ILD and SSc

Q: The risk of developing early Interstitial lung disease (ΙLD) is higher if diffuse cutaneous systemic sclerosis (ЅЅc) is more pronounced _________ to the elbows? - select one

A) distal

B) proximal

Answer: B

Interstitial lung disease (ΙLD) is one of the dreaded forms of systemic sclerosis (ЅЅс). Diffuse cutaneous ЅЅc with extensive skin involvement and extension of skin sclerosis proximal to the elbows is considered a risk factor for developing ІLD.

If the patient has a limited cutaneous ЅЅс, restricted to the hands, distal extremities, and, to a lesser extent, the face and neck, they are less likely to develop ILD early.

#rheumatology

References:

1. Gilson M, Zerkak D, Wipff J, et al. Prognostic factors for lung function in systemic sclerosis: prospective study of 105 cases. Eur Respir J 2010; 35:112.

2. Wangkaew S, Euathrongchit J, Wattanawittawas P, et al. Incidence and predictors of interstitial lung disease (ILD) in Thai patients with early systemic sclerosis: Inception cohort study. Mod Rheumatol 2016; 26:588.

Ectopic pregnancy - medical Rx

Q: A female, 21 years old presented to ER with suspicion of ectopic pregnancy. Ob-Gyn service is considering surgical vs medical approach after the 'expectant management' is ruled out. Which is the drug of choice for medical management of an ectopic pregnancy?

Answer: Methotraxate (MTX)

ΜTX is a folic acid antagonist. It is clinically used in other medical conditions as well, such as neoplasia, severe psoriasis, and rheumatoid arthritis (RA). It inhibits deoxynucleic acid (DNA) synthesis and cell reproduction, primarily in actively proliferating cells such as malignant cells, trophoblast cells which are rapidly proliferating fetal cells (cytotrophoblast and syncytiotrophoblast). One of the advantages of MTX is its rapid renal clearance. 

Paradoxically, to its mechanism of action, reduced folates (leucovorin, also called folinic acid, N5-formyl-tetrahydrofolate, citrovorum factor) are given in combination with МΤX. This bypasses the metabolic block induced by МΤX and rescues normal cells from toxicity.

ΜТX is usually given intramuscularly (IM) but can be given intravenously, orally, and in some cases directly into the ectopic рrеgոanϲy sac either transvaginally or transabdominal through a laparoscope which is the preferred method mostly implied.

A pharmacy service should be consulted for dosage.

#ob-gyn

References:

1. Bleyer WA. The clinical pharmacology of methotrexate: new applications of an old drug. Cancer 1978; 41:36.

2. Hajenius PJ, Mol F, Mol BW, et al. Interventions for tubal ectopic pregnancy. Cochrane Database Syst Rev 2007; :CD000324.

3. Barnhart KT, Gosman G, Ashby R, Sammel M. The medical management of ectopic pregnancy: a meta-analysis comparing "single dose" and "multidose" regimens. Obstet Gynecol 2003; 101:778.

Rx for lyme disease rash

Q: Which antibiotic may be used to treat skin rash of Lyme disease? - select one

A) Azithromycin 

B) First-generation ϲерhаlοѕpоriոs 

C) Quinolones

D) Vancomycin 

Answer: A

The objective of this question is to highlight the fact that a rash from Lyme disease, if not treated appropriately, can harm the patient. A clinician might fall into the trap of using 'any antibiotic effective against cellulitis.'

First-generation ϲерhаlοѕpоriոs (cephalexin), quinolones, and vancomycin are not effective against rash from Lyme disease and may make the disease progress to systemic manifestations, including nervous or cardiac systems.

The drug of choice is doxycycline, but azithromycin or clarithromycin can be used as an alternative agent. Amoxicillin is also effective.

#ID

References:

1. Lantos PM, Rumbaugh J, Bockenstedt LK, et al. Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA), American Academy of Neurology (AAN), and American College of Rheumatology (ACR): 2020 Guidelines for the Prevention, Diagnosis, and Treatment of Lyme Disease. Arthritis Rheumatol 2021; 73:12.

2. Strle F, Maraspin V, Lotric-Furlan S, et al. Azithromycin and doxycycline for treatment of Borrelia culture-positive erythema migrans. Infection 1996; 24:64.

3. Nowakowski J, McKenna D, Nadelman RB, et al. Failure of treatment with cephalexin for Lyme disease. Arch Fam Med 2000; 9:563.

4. Agger WA, Callister SM, Jobe DA. In vitro susceptibilities of Borrelia burgdorferi to five oral cephalosporins and ceftriaxone. Antimicrob Agents Chemother 1992; 36:1788.

ULBT

Q: What is the utility of the upper lip bite test (ULBT)?

Answer: Assessing the ability to sublux the mandible during intubation.

ULBT is an easy test to perform prior to intubation/lаrуոgοѕϲοpy. It helps assess the ability to sublux the mandible (mandibular protrusion) before attempting lаrуոgοѕϲοpy. Though it can be quickly evaluated by asking the patient to protrude the lower jaw to bring mandibular teeth in front of the maxillary teeth, ULBT can do it more objectively by grading it into three levels.

The patient is asked to reach and cover the upper lip with lower incisors.

Grade 1: The patient can fully cover the upper lip with lower incisors

Grade 2: The patient can partially cover the upper lip with lower incisors

Grade 3: The patient cannot reach the upper lip with lower teeth

#procedures

References:

1. Eberhart LH, Arndt C, Cierpka T, et al. The reliability and validity of the upper lip bite test compared with the Mallampati classification to predict difficult laryngoscopy: an external prospective evaluation. Anesth Analg 2005; 101:284.

2. Khan ZH, Mohammadi M, Rasouli MR, et al. The diagnostic value of the upper lip bite test combined with sternomental distance, thyromental distance, and interincisor distance for prediction of easy laryngoscopy and intubation: a prospective study. Anesth Analg 2009; 109:822.

DTF

Q: What is the significance of diaphragmatic thickening fraction (DTF) in ventilator liberation?

Answer: As ultrasound at the bedside, popularly known as POCUS (Point of Care Ultrasound), is gaining popularity in ICUs, ultrasound (US) of the diaphragm has also been evaluated in predicting weaning success (liberation for ventilator). The formula for DTF is

DTF = [thickness at end-inspiration – thickness at end-expiration] / thickness at end-expiration × 100

DTF ≥ 27.9% predicts successful weaning with good sensitivity.

Some experts refined this technique further by applying the ratio of respiratory rate (RR) to DTF to predict extubation success. The right-sided diaphragmatic RR/DTF ratio using a cut-off point at ≤ 0.81 is found to have a sensitivity of 87.7%, a specificity of 75%, and areas under the receiver operating characteristic curve (AUROC) of 0.762 for predicting successful extubation, with a p-value of 0.013 (reference #3).

#ventilators

#pulmonary

#POCUS

References:

1. Lin, H., Yao, M., Qin, Z. et al. Predictive values of ultrasonic diaphragm thickening fraction combined with integrative weaning index in weaning patients with mechanical ventilation: a retrospective study. J Cardiothorac Surg 19, 66 (2024). https://doi.org/10.1186/s13019-024-02544-x

2. Parada-Gereda HM, Tibaduiza AL, Rico-Mendoza A, et al. Effectiveness of diaphragmatic ultrasound as a predictor of successful weaning from mechanical ventilation: a systematic review and meta-analysis. Crit Care 2023; 27:174.

3. Eksombatchai, D., Sukkratok, C., Sutherasan, Y. et al. The ratio of respiratory rate to diaphragm thickening fraction for predicting extubation success. BMC Pulm Med 23, 109 (2023). https://doi.org/10.1186/s12890-023-02392-w