From the Guidelines
The best way to follow a patient with septic shock in the ICU is option C: Base deficit and lactic acid level. While all the listed parameters are important in monitoring critically ill patients, serial lactate measurements and base deficit provide the most specific information about tissue perfusion and the effectiveness of resuscitation efforts in septic shock. Elevated lactate levels indicate tissue hypoperfusion and anaerobic metabolism, while base deficit reflects metabolic acidosis resulting from shock. Normalization of these values correlates with improved outcomes and suggests successful treatment. The Surviving Sepsis Campaign guidelines recommend repeated lactate measurements to guide resuscitation 1. Although pulse rate, oxygen saturation, and urine output are valuable vital signs to monitor, they can be influenced by many factors beyond shock status and may not directly reflect tissue perfusion at the cellular level. For comprehensive monitoring, clinicians should track lactate clearance (aiming for >10-20% reduction every 2-4 hours), along with other parameters including mean arterial pressure (targeting >65 mmHg) 1, central venous pressure, and clinical signs of improved perfusion such as capillary refill and mental status.
Some key points to consider when monitoring a patient with septic shock include:
- Frequent reassessment of hemodynamic status to guide additional fluid administration 1
- Use of dynamic over static variables to predict fluid responsiveness, when available 1
- Targeting a mean arterial pressure of 65 mmHg in patients with septic shock requiring vasopressors 1
- Guiding resuscitation to normalize lactate in patients with elevated lactate levels as a marker of tissue hypoperfusion 1
It's also important to note that advanced hemodynamic variables, such as cardiac output/cardiac index, systemic vascular resistance, or central venous oxygen saturation, can be useful in guiding resuscitation when available 1. However, the most recent and highest quality study 1 supports the use of lactate measurements and base deficit as the primary markers for monitoring tissue perfusion and the effectiveness of resuscitation efforts in septic shock.
From the Research
Monitoring Septic Shock
To monitor the status of a patient with septic shock, several parameters can be used, including:
- Pulse rate
- Oxygen saturation
- Base deficit and lactic acid level
- Urine output
Parameters for Monitoring
These parameters are crucial in assessing the patient's response to treatment and guiding further management. According to 2, markers of tissue perfusion, such as central venous oxygen saturation and lactate, can be used to characterize tissue hypoperfusion and guide haemodynamic optimization.
Lactate and Central Venous Oxygen Saturation
The combination of lactate and central venous oxygen saturation (ScvO2) can be used to predict mortality in patients with septic shock, as shown in 3. A study by 4 found that using blood lactic acid concentration as a treatment guide target can improve resuscitation results and reduce mortality in septic shock patients.
Fluid Resuscitation
Fluid resuscitation guided by lactate clearance rate and ScvO2 can be effective in patients with septic shock, as demonstrated in 5. This approach can lead to improved outcomes, including reduced 28-day mortality and shorter lengths of stay in the intensive care unit.
Peripheral Perfusion Markers
Recent evidence, such as 6, suggests that peripheral perfusion markers, including capillary refill time, may be useful in guiding resuscitative interventions and avoiding fluid overload in septic shock patients. A multimodal approach to assessing perfusion status can aid clinicians in making informed decisions about patient care.