POTD: Local Anesthetic Toxicity

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Max amounts of local anesthetic:

 For a 70 kilogram, that means 35 mls of 1% Lidocaine, 49 mls of !% Lidocaine w/ epi, etc.

 

Mechanism of toxicity; sodium channel blockade effects block cardiac myocyte function and electrophysiology, resulting in arrhythmias. Intravascular absorption of LA also may travel to the CNS, causing its neurologic effects.

 

Symptoms: a prodrome of perioral numbness, tinnitus, agitation, dysarthria, and confusion. Followed by possible seizures and coma.

 

Cardiovascularly,  patients initially present with hypertension and tachycardia, which progresses to bradycardia and hypotension. This eventually progresses to ventricular arrhythmias and asystole.

 

The majority of adverse events occur within 1 minute of injection, but some cases may more than 1 hour after injection.

 

Bupivicaine’s higher toxicity is linked to its higher lipophilicity.

Toxicity is more common in this with hepatic and renal dysfunction, and those with heart disease and heart failure are at increased risk, as are those at the extremes of age, and in the ED setting are  most common in peripherals nerve blocks

Prevention:

Always aspirate before injection of local anesthetic.

 Treatment:

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POTD: Anorectal symptoms in Men who have receptive-anal sex

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Approach:

Should begin with a thorough examination of the external anus, evaluating for any lesions, fissures, or hemorrhoids.

If any abnormalities are discovered, or if the patient is complaining of rectal pain, bleeding, or purulent or bloody discharge, anoscopy and digital rectal exam is recommended.

 

Lidocaine ointment and may be used to facilitate examination if the patient is experiencing a great deal of pain

 

Infectious Etiologies:

 

Infectious proctitis:

Most often caused by gonorrhea

Symptoms are rectal pain, bleeding, +- purulent discharge, and can be associated with urgency or feelings of constipation. The external anal exam is normal, but the digital exam is noteworthy for diffuse tenderness.

 

STI testing is done through anal swabs for chlamydia and gonorrhea. If a visible lesion is present, swabbing the lesion for HSV PCR is indicated.

 

Diffuse ulcerations, systemic symptoms (fevers, chills), and lymphadenopathy should raise your suspicion for lymphogranuloma venereum (LGV), which is caused by Chlamydia trachomatis serovars L1, L2, and L3, have been reported in MSM.

 

If any ulcerations are present, it should raise suspicion for syphilis, HSV, or LGV.

 

An anal pap test may also be taken as MSM are at an increased risk of HPV related disorders, including anal warts/anal cancer

LGV:

Infection caused by specifically Gonorrhea L1, L2, and L3. In the Western world, it is most commonly found in HIV positive men who have sex with men.

 

Its pathogenesis is as follows:

Stage 1: 3-21 days after exposure: a painless blister or sore develops at the site of infection; most commonly the rectum, genitals, or mouth. This is commonly unnoticed. This develops into groups of blisters and can become more diffuse, spreading throughout the body. In rectal infection, proctitis can develop.

 

Stage 2: At 10-30 days, inflamed and swollen lymph glands appear in the groin, armpit, or neck. Anal infection can cause painful ulcerations, discharge, and bleeding. Systemic symptoms of fever or rash may develop.

 

Stage 3: if untreated, LGV can become more severe, causing general swelling of the lymph glands, swelling of the genitals, and severe ulcerations of the genitals, causing lasting damage, fibrosis, strictures, fistulas, and deformity.

 

Testing: Testing for chlamydia in the ER will rule out LGV. Further speciated chlamydial testing generally takes weeks to perform, and are not of particular use.

 

Treatment:

 

For all MSM patients with proctitis, treatment should be initiated for gonorrhea and chlamydial infections, with Ceftriaxone 500 mg IM and doxycycline 100 mg orally BID for 7 days.

 

For patients with ulcers, HSV treatments hould be initiated with valacyclovir 1g orally twice a day for 7-10 days.

 

For patients in whom you suspect LGV, doxycycline therapy should be extended to 3 weeks.

Anal warts:

MSM are at a higher risk of anal warts secondary to HPV, as seen below.

Treatment:

Prescriptions of Podofilox or imiquimod, which are patient applied creams in the case of immune modulators, can be given to the patient. Follow up with colorectal surgery should be given.

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POTD: New anticoagulant reversal recommendations

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The American College of Gastroenterology and their corresponding Canadian group recently published a new guideline for the management of anticoagulants and antiplatelets during acute GI bleed.

 

Their recommendations in the setting of ACUTE GI BLEED are as follows:

 

·      For patients on warfarin, they suggest AGAINST giving FFP or Vitamin K; if needed, they suggest PCC compared with FFP. Their review of the data suggests PCC resulted in a quicker resolution of supratherapeutic INR, but no direct comparison of mortality or hemostasis, against FFP or even placebo. 

 

·      For patients on DOACs (Apixaban (Eliuquis)  Dabigatran (Pradaxa), Rivoraxaban (Xarelto)), they suggest AGAINST PCC administration; they suggest AGAINST direct reversal with idarucizumab in the case of Pradaxa, or andexanet alfa in the case of Eliquis or Xarelto. (Their is a paucity of data regarding their use and thrombotic potential. There appears to be a trend towards improvement of hemostasis, and they do open the door for conditional use in life threatening GI bleed where the DOAC has been taken within 24 hours. 

 

·      They suggest AGAINST platelet transfusions for those on platelet inhibitors. (data suggests harm and increased thrombotic events)  

 

·      For patients on ASA, they suggest AGAINST holding it; if it has been held, they suggest resumption on the day hemostasis has been endoscopically confirmed.

 

NOTABLY,  all of these recommendations are CONDITIONAL, with LOW TO VERY LOW CERTAINTIES of EVIDENCE.

 

The guidelines were developed by a working group from the ACG and GAC, including gastroenterologists, cardiologists, and hematologists, who attempted to make an evidenced based approach to these clinical questions, reviewing relevant literature and RCTs.

 

As an overall summation of the data, there is poor evidence that in ACUTE GI bleed, administration of reversal agents resulted in less bleeding, and have a risk of thromboembolic events. The cited RCTs are mostly with very small n-values (most less than 200), are often manufacturer funded, and mortality and outcomes based data is incredibly limited.  

 

This is obviously a very gross overview. A more detailed discussion can be found in their paper below: 

https://pubmed.ncbi.nlm.nih.gov/35368325/

 

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