PICU Flashcards
Pathology of a stress ulcer
Stress, splanchinc hypoperfusion, gastric mucosal breakdown and impaired gastric motility, leading to prolonged gastric acid exposure.
What are some regmens for stress ulcer
PPI’s… max effect not until 48 hrs
H2 antagonists, quicker onset of action but less effective
*neither of these demostrated decreased mortality, ICU stay, rate of HAP/VAP, or rate of ulcers on meta analysis
What are you supposed to use if there is a stress ulcer and a risk of thrombocytopenia?
PPI’s
-use if Plt <50,000… cimetidine inhibits cytP450 (this is a problem with PPI useage)
Incidence of DVT in kiddos compared to adults
10x lower
main ICU risk factor for DVT?
CVL (central line?), the other risk factors are what you think they are, immobility etc…
Does a negative U/S rule out a DVT?
absolutely not because it has low sensitivity
-so, if you have high suspicion, treat until able to confirm with contrast CT or venogram (gold standard)
What do you do for DVT ppx in kiddos?
TEDs or pneumoboots, rarely LMWH
- no benefit of ppx in trauma pts <13 yo or with warfarin in pedi-onc pts w/ CVL
- Bottom line: consider ppx for adult sized pts with significant risk factors (long term immobiliation, CVC, malignancy)
What is a good way to decrease catheter related blood stream infections?
- CVC care bundle whatever that is… (ask them on rotation)
- decrease insertion time and use of parenteral nutrition??
- only use chlorhexadine prep if child is older than 6 months
Oral to IV equivalents of analgesics
Morphine 30 to 10
Dilaudid 7.5 to 1.5
Which analgesic has the quickest onset of action?
fentanyl (look at book for dosing cuz it’s nutzo)
Peds dosing of dilaudid
0.015 mg/kg/dose q3-6h prn
dosing for morphine
0.05 mg/kg/dose, usual 0.1-0.2 mg/kg /dose q2-4 h prn (max 15 mg/dose)
Define respiratory failure
Failure of xygenation, ventilation, gas exchange or airway protection
- PaO2 <60
- PaCO2>50
- pH< 7.35
- if chronic resp innsuff, acute hypercarbia is an increase in PCO2 20mm Hg above baseline
workup for resp failure
ABG (VBG to r/o hypercapnea), CXR (r/o PNA, edema), consider CBC (anemia), CT (if suspect PE), ECHO, BNP (if suspect shunt or CHF)
Oh god… calculation for the A-a gradient
PAO2-PaO2 - (FiO2 x 713)- (PaCO2/0.8)
What is the normal value for the A-a gradient?
about 2.5 + (0.21 x age in years)
What is PaO2/ FiO2 ratio used for?
this is called the oxygenation index and it’s used to measure severity
- normal >300
- ALI: 201-300
- ARDS <200
How does one measure PaCO2?
just think about CO2 production/ alveolar ventilation
- the equation is k x (VCO2/ (RR x VT x (1-VD/VT)))
- so, use this to watch out for hypercapnea (increased PaCO2)
What are the different etiologies of Hypoxemia (decreased Pa O2)
- Hypoventilation
- O2 delivery/consumption imbalance
- True Shunt
- VQ mismatch
What is specific about a true shunt,
it does NOT correct with O2
What etiology of hypoxemia DOES correct with O2
VQ mismatch suckaaaaa
What is the actual difference between CPAP and BiPAP?
- CPAP: continuous PEEP. Useful for HYPOXIA (Atelectasis, edema, OSA, HMD)
- BiPAP: Pt-triggered PIP + CPAP. Useful for HYPOVENTILATION (CF, NM disease)
What are the invasive options for mechanical ventilation?
- Support (PS/VS)
- Assist/control (AC)
- SIMV
- HFOV
What is support mechanical ventilation
spont breaths assisted to reach goal pressure (P) or volume (V)
- no set rate, pt MUST initiate breaths. Pt determines inspiration time
- less efficient if ETT leak
What is AC with regards to mechanical ventilation?
- Assist/control (AC): vent delivers minimum # of supported breaths (synch to pt effort) with add’l pt-initiated breaths getting full assist to reach goal P or V 2. controlled inspiration time
- downside: uncomfortable, dyssynchrony and auto-PEEP (breath stacking)
What is SIMV (mechanical ventilation)?
Vent delivers minimum #of supported breaths (sync to pt effort) but add’l pt-initiated breaths get no assist. May add PS to assist spont breaths (SIMV + PS)
*downside: inc resp effort (pt must overcome circuit resistance during spont breaths)
What is HFOV (mechanical ventilation)?
Rapid oscillatory breaths given at set frequency (Hz); manipulate MAP and change in Pressure
- downside: can easily hypervent. Vent change may take longer to equilibrate on blood gas
- used when conventional ventilation fails
- initial trials supporting HFOV over conventional vent strategies were done before ARDSNet low TV protocols, which appear to have the same mortality. They are likely equal but HFOV may be an easier way to obtain the same result (Crit Care 2005)
What do you do with acute desaturation in pts w/ artificial airway on mechanical ventilator?
Think DOPE
- Dislodgement (ETT)
- Obstruction (musuc plug)
- Pneumothorax
- Equipment failure
- remember that oxygenation depends on mean airway pressure and ventilation depends on minute ventilation and dead space
What parameters does conventional ventilation increase?
RR, FiO2, PEEP, PIP, inspiration time (though it should not be first line for this)
What parameters does HFOV increase?
MAP and change in pressure
What 3 parameters will increase the pCO2?
RR, PIP, and change in pressure
What are the extubation readiness criteria?
- Pt awake 2/ intact airway reflexes (cough, gag), hemodynamicall stable, manageable secretions, acceptable gas exchange, P2 requirement <40%
- Air leak: used to predict upper airway obstruction (swelling) after extubation… presence of audible leak around ETT @ <25 cm H20, consider steroids if no leak (role unclear, may decrease risk re intubation), negative inpiratory fice: strenght of resp muscles in pts w/ neuomuc weakness (NIF > 30 mm Hg.. not validated in children… unreliable
- Spontaneous breathing trial (CPAP or PS + PEEP) prior to extubation
What dose of steroids do you give a kid who does not have an audible leak from ETT when considering extubation?
decadron 0.5 mg/kg q6h x 6, 12 hr prior to extubate (crit car med 1996)
