Questions of the Week for 4/2/2024
Author: Christian Gerhart
Q: You have a patient who presents as a trauma with multiple facial lacerations. What areas of involvement would prompt ophthalmology consultation?
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Any concern for open globe or orbital compartment syndrome would prompt ophthalmology consultation. Involvement of the lid margin, concern for lacrimal canaliculus involvement or penetration into the deep structures with exposed orbital fat or ptosis (indicating injury to the levator mechanism) would be other reasons for ophthalmology consultation. It can be challenging to discern which patients have lacrimal canaliculus involvement. If there is concern, speaking with ophthalmology is advised as they may need to probe/test the duct to see if there is any injury and if there is then it usually requires operative repair.
Q: A patient presents with a complex ear laceration that requires repair. How should you anesthetize the ear?
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A ring/diamond block. The ear can be a challenging region for which to obtain adequate anesthesia, but the ring block is usually effective. This is performed using two injections sites (above/below ear), which should anesthetize the entire ear.
See more here:
lacerationrepair.com
https://www.youtube.com/watch?v=6ZiB_9eNpcA
Q: You have a patient who presents with jaw pain after being struck in the face. They have mild tenderness overlying the mandibular body on palpation but otherwise a normal examination. What bedside test can be used to assess for a mandibular fracture?
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The tongue blade test. This is a bedside exam technique where the patient is asked to bite down on a tongue depressor while the examiner applies a torsional force. If the patient is able to maintain their bite and the stick is breakable, it is unlikely they have a fracture since patients with a fracture will have severe pain and usually are not able to maintain their bite. This has been shown to have a sensitivity of approximately 85-100% in previous studies and can be particularly useful in pediatrics for sparing radiation. (1,2)
https://www.aliem.com/trick-of-trade-tongue-blade-is-as/
Q: You are caring for a patient in septic shock who was started on peripheral vasopressors but now requires a central line. She has thrombocytopenia attributed to hematologic malignancy and her platelets today are 19,000. She has not had any reported bleeding. Should you administer platelets prior to central line placement?
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This patient would probably benefit from platelet transfusion prior to central line placement if time allowed. It would also be advisable to select a more compressible site (such as the internal jugular instead of the subclavian) given her high risk of bleeding. The 2015 American Association of Blood Banks (AABB) Guidelines recommend platelet transfusion for patients undergoing central line placement. (4) This was more recently studied in a 2023 NEJM randomized controlled trial. (3) This was a noninferiority trial looking at patients with platelets of 10k-50k who needed non-crash, ultrasound-guided central lines. Patients were randomized to either receive a unit of platelets or to no treatment. They found that there was more bleeding in the group that did not receive a platelet transfusion and concluded that withholding of prophylactic platelet transfusion before central line placement was not noninferior. Interestingly, the internal jugular group did not have a statistically significant difference in bleeding complications among those who received platelet versus those who didn’t, whereas the femoral and subclavian line groups did. Importantly, it may not be advisable to place a subclavian line in a thrombocytopenic patient as the site is poorly compressible. Hematology patients seemed to benefit more than general ICU ward patients as did those with platelets less than 20k, thus this patient seems to fit into a subgroup that would benefit from platelet transfusion.
Q: What is the threshold platelet count for transfusion in the following scenarios?
- Asymptomatic, no active bleeding, no fever
- Patient with fever or critical illness
- Actively bleeding patient
- Patient with Acute Myeloid Leukemia
- Patient undergoing neuraxial/ophthalmologic surgery
- Patient undergoing non-neuraxial surgery or endoscopy
- Patient undergoing central line placement
- Patient undergoing lumbar puncture
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Much of this is based on expert opinion without much in the way to hard evidence. The numbers vary a bit between professional societies and different experts. However, these are what appear to be the generally suggested thresholds. These procedural thresholds are mainly based on elective procedures. The benefits may outweigh the risks for more emergent procedures.
- Asymptomatic, no active bleeding, no fever 5,000-10,000
- Patient with fever or critical illness 10,000
- Actively bleeding patient 50,000
- Patient with Acute Myeloid Leukemia 30,000
- Patient undergoing neuraxial/ophthalmologic surgery 100,000
- Patient undergoing non-neuraxial surgery or endoscopy 50,000
- Patient undergoing central line placement 20,000, see above question for more
- Patient undergoing lumbar puncture 50,000 (may be lower in immune thrombocytopenia or patients with hematologic malignancy)
References:
1) Alonso L, Purcell T. Accuracy of the tongue blade test in patients with suspected mandibular fracture. J Emerg Med. 1995;13(3):297-304.
2) Neiner J, Free R, Caldito G, Moore-Medlin T, Nathan CA. Tongue Blade Bite Test Predicts Mandible Fractures. Craniomaxillofac Trauma Reconstr. 2016;9(2):121-124. doi:10.1055/s-0035-1567812
3) van Baarle FLF, van de Weerdt EK, van der Velden WJFM, et al. Platelet Transfusion before CVC Placement in Patients with Thrombocytopenia. N Engl J Med. 2023;388(21):1956-1965. doi:10.1056/NEJMoa2214322
4) Kaufman RM, Djulbegovic B, Gernsheimer T, et al. Platelet transfusion: a clinical practice guideline from the AABB. Ann Intern Med. 2015;162(3):205-213. doi:10.7326/M14-1589
5) Vlaar AP, Oczkowski S, de Bruin S, et al. Transfusion strategies in non-bleeding critically ill adults: a clinical practice guideline from the European Society of Intensive Care Medicine. Intensive Care Med. 2020;46(4):673-696. doi:10.1007/s00134-019-05884-8
6) Yuan, S. (2024, April 17). Platelet transfusion: Indications, ordering, and associated risks. UpToDate. Retrieved May 15, 2024, from https://www-uptodate-com.beckerproxy.wustl.edu/contents/platelet-transfusion-indications-ordering-and-associated-risks?search=platelet%20transfusion&source=search_result&selectedTitle=1%7E150&usage_type=default&display_rank=1#H558384432
7) Stanworth SJ, Shah A. How I use platelet transfusions. Blood. 2022;140(18):1925-1936. doi:10.1182/blood.2022016558