Questions of the Week for 2/13/2024

Author: Christian Gerhart

Q: You are evaluating a patient who had an unknown chemical splashed in their eye. The initial ocular pH is 5.1. You administer ocular irrigation with a Morgan Lens for 30 minutes. On recheck their ocular pH is 5.2. You irrigate for an additional 30 minutes but again have no significant change in pH. What could be limiting your ability to decontaminate their eye?

  • In some cases, the patient may have particulate matter on the underside of the eyelid. Be sure to evert the lid to be sure there is no evidence of retained particulate matter that could continue to damage the eye despite irrigation. The ocular pH should be measured at the fornix BEFORE installation of local anesthetic (acidic pH of anesthetic can alter ocular pH). Either sterile water or isotonic saline can be used. For situations where particulate matter is found or suspected, manual irrigation may be more effective. Removal of particulate matter can be performed with moist cotton swab if necessary. A normal ocular pH is 6.5 to 7.5. Once a normal ocular pH is achieved it should be remeasured 30 minutes later to ensure no intraocular ion leakage which can cause a delayed ocular pH change.

Q: You are taking care of a young male who works as a welder. He presents to the ED on Monday evening with chills, cough and myalgias. He reports having similar symptoms at the start of the work week the past few weeks. What diagnosis should be considered?

  • Metal fume fever. This disease is most commonly seen in welders and is caused by zinc oxide gas inhalation. Generally, symptoms are worst towards the beginning of the week and diminish towards the end of the week as workers develop tolerance to the toxin. The disease is typically self-limited with only supportive care needed for otherwise healthy individuals, though patients with significant cardiopulmonary comorbidities may require admission or oxygen support if symptoms are severe. Cadmium, which can be found in a number of metals, can cause a more severe pneumonitis leading to respiratory failure and should be considered if symptoms are more severe.

Q: You have a patient who presents with burns from hydrofluoric acid. What is the most common cause of death in these patients?

  • Cardiac dysrhythmias. Hydrofluoric acid poisoning leads to hypocalcemia, hypomagnesemia and hyperkalemia. These electrolyte abnormalities often contribute to ventricular fibrillation. Aggressive electrolyte repletion, hyperkalemia treatment, and limitation of further dermal exposure should be pursued in these patients.

Q: When should an evaluation for blunt cardiac injury be obtained?

  • The guidelines published by the Eastern Association for the Surgery of Trauma (EAST) state that patients with “with any significant blunt trauma to the anterior chest should be screened”, but also state that there are no clear guidelines as to what specific injury patterns constitute “significant” and which warrant screening. Injury patterns that have been proposed to place patients at high risk for blunt cardiac injury (BCI) are sternal fractures, manubrial fractures, retrosternal hematomas, flail chest from rib fractures, pulmonary contusions, and aortic injuries. The data on which injury patterns predict BCI is not robust. Other authors propose utilizing a screening process based on the presence of chest pain, hemodynamic instability not explained by hemorrhage or the presence of any dysrhythmia rather than a specific injury pattern. The EAST guidelines do recommend screening with EGK and troponin for cases of suspected BCI as EKG alone is insufficient to rule out BCI.

Q: When should an evaluation for blunt cerebrovascular injury (BCVI) be obtained?

  • There are various guidelines for screening trauma patients for BCVI. Our institution has a publicly searchable guideline, which is attached. The Denver criteria and Memphis criteria are the most commonly referenced screening criteria. It is recommended that any trauma patient with a focal neurological deficit that is new or presumed new from their baseline should undergo a CTA of the head and neck. There are a number of other high-risk injuries for which imaging should be considered even if the patient does not have active neurological symptoms as they may have delayed onset of symptoms due to an intimal injury that can increase in size over hours to days. Treatment generally consists of neurosurgery (intracranial carotid or vertebral artery injury) or vascular (extracranial carotid injury) consultation and consideration of antiplatelet therapy or anticoagulation if not otherwise contraindicated.

References

  1. Ball NS, Knable BM, Relich TA, et al. Xylazine poisoning: a systematic review. Clin Toxicol (Phila). 2022;60(8):892-901. doi:10.1080/15563650.2022.2063135

  2. Greenberg MI, Vearrier D. Metal fume fever and polymer fume fever. Clin Toxicol (Phila). 2015;53(4):195-203. doi:10.3109/15563650.2015.1013548

  3. Malaguarnera M, Drago F, Malaguarnera G, et al. Metal fume fever. Lancet. 2013;381(9885):2298. doi:10.1016/S0140-6736(13)60689-3

  4. Seidal K, Jörgensen N, Elinder CG, Sjögren B, Vahter M. Fatal cadmium-induced pneumonitis. Scand J Work Environ Health. 1993;19(6):429-431. doi:10.5271/sjweh.1450

  5. Prasad A, Ibrahim H, Mortimore K, Vandabona R. Critical care management of hydrofluoric acid burns with a negative outcome. BMJ Case Rep. 2021;14(6):e242187. Published 2021 Jun 23. doi:10.1136/bcr-2021-242187

  6. Chen RJ, O'Malley RN, Salzman M. Updates on the Evaluation and Management of Caustic Exposures. Emerg Med Clin North Am. 2022;40(2):343-364. doi:10.1016/j.emc.2022.01.013

  7. Su MK. Hydrofluoric Acid and Fluorides. In: Nelson LS, Howland M, Lewin NA, Smith SW, Goldfrank LR, Hoffman RS. eds. Goldfrank's Toxicologic Emergencies, 11e. McGraw-Hill Education; 2019. Accessed February 23, 2024.

  8. Clancy K, Velopulos C, Bilaniuk JW, et al. Screening for blunt cardiac injury: an Eastern Association for the Surgery of Trauma practice management guideline. J Trauma Acute Care Surg. 2012;73(5 Suppl 4):S301-S306. doi:10.1097/TA.0b013e318270193a

  9. Bellister SA, Dennis BM, Guillamondegui OD. Blunt and Penetrating Cardiac Trauma. Surg Clin North Am. 2017;97(5):1065-1076. doi:10.1016/j.suc.2017.06.012

  10. Kim DY, Biffl W, Bokhari F, et al. Evaluation and management of blunt cerebrovascular injury: A practice management guideline from the Eastern Association for the Surgery of Trauma [published correction appears in J Trauma Acute Care Surg. 2020 Aug;89(2):420]. J Trauma Acute Care Surg. 2020;88(6):875-887. doi:10.1097/TA.0000000000002668

Washington University Emergency MedicineComment