Annals of B Pod: Quick Hits Corner
/ETHICS CORNER: END OF LIFE CARE IN TRANSPLANT RECIPIENTS
Image demonstrating the nuanced end of life care in patients with liver transplantation. Illustration by Olivia Gobble, MD.
Some liver transplantation centers require either implicitly, or explicitly, that in order to be considered eligible for a liver transplant, they must maintain a “full code” status and suggest that having a DNRCCA or other code status is antithetical to / inconsistent with the wish to receive an organ and for life prolongation. This full code concept is not a UNOS mandate or requirement.
However – consider this clinical scenario. Imagine a patient with NASH cirrhosis with recurrent GI bleeds, hepatic encephalopathy (HE), poor quality of life – if they were to have cardiac arrest, and get a pulse back, would they want to live with the post-arrest complications, pain, etc.? Why could they not maintain “DNRCCA” for this case to protect the potential for unwanted interventions, pain, and life prolongation in a situation they may never want to be alive in? One paper looked at palliative care involvement in transplantation centers, and 33/35 do not involve palliative care in the preoperative period. One survey (~80 some providers) found that 40% bring up goals of care conversations when discussing transplantation.
All of this being said, this is a very nuanced topic, and unique in each. This is a very nuanced conversation and unique in each subtype of organ transplantation. Every transplant surgeons is highly invested in the care and wellbeing of their patients. At the end of the day, each of us aims to provide the best care for our patients.
MURPHY'S CASE: WHAT CAN GO WRONG, WILL GO WRONG
Dr. Murphy is a rather unfortunate EM doctor at Enter-at-Your-Own Risk-And-May-Leave-With-One-Missing-Digit OSH. He has a unique talent of creating more problems for the patients he treats; which is a great deal for your problem-solving and a bad deal for him and his medico-legal team.
A 22-year-old, 60kg man presents to the ED for “sore throat”. He appears uncomfortable, is febrile to 102F, and has large left-sided tonsillar pillar fullness and fluctuance. You prep him for an incision and drainage and atomize 30mL of 4% lidocaine into the oropharynx and inject some for good measure. He becomes drowsy, and starts pulling at the sheets as you notice his heart rate increase to the 120s. He subsequently falls backward onto the flat stretcher and seizes. Dr. Murphy scuttles over to the door and asks for Ativan, and calls pharmacy to STAT order a medication that is milky white in appearance…
Close call. The medication is infused, and patient avoids bradycardia and the adverse effect of cardiovascular collapse. He regains consciousness. You still have not drained that pesky peritonsillar abscess... Luckily, the patient brought Orajel, asks to spread it in his mouth to numb it up. You tell him “no”. However, after you emerge from a snapping-turtle-induced digital amputation three rooms over, you return to the patient and find an empty bottle of Orajel next to him. He is dusky, swaying in bed, confused, with an SPO2 of 85% blinking on the monitor.
After many years of waiting to order this medication, you finally hit the “sign” button with enthusiasm while placing the patient on flush flow NRB – with no change in the oxygen saturation. Your VBG analyzer is down. However, the ABG one is not. You send an ABG and it shows a PaO2 of 324. Does this make sense with an O2 sat of 85%?
After this treatment, the patient recovers, and promptly leaves AMA.
Answers Below!
THE UNFAIR CPC
Illustration by Lauren gillespie, md
A forty-year-old woman presents to your ED at the ripe hour of 1am for “rash”. She is otherwise healthy, is currently unemployed, and is currently undomiciled. No allergies. She tells you it started around her mouth about 3 weeks ago, and progressed to involve her neck and hands. She has been trying to stay in the shade while outside in the summer heat as the rash worsens with sun exposure.
Review of Systems
+: diarrhea, unintentional weight loss.
– : fevers, vomiting, dyspnea, chest pain, hemoptysis, recent travel, dysuria, arthralgias, myalgias
Medications: None
Social History: Denies alcohol, tobacco or recreational drug usage Allergies: No known medical allergies
Surgical History: None
Physical Exam
Skin: Exudative coalescing plaques along the collar line with similar lesions around the mouth and sun-exposed dorsal regions of both hands.
GI: Mild diffuse abdominal tenderness without masses or peritoneal signs.
Neuro: Oriented to person, place, but not time; speech is fluent and linear. Unable to name the recent holiday (4th of July).
Labs
CBC: unremarkable
BMP: Na+ 131, HCO3- 17, AG nml, K+ of 3.0, Mg2+ 1.1 HCG: negative
Hepatic: unremarkable
Urinalysis: unremarkable
And then, a test was ordered...
Hint: This test does not come back in real time, and you have probably never ordered it... (if you do, we want to hear about it!)
BONUS if you can name the classic finding for the neck picture...
Answer will be revealed on Twitter/X! @TamingTheSRU
DR MURPHY: REVISITING NEAR CALAMITY
Part 1: This was a can’t-stop-looking wreck of a case of local anesthetic systemic toxicity (LAST), which was treated with Intralipid (fun fact: formal recommendations say that you can NOT use propofol, despite its lipid properties, as a replacement).
Intralipid works less as a “lipid sink” (i.e just binds the toxin as a separate intravascular “compartment”) and more as an active scavenger to pull the anesthetic toxin away from perfusion-rich vascular beds (ex. brain, heart, etc). In LAST, the presentation can be variable, but most frequently starts with CNS symptoms that the patient can tell you about – anxiety, metallic taste, psychiatric symptoms– then progresses to obtundation, seizures, cardiac arrhythmias, cardiovascular collapse, and even death.
The maximum 4% lidocaine dose by volume for this patient should have been 7.5mL – a bit of an overshoot (was given ~30mL; max should be ~5mg/kg which → 300mg total max dose/40mg per mL in 4% > 7.5mL). Another safety check is to use the Safe Local app – it’s free and allows you to pick your anesthetic and comorbidities, and calculates out max dose/kg. If these patients do progress to death, they are excellent ECLS (extracorporeal life support) candidates. For seizures, benzodiazepines remain first line in addition to treating the LAST.
Part 2: Our unfortunate patient uses Orajel, which contains benzocaine...which is a not-uncommon cause of methemoglobinemia! The ferrous/good/reduced/Fe2+ state is converted to ferric/bad/ oxidized/Fe3+ state, which is unable to accept oxygen for transport (HbFe3+OH = methemoglobin(MetHb)).
Symptoms are a result of hypoxia. Clinically, patients won’t start to look dusky and cyanotic until they’re roughly above ~10% MetHb. The pulse oximetry correlation is a key clinical finding with cyanosis. A pulse oximetry reading of 85% doesn’t really cause cyanosis as profound as seen as in MetHb, but this is typically what the monitor will read – although know that it won’t decrease further (i.e., worsening “hypoxia” doesn’t correlate with increasing MetHb burden).
The PaO2 (unbound oxygen) is normal to high – but percentage of oxygenated Hb is NOT. Thus, your ABG will probably look hyperoxic. So, then, why is the patient still cyanotic and hypoxic if they are also hyperoxic? This leads back to the oxygen delivery equation: DO2 (delivery of O2) = CO x (1.39 x Hgb x SaO2 + (0.003 x PaO2))
Even if you hyperoxygenate to optimize PaO2 ... you’ll never surmount the relative impact of the Hgb saturation. Look at the numbers (0.003 x PaO2 versus SaO2x Hgb x 1.39).
Treatment? Methylene blue, which reduces Fe3+ > Fe2+. Too bad I didn’t give this patient a history of G6PD!
FROM UCEM RESIDENTS: WHAT I LOOKED UP LAST SHIFT
It is rare that we go by on a shift and don’t utilize our favorite reference resources to answer a question, whether about test characteristics of a lab or imaging examination, or how to treat conditions like autosomal-dominant and X linked recessive pseudo-pseudo-pseudo-hyperparathyroidism-with-concomitant-beryllium-pneumoconiosis (classically termed, “ADXLRPPPHCBP”, pronounced “ad-exel-rip-p-hic-bee-pee”).
This section is aimed at highlighting questions and/or additional unique clinical pearls that our colleagues had and learned from on shift. These topics came directly from current UCEM resi- dents, with occasional added evidence by the author.
Resident Submissions:
"Using Dermabond on the edges of a laceration on thin skin to increase tensile strength on sutures. "
"5-FU chemotherapy can, rarely, cause hyperammonemic encephalopathy; consider this in patients on outpatient 5-FU chemotherapy pumps with AMS. "
This seems to be associated with higher dose infusion of 5-FU, and is a diagnosis of exclusion. 5-FU functions as a “trojan horse” pyrimidine analog that, when incorporated into RNA and DNA, inhibits cell growth. Additionally, through its sneaky mechanisms, its active metabolite F-dUMP inhibits thymidylate synthetase, a required component for DNA production.
The connection to ammonia: High dose infusions of 5-FU→ production of fluoroacetate → inhibits the Krebs cycle → limits urea cycle activity secondary to inadequate ATP production and availability.
"To estimate TBSA, it is best to use a Lund and Browder chart (as opposed to rule of 9s, which causes overestimation)."
"I started a patient on naloxegol, which necessitated a discussion with pharmacy about his opioid-induced constipation meds."
Naloxegol: mu opioid receptor antagonist naloxone, that is conjugated with polyethylene glycol which prohibits crossing of the blood-brain-barrier (thus preserving the analgesic effects of opiate medications otherwise).
• "Causes of positive qualitative, negative quantitative serum hCG tests."
Okay, this is a weird one. Depending on the lab test/company, a quantitative is actually more sensitive than qualitative... this could be a whole analysis section. But the main things to know:
Sensitivity of each type of diagnostic test. The type of test DOES matter.
Common cutoff values for hCG positivity:
| Urine qualitative (hospital or home) | Serum qualitative | Serum quantitative |
|---|---|---|
| ~20-25 mIu/mL | ~6 mIu/mL | ~3-5mIu/mL |
2. Non-pregnancy causes of + hCG
| Malignancy | Trophoblastic-related | Non-malignant, ectopic hCG | Exogenous |
|---|---|---|---|
| Solid organ (lung, stom- ach, endometrial, and many others) and certain hematologic forms (ex. multiple myeloma) | Choriocarcinoma; germ cell tumor | Hydatidiform mole (mo- lar pregnancy) – nonin- vasive, but technically neoplastic | Assisted reproductive therapy, steroids, etc. |
3. Lab errors and cross reactivity
IgA deficiency, Rheumatoid factor +, or rarely, chronic renal failure
Heterophile antibodies (exposure to animal products → poorly specifgic antibodies that cross react with assay)
So, was this just a false serum positive, one of the roughly 1/10,000? If heterophile antibodies, both serum should be positive; yet, urine would be negative as the antibodies are typically filtered out at the level of the glomerulus... this remains a mystery.
AUTHORED BY Lauren gillespie, MD
Dr. Gillespie is a PGY-4 in Emergency Medicine at the University of Cincinnati
EDITING BY ryan lafollette, MD AND THE ANNALS OF B POD EDITORS
References
1. Olivera, A., Sanches, M. and Selores, M. (2011), Azathioprine-induced pellagra. The Journal of Dermatol- ogy, 38: 1035-1037.
2. Yi HJ, Hong KS, Moon N, Chung SS, Lee RA, Kim KH. Acute hyperammonemic encephalopathy after 5-fluorouracil based chemotherapy. Ann Surg Treat Res. 2016;90(3):179-182.
3. Oyatogun O, Sandhu M, Barata-Kirby S, Tuller E, Schust DJ. A rational diagnostic approach to the "phantom hCG" and other clinical scenarios in which a patient is thought to be pregnant but is not. Ther Adv Reprod Health. 2021;15:26334941211016412.
4. Betz D, Fane K. Human Chorionic Gonadotropin. [Updated 2023 Aug 14]. In: StatPearls [Internet]. Trea- sure Island (FL): StatPearls Publishing; 2023 Jan.
5. Braunstein GD. False-positive serum human chorionic gonadotropin results: causes, characteristics, and recognition. Am J Obstet Gynecol. 2002 Jul;187(1):217-24.
6. Larissa V. Furtado, Christopher M. Lehman, Catherine Thompson, David G. Grenache, Should the Quali- tative Serum Pregnancy Test Be Considered Obsolete?, American Journal of Clinical Pathology, Volume 137, Issue 2, February 2012, Pages 194–202.
7. Human Chorionic Gonadotropin (hCG), Beta-subunit, Qualitative. LabCorp. Updated January 2023. Accessed August 2023. https://www.labcorp.com/tests/004556/human-chorionic-gonadotropin-hcg-sub- unit-qualitative
8. Haninger-Vacariu, N., Herkner, H., Lorenz, M. et al. Exclusion of pregnancy in dialysis patients: diagnostic performance of human chorionic gonadotropin. BMC Nephrol 21, 70 (2020).
9. Longley, D., Harkin, D. & Johnston, P. 5-Fluorouracil: mechanisms of action and clinical strategies. Nat Rev Cancer 3, 330–338 (2003).
