REBEL Core Cast 138.0: A Simple Bedside Approach to Shock

Shock represents a critical supply-demand mismatch that, if left unaddressed, leads to irreversible organ damage. Effective bedside assessment begins by distinguishing between compensated and decompensated states using the "4Ls" mnemonic: mental status (lucid), extremity perfusion (limbs), urine output (leak), and serum lactate levels. Hemodynamic evaluation hinges on analyzing blood pressure components, specifically pulse pressure. A narrow pulse pressure indicates cold shock, typically stemming from cardiogenic, hypovolemic, or obstructive causes like tension pneumothorax, tamponade, or pulmonary embolism. Conversely, a wide pulse pressure signals distributive shock, most commonly sepsis, though clinicians must also consider neurogenic, anaphylactic, adrenal crisis, and hepatic failure. By integrating these physical findings with physiological principles—specifically the determinants of stroke volume—clinicians can rapidly narrow their differential diagnosis and guide targeted resuscitation strategies for the critically ill.