Doxycycline is an oral and intravenous bacteriostatic tetracycline antibiotic which binds to the 30S bacterial ribosomal subunit rendering protein synthesis ineffective. This class of antibiotics has a broad range encompassing some coverage for MRSA, gram negatives, and atypical organisms. Among these are early Lyme disease, vibrio, brucellosis, Q fever, anthrax,…
The P/F ratio is a simple way to assess the severity of hypoxemia. It’s the ratio of the PaO2 (arterial oxygen partial pressure obtained from an arterial blood gas) to the FiO2 (fraction of inspired oxygen expressed as a decimal). For example, a person breathing room air (21% oxygen, or…
Paracentesis is a procedure performed to remove new ascites in the context of fever, abdominal pain, worsening renal function, and acidosis usually in patients with decompensated cirrhosis. I use a standard paracentesis kit and a “Z-tracking” approach with my needle so the soft tissue and abdominal wall “seal off” the…
Left ventricular (LV) wall motion abnormalities (WMA) are associated with myocardial ischemia and can be generalized or regional. In this transgastric mid-papillary short-axis view of the LV, one sees a clear difference in how the inferior and lateral walls are contracting compared to the septal and anterior walls. Decreased inward…
Here’s a transesophageal echo (TEE) clip I’ve taken of an interesting congenital condition: transposition of the great arteries (TGA). Whereas the aorta (Ao) normally comes off the left ventricle (LV), in this case, it comes off a very hypertrophied right ventricle (RV). TGA comes in two variants. D-TGA has atrioventricular…
The Couinaud classification system divides the liver into eight functionally independent segments, each with a center consisting of a portal vein, hepatic artery branches, and bile duct drainage. The periphery of each segment is where vascular outflow occurs via the hepatic veins. The numbering system begins with the caudate lobe…
Post dural puncture headache (PDPH) is a potential complication following neuraxial procedures when the dura is punctured and entry into the subarachnoid space permits drainage of cerebrospinal fluid (CSF). In the case of lumbar punctures (LP) and lumbar drains, this is intentional to drain CSF and measure intraspinal pressure. In…
Superior vena cava (SVC) syndrome is characterized by facial plethora, upper body venous engorgement, chest pain, soft tissue swelling, dyspnea, and even neurologic changes. Anything that impairs SVC drainage by intrinsic obstruction (thrombosis, anatomic narrowing) or extrinsic compression (mediastinal masses, non-small cell lung cancer, non-Hodgkin’s lymphoma, etc.) can result in…
Epidural blood patches (EBP) are procedures used to treat post dural puncture headaches (PDPH) refractory to conservative therapies such as NSAIDs, caffeine, hydration, and steroids. As a cardiothoracic anesthesiologist, the most common time I’ll be called to perform an EBP is after a lumbar drain is placed to facilitate cerebrospinal…
Rifampin is the most commonly used oral/IV antibiotic among the rifamycins (rifabutin, rifapentine, etc.) Rifampin acts at the level of RNA transcription by inhibiting bacterial DNA-dependent RNA polymerase. This drug has excellent oral bioavailability and tends to concentrate intracellularly. Classically, rifampin is used in combination with medications like isoniazid to…