HY lecture notes:
Tx for Pneumocystis jirovecii pneumonia (PJP) = TMP-SMX. However, add steroids when A-a gradient is >35, or pO2 <70 mm Hg.
New literature (2019) has suggested mortality rates improve when adding steroids in patients with pO2 <60 mm Hg.
The bottom line is that if a patient is in severe respiratory distress in the vignette and has PJP, AND they give you TMP-SMX + steroids as an option alongside standard TMP-SMX, the former is correct.
Zenker diverticulum (false diverticular outpouching of posterior esophageal wall) will present classically with halitosis (bad breath), regurgitating undigested food, and/or gurgling sound when drinking fluids.
Sometimes what they’ll do is give you an equivocal vignette and then show you a barium (or a gastrografin water soluble contrast) swallow where there’s an outpouching, and the answer is: “Cricopharyngeal muscle spasm.”
Increased oropharyngeal pressure is also a big risk factor for Zenker, as this is conducive for the herniation to occur. This can be seen in patients who have dysphagia, as this can lead to increased strain/force required by the patient to achieve swallowing. Tx is surgical.
Achalasia classically presents as dysphagia to both solids and liquids. Neurogenic causes present with dual dysphagia. Esophageal manometry (pressure studies) is best test to diagnose, but barium (or gastrografin) swallow is best next step.
If they give you both barium swallow and esophageal manometry as answers in someone with a vignette that might sound like achalasia, choose barium, not manometry, as the next best step.
Manometry will be the answer if they show you a radiographic image of a contrast swallow exhibiting the “bird’s beak” appearance:
Achalasia is often idiopathic but may also be due to Chagas disease (Typanosoma cruzi).
Treatment for achalasia is either medical therapy with nitrates or calcium channel blockers, or surgical with pneumatic dilatation or myotomy. The latter is more effective than balloon dilatation.
Dysphagia to solids that PROGRESSES to dysphagia to solids and liquids = esophageal cancer. This is especially the case in someone with big Hx of GERD (adenocarcinoma) or heavy smoking/drinking (squamous cell carcinoma).
It’s generally the answer on the USMLE to do an endoscopy in a patient who has history of GERD and new-onset dysphagia. We talked above about how contrast swallows are done first for suspected Zenker and achalasia, but if the patient has Hx of GERD, that changes everything and he or she needs an endoscopy. Equivocal vignettes that give you, e.g., a presentation that sounds similar to Zenker or achalasia, in a patient who is clearly a heavy smoker/drinker, the USMLE wants endoscopy for that too.
CREST syndrome is also known as limited systemic sclerosis. Systemic sclerosis can be either diffuse or limited.
Limited systemic sclerosis = CREST = scleroderma = anti-centromere Abs = less propensity for systemic phenomena such as renal involvement.
Diffuse = anti-topoisomerase (anti-scl70 Abs) = renal involvement.
Both can cause pulmonary fibrosis with restrictive lung disease –> normal or increased FEV1/FVC.
Pulmonary hypertension can result from the fibrosis, so if you get a vignette of CREST and they say what is this patient at increased risk for, the answer is pulmonary hypertension.
Pulmonary hypertension can cause cor pulmonale –> right-sided heart failure due to a pulmonary origin. That is, the cause cannot be left heart failure. Pulmonary capillary wedge pressure (PCWP) is normal in cor pulmonale because the left heart is fine. If PCWP is high, the Dx is not cor pulmonale.
PCWP is elevated in cardiogenic shock.
For CREST syndrome (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), you need to know LES tone and esophageal peristalsis are both decreased (both down arrows); this was on one of the retired Step 1 NBMEs.
CREST can also involve the intestines in a smaller fraction of patients. There’s a question on one of the surgery forms where they said a patient with CREST had a 12-cm cecum, and the answer was laparotomy because the Dx was toxic megacolon.
Tx Raynaud phenomenon with calcium channel blockers.
Most common cause of nephrotic syndrome in sickle cell is focal segmental glomerulosclerosis (FSGS). So protein in the urine + no blood = FSGS in sickle cell.
If this patient has ascites as a result of the nephrotic syndrome, this can lead to spontaneous bacterial peritonitis (SBP). Must diagnose with paracentesis (aspiration of peritoneal fluid). Don’t confuse with pericardiocentesis.
Do a gram stain of the peritoneal fluid. Also check for >250 white cells per high-power field.
SBP will be seen in three different vignettes: hepatic cirrhosis with ascites; someone who’s just undergone peritoneal dialysis; or someone with nephrotic syndrome. On one of the newer peds forms, a vignette gives an 8-year-old with nephrotic syndrome who has a diffusely tender abdomen + fluid wave + fever; answer = paracentesis. Tx SBP with ceftriaxone.
