Starting Mechanical Ventilation Flashcards

Question

Initial Setting of Peds Vent Circuit

Answer 1

\<25 kg for a neonate \>25 kg Adult Neo circuit is always heated Adult circuit will depend upon the size of the pediatric

Answer 2

Smaller child 1.0 seconds Longer for a larger child

Answer 3

* RR (breath/min) * 20-35 * Vt (ml/kg) * 5-8 * Inspiratory Time * 0.6-0.7 * PEEP * 5

Answer 4

* RR (breath/min) * 20-30 * Vt (ml/kg) * 6-9 * Inspiratory Time * 0.7-0.8 * PEEP * 5

Answer 5

* RR (breath/min) * 18-25 * Vt (ml/kg) * 7-10 * Inspiratory Time * 0.8-1 * PEEP * 5

Answer 6

* RR (breath/min) * 12-20 * Vt (ml/kg) * 7-10 * Inspiratory Time * 1-1.2 * PEEP * 5

Answer 7

* pH * 7.35-7.45 * PaCO2(mmHg) * 35-45 * PaO2(mmHg) * 80-100 * \*May be less on capillary gas * HCO3- (mmol/L) * 22-26 * SpO2 * 95-100% * Goal is just higher than 90%

Answer 8

6-10 mL/kg May be as high as 10ml/kg for patients with neuromuscular and post op patients Lung protective strategies will be 4-6 ml/kg

Answer 9

12-16 Higher rates run the risk of air trapping

Answer 10

0.8-1.2 seconds Targeting an I:E of 1:2 or lower

Answer 11

Typically start at 5 cmH20 Aim for an optimal PEEP Increase typically made in increments of 2-3 cmH2O Watch for CV compromise Contraindications to PEEP- Increased ICP, untreated pneumothorax, hypotension\*

Answer 12

~100 mL/kg to start 80-100ml/kg IBW Can also use ♂- 4 x BSA ♀-3.5 X BSA Febrile patient will require a higher MV Will be adjusted based on PaCO2

Answer 13

* The beneficial effects of PEEP may be outweighed by the effects that PEEP has on hemodynamics. * PEEP will result in a reduction in venous return due to the elevated intrathoracic pressure, and by an increased right ventricular afterload that is secondary to the rise of pulmonary vascular resistance. * PEEP redistributes cardiac output in favor of brain, heart, adrenals and intestines, whereas the perfusion of stomach, pancreas and thyroid is diminished * Reduction of hepatic artery flow, at higher levels of PEEP, may jeopardize liver tissue oxygenation. * Under clinical conditions, individual differences regarding pre-existing cardiopulmonary and peripheral-vascular diseases may modify the PEEP-induced hemodynamic alterations in a wide range out of proportion to the fall of cardiac output.

Answer 14

**pH-** 7.35-7.45 **PaCO2:** 35-45 **PaO2:** 80-100 (goal 60-100) **HCO3:** 22-26 **SaO2:** 95-100% (Goal \>90%)

Answer 15

Head injury-PaO2 80-120 (CHR TBI protocol), PaCO2 on low side normal

Answer 16

Time constants represent how fast pressures equilibrate between the circuit and the alveoli It represents the maximal rate at which exhalation occurs Time constant is calculated through multiplying compliance and resistance The time constant related to inspiratory filling and expiratory emptying of the lungs Mouth pressure or proximal airway pressure will equilibrate with alveolar pressure in 3-5 time constants (this will be ~0.33 seconds in a newborn and 0.25 seconds in adults)

Answer 17

1stTime Constant- 63% of the volume is delivered or exhaled 2ndTime Constant- 86.5 % of the volume is delivered or exhaled 3rdTime Constant- 95% of the volume is delivered or exhaled 4th Time Constant- 98.2% of the volume is delivered or exhaled 5th Time Constant- 99.3% of the volume is delivered or exhaled

Answer 18

In babies with severe respiratory distress and decreased lung compliance one time constant can equal 0.05 seconds This means that pressure equilibrium occurs in 0.15-0.20 seconds which is the minimum inspiratory time required to ensure complete delivery of tidal volume

Answer 19

When airway resistance is high such as in MAS the time constant will become longer meaning we have to use a longer inspiratory time, lower inspiratory flow, and longer exhalation times to ventilate these infants

Answer 20

Monitoring respiratory system mechanics to derive time constants can assist in properly adjusting adequate inspiratory time and expiratory time during ventilation The time component is important when using rapid rates to allow for adequate exhalation without developing breath stacking and automatic positive end expiratory pressure (auto PEEP) and to minimize lung damage

Answer 21

* You will set on the ventilator the following parameters * Tidal Volume * Rate * Inspiratory Time * PEEP * In PRVC rememeber that Pplat and PIP will be the same

Answer 22

* Because your tidal volume will stay the same you will need to have an increase in PIP and Pplat * There will also be an overall increase in Pmean * Will change the time constant * Your minute ventilation will not change because you control both rate and tidal volume * As compliance decreases your Tidyanwill decrease Tistatic will increase and flow will increase * The Titotal will not change which means that your Te and I:E will not change

Answer 23

Your pressures will remain the same it will be the speed of the flow that will be changing due to the change in the airway diameter Because it is flow is changing it will be the Ti dynamic and Ti static that will change As resistance increases Tidyn will increase and Tistatic will decrease (Titotal will not change) Peak flow will be directly proportional to resistance but overall flow will not change (and we can not measure)

Answer 24

* Your Ti total will decreased and it might be decreased to the extent that we do not reach equilibrium before exhalation starts. * Because Ti total is shorter it means that Te is longer. So I:E will decrease * As Ti is shorter there will be a higher pressure (PIP) needed in order to deliver the set tidal volume * However because of the time that we are delivering that pressure there will be an overall decrease in Pmean * Note that there is a larger change in PIP (increase) than there is in Pmean (decrease) * In the mode of PRVC if we decrease Ti resulting in a truncation of inspiratory flow what is the affect on peak pressure and the plateu pressure in the lungsPeak pressures will go up but plateau pressures (in the lungs) will not change * Ventilator Pplat will go up as it will be the same as PIP in PRVC

Answer 25

You will set on the ventilator the PC Absolute/PIP Rate Ti PEEP

Answer 26

* Tidal volume will increase as we can increase the volume delivered at a certain pressure * Because our tidal volume is increasing our minute ventilation will increase as well * Ti dyn will increase and Ti pause will decrease * Because Ti dyn will increase flow will decrease also your Pmean will increase with an increased Ti dyn * You Ti total will not change (so I:E will not change)

Answer 27

The only thing that will change is that your Ti dyn will get longer Remember as resistance increase your flow will decrease making a longer Ti dyn and a short Ti static

Answer 28

* **Prevent Hypoxia (SpO2 88-92)** * Manipulate the FiO2 * If FiO2 is \>0.60 increase the PEEP * Manipulate the mean airway pressure * Do this through manipulation of Ti (increase in Ti will increase MAP), I:E, or PEEP * **Prevent Lung Injury** * Limit FiO2 with PEEP * Wean FiO2 if possible * Limit Pplat (\<30 cmH2O) * **Prevent Acidosis** * Increase rate in order to decrease WOB * Increase rate to keep pH above 7.25 * Cause of acidosis * Hypoxemia, hypoxemia, hypoxemia

Answer 29

Try decreasing rate and watch WOB (SBT) Wean FiO2 (decrease when SpO2 \>93%) Wean PEEP when FiO2 is below 0.4 – 0.5 We don’t wean aggressively on babies that are losing weight or having huge apneic periods

Answer 30

* To prevent hypoxemia * Allow for normal tissue metabolism * Optimize surfactant production * Prevent R to L shunting * Optimize fluid management * Balance between avoiding hypovolemia and shock and on the other side also trying to avoids edema * Reduce Metabolic Demands * Prevent worsening atelectasis and pulmonary edema * Minimize oxidant lung injury * Minimize lung injury cause by mechanical ventilation

Answer 31

Rule out you differential diagnosis before you CHD cause they are very rare PGE you have to intubate because a side effect of PGE is associated with central apneas

Answer 32

Minimal ventilator parameters to decrease WOB if needed.

Answer 33

Minimal ventilator parameters to decrease WOB if needed with minimal FiO2 as SpO2 is not improved and due to the danger of closing the PDA.

Answer 34

Normally a PDA is not a big problem, but when there is a left to right shunt the problem is that this leads to chronic pulmonary edema and it is this edema which is why babies are oxygen dependent This leads to BPD and when you touch the baby and they cry it will create pressure in their lungs which will increase pressures creating a right to left shunt, which will decrease saturations as the deoxygenated blood being dumped into the aorta and being delivered to the body. So as a RT you will want to increase FiO2 but you should not touch the FiO2 because as soon as the baby relaxes it will return to being a left to right shunt and we will have an increase in saturations again. If there is major fluctuations in saturations will be used to determine whether there is a problematic PDA

Answer 35

* **Excessive tidal volume and decreased lung compliance** * ****Volutrauma * **Increase inspired oxygen,** defifcent antioxidant system, nutritional defiecnies * Oxygen toxcicty * Pre/postnatal infections, PMN activation * inflammatory mediators, elestase/proteinase, inhibitor imbalance * **PDA,** excessive fluid intake * increase pulmonary edema and lung edema All will lead to acute lung injury inflammatory response

Answer 36

* **Airway Damage** * ****Metaplasia, smooth muscle hypertrophy, increase mucus secretiosn * **Airway obstruction and emphysema atelectasis** * **Vascular Injury** * ****Increased permeability, smooth muscle hypertrophy, decreased vascularization * **Pulmonary edema and hypertension** * **Intersitial Damage** * ****Increased fibronectin and elastase, decreased alveolar septation * **Fibrosis and decreased number of alveoli-capillaries** ## Footnote **All lead to Chronic Lung Disease**

Answer 37

Supplemental oxygen is the main therapy for infants with BPD but the appropriate target remains controversial Oxygen saturations are accepted at 85-90% after preterm birth Keep in mind though that patients with severe BPD usually are \<36 weeks which is past the time when ROP is a major concern For BPD, growth failure, respiratory exacerbations and PPHN however we accept saturations of 92-95%

Answer 38

* Strategies to prevent acute lung injury * Low Vt (5-8 ml.kg) * Short inspiratory time * Increase PEEP at needed lung recruitment without overdistension or reflection at high peak airway pressure * Achieve lower FiO2 * Goals for Gas Exchange * Adjust FiO2 to target lower O2 saturations (85-90%) * Permissive hypercapnia

Answer 39

* Marked regional heterogenely * Larger Vt (10-12 ml/kg) * Longer inspiratory time (\>/= 0.6 sec) * Airway Obstruction * Slower rates allow for better emptying especially with larger Vt * Complex roles for PEEP with dynamic airway collapse * Interactive effects of vent strategies * Changes in RR, Vt, inspiratory and expiratory time, pressure support are highly interdependent * Overdistention can increase agitation and paradoxically worsen ventilation * Permissive hypercapnia to facilitate settings

Answer 40

Right to left shunting Chronic pulmonary edema Incidence of greater hypoxemia and possibly metabolic acidosis If failure to spontaneously close or with drug treatment (indomethacin), may require surgical closure. Note to clinicians: be wary of increasing FiO2 to compensate as it will not improve SpO2 but may expose patient to toxically high FiO2

Answer 41

1. Apnea-Only absolte indication Acute Ventilatory Failure Impending Ventilatory Failure Severe Refractory Hypoxemia

Answer 42

Type 2 Respiratory Failure (hypercapnic) pH\<7.25 despite use of CPAP and supplemental oxygen of FiO2 \>0.60

Answer 43

When signs and symptoms of respiratory distress are exhibited, non-invasive CPAP may be trialled prior to intubating and mechanically ventilating (assuming pH \> 7.25)

Answer 44

Hypoxemic respiratory failure (PaO2\<50 mmHg) despite the use of CPAP and supplemental oxygen (FiO2³0.60) Associated with: * Any kinds of shunt * Intrapulmonary shunting * Due to MAS, sepsis, pneumonia (not effective opening up the lungs * Intracardiac shunting * PDA, PFO

Answer 45

* Lung hypoplasia * CDH * Tracheal anomalies * Cardiac defects

Answer 46

The need for surfactant require intubation and ventilation After meconium aspiration Surfactant deficiency associated with prematurity The neonate may be intubated to administer surfactant but then, depending on the gestational age and respiratory status, may be extubated to CPAP/SiPAP

Answer 47

* Retractions * Intercostal, suprasternal, substernal * Grunting * Nasal flaring * Increasing oxygen requirements * Cyanosis * Tachypnea * RR \> 60 bpm

Answer 48

Similar to the ones on the adult but more evident in kids The higher the silverman score the high the distress Score 10=Severe respirtory distress Score \>/=7 Impending respirtroy failure Score 0 No respirtory distress

Answer 49

1. Apnea 2. Acute ventilatory failure- Hypercapnia with a pH \< 7.25 3. Impending ventilatory failure- Clinical signs: Tachypnea, substernal and intercostal retractions, expiratory grunting, nasal flaring, cyanosis, head bobbing 4. Severe refractory hypoxemia

Answer 50

PIP PEEP I:E Ratio Flow

Answer 51

We tend to spend more time in exhalation than inspiration which is why PEEP helps improve oxygenation

Answer 52

Decrease MAP

Answer 53

6-8 ml/kg ## Footnote May be as high as 10ml/kg for neuromuscular and post op pts. Lung protective 4-6 ml/kg.

Answer 54

12-16 bpm Higher rate run the risk of air trapping

Starting Mechanical Ventilation Flashcards

(79 cards)