How should fluid replacement volume be properly monitored in shock patients?

Proper monitoring of fluid replacement in shock patients requires ensuring adequate but not excessive fluid administration through methods such as urine output monitoring, vital signs observation, circulatory perfusion assessment, central venous pressure (CVP) monitoring, and dynamic adjustment of infusion rates. If sudden decrease in urine output, unstable blood pressure, or similar issues occur during monitoring, immediate medical attention is recommended.

1. Urine Output Monitoring: Record hourly urine output. Normal output should be maintained at more than 30 mL/h. Output below 20 mL/h suggests inadequate fluid resuscitation and may require increasing the fluid volume; excessively high urine output may indicate fluid overload, necessitating a slower infusion rate. Urine output provides a direct reflection of renal perfusion.

2. Vital Signs Observation: Continuously monitor blood pressure, heart rate, and respiration. Maintaining systolic blood pressure above 90 mmHg and a stable heart rate indicates appropriate fluid administration. Persistently low blood pressure with tachycardia may suggest insufficient fluid resuscitation requiring adjustment, while avoiding abrupt rises or drops in blood pressure.

3. Circulatory Perfusion Assessment: Observe skin and mucous membrane color and temperature. Warm, pink skin indicates good perfusion, whereas pale, cold, clammy skin may suggest inadequate fluid resuscitation, requiring increased fluid administration. Additionally, assess capillary refill time, which should normally be less than 2 seconds.

4. Central Venous Pressure Monitoring: Measured via a central venous catheter, the normal CVP range is 5–12 cmH₂O. A value below 5 cmH₂O indicates hypovolemia and may require faster fluid infusion; values exceeding 15 cmH₂O may indicate fluid overload, requiring reduced infusion rate to guide precise fluid management.

5. Dynamic Adjustment of Infusion Rate: Adjust infusion speed based on changes in monitoring parameters. Initial rapid fluid administration may be used to improve perfusion, followed by slowing the rate once parameters stabilize, to prevent pulmonary edema caused by excessive fluid in a short period and ensure fluid delivery matches the body's needs.

In daily care, provide the patient with a quiet and comfortable environment, maintain airway patency, assist with regular turning to prevent pressure ulcers, ensure warmth during fluid therapy, and monitor the patient’s level of consciousness, offering supportive assistance for medical monitoring.