1.Monitoring technology
(1) Routine monitoring
a. Blood pressure
Low cardiac output can sometimes be compensated for by maintaining normal blood pressure, and the determination of whether blood pressure is normal should be combined with the patient’s basal blood pressure. Patients with hemodynamic instability should have an arterial catheter in place to continuously monitor blood pressure and to facilitate monitoring of blood gas analysis.
b. Central venous pressure
Except in cases of severe hypovolemia, overload, or heart failure, absolute central venous pressure is usually not helpful in determining circulating volume and cardiac function. The correct approach is to combine changes in pressure after fluid shock with changes in other indicators (e.g., heart rate, blood pressure, urine output) and clinical signs (e.g., skin color, temperature, and perfusion) to make a comprehensive judgment.
c. Floating catheter
The floating catheter can improve the accuracy of diagnosis, and guide the rational application of vascular or sexual drugs and positive inotropic drugs. However, the impact on prognosis is controversial. Inexperience and incorrect judgment may have a greater impact on prognosis than the complications of the catheter itself, and must be applied under the guidance of an experienced supervising physician. Placement of a floating catheter should be considered in the following situations.
Shock-unknown diagnosis and poor therapeutic response for guiding drug and fluid therapy.
Hemodynamic instability where the diagnosis is unknown.
Severe multiple injuries-guiding fluid resuscitation and hemodynamic support.
Myocardial infarction-hemodynamically unstable, unresponsive to therapy in, differentiation of cardiogenic shock from hypovolemic shock.
pulmonary edema-differentiation of cardiogenic pulmonary edema from non-cardiogenic pulmonary edema, hemodynamic support in heart failure and ARDS.
COPD-combined cardiac failure, search for some reversible factors leading to withdrawal failure.
High-risk surgical patients.
Pulmonary embolism-aided diagnosis, determination of disease severity, guidance of hemodynamic support.
(2) Tissue perfusion monitoring
a. Clinical monitoring
Skin color, temperature, capillary filling time, pulse, sweating.
b.Core-peripheral temperature gradient
Increased temperature difference often indicates hypovolemia
c. Urine output
Significantly decreased renal perfusion usually results in anuria.
d. Metabolic acidosis with increased lactate concentration
Commonly seen in tissue hypoperfusion leading to cellular hypoxia and anaerobic enzymes, metabolic disturbances in infectious shock and hepatic and renal dysfunction can also cause severe lactic acidosis.
e. Gastric tonometer
Gastric mucosal PH or gastric-arterial PCO2 difference can be used for guidance of resuscitation, clinical value to be studied
(3) Hemodynamic index
2.Shock
(1) Basic concept
(a) Routine monitoring of shock includes cardiac monitoring and monitoring of arterial itch status.
Arterial cannulation should be given to measure blood pressure to obtain accurate blood pressure and timely adjustment of treatment
central venous line should be given to monitor central venous pressure and, if necessary, a floating catheter should be placed
Resuscitation measures are continuously adjusted to achieve therapeutic goals, such as blood pressure, mean arterial pressure, heart rate, urine output, skin perfusion and state of consciousness, and indicators of tissue perfusion such as lactate levels and SVO2.
Human body fluid distribution
Body fluids Male Female
Total body fluid 600 mL/kg 500 mL/kg
Whole blood 66 mL/kg 60 mL/kg
Plasma 40 mL/kg 36 mL/kg
Red blood cells 26 mL/kg 24 mL/kg
Body weight is defatted weight
(2) Estimation of blood volume in hypovolemic shock
class1 class2 class3 class4
Blood loss % 〈15% 15~30% 30~40% 〉40%
Pulse 〈100 〉100 >120 >140
Blood pressure in the horizontal position Normal Normal Decrease Decrease
Urine output (ml/h) >30 20~30 5~15 4.5L/min/m2) treatment strategy does not improve prognosis.
Vasoconstrictor drugs (e.g., norepinephrine) and positive inotropic drugs (e.g., dobutamine) should be adjusted to maintain MAP and CO, respectively.
(3) Vasoactive drug preparation method
Vasoactive drug preparation method.
Liquid volume (mL) 50mL 100mL
Drug dose (mg) kg*3 kg*0.3 kg*0.03 kg*6 kg*0.6 kg*0.006
1.0mL/hr (ug/kg/min)1 0.1 0.01 1 0.1 0.01
(4) Adrenal corticosteroids
Glucocorticoids only for infectious shock.
Patients with infectious shock may be considered for hormone application only if they remain dependent on boosters after aggressive fluid resuscitation.
Hormone application method: intravenous application of hydrocortisone 200-300mg/day, divided into 2-3 times or continuous intravenous injection, continuous application for 7 days.
Before applying hydrocortisone, ACTH test should be performed (250ug intravenous push, 0 blood samples should be taken for 30-60 minutes and sent to cortisol) if the elevation of cortisol is greater than 9ug/dL in 30-60 minutes, then stop applying hydrocortisone.
Hormones should not be used in non-special cases (such as the need for treatment of the original underlying disease) without shock.
3.Early treatment goal (EGDT)
Objectives within the first 6 hours of fluid resuscitation.
Central venous pressure of 8 to 12 mmHg.
Mean arterial pressure ≥ 65 mmHg.
urine volume ≥ 0.5 ml/kg/h.
–central venous (superior vena cava)/mixed venous itch saturation ≥ 70%.
When the central venous pressure reaches 8~12 mmHg while the central venous (superior vena cava) itch saturation after resuscitation by fluids.