PICU Basics/Monitoring
Normal Peditric Vital Signs
Pediatric Glascow Coma Scale
Invasive Vascular Access
Arterial Lines
For continuous BP monitoring, frequent lab draws, arterial blood gases (PaO2)
Typically placed peripherally (radial, ulnar, dorsalis pedis, or posterior tibal arteries) but can also be placed centrally (femoral)
Ordering Tip: Arterial line fluids can have heparin and/or papaverine added to normal saline to prevent clots and vascular spasm --> Specific order in PICU LINE MANAGEMENT
Central Venous Lines (IJ, femoral, subclavian)
For secure venous access to administer caustic meds, TPN, vasoactives, measure central venous pressure (CVP), measuring /trending SvO2
Not meant for long term (> 28 day) access
Intracardiac lines
Post-op cardiac patients may have lines placed directly through their incisions and into whatever chamber is to be monitored
RA and SVC lines may be used for drug and fluid administration
LA lines are only monitoring lines because of the risk of air embolism directly into the arterial system if the line is opened
End Tidal CO2 monitoring (Capnography)
Measures the exhaled concentration of carbon dioxide
We can measure CO2 concentrations on patients who are not intubated using an end tidal nasal cannula
All intubated patients (and trach patients) should be connected to end tidal monitoring, which measures CO2 concentration of each exhaled breath
Estimation of PaCO2
Various Capnography tracings that indicate different clinical scenarios
Pulse Oximetry
Continuous estimate of percent (%) saturation of oxyhemoglobin in arterial blood (what is the percent saturation of oxygen)
Measured using a light emitting diode on one side and detector on the other
Diode emits red and infrared light which estimates oxyhemoglobin and deoxyhemoglobin via absorption and transmission of the light by the Hb complex
These signals fluctuate in time because the pulsing of arterial blood with each heartbeat
Oxygenated Hb absorbs more infrared light and allows more red light to pass through.
Deoxygenated hemoglobin allows more infrared light to pass through and absorbs more red light.
With the help of the Beer-Lamber Law, can use proportions of deoxyhb to oxyHb and conver to a SpO2 (saturation)
NOTE: Methemoglobinemia (in high enough concentrations) will trick the oximeter and read 82-86% no matter how high or low the PaO2 is.
Cardioversion:
Synchronized cardioversion 0.5-1 J/kg (double for subsequent attempts)
Defibrillation 2-4 J/kg (max 360 J)