Attach Cardiac Monitor to Patient
01. Improve Inravascular Volume
Vasopressors are used when there has been an inadequate response to volume resuscitation or if there are contraindications to volume infusion.
Vasopressors are most effective when the vascular space is "full".
Patients with chronic hypertension may be at greater risk of renal injury at lower blood pressures; These patients need to be with a higher MAP calculated from their currrent high systolic and diastolic pressures.
In others, there appears to be no mortality benefit in raising MAP above the 65 to 70 mm Hg range.
Vasopressor agents have variable effects on the α-adrenergic, β-adrenergic, vasopressin, and dopaminergic receptors.
Although vasopressors improve perfusion pressure in the large vessels, they may decrease capillary blood flow in certain tissue beds, especially the GI tract and peripheral vasculature.
If multiple vasopressors are used, they should be simplified as soon as the best therapeutic agent is identified.
In addition to a vasopressor, an inotrope may be needed to directly increase CO by increasing contractility and stroke volume.
All vasopressors increase myocardial oxygen demand; most should be titrated to desired effect
| Dose | Action | Cardiac Contractility | Vasoconstriction | Vasodilation | Cardiac Output |
|---|---|---|---|---|---|
| 2.0–20.0 micrograms/kg/min | β1, some β2 and α1 in large dosages | ++++ | + | ++ | Increases |
| Side effects and comments | Inotrope only; Causes tachydysrhythmias, occasional GI distress, hypotension in volume-depleted patients; has less peripheral vasoconstriction than dopamine; can cause fewer arrhythmias than isoproterenol | |||||
| Dose | Action | Cardiac Contractility | Vasoconstriction | Vasodilation | Cardiac Output |
|---|---|---|---|---|---|
| 0.5–20 micrograms/kg/min | α, β, and dopaminergic | ++ at 2.5–5 micrograms/kg/min | ++ at 5–20 micrograms/kg/min | + at 0.5–2.0 micrograms/kg/min | Usually increases |
| Side effects and comments | Tachydysrhythmias; a cerebral, mesenteric, coronary, and renal vasodilator at low doses; Surviving Sepsis Campaign second line, lot of overlap with α/β/dopaminergic receptors and dose; can be given through a peripheral IV | |||||
| Dose | Action | Cardiac Contractility | Vasoconstriction | Vasodilation | Cardiac Output |
|---|---|---|---|---|---|
| 2–10 micrograms/min | α and β | ++++ at 0.5–8 micrograms/kg/min | ++++ at >8 micrograms/kg/min | +++ | Increases |
| Side effects and comments | Causes tachydysrhythmia, leukocytosis; increases myocardial oxygen consumption; may increase lactate; no real maximum dose | |||||
| Dose | Action | Cardiac Contractility | Vasoconstriction | Vasodilation | Cardiac Output |
|---|---|---|---|---|---|
| 0.01–0.05 micrograms/kg/min | β1 and some β2 | ++++ | 0 | ++++ | Increases |
| Side effects and comments | Inotrope; causes tachydysrhythmia, facial flushing, hypotension in hypovolemic patients; increases myocardial oxygen consumption; never use alone in shock | |||||
| Drug | Dose | Action | Cardiac Contractility | Vasoconstriction | Vasodilation | Cardiac Output |
|---|---|---|---|---|---|---|
| 0.5–50 micrograms/min | Primarily α1, some β1 | ++ | ++++ | 0 | Slightly increases | |
| Side effects and comments | Useful when loss of venous tone predominates; first-line agent for most situations; should be given through a central line | |||||
| Dose | Action | Cardiac Contractility | Vasoconstriction | Vasodilation | Cardiac Output | |
|---|---|---|---|---|---|---|
| 10–200 micrograms/min | Pure α | 0 | ++++ | 0 | Decreases | |
| Side effects and comments | Reflex bradycardia, headache, restlessness, excitability, rarely arrhythmias; can be used on patients in shock with tachycardia or supraventricular arrhythmias; not good comparatively for septic shock | |||||
| Drug | Dose | Action | Cardiac Contractility | Vasoconstriction | Vasodilation | Cardiac Output |
|---|---|---|---|---|---|---|
| 0.01–0.04 units/min | Directly stimulates V1 receptor on smooth muscle | 0 | ++++ | 0 | 0 | |
| Side effects and comments | Primarily vasoconstriction; usually started at max dose and not titrated | |||||
Note: 0 = no effect; + = mild effect; ++ = moderate effect; +++ = marked effect; ++++ = very marked effect.
Determine oxygen delivery (Do2).
(DO2) is the volume of oxygen delivered to the systemic vascular bed per minute and is the product of cardiac output (CO) and arterial oxygen concentration (CaO2): DO2 = CO x CaO2.
Oxygen uptake is the amount of oxygen that diffuses from capillaries to mitochondria.
cardiac rhythm monitoring
Adequate central venous pressure
Adequate mean arterial pressure
Adequate central venous oxyhemoglobin saturation
A comprehensive assessment of the adequacy of perfusion is useful to guide resuscitation, rather than merely aiming for an arbitrary mean arterial pressure.