Test 8 Notes Flashcards
What happens when you place a patient on a ventilator
we reverse the normal pressure changes in the chest
- Normal insp causes negative pressure in chest, this expands blood vessels and heart aiding in blood delivery to the heart
- PPV will put pressure on the blood vessels and heart impeding blood delivery to the heart and lung
Minimize effects Positive Pressure ventilation
Primary way to diminish effects of PPV on pulmonary and cardiovascular system is to keep mean airway pressure at its lowest
Cardiovascular - Most likely to affect cardiac patients and patient without lung disease
Decreased compliance (stiff lungs) and airway disease pressure not transferred to heart
PPV in chest of pt with CHF may improve
cardiac function
- pushes blood out of heart and vessels so makes it easier for the muscle to pump the blood
- PEEP is commonly used to treat left heart failure
Cardiac monitorings
ECG, a common cause of dysrhythmias is hypoxia
- Arterial blood pressure monitoring
- Continuous monitoring via arterialcatheter (Art-line)
- Oxygen delivery is dependenton a good BP and CO
Hemodynamics Direct measurements
Pulmonary Artery Catheter (Swan-Ganz)
Central Venous Pressure (CVP)0-8 mmHg
Right Atrial Pressure (RAP) 0-8 mmHg
Pulmonary Artery Pressure (PAP) 15-30/4-12 mmHg
Mean Pulmonary Artery Pressure (PAP) 9-18 mmHg
Pulmonary Capillary Wedge Pressure (PCWP) 4-12 mmHg
Cardiac Output (CO) 4-8 L/mi
Barotrauma vs. Volutrauma
Caused by overdistention
-Barotrauma caused from too much pressure in lungs.
Volutrauma caused from too much volume in lungs, regardless of pressure
controversy over pressure vs volume, usually both pres
Overdistention of lungs can cause
Alveolar capillary level damage From: Stiff lungs ETT in rt mainstem bronchi Too much volume in lungs Vt too high Auto PEEP
pressure ventilation can cause
lung damage to tissue leading to ALI and ARDS causes of overdistention
Avoid VILI monitor
Peak Pressures and set alarms appropriately
Plateau pressures
Auto-PEEP
CX
Prevention of VILI
small Vt decrease Vt when raising PEEP keep plateau below 30 mcH2O keep peak pressure below 35 cmH2O avoid mainstem intubation don’t use pause pressure with volume ventilation monitor and treat autoPEEP use PEEP for optimal lung recruitment permissive hypercapnia
Other causes of auto PEEP
high minute ventilation>10
High RR
I;E
how to find auto PEEP
EASIEST WAY: FLOW TIME CURVE -exp flow not returning to baseline Increased resonance on percussion Decreased BS Expiratory Hold
How to get rid of auto PEEP
increase E time -faster flows, smaller Vt Lower rate Large ETT or allow permisive hypercapnia
Inverse I:E ratios cause
autoPEEP and improves O2
O2 toxicity leads to
ALI/ARDS
In pneumothorax mediastinum moves
towards affected side, tension moves away
Pneumothorax
air enters pleural space
- increased pressure in pleural space crushes the heart and great vessels causing cardiovascular collapse and death
- treat all with chest tube unless very small and no problem
Signs of pneumothorax
subcutaneous emphysema
Subcutaneous emphysema
air leaks out of lungs and into soft tissue
which is a sign of pneumo, always get CXR
signs of tension pneumo
-Increased Peak Pressures
-Increased WOB
-Absent BS on affected side
-Mediastinal shift away
-Increase in HR and decrease Spo2
-Loss of BP/CO
CHEST XRAY IS BEST DX
Emergent tx for tension pneumo
14 guage needle
- anterior 2nd and 3rd on affected side, midclavicular space
- pt head up position
papillary response
pinpoint, drug overdose
dilated and fixed, atropine
mid-position and fixed, severe cerebral damage
gag reflex used to
used to test cranial nerve function but also to assure airway protection post extubation.
-Place a tongue depressor in back of throat and there should be a response of those muscle
what controls breathing
brainstem, there would be no breathing if this is affected
Cheyenne stokes breathing
increase in ICP, CHF, Hyoxia
ICP
amount of pressure in brain
- increased pressures cause decreased perfusion in brain
- goal to keep lowest pressures possible in chest keeps blood from entering the chest causing a back up of blood in the skull leading to increased ICP
What will decrease ICP
hyperventilation- CO2 is a cerebral vasodilator
-Keep CO2 28-32 on closed head injury 24-36 hours
ICP Monitoring
normal mean ICP is 10-15 in a supine position
15-20 compress the capillary bed and compromise circulation
30-35 venous drainage is impeded and edema develop
40-50 perfusion cannot be maintained
Cerebral perfusion pressure (CPP)
blood floww through brain, maintain above 70
CPP=
MAP-ICP
wanna maintain above 70
Glasgo Coma Scale
Scale 3-15
9-13 need ICU
8 or less need an ICP
Endocrine effects
increase in anti-diuretic hormone(ADH) causes lower urine output
several other hormone changes that may lead to lower urine output
ABG with RENAL FUNCTIONS
(Kidney, Endocrine, ABG)
lower PaO2 and higher PaCO2 lead to lower urine out
Normal urine output
is 1ml/kg/hr or about 30-70 ml/hr
-poor urine output leads to pulmonary edema from too much fluid in the body and acid base problems, usually acidosis
PPV and liver functions
PPV can lead to venous distention with ischemia to the liver
increased bilirubim
Gastric effects with PPV
PPV can lead to GI bleed and ulcers
acid reflux can lead to pneumonia
pt needs to be on antacids and histamine H2 blockers (Pepcid)
Nutrition and PPV
Nutrition
not enough calories to breath
too many carbs lead to increase CO2, makes weaning difficult for COPD
Oral feedings best
Lung protective Strategies
keep peak pressures <35
Keep Plateau pressures <30
Vt 6 ml/kg may need to increase RR to compensate
Permissive hypercapnia
Lung recruitment maneuver
Sustained high-pressure inflation Intermittent sigh Extended sigh Intermittent PEEP increase Pressure control + PEEP
VAP causes within
48-72 hours, usually bacterial
Causes of VAP
Aspiration of oral secretion Aspiration of gastric contents Inadvertent instillation of an infectious agent down the artificial airway Inhalation of infectious aerosol
Risks of VAP
nasal intubation Reintubation Low endotracheal tube cuff pressures Supine position Enteral feeding Hyperglycemia Blood transfusion Inadequate staff
CVP Catheters
Filling pressure or preload of rt atrium
-most useful in pts with volume-depleted state
PA catheter
Estimate SVR and PVR
-Assess pulm hypertension
adding a plt will
Increase the MAP
add to the I time
Improve O2
Does rate affect Pressures and volumes
NO
