@chenxzhe on GrepMed

For my UME micro course, I made a figure that captures this terminology and lets learners compare/contrast spectra of activity visually. Let’s start with a horizontal bar that represents the spectrum of clinically important bacteria. We will represent antibiotics above that spectrum with another horizontal bar. If you shined a light from above the antibiotic, it would cast a shadow on that part of the spectrum – you might say it ‘covers’ that part of the spectrum. Narrow spectrum antibiotics cover only a sliver of the spectrum. We ‘expand’ or ‘broaden’ this coverage by selecting a ‘broad spectrum’ antibiotic. I’ve drawn the broad spectrum abx above the narrow spectrum abx to illustrate the concept of “escalation” and “de-escalation”. Let’s add names to the spectrum. On the left is Gram pos and on the right is Gram neg. I’ve also dropped 2 vertical lines – Abx A covers ONLY Gram pos, Abx C covers ONLY Gram neg, and Abx B covers a bit of both. Ideally, we could arrange all the clinically important organisms in a way that allowed us to depict every abx as a continuous horizontal bar – alas, this is not possible, and thus most abx have “holes” in their coverage! Let’s take it a step further and put actual organism names on the spectrum – this lets us compare/contrast important drug classes with granularity. For example, here’s the Gram pos part of the spectrum filled in with the penicillins and cephalosporins. Here’s the Gram neg end of the spectrum comparing some common beta lactam drugs. We can combine these two ends into 1 continuous spectrum. I also add anaerobes as the bridge between the two, and place intracellular organisms (like Legionella and Mycoplasma) on one end. In the next tweet will be the composite figure with all the commonly encountered abx! In this final figure, abx are divided by beta lactam and non beta lactam. Since we know that in vitro activity does not equal clinical use, I’ve color coded the abx bars – green means active and preferred, dark blue means active, and light blue means unreliably active. Dr. Varun Phadke @VarunPhadke2 #antibiotics #coverage #antibiogram #pharmacology #management #spectrum #table #sensitivities

CNS Ring-Enhancing Lesions - Differential Diagnosis Framework Ring Completeness • Incomplete: Demyelinating Disease • Complete (MAGIC): - Malignancy / Metastasis - Autoimmune - Glioblastoma - Infection / Infarct - Contusion By Valeria Roldán @valeroldan23 #CNS #Ring #Enhancing #Lesions #Differential #Diagnosis #neurology #neuroradiology

Assessment of Chest Tube Drains Stepwise assessment of Chest Tube Function TUBE POSITIONING • Look at the CXR: is the chest tube correctly positioned to drain air/fluid? Are all six of the side holes within the chest cavity? Has it moved since a prior CXR? • If a chest tube is mal-positioned it may need to be removed/replaced. CHEST TUBE OUTPUT • How much fluid output has there been in the last 24 hours? Check the DRAINAGE area of the chest drain. • Generally, it is reasonable to remove a chest tube if the output is <200 ml/day. • If a tube stops draining, fibrinolytics can be used to clear obstructions. TIDALING (RESPIRATORY VARIATION) • Tidaling indicates that the chest drain is within the pleura and transducing the pleural pressures. Look for movement of the indicator ball in the chest drain. Also look for cyclic movement of fluid in dependent loops of tubing. • You can temporarily disconnect suction (bend the suction tubing to occlude it) to make it easier to evaluate tidaling. AIR LEAK • Air leak is the presence of bubbles in the WATER SEAL chamber indicating that air is present within the chest (or a leak is present in the drainage system). • Intermittent air leak occurring with the respiratory cycle (typically at end inspiration) indicates an injury to the lung or airways. Have the patient cough to see if air leak occurs with higher pressures. • Continuous air leak — throughout the respiratory cycle suggests either a large injury to lung or airways or a leak in the tubing. SUCTION • Is the drain connected to suction? How much suction is applied? Be cautious about applying suction to large effusions as rapid drainage can precipitate re-expansion pulmonary edema. CHEST TUBE SIZING & POSITIONING Tubes sized by internal diameter (1 Fr = 0.3 mm). Recommended size varies by indication: • 14-22 Fr stable pneumothorax • 24-28 Fr tension pneumothorax • 28-32 Fr hemothorax/empyema • Smaller pigtail drains placed by Seldinger technique may have equivalent outcomes. Ideal direction where tube is placed: • For air -> anterior superiorly • For fluid -> posterior inferior WEANING A CHEST TUBE • Generally, chest tubes are initially placed on suction. This facilitates air/fluid removal from the thorax. • Upon resolution of the pneumothorax or drainage of an effusion, suction can be discontinued (this is called "being on water sear') • Clamping a chest tube simulates removal. Though usually unnecessary, this is done prior to removal to ensure a pneumothorax does not recur. This can be useful if considering removing a chest tube while on positive pressure ventilation. - Dr. Nick Mark MD @nickmmark #ChestTube #Drains #Diagnosis #Assessment #Pulmonary

Enteral Nutrition - ICU One Pager • When to start enteral feeds • When NOT to start enteral feeds • Enteric feed formulas • Calculating Caloric Needs • Gastric Residuals • Feeding Tubes: Nasal, Gastric, Post-pyloric, Jejunal by Nick Mark MD @nickmmark #Enteral #Nutrition #criticalcare #icu #pharmacology #diagnosis #management

Giant Cell (Temporal) Arteritis: Clinical findings and Complications Signs/Symptoms: - Headache (usually constant, superimposed by waves of pain corresponding to pulsations of blood) - Scalp painful to palpation - Temporal artery tender, nodular, may be pulsatile - Masseter muscle pain when chewing claudication) - Vision loss (mono- or binocular) - Can lead to blindness! - Diplopia (seeing double) - Stroke or TIA-like symptoms (weakness, aphasia, dysarthria, etc) - Papillary Edema, Flame Hemorrhages #GiantCell #Temporal #Arteritis #Complications #Signs #Symptoms #diagnosis #Vasculitis

Giant Cell (Temporal) Arteritis: Pathogenesis and investigations Risk Factors: - Unclear environmental triggers (may be viral, not proven) - Genetic abnormalities (i.e. HLA-DR4 mutation) that alter inflammatory cytokine expression - Age: GCA is almost never seen in patients < 50 yrs old; F>M Signs/Symptoms: - Fever - High serum CRP. ESR - Thrombocytosis - Normocytic Anemia - Giant cells seen on biopsy - Vessels will be enlarged, usually painful to palpation - Vasculitic skin lesions - Muscle-soreness (associated with Polymyalgia Rheumatica) - Focal neurological findings #GiantCell #Temporal #Arteritis #Pathophysiology #Diagnosis #Signs #Symptoms #Vasculitis

Classic signs of arteritic anterior ischemic optic neuropathy or giant cell arteritis are mild arterial narrowing and chalky white disc swelling in right and left eyes. (National Library of Medicine: Korean Journal of Ophthalmology) #AAION #anterior #ischemic #optic #neuropathy #giant #cell #arteritis #photo #disc #nerve #Ophthalmology

Giant Cell (Temporal) Arteritis Dr. Ann Marie Kumfer @AnnKumfer #GiantCell #Temporal #Arteritis #Diagnosis #Management #GCA #rheumatology

Polyarteritis Nodosa (PAN): Pathogenesis and Clinical Findings Medical Comorbidities Malignancies (most commonly hairy-cell leukemia) Immunogenetic Predisposition: patient is genetically predisposed to a dysregulated immune response Environmental triggers - Infectious/viral agents (commonly Hepatitis B) - Postulate 1 - Viral antigen-antibody complexes deposit in vasculature, causing lesions and activating cellular inflammatory response - Postulate 2 - Viral replication causes direct injury to vascular endothelial cells - Palpable or necrotic purpura - Malignant Hypertension - Renal Insufficiency - Myocardial ischemia - Heart failure - Diffuse myalgias - Orchitis: Testicular pain, erythema and/or swelling - GI Manifestations: Non-specific abdo pain, GI hemorrhage, Small intestine perforation - Peripheral sensory changes: Distal mononeuropathy multiplex #PAN #PolyarteritisNodosa #Pathophysiology #Diagnosis #Signs #Symptoms #Vasculitis

Diagnosis and management of Polyarteritis Nodosa (PAN) Chapel Hill 2012 definition: Necrotizing vasculitis ofmedium or small arteries without glomerulonephritis or vasculitis in arterioles, capillaries, or venules, and not associated with ANCA FFS 1996 Prognostic Score - Proteinuria >1 g/d - Creatinine >140 umol/L - GI tract involvement - Cardiomyopathy - CNS involvement French Vasculitis Study Group - Dr. Benjamin Terrier @ https://twitter.com/TerrierBen #PAN #PolyarteritisNodosa #Rheumatology #Diagnosis #Management #Vasculitis #Differential