acute respiratory alterations and ventilators

ventilation

process of moving air in and out of respiratory tract

diffusion

process of moving and exchanging O2 and CO2 across alveolar capillary membranes

perfusion

process of supplying oxygenated blood to the lungs and organ systems via blood vessels

hypoxemia vs. hypoxia

decreased oxygen in arterial blood

vs.

oxygen depravation of the cells

cheyne-stokes respirations vs. Kussmaul respirations

respirations increase in rate and depth and then become shallow and slow

vs.

deep and rapid respirations

flail chest

usually caused by blunt trauma and force that fractures 3 or more consecutive ribs in 2 or more separate places

manifestations:

• paradoxical movement during breathing (moves opposite your chest)

• rapid shallow breathing due to pain

• tachycardia to compensate

diagnostics and treatment of flail chest

do H&P, chest x ray, and CT to visualize lung tissue

auscultate and still palpate around the area

• give oxygen ventilation

• O2 therapy but if above 98% its not necessary

  • diffusion is not the issue, ventilation is

• promote lung expansion with deep breathing and incentive spirometer

• analgesia to promote adequate respiratory

pneumothorax

air in plural space; negative pressure becomes positive and lung collapses

could be primary with no apparent cause / absence of lung disease and be caused by damage to the area

or could be secondary which occurs in the presence of an existing lung patho

open vs. closed pneumothorax

results from a penetrating thoracic injury

vs.

is the accumulation of air originating from the respiratory system within the pleural space

spontaneous pneumothorax

damage to the pleura → air fills the pleural space → drops the negative pressure in the thoracic cavity → affects lung recoil → lung collapses toward hilium

tall thin males are at greater risk

other risk factors: connective tissue disorders, smoking, scuba diving, high altitudes

iatrogenic pnemothorax

can be caused by lung biposies and ventilators

tension pneumothorax

damage to the pleural space via chest injury → air is allowed in with inspiration but not expired out → air pushes again the lung causing damage to alveoli and displacement of heart, great vessels, and trachea (mediastinal shift)

IS LIFE THREATENING

manifestations of a pneumothorax

• chest tightness

• dyspnea

• decreased movement of the chest wall

• decreased or absent breath sounds on affected side

• hyperresonance to percussion

manifestations specific to tension pneumothorax

• air hunger - look like they are eating the air

• cyanosis

• subcutaneous emphysema - they will have air under their skin; feels like bubble wrap

• neck vein distention

• tracheal deviation AWAY from affected side

  • late sign

treatments for pneumothorax

• chest tube for regular PTX

  • makes lung expand by adding positive pressure in pleural cavity

  • PO2 should increase, and will have deep unlabored breathing

• needle decompression and then chest tube for tension PTX

  • since its an emergency, decompression comes first

• pleurodesis for recurrent PTX

pleurodesis

a substance introduced into the pleural space that causes inflammation → makes two pleural layers adhere to each other → seals off pleural space

move patient around for the substance to be able to fill all of pleural space

hemothorax

an accumulation of blood in the pleural space from injury to the chest wall, diaphragm, lung, blood vessels, or mediastinum

manifestations:

• respiratory distress (lungs are not inflating)

• tachycardia (compensation)

• decreased or absent breath sounds

• dullness to percussion

• hypoxia

• hypotension (due to blood loss)

needs a H&P, chest x-ray, and chest CT

chest tube is main treatment

is blood loss expected in a hemothorax patient with a chest tube?

yes; but more than 100mL/hr of blood loss is bad and the provider must be notified

nursing interventions for hemothorax

• assess rate, depth, and ease of breathing

• watch for signs of distress (JVD, labored breathing, tachycardia)

• auscultate lungs

  • absent before treatment is expected

  • after reinflation, it should not be absent

• monitor O2 sats

• keep in semi/high Fowler’s

• encourage frequent repositioning (so muscle won’t atrophy)

• encourage deep breathing and mobility

chylothorax

the presence of lymphatic fluid in the pleural space related to damage to the lymphatic system usually from trauma or malignancy (common in cancer patients)

manifestations: severe cough, chest pain, and difficulty breathing

• do H&P - symptoms are vague so a physical will show diminished/absent breath sounds

treatment:

• thoracentesis

• octreotide - reduces the flow of lympathic fluid

• pleurodesis

thoracentesis

a procedure to remove fluid or air from around the lungs

a needle is put through the chest wall into the gap between the pleura and inner chest wall

is usually a treatment for pleural effusion and chylothorax

there is a risk of clipping the lung and causing a pneumothorax, infection, bleeding, or liver or spleen injury - symptoms will get worse during the procedure if these happen

nursing interventions:

• keep them in a hunched over position, sitting upright

• monitor respiratory status

chest drainage systems aka chest tubes

used to treat spontaneous and traumatic pneumothorax and hemothorax

used to re-expand the lung and remove excess air, fluid, or blood

there are 3 types: traditional water seal, dry suction water seal, and dry suction

output should be less than 100mL an hour → if not, call physician because patient should go into volemic shock

do NOT clean it, just throw it away and get a new one

mark and initial new output measurements every shift

chest tube placement Do’s

• site should be in mid to anterior axillary line in the 4th or 5th intercostal space above the rib

• tape connector sites and keep a straight line of tubing from bed to collection system

  • maintains water seal

• document COCA

• mark drainage on the receptacle every shift

• report if drainage exceeds 100mL/hr

• keep sterile water, rubber-tipped clamps, petroleum gauze, and tape at bedside

• keep system below level of bed (let gravity do its thing)

chest tube placement Don’t’s

• pin or restrain tubing

• leave kinks in tubing

• strip/milk chest tubing

• clamp tubing → tension pneumothorax

• apply a gloved hand to wound if it disconnects

what do you do if the chest tube disconnects from the patient?

• wipe ends with alcohol and reattach

• place distal end in sterile water to restore water seal

• apply occlusive dressing (petroleum gauze) to the wound immediately

pulmonary embolism

a blockage of one or more pulmonary arteries by a thrombus/embolus; is a perfusion problem

most commonly starts as a DVT in leg and migrates to the right side of the heart and into pulmonary vasculature

caused by:

• blood clots - slow/stagnant blood

• tissue fragments - IV drug use with dirty needles

• fat

• foreign body - bullet, pill

• air bubble - IV injection. central line improperly removed

• amniotic fluid - after C-section, abortion, amniocentesis, trauma

risk factors:

• limited mobility

• diseases that cause hypercoagulability

• oral contraceptives and hormone replacement

• injuries to vascular endothelial cells (infection)

• genetics

• smoking

manifestations of a PE

depends on size, type, and extent

• acute onset SOB (classic)

• pleuritic chest pain (classic)

  • pain when taking deep breaths

• cough

• hemoptysis

• crackles

• wheezing

• tachypnea/tachycardia

• anxiety

• syncope

diagnostics for PE

along with CMP and BMP

• D-dimer - but its only 50% right

• PT/INR and PTT

  • need to know patient’s baseline before putting them on thromboembolitics

• CT with IV contrast

  • if they are not allergic to iodine or shellfish

  • if they are → VQ scan

• VQ scan

VQ scan (ventilation-perfusion scan)

perfusion scan that involves IV injection of a radioisotope which shows pulmonary circulation

ventilation scanning involves inhaling radioactive gas which shows gas distribution through the lung

is interpreted by 3 probabilities, so CT w/ contrast is first option

could have a low probability and still have a PE

treatment for PE

• anticoagulants (if caused by blood clots)

  • Heparin - IV drip or subQ

  • Lovenox - subQ

  • Coumadin - PO

• tPa in extreme cases

• surgery

  • pulmonary embolectomy

  • IVC filter

• nursing interventions: VS, monitor PTT and signs of bleeding (stop infusion), monitor any decline in respiratory status (cap. refill, O2 sat), give oxygen if needed, monitor cardiac

respiratory compensation

lungs fix the metabolic problem

• happens fast (minutes to hours)

• lungs blow out / retain CO2 to fix pH

• if pH is acidic = lungs breath faster

• if pH is alkalotic = lungs breath slower

metabolic compensation

kidneys fix the metabolic problem

• happens slowly (hours to days)

• kidneys hold onto / excrete bicarb

• if pH is acidic = kidneys retain HCO3

• if pH is alkalotic = kidneys excrete HCO3

uncompensated vs. partially compensated vs. fully compensated

pH is off and there is no help from others systems yet (pH AND CO2 OR bicarb are abnormal)

vs.

pH is off but other systems are trying to help (pH, CO2, and HCO3 are all abnormal)

vs.

pH is normal but other values are still abnormal

invasive ventilation vs. noninvasive ventilation

the patient is connected to the vent through an endotracheal tube or tracheostomy

vs.

vent support is provided through a mask or nasal prongs ex.

• continuous positive airway pressure (CPAP)

• Bilevel positive airway pressure (BIPAP)

continuous positive airway pressure (CPAP)

delivers continuous pressure during inhalation and exhalation

keeps airways open, especially during sleep or in case of collapse

ideal for obstructive sleep apnea and atelectasis

NOT ideal for patients who have trouble exhaling against pressure and have CO2 retention like in COPD

Bilevel positive airway pressure (BIPAP)

delivers two levels of pressure

• IPAP: increases pressure during inhalation

• EPAP: decreased pressure during exhalation

helps with oxygenation and ventilation (blowing off CO2)

used for:

• COPD exacerbation

• respiratory failure

• neuromuscular disorders

• obesity hypoventilation syndrome (when they lay down, their weight puts pressure on them)

NOT used for sleep apnea without CO2 retention

we try this before intubation; beware that some feel claustrophobic so they need to be able to tolerate it, protect their airways, and understand how to use it

tidal volume (Vt)

amount of air delivered to the lungs (when they inhale) with each breath

normal range: 6-8 mL/kg of ideal body weight

ex. someone who is 5’5” and 100lbs and another who is 5’5” and 200lbs get the same amount

goal: avoid over distending the lungs (or they’ll pop)

fraction of inspired oxygen (FiO2)

percent of O2 delivered to the patient

normal range: 21% (room air) to 100%

goal: maintain an adequate PaO2 (ABGs) and SpO2 (pulse ox)

doctor decides to turn it down if needed

(Feed/Fi-ed me O2)

positive end-expiratory pressure (PEEP)

pressure maintained in the lung at the end of exhalation to prevent alveolar collapse

normal range: 5cm H2O; can go up to 35

as this increases, BP decreases, even vasopressors cannot fix

goal: improve O2 by keeping the alveoli open, particularly in conditions like ARDS

(____ Pushes open alveoli)

peak inspiratory pressure (PIP)

highest pressure during inspiration

increase suggests worsening airway resistance or decreased compliance = the worse the patient is

volume controlled ventilation (VCV)

type of Assist Control for ventilators - patient cannot breathe on their own (Actively Controls breathing - usually after CPR or for life support)

delivers a preset tidal volume with each breath

ex. patient will breathe 14 times with a Vt of 500

it provides full support for rate and tidal volume

used in patients with severe respiratory failure, sedated, or paralyzed

pressure controlled ventilation (PCV)

type of Assist Control for ventilators - patient cannot breathe on their own (Actively Controls breathing - usually after CPR or for life support)

delivers a set inspiratory pressure for a predetermined time

tidal volume varies depending on lung compliance

often used in ARDS to minimize barotrauma

Synchronized intermittent mandatory vent (SIMV)

(S for Step down)

type of assisted mode for ventilators - patient initiates breaths

delivers a determined respiratory rate with a preset tidal volume but patient can initiate additional breaths

allows patient to breath spontaneously in between mandatory breaths

can be helpful in weaning the patient off the vent by gradually reducing mandatory support

pressure support vent (PSV)

type of assisted mode for ventilators - patient initiates breaths

provides pressure assistance during spontaneous breathing

the patient initiates all breaths, but the vent assists by delivering a set pressure during inspiration (makes sure they are breathing in Vt they need)

used to help patients wean from mechanical vent

spontaneous breathing trials (SBT)

when patient is switched to a mode like CPAP or pressure support vent (PSV) to assess their ability to breath independently

they need a gradual reduction in support by reducing fraction of inspired oxygen (FiO2) or PEEP or decrease the set RR

must assess their ABGs, respiratory effort, and ability to protect their airway (or they could aspirate)

readiness to wean factors

• underlying cause for mechanical ventilation is resolved

• have hemodynamic stability and adequate cardiac output (BP, HR, MAP)

• adequate respiratory muscle strength

• adequate oxygenation without a high FiO2 and/or high PEEP

• absence of factors that impair this process ex. off of pain meds and sedation

• mental readiness, do they follow commands?

• minimal needs for medicines that cause respiratory depression

respiratory signs to STOP weaning

• RR above 35 or below 8

• labored respirations

• low spontaneous breaths

• use of accessory muscles

• abnormal breathing pattern

• low oxygen sat (below 90%)

cardiac and neuro signs to STOP weaning

• HR or BP changes 20%+ from baseline

• dysrhythmias

• ST elevation = heart attack from not getting enough oxygen

• diaphoresis - dripping sweat, cold, clammy

• decreased LOC

• anxiety/agitation (needs to be brought down before weaning)

• subjective discomfort

  • ex. pain when taking deep breaths

  • throat pain is expected

barotrauma

injury to the lungs from high pressures

can lead to pneumothorax

needs appropriate Vt, ARDS needs lower Vt

maintain adequate PEEP (5-10), higher PEEP for ARDS

keep PEEP under 35

ventilator associated pneumonia (VAP) prevention

1. hand hygiene

2. oral care q4hrs: cracked mouth → bacteria

3. elevate HOB

4. prevent aspiration

5. routine suctioning

6. vent circuit care

   1. clean / switch out tubing because moisture gets trapped → bacteria

7. early extubation and weaning

ventilator induced diaphragm dysfunction (VIDD)

diaphragm atrophy and weakness from prolonged mechanical ventilation

minimize duration of vent and minimize use of high levels of sedation

how to prevent ventilator related infection

• elevate HOB 30º

• awaken daily and assess readiness to wean

• DVT prophylaxis (Pertonix subQ or heparin drip)

• oral care every 4 hours

high pressure alarm

could be triggered by secretions, kinking, coughing, or bronchospasm

indicates the vent is having difficulty delivering the set tidal volume

(High blockage)

low pressure alarm

could indicate disconnection, leak in the circuit, or endotracheal tube (ETT) cuff leak

alerts nurse to possible loss of pressure in system

for the ETT, call RT because it is not a nursing thing

(Loss of connection or Leak)

low exhaled volume alarm

may be caused by leak or poor ventilation

alerts the nurse if the patient is not receiving the expected volume

if a ventilator alarm goes off, you did everything like check for displacement of tube, looked for kinks and obstructions, and patient begins to become cyanotic, what do you do?

start using bag-valve mask (BVM) and begin respirations then call RT

DOPE checklist for vent alarms

displacement of endotracheal tube

obstruction in the airway or tube

pneumothorax

equipment failure

(call RT)

acute respiratory distress syndrome (ARDS)

when lungs become severely inflamed and filled with fluid leading to difficulty breathing and low oxygen levels

caused by: pneumonia, inhalation injuries, trauma, COVID, aspiration, SEPSIS

progression from lung injury to respiratory distress within 24-48hrs

can be reversed if caught early but can cause multisystem organ failure if left untreated

exudative phase of ARDS

damage to the alveolar epithelium and vascular endothelium produces leakage of water, protein, RBCs, and inflammatory cells into the interstitium and alveolar lumen

(basically the initial inflammatory response)

usually happens in the first 7 days after exposure to a risk factor

proliferative phase of ARDS

type II cells with some epithelial cell regeneration, fibroblastic reaction, and remodeling

lasts up to 7-10 days

most recover rapidly and are weaned from mechanical ventilation during this phase

fibrotic phase of ARDS

collagen deposition in the alveolar, vascular, and interstitial beds with development of microcysts

very few progress to this phase

elasticity is worn away

ARDS manifestations

• tachypnea and dyspnea

• severe SOB/retractions

• crackles due to fluid accumulation

• low O2 levels - even with O2 support

• cyanosis and hypoexemia

• restlessness

• anxiety

• bilateral infiltrates on chest

acute onset less than 7 days

ARDS diagnostics

• CBC - WBC

• ABGs - PaO2 will be low

  • increased PaCO2 in severe cases due to respiratory failure

  • will be normal or low initially

  • respiratory alkalosis in early stages (breathing faster) → respiratory acidosis in late stages (tired of breathing fast)

• blood cultures to detect sepsis

• chest radiograph

  • will be normal early but progresses to infiltrates advancing to total opacity

• CT chest

treatment for ARDS

• remove causative factors

• O2 therapy

• use of PEEP to keep alveoli open

• mechanical vent

• PRONE PATIENT

  • place patient on their stomach to breathe better

  • needs an order

• fluid management (just don’t overload because they are already full of fluid)

• sedation and analgesics if needed

• consider high PEEP

extracorporeal membrane oxygenation (ECMO)

a machine that takes over the function of the lungs and heart, oxygenating blood from outside the body

used in severe cases of ARDS when other treatments are not effective

benefits of proning a patient with ARDS

• reduced risk of ventilator induced lung injury like barotrauma

• less lung compression

• more efficient gas exchange

• improved heart function and O2 delivery to body

• better drainage of secretions