateau pressure. In general, the plateau pressure should be kept under 30 cmH2O. The plateau pressure indicates the pressure at the alveoli.

13. In general, we should aim for a lung protective ventilation strategy for most of our intubated patients. What are some specific scenarios that may necessitate a different ventilation strategy? 

• Answer

  Patients who require a high minute ventilation to compensate for a severe metabolic acidosis such as salicylate poisoning or DKA.

14. You intubate a male patient with severe COVID pneumonia. They weigh 100kg and their height is 6’0”. What should you set your initial tidal volume at? 

• Answer

  We should set our tidal volume between 6-8cc/kg of IDEAL BODY WEIGHT. This is based on the patient’s height. You can usually use 6cc/kg and increase if necessary to ventilate them while keeping your volumes within the 6-8cc/kg range. This patient should have a tidal volume of approximately 470cc. IBW is 78kg x 6cc/kg = 470cc.

  Use this calculator: https://www.mdcalc.com/calc/3928/endotracheal-tube-ett-depth-tidal-volume-calculator