A 48-year-old man presents with cough and fever, and a nasopharyngeal swab confirms influenza A. He begins treatment with oseltamivir but returns to the ED within 24 hours with high-grade fever, multifocal lung opacities on chest x-ray, and respiratory failure necessitating intubation and ICU admission. Blood cultures and bronchoalveolar lavage (BAL) reveal methicillin-resistant Staphylococcus aureus (MRSA). After receiving a 2-liter crystalloid bolus and appropriate antibiotics, he develops progressive hypotension. A central venous catheter (CVC) is inserted via the right internal jugular vein. His vital signs show mean arterial pressure (MAP) at 45 mm Hg, central venous pressure (CVP) at 11 mm Hg, central venous oxygen saturation (ScVO2) at 89%, arterial lactate at 10.2 mmol/L, and urine output of 10 cc/hr over the last 4 hours.
Right Answer:A. The next best option is to initiate norepinephrine and perform a passive leg raise (PLR) to assess whether he is likely to respond to additional fluids. This statement is accurate. In cases of septic shock, norepinephrine is the preferred initial treatment due to its effectiveness in raising blood pressure while causing fewer tachyarrhythmias compared to dopamine. Performing a Passive Leg Raise (PLR) can help assess fluid responsiveness and guide further fluid administration. This dynamic assessment is more dependable than static measures such as CVP or ScVO2.
Clinical Pearls: Passive Leg Raising (PLR) Test: Description: PThe PLR test involves moving the patient from a semi-recumbent position to a position where the legs are passively raised to 45 degrees. This manoeuvre increases venous return to the heart, mimicking a fluid challenge without administering fluids. Steps: 1. Baseline Measurements: The patient starts in a semi-recumbent position, and baseline hemodynamic measurements (such as blood pressure, and cardiac output) are taken. 2. Leg Raise: The patient’s legs are passively raised to 45 degrees while the upper body is laid flat. This position change increases venous return, akin to an "autotransfusion" of approximately 300 mL of blood. 3. Monitor Response: Hemodynamic parameters are monitored to assess the increase in stroke volume or cardiac output, indicating fluid responsiveness. Benefits: ● Non-invasive: No need for actual fluid administration. ● Reversible: Hemodynamic effects are rapidly reversible, avoiding fluid overload risks. ● Predictive Value: Helps determine if a patient will benefit from further fluid resuscitation. Limitations: ● Not Suitable for All Patients: Less reliable in patients with severe hypovolemia or high intra-abdominal pressure. ● Requires Monitoring: Accurate assessment requires continuous cardiac output monitoring. Figure 1. Technique of performing PLR
Wrong Answer: The next best option is to initiate dopamine. Dopamine is not preferred over norepinephrine due to its association with higher rates of tachyarrhythmias and potentially worse outcomes in septic shock patients. Therefore, this option is incorrect.
Wrong Answer: C: The next best option is to continue to administer IV fluids until CVP is ≥12 cm H2O. This is an incorrect statement. Relying solely on CVP to guide fluid administration is not recommended. Studies have shown no benefit and potential harm from over-resuscitation. Dynamic measures like PLR are preferred to assess fluid responsiveness.
Wrong Answer:D.Because of the dangers associated with volume overload, the patient should not have been treated with a 30 cc/kg fluid bolus and should receive no further fluids. This is incorrect statement. Initial fluid resuscitation with 30 ml/kg is recommended for septic shock, but further fluid administration should be guided by dynamic hemodynamic monitoring. Complete avoidance of additional fluids without assessing responsiveness is not appropriate.
Wrong Answer:E. Because the ScVO2 is >70%, oxygen delivery to his tissues is adequate and therefore no additional treatment is warranted.This is incorrect statement. An ScVO2 >70% does not necessarily indicate adequate tissue oxygenation, especially when other signs of poor perfusion (high lactate, low urine output) are present. High ScVO2 can indicate impaired oxygen utilization by tissues, necessitating further intervention.
