Protamine is an intravenous protein used to reverse the blood thinner heparin. This medication was initially derived from salmon sperm but is now synthesized with recombinant DNA technology. Heparin (negatively charged) forms an ionic bond with protamine (positively charged) creating inactive complexes metabolized by the reticuloendothelial system. Protamine reactions are…
As an anesthesiologist and intensivist, the “can’t intubate, can’t ventilate” situation is one of my worst nightmares. Airway rescue procedures like needle cricothyrotomy are essential to know. This rescue technique can be utilized if more conventional airway techniques (e.g., mask ventilation, supraglottic airway, endotracheal intubation) fail. Remember, this is a…
Antithrombin III (AT) is a protease that disrupts coagulation by inactivating thrombin. Congenital AT deficiency can be a quantitative and/or qualitative issue. Fortunately, AT concentrates like Thrombate III (pooled from human plasma) can replenish deficits. As a cardiothoracic anesthesiologist, I routinely administer large amounts of heparin to potentiate AT activity.…
Endovascular aneurysm repair (EVAR) offers many patients a minimally invasive option to address vascular pathologies like aortic aneurysm. By deploying a fabric-covered stent within the aneurysm, blood is rerouted through this conduit thereby excluding the aneurysm sac and preventing further dilation of the aorta. An endoleak occurs when blood flow…
Here’s a transesophageal echo (TEE) of a subaortic membrane (encircled in yellow) causing left ventricular outflow tract (LVOT) obstruction. Also note the fluttering of the aortic valve (AoV) leaflets during systole, turbulent flow in the LVOT, and chordal systolic anterior motion (SAM) of the mitral valve (MV). Surgeons will resect…
Ogilvie’s syndrome is an acute, paralytic ileus of the colon without mechanical obstruction associated with massive right colon dilation. Symptoms can include abdominal distension/pain, constipation, and in more severe situations, leukocytosis with fevers. In line with Laplace’s Law (tension ~ intraluminal pressure * radius), since the cecum has the largest…
Fungal endocarditis (inflammation of the heart’s inner lining) is most commonly caused by Candida species and is associated with a high mortality rate. Risk factors include long-term antibiotic therapy (especially with indwelling central lines), immunosuppression, prosthetic heart material (valves, implantable devices, etc.), and IV drug use. Like bacterial endocarditis, patients can present…
Variable area flowmeters consist of a tapered, vertically-oriented tube with the smallest diameter at the base and largest at the top. As a result, the cross-sectional area of the tube changes based on height. In this example, a ball indicator sits at the base due to the downward force due…
Sodium is the primary cation (positive-charged ion) in the extracellular space. Therefore, dilutional hyponatremia can occur if free water is added to the extracellular space from fluid shifts and infusions. Let’s look at this basic metabolic profile. Glucose 751 mg/dL (critically high). Sodium 123 mEq/L (low). Hyponatremia is an expected…
Olanzapine (Zyprexa) is a second-generation (“atypical”) antipsychotic that can be administered as an oral disintegrating tablet (ODT) or intramuscular (IM) injection. Like most antipsychotics, olanzapine works by blocking postsynaptic dopamine (D2) and serotonin (5HT2) receptors in the central nervous system and is helpful in treating schizophrenia and bipolar disorder. Common…