Mechanical Ventilation and Respiratory Failure, Exams of General Surgery

Comprehensive information on mechanical ventilation, its indications, delivery methods, settings, and associated risks and complications. It covers various ventilator modes such as bipap, aprv, peep, and pps, and discusses the use of ventilators in different patient scenarios, including acute lung injury and respiratory distress syndrome. The document also provides guidance on how to approach a patient for treatment and asks the right questions for effective therapy.

Typology: Exams

2023/2024

Available from 05/31/2024

DrShirley
DrShirley 🇺🇸

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Critical Care/ICU Competency
VersaCare Bed -
- blue air mattress that provides pressure relief for pts with *up to Stage III pressure sores*
--> air fills up on one side in order to turn the pt
--> pressure relief primarily to UB (staff must reposition LB in order to provide full body relief)
Total Sport Care Bed -
- each ICU unit owns 1-2 total sport care beds. Include *pink air mattress that provides some
pressure relief to the pt with rotation in UB*
--> provides pulmonary care to pts who require frequent chest physical therapy by providing
*percussions/vibrations to pt's chest*
--> also provides option of *chair egress* with stand assist to allow for full upright seated position and
ease with standing
Portable Monitors -
In the CICU, check with nursing for availability of a portable telemetry unit in order to
progress a pt through Phase I Cardiac Rehab staging. Unless they have transfer orders to the GPU pts
should be monitored during the session unless otherwise noted by nursing. Travel monitors/portable
tele is avail on all ICU's to advance pts
Arterial Line/Arterial BP (ABP) -
- arterial line is a thin catheter that is inserted directly into the artery to measure real-time BP
- Inserted:
--> Radial art
--> Femoral art at the groin: *avoid hip flexion beyond 90 to prevent kinking of the catheter
--> Brachial art
--> Axillary art
- important to the tx of your pt: Art lines are dynamic and positional changes will cause fluctuations in
the pressure due to the positional nature of this line
- the transducer is zeroed or calibrated on the bedside monitor when it is positioned at the level of the
RA and it is attached to the pt's upper arm
--> transducer ABOVE heart = *displays drop in BP*
--> transducer BELOW heart = *displays elevation of BP*
- monitor alarms are set for acceptable BP ranges for each specific pt while pt is lying
--> important to determine if alterations are d/t movement or actual changes in BP
--> BP should return to baseline once activities have stopped and limb is returned to resting position
--> follow the same guidelines in the lab values competency to determine whether a pt is appropriate
for tx
- MAP is constantly available
--> gives you an indication of the average perfusion pressure across the entire cardiac cycle
--> <60 may not be good for tx
Central Venous Line (CVP) -
- used to measure right atrial pressures and fluid status
- Inserted:
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Critical Care/ICU Competency

VersaCare Bed -

  • blue air mattress that provides pressure relief for pts with up to Stage III pressure sores --> air fills up on one side in order to turn the pt --> pressure relief primarily to UB (staff must reposition LB in order to provide full body relief) Total Sport Care Bed -
  • each ICU unit owns 1-2 total sport care beds. Include pink air mattress that provides some pressure relief to the pt with rotation in UB --> provides pulmonary care to pts who require frequent chest physical therapy by providing percussions/vibrations to pt's chest --> also provides option of chair egress with stand assist to allow for full upright seated position and ease with standing Portable Monitors - In the CICU, check with nursing for availability of a portable telemetry unit in order to progress a pt through Phase I Cardiac Rehab staging. Unless they have transfer orders to the GPU pts should be monitored during the session unless otherwise noted by nursing. Travel monitors/portable tele is avail on all ICU's to advance pts Arterial Line/Arterial BP (ABP) -
  • arterial line is a thin catheter that is inserted directly into the artery to measure real-time BP
  • Inserted: --> Radial art --> Femoral art at the groin: *avoid hip flexion beyond 90 to prevent kinking of the catheter --> Brachial art --> Axillary art
  • important to the tx of your pt: Art lines are dynamic and positional changes will cause fluctuations in the pressure due to the positional nature of this line
  • the transducer is zeroed or calibrated on the bedside monitor when it is positioned at the level of the RA and it is attached to the pt's upper arm --> transducer ABOVE heart = displays drop in BP --> transducer BELOW heart = displays elevation of BP
  • monitor alarms are set for acceptable BP ranges for each specific pt while pt is lying --> important to determine if alterations are d/t movement or actual changes in BP --> BP should return to baseline once activities have stopped and limb is returned to resting position --> follow the same guidelines in the lab values competency to determine whether a pt is appropriate for tx
  • MAP is constantly available --> gives you an indication of the average perfusion pressure across the entire cardiac cycle --> <60 may not be good for tx Central Venous Line (CVP) -
  • used to measure right atrial pressures and fluid status
  • Inserted:

--> subclavian vein --> internal jugular vein --> femoral vein: *avoid hip flexion beyond 90 to prevent kinking of the catheter

  • Norms: 0-6
  • very positional and requires transducer to be at the level of the RA
  • if the pt does not have enough fluid, the CVP will be LOW
  • overloaded with fluid, the CVP will be HIGH
  • position sensitive
  • repositioning or movement of pts may cause PVCs or VPB on the monitor Swan Ganz Catheter (PAPC) -
    • pts who are hemodynamically unstable and need cont. monitoring of their cardiac output, pulmonary artery pressures (systolic and diastolic), pulmonary capillary wedge pressures (left ventricular end-diastolic pressure), and mixed venous saturation will have a Swan Ganz/Pulmonary Artery Catheter. The line is a large yellow catheter covered by corrugated plastic and is inserted into the jugular vein or subclav vein, fed through the SVC, through the R side of the heart and rests in the pulmonary art. (usually located on pt's right side)
  • may be too sick for therapy or may be limited to ROM only. ROM on the side of the catheter should be done with care, avoid shoulder ranges greater than 90 & limiting shoulder external rotation to no greater than 45 --> if pt's condition warrants mobilization or ambulation, the therapist should obtain consent from the physician prior to mobilizing the pt w/ Swan Ganz catheter. Disconnection of the transducer should be avoided, but if necessary, done only by nursing.
  • norms for pulmonary art wedge pressure are 5-15 mmHg --> if the pulmonary art wedge pressure reading is *>12 the pt SHOULD NOT be placed in a horizontal position to limit venous return which increases the workload on the ventricle VIGILEO -
    • continuously computes stroke volume from the pt's art pressure signal to determine cardiac output through the use of the Flo Trac Sensor --> the Flo Trac Sensor is a fancy transducer that can be hooked up to any art line
  • can be used to monitor continuous cardiac output (with the Flo Trac) or continuous central venous oxygen saturation
  • displays key hemodynamic parameters on a continuous basis (every 20s) VIGILEO: Stroke Volume, Cardiac Output, Cardiac Index, and Stroke Volume Variation -
    • SV, CO, CI should all increase with activity/exercise --> if pt's SV, CO, CI are below norms, or if you see a decrease w/ activity/exercise it may indicate that the pt's heart is having a difficult time keeping up with the heart and body's demand for O2, and it may not be appropriate for tx.
  • Stroke Volume: the amount of blood pumped by the LV of the heart into the circulatory system in one contraction. Normally, only about 2/3 (66%) of the blood in the ventricle is expelled with each beat --> 60-100 mL/beat
  • Cardiac Output: the volume of blood pumped by the heart into the circulatory system in 1 min. CO= SVxHR --> Norm: 4.7L L/min --> 4.0-8.0 L/min
  • Cardiac Index: the volume of blood pumped out by the heart in relation to body surface area. Shows the performance of the heart in proportion to the size of the individual

VV-ECMO -

Veno-venous ECMO (VV-ECMO): blood is drained from the venous system, oxygenated outside the body, and then is returned to the venous side of the circulation. This provides gas exchange but is unable to provide cardiac support

  • VV-ECMO provides support for a pt in severe respiratory failure without major cardiac dysfunction: severe pneumonia, ARDS, acute lung graft failure following transplant VA-ECMO - Veno-arterial ECMO (VA-ECMO): blood is drained from the venous system, oxygenated outside the body, and then is returned to the arterial side of circulation. This provides both gas exchange and cardiac support
  • VA-ECMO provides support for severe cardiac failure with or without respiratory failure: Specialized Neuro Monitoring -
    • some pts in the neuro ICU may have invasive monitor that could indicate they are not yet stable for therapy intervention. Check with the nurse or medical team to confirm
  • Raumedic catheter is used which measures ICP and PbTO2 (partial pressure of O2 in the brain or cerebral perfusion). This catheter can be inserted through a bolt un the skull. These pts are generally not stable for therapy
  • PiCCO2 (pulse index continuous cardiac output) monitor is for invasive cardiac and lung function monitoring. --> monitoring hemodynamics is important in maintaining cerebral perfusion --> less invasive than a Swans Ganz, but more accurate than a vigileo --> vigileo and PICCO2 both calculate the CO, CI, SVV, and SVRI (these measure cardiac index, stroke volume, some preload, and afterload). However, with thermodilution, the PICCO2 can also calculate the CFI, GEDI, and ELWI on top of those measurements --> CFU is Cardiac Function Index which measures heart contractility or the performance of cardiac muscle. (ratio of flow and preload) --> GEDI is the Global End-diastolic Index used to asses preload more adequately --> Preload is the volume of blood in the heart that is available to be pumped --> ELWI is the Extravascular Lung Water Index which helps assess extravascular water that could be in the lung tissue (this could help identify pts in pulmonary edema) --> one of the complications that can occur with neuro injury is neurogenic pulmonary edema. Usually the pts that have the PICCO2 connected to them are relatively sick or unstable. It is seen in some of the more severe neuro injuries Continuous Renal Replacement Therapy (CRRT) - involves either dialysis or filtration treatments that operate in a continuous mode
  • is a broad term that includes SCUF (slow continuous ultrafiltration), SLED (sustained low-efficiancy dialysis), and CVVH (continuous venovenous hemofiltration)
  • there are types of dialysis that achieve the same results using different waste removal mechanisms
  • the treatment is slow enough that it lasts much longer than typical intermittent HD, often running 24hrs/day --> the slow rate helps to prevent hypotension in hemodynamically unstable pts --> this type of dialysis is used when a pt is not a candidate for PD and is too hemodynamically unstable for HD
  • even with CRRT, hypotension can still occur if too much fluid is removed or if fluid is removed too quickly
  • you must confirm with the RN and ICU team that the pt is tolerating treatment and is stable for therapy intervention
  • the pt may only tolerate intervention in supine or supported sitting in bed --> roles of citrate and calcium: Citrate acts as an anticoagulant in the blood circulating in the machine. Calcium is added to ensure adequate level of cardiac function --> the pt is connected through a double-lumen catheter in a central vein. In CVVH and SLED, the dialysis machin/lines contain ~200cc of blood. In SCUF and intermitted HD, due to the faster flow and greater volume of blood that would be at risk of loss is the line disconnected --> most machine alarm you may hear with mobilization would be access pressure and flow alarm easily reset by an ICU nurse. The machine does stop the pump when alarming, but the pt is not negatively impacted due to the presence of citrate that prevents blood clotting. If the alarm does not clear a CRRT tech could be there in a few mins or if you are more comfortable you could ask for a CRRT tech to be present during your session --> There is no contraindication from nephrology standpoint to mobilize SLED-RCA pts, but you must take into account a few important considerations: -
    1. most SLED-RCA pts are very sick and at risk of bp drops when sitting or standing. The PRIMARY ICU team must approve any mobilization in advance based on the perceived hemodynamically stability of the pt. Not all pts may be appropriate for mobilization out of bed, but may tolerate activity in bed
  1. pts who have non-tunneled temporary HD catheters in the fem vein should not be mobilized out of bed as the cath are less secure and have a higher risk of becoming dislodged. Tunneled fem caths are secure as a portion of the line tunnels subcutaneously, and these pts are usually safe to sit and stand. IJ caths can be either type without this mobilization concern. Nephrology, the ICU team, or the nurse can identify why type of fem cath the pt has. You may also find this info in LDA
  2. mobilizing pts has to be done very carefully as not to disconnect any element of the blood circuit or the citrate or Ca infusion. This may require the presence of the ICU nurse or a CRRT tech during therapy
  3. if you need to move the dialysis machine, take care not to press any buttons but hold the machine by the sides Blood Gases -
    • art blood gases are sensitive indicators of a pt's changing physiological state. they help to determine if a pt is being adequately oxygenated
  • the primary blood gases of concern in the ICU are PaO2 (partial pressure of O2 in the blood) and PaCO2 (partial pressure of carbon dioxide in the blood) --> these #s are obtained through a blood draw
  • blood gases drive a physicians decision whether to give supplemental O2, how much, as well as whether to progress to a venti-mask or ultimately to intubate. These decisions are made when the blood gases deteriorate below norms
  • PaO2 is the pressure gradient between the capillaries and tissues that determines the movement of O2 from the blood into the tissues --> Norms: 80-100 mmHg --> lower pressure gradients indicate a stronger bond between the O2 and hemoglobin, leading to a less effective transfer of O2 to the tissues --> at PaO2 levels <40, hypoxemia can occur
  • each day, adults generate large amounts of acids that must be excreted, metabolized, and/or buffered to avoid fatal acidemia
  • the acids rise from CO2 and from norm metabolic reactions within the body and from a person's diet
  • acid-base balance is maintained by norm pulmonary excretion of CO2, metabolic utilization of organic acids, and renal excretion
  • Norms: 7.35-7.45
  • if an increase in acid overwhelms the body's acid-based control systems, the blood will become acidic
  • as blood pH drops (becomes more acidic), the parts of the brain that regulate breathing are stimulated to produce faster and deeper breathing (respiratory compensation) --> breathing faster and deeper increases the amount of CO2 exhaled
  • the kidneys also try to compensate by excreting more acid in the urine --> however, both mechanisms can be overwhelmed if the body continues to produce too much acid, leaving to severe acidosis and eventually heart problems and coma Acidosis can be classified as a metabolic or respiratory: - Metabolic acidosis: develops when the amount of acid in the body is increased through ingestion of a substance that is, or can be metabolized into, and acid; or from abnormal metabolism
  • Excess acid is also produced in advanced stages of shock and poorly controlled type 1 DM
  • even the productions of norm amounts of acid may lead to acidosis when the kidneys are not functioning normally --> theses pts may experience nausea, vomiting, and fatigue --> breathing may become deeper and faster in an attempt to compensate --> confusion may develop
  • in severe cases, cardiac function may become impaired and BP can fall, leading to shock, coma, and death Respiratory acidosis: develops when the lungs do not expel carbon dioxide adequately
  • this is a problem that can occur in disorders such as emphysema, chronic bronchitits, severe pneumonia, pulmonary edema, and asthma
  • respiratory acidosis can also develop when disorders of the brain or of the nerves or muscles of the chest impair breathing
  • in addition, people can develop respiratory acidosis when their breathing is slowed due to oversedation from opioids or strong drugs that induce sleep --> as a result of the slowed breathing, the level of oxygen in the blood may be also be low --> pts may feel headache and drowsiness initially, with progression to stupor and coma as oxygen levels drop Acid-Based Disorder - Respiratory Alkalosis
  • pH: >/= 7.45
  • PaCO2: </= 35
  • Cause: anxiety sedatives, COPD, pain, fever, CHF, CVA, PE meningitis, psychosis
  • Symptoms: dizziness, paresthesia, chest pain , confusion, seizure
  • Implications: may need to coordinate treatments around ventilation --> expect somnolence and fatigue Respiratory Acidosis
  • pH: </= 7.35
  • PaCO2: >/= 45
  • Cause: decreasing ventilation, depression of central respiratory center (drugs v. cerebral disease), neuromuscular disease (ALS, GBS, MD), asthma/COPD
  • Symptoms: confusion, fatigue and/or lethargy, SOB, somnolence
  • Implications: may need to coordinate treatments around ventilation --> expect somnolence and fatigue Metabolic Alkalosis
  • pH: >/= 7.45
  • HCO3: >/= 30
  • Cause: severe vomiting, diarrhea, severe dehydration (diuretics), retention of bicarbonate, decreasing ventilation, causing increasing hypercapnia, cystic fibrosis, chloride-resistant
  • Symptoms: CO2 retention
  • Implications: may need to coordinate treatments around ventilation --> expect somnolence and fatigue Metabolic Acidosis
  • pH: </= 7.35
  • HCO3: < 24
  • Cause: increased acid production, decreased renal acid, excretion, laxative abuse, thiazide diuretics, massive diuresis
  • Symptoms: lactic acidosis, ketoacidosis, kidney disease, cardiac arrhythmia w/ pH <7.1, diarrhea or other intestinal losses, anxiety related to hypoxia
  • Implications: may need to coordinate mobility around dialysis (CVVHD v. HD)
  • expect somnolence and fatigue
  • consider risk of arrhythmias with mobility MICU checklist for chart review -
    1. Summary > Index PT/OT
  • last labs in 24hrs (middle of page) (or use Chart Review Labs tab) > blood gas, troponin ordered, transfusion orders --> Current Meds (middle of page, or can use Chart Review Meds tab) > Nimbex - Definite hold; Propofol - probable hold, check w/ RN; Levophed, Versed, Fentanyl, Amiodarone - if trending up dosage may be a hold
  1. Chart Review > Imaging, Procedures (Dopples, Dialysis for planning), Notes (prior and current admission PT, OT, CM notes), Meds/Labs if not above, Other Orders (transfer orders, plans for extubation)
  2. Flowsheets > VS Complex for BP, HR, RR, SaO2 trends; > Mechanical Vent for setting
  • Notes > Last 1-2 RN notes (presentation, alertness, mobility) -> PA, resident, fellow (active problems/plans) -> Neuro, Ortho, Cardio consult (prob for precaution, WBS, planned procedures)
  1. if pt on HD/SLED coordinate accordingly. Dialysis/SLED: 169571, 169565, 169564
  2. if opposite discipline not available per chart review or Therapist communication see who could be a one person. Could ask RN/NA assistance
  3. if pt seems ML-5, can either talk to pt if any concerns, but if unsure, can do a quick eval decide. Same way if pt at baseline, speak to family or can do a quick eval and document in epic. Note from us in EPIC in first 24nrs
  4. RT Manager for travel or portable vent next day: 160627 Contraindications for PT/OT -
  • if a pt is agitated or their med status requires to use of versed, this will be added in addition to the Fentanyl
  • it is likely that an IV push of versed will be initiated first and based on the pt's response may be increased as needed all the way up to an IV infusion if required --> if your pt has a hx of IVDA, the addition of versed may not cause the sedative effect in normally would on most pts. These pts have a high tolerance to control pain therefore they may be able to participate in therapy despite this med --> if your pt is unable to remain alert while on this med, you will likely want to defer therapy at that time Precedex -
    • is often used to decrease pt agitation
  • the benefit is that it can control restlessness and agitation without causing respiratory depression --> if this reason, you may see it used in a pt that is needing assist with being able to wean from the ventilator
  • the pt's ability to participate in therapy will need to be assessed on a case by case basis after discussion with the RN or MD Propofol -
    • is used as a general anesthetic for surgery and as a heavy sedative for critically ill pts in the ICU
  • if a pt is on this med, you may want to hold therapy at that time as the pt will not likely be able to successfully participate
  • it may also be a sign that the pt is too ill for therapeutic intervention and that the medical team is trying to heavily sedate the pt so their body can rest and heal
  • despite the general rule that the pt on propofol will not be able to participate, always check with the RN before assuming
  • a pt that has a history of alcohol or drug use may not respond the way to would expect to receiving proprofol
  • in some cases, a pt may still be able to participate Nimbex -
    • is a paralytic that is often used when the pt is very medically compromised and requires paralysis in order for their body to heal. If your pt is on this med, therapy is contraindicated Documentation Tip: Care Plan -
    • use smartphrase .phtmicueval or .phtmicuprog (.otmicueval or .otmicuprog) --> includes phrase related to early rehab and a place to include total time spent in care of the pt (to justify charges further) Delirium and Cognition - Delirium: a disturbance of consciousness characterized. by acute onset and fluctuating course of inattention accompanied by either a change in cognition or a perceptual disturbance, so that a pt's ability to receive, process, store, and recall info is impaired
  • develops over a short period of time (hours-days), is usually reversible, and is a direct consequence of a medical condition, substance intoxication or withdrawal, use of meds, toxin exposure, or a combo
  • many delirious ICU pts have recently been comatose, indicating a fluctuation of mental status. Comatose pts often, but not always, progress through a period of delirium before recovering to their baseline mental status
  • think: rapid onset, inattention, clouded consciousness (bewildered), fluctuating
  • ICU delirium is a predictor of: *^ mortality, length of stay, time on vent, costs, re-intubation, long- term cognitive impairment, and discharge to long-term care facility
  • there are three subtypes of delirium: hyperactive, hypoactive, and mixed --> Hyperactive delirium: characterized by agitation, restlessness, and attempts to remove tubes and lines --> Hypoactive delirium: characterized by withdrawal, flat affect, apathy, lethargy, and decreased responsiveness --> Mixed delirium: when pts fluctuate between the two. In ICU pts mixed and hypoactive are the most common, and are often undiagnosed (invisible) if routine monitoring is not implemented. Few ICU pts (<5%) experience purely hyperactive delirium Why do we need to understand delirium? - people with delirium have difficulty paying attention and it can affect the ability to maintain awareness of their surroundings. Confusion regarding day-to-day events, daily routines and roles of familiar people is common. Delirium can cause hallucinations, paranoia as well as changes in personality. Understanding delirium and how it may affect a pt may allow us to provide more pt- centered treatments as well as make appropriate goals and discharge recommendations. Up to 80% of intubated pts experience some level of delirium that can be present for weeks and even months post discharge from the ICU and hospital. Our goal is to help pts regain function as well as independence and delirium is a barrier to just that The Confusion Assessment Method (CAM-ICU) and Richmond Agitation Assessment Scale (RASS) - the CAM-ICU is a bedside tool used to assess delirium
  • before assessing delirium we have to assess consciousness which we do using the RASS --> if a pt has a RASS score >/= -3 process to the CAM-ICU --> if a pt has a RASS score of -4/-5 = considered unconscious and not appropriate for the CAM- ICU Step One: Level of Consciousness Assessment (RASS) - RASS >/= -3 proceed to CAM ICU (is pt CAM-ICU positive RASS -4/-5 STOP (pt unconscious) RECHECK later Procedure for RASS Assessment -
    1. observe pt
  • a: pt is alert, restless, or agitated (score 0 - +4)
  1. if not alert, state pt's name and say to open eyes and look at speaker
  • b: pt awakens with sustained eye opening and eye contact (score -1)
  • c: pt awakens with eye opening and eye contact, but not sustained (score -2)
  • d: pt has any movement in response to voice but not eye contact (score -3)
  1. when no response to verbal stimulation, physically stimulate pt by shaking shoulder and/or rubbing sternum
  • e: pt has any movement to physical stimulation (score -4) -f: pt has no response to any stimulation (score -5) Step Two: Delirium Assessment (CAM-ICU) -

Failure to Oxygenate

  • the inability to distribute O2 to the body (there is an obstruction of gas exchange between the alveoli and capillaries)
  • Hypoxic Respiratory Failure --> inadequate exchange of gases at the alveolar level, as seen in ARDS --> decreased PaO2 (<50) --> PaO2 of less than 80 on supplemental O2 or less than 60 on room air --> can occur despite normal ventilation --> occurs at pulm-alveloar interface due to pulm edema or fibrosis --> reduced diffusing capacity and V/Q mismatch Airway Protection
  • pts in shock with SBP less than 80
  • severe head injury or unconsciousness
  • anticipated surgery
  • airway obstruction that cannot be simple relieved Acute Lung Injury/Acute Respiratory Distress Syndrome
  • alveolar filling disorders causing pulm edema and stiffness in lungs, making difficult to ventilate --> clinical presentation: *acute onset, bilateral infiltrates, severe dyspnea and tachypnea, hypoxemia, can be caused by a variety of factors, usually inflammatory in nature pulmonary (pneumonia) vs. extra pulmonary (sepsis) Risks/Complications Of Mechanical Ventilation -
    • asynchrony- "buckling" or fighting the vent
  • auto PEEP: pt doesn't expire full tidal volume and air becomes trapped
  • Barotrauma: damage to alveoli caused by increased pressure and volume
  • hemodynamic compromise
  • Nosocomial Infection (pneumonia)
  • anxiety/stress/sleep deprivation
  • ulcers/gastritis/malnutriiton
  • muscle deconditioning
  • vent dependence
  • increased intrathoracic pressure can cause systemic edema due to decreased venous return
  • tidal volumes too small may increase dead space
  • prolonged exposure to high levels of O2 can be toxic to the lungs
  • high FiO2 (>.5) can lead to atelectasis Ventilator Delivery Methods - Intubation (Endotracheal Tube: ETT)
  • can be placed orally (most common) or basally
  • passes through the vocal cords Tracheostomy Tube
  • inserted below the vocal cords
  • used in more long-term airway management
  • Cuff v. Cuffless
  • Airway Cuffs:

--> assists with holding the airway in place --> allows positive pressure ventilation without loss of tidal volume --> may reduce risk of aspiration of oral and gastric secretions --> if pt can talk of is losing tidal volume....cuff may be not full inflated Masked Ventilation

  • BiPAP, CPAP Ventilator Settings -
    • the amount of assistance the ventilator provides to the pt is based on the mode of the ventilator and additional assistance settings
  • modes can be volume controlled or pressure controlled --> Volume controlled setting maintain a set tidal volume and guarantee and precise minute ventilation. Most commonly used in the OR and are less seen in pts appropriate for therapy intervention --> Pressure controlled settings do not ensure a precise minute ventilation but allow the pt to do more of the work as they are able
  • trigger sensitivity setting is a variable that determines how much respiratory effort the pt needs to exert to activate the delivery of a breath by the ventilator regardless of the ventilator mode --> the higher sensitivity setting, the les effort the pt must put forth to trigger the vent; breath initiation can even be triggered by the ANS --> as the pt begins to generate greater inspiratory efforts, the setting can be changed to have the pt perform more of the work
  • Ventilator Settings Include: --> Tidal Volume --> PEEP --> Mode --> Rate --> FiO2 --> PSV Ventilator Modes -
    • the most common mode of the ventilator seen at HFH are: Pressure Control
  • PC delivers a breath as constant present pressure during time and frequency Controlled Mandatory Ventilation (CMV)
  • CMV delivers a present tidal volume during a present time and frequency
  • on this mode, the ventilator is set for a min # of breaths per min
  • pt must initiate some level of inspiration to generate the breath (trigger sensitivity can be adjusted), but the machine then takes on all of the work of breathing to reach a certain tidal volume for each breath --> these breaths are "controlled" or "mandatory" breaths --> if the pre-set min is 15breaths/min, the ventilator will provide those 15 breaths at a consistent tidal volume
  • the pt can take an unassisted breath while on this mode in addition to the pre-set min, thus the set number of breaths may differ from the actual of # of breaths --> you may use this difference as indicator of the pt's respiratory effort and strength
  • the combo of the pt breaths and vent breaths should meet or exceed the pre-set min
  • the machine synchronizes with the pt's breaths cycle so that it does not provide a breath just as the pt is about to exhale or in the middle of another breath (to avoid breath staking)
  • the pt shows that they are getting stronger and weaning from the vent when they are providing more breaths than the machine
  • the pt can then be weaned to CPAP
  • Summary: --> similar to CMV, but pts can take own breath with their own TV between mechanically assisted breaths
  • can be used as a primary mode or a weaning mode
  • may lead to low RR in a pt who does not initiate breaths if rate is set low Continuous Positive Airway Pressure (CPAP) -
    • on this mode, the pt is initiating and following through with each breath but the vent is assisting those breaths y providing a continuous positive pressure throughout the breathing cycle to assist with vent and decreased the work of breathing
  • CPAP provides assistance throughout inspiration and expiration, helping to keep the pt's functional residual capacity (FRC) from decreasing
  • if the pt fails to meet the pre-set min breaths/min, the vent will alarm BUT WILL NOT PROVIDE ADDITIONAL BREATHS!
  • this is usually the mode that the pt will be on during spontaneous breathing trials prior to vent weaning --> however, some pts may transition to BiPAP, CPAP can also be administered non-invasivelt via a face or nasal mask for sleep apnea pts
  • Summary: --> constant positive airway pressure provided during BOTH inspiration and expiration --> vent provides O2 and alarms, BUT NOT RESPIRATIONS --> improved gas exchange and oxygenation in pt able to breathe on their own BiPAP (Bi-level Positive Airway Pressure) -
    • on this mode, the *pt initiates and follows-through with every breath but is provided with separate inspiratory and expiratory positive pressures to assist with delivery of O2 and removal of CO
  • there are no additional support modes with BiPAP
  • may be used as a primary ventilatory support setting for pts with acute respiratory compromise or as a support for breathing abnormalities during sleep such as Obstructive Sleep Apnea (OSA) Airway Pressure Release Ventilation (APRV)
  • this mode differs from conventional vent as it cycles between a raised CPAP level of airway pressure and a short period of low pressure to assist with gas exchange
  • this elevation of airway pressures with brief intermittent releases of airway pressure facilitate oxygenation and CO2 clearance
  • this may be an improved way to treat ALI/ARDS
  • the functional residual capacity is maintained with the CPAP level Positive End Expiratory Pressure (PEEP) -
    • this assistance mode provides a positive pressure at the end of expiration to keep the airways from collapsing, thus decreasing O2 requirements, improving FRC and PaCO2 levels, while decreasing the WOB
  • this pressure pops the alveoli open and allows increased time for O2 exchange them for O2 exchange
  • PEEP will lower O2 requirements by recruiting more surface areas
  • norm PEEP is ranges from *5-24cm H20 and is set based on pt FiO2 requirements in order to achieve optimal ventilation
  • there is potential for PEEP to be set higher based on pt needs and medical status, however this does increased the risk of barotrauma
  • PEEP setting >10cm H20 pressure = may want to initiate a discussion with the RT/team to determine whether therapy should be deferred at that time or if modified treatment is safe --> increased PEEP (and PSV) settings may compromise a pt's cardiovascular status due to barotrauma or pneumothorax, or by increasing intra-thoracic pressure and lung volumes, leading to decreased venous return and altered SVs Positive Pressure Support (PPS) or Positive Support Ventilation (PSV) -
    • as with PSV/PPS, the pt can be on any of the modes of the vent and have a PEEP setting as well
  • some vents describe CPAP and PEEP as the same thing --> when CPAP is being used as a mode of the vent, the pressure from the PEEP setting is "above CPAP" since both demo positive pressure applied at the end of expiration
  • this assistance mode provides an extra positive pressure during inspiration to overcome airway resistance in order to help the pt reach a set TV for each inspiration
  • as the pt is able to generate enough inspiratory pressure to keep the airways adequately open, the PSV or PPS can be decreased
  • higher amounts of PSV are needed when lung compliances is decreased or airway resistance is high or when the pt can only make weak inspiratory efforts --> PSV 5 is considered a low amount --> PSV 10 or > is considered a high amount --> PSV can only be set in modes that support spontaneous breathing
  • the pt can be on any of the modes of the vent and have a PSV or PPS setting as well (sometimes a pt may be on just a PSV setting as the mode of the vent. This usually occurs after they have done well on CPAP but are not quite ready to try a full Briggs or weaning trial. The pt receives assistance during inspiration only while on PSV whereas assistance is given for inspiration and expiration while on CPAP. Since the pt controls the rate, TV, flow rate and duration of inspiration, pts may be more comfortable on PSV Ventilator Alarms -
    • General principles..... --> look at the pt first!!! Then follow tubing to the vent to search for any disconnections --> if you can't find the prob and the pt is in distress, disconnect the ot from the vent and bag w/ 100% O2 and call for help Higher Pressure Alarm
  • the high pressure alarm will sound when the machine senses a higher pressure resistance to the ventilatory process (common alarm to come and go...more serious if it continues to alarm) Ex:
  1. when a pt coughs or bronchospasm
  2. when the RR increases about set limits
  3. water build-up in the tubing
  4. a kink in the lines or obstruction of the trachea or malposition of ETT
  5. migration of the tube into the main stem bronchi

--> first trach change will be done by MD. Subsequent trach changes can be done by RT, unless pt airway needs require MD intervention to manage tracheostomy. This may be the case if the pt has a diff. airway --> pt will not usually travel off of the unit for the first 24hrs post new trach Ventilator Weaning - Indications:

  • the RTT will initiate the weaning process when the pt meets the following indications: --> cause of respiratory failure has been identified and treated with significant improvement or resolution --> adequate ventilatory drive, ability to initiate as inspiratory effort --> no muscular fatigue, neurological or nutritional indications for continued mechanical vent --> hemodynamic stability; as defined by the absence of active myocardial ischemia and the absence of clinically important hypotension (a condition requiring no vasopressor therapy or only low-dose vasopressors such as dopamine or dobutamine < 5 micro g/kg/min) —> adequate oxygenation: PaO2 >/= 60 and SpO2 >/= 92% on FiO2 </= 50% and PEEP no greater than 5 —> good cough/gag —> minimal sedation —> minimal secretions/suctioning less than every 2hrs —> chest tube output less than 100m/hr (when applicable) Guidelines
  • active weaning will take place between the hours 0600 and 2200
  • MICU pts will be routinely assessed for weaning every morning between 6-8 a.m.
  • SICU pts will be routinely assessed for weaning in the following manner: —> Post-op Day 1 and 2: immediately upon admission to SICU, then every 2hrs during active weaning hours —> Day 3 and after: every morning between 6-8a.m.
  • procedure for neuro pts regarding weaning is not specified in RT weaning policy Indications for Reinstituaiton of Medchanical Ventiliation or Signs of Distress During Weaning -
    1. Fall in PaO2 below 60 when breathing 10L/min or 40% O2 by an aerosol humidifier
  1. Increase in PaCO2 of 10/hr or 5 for 3 consecutive hours
  2. RR consistently exceeding 50
  3. Increased HR
  4. Irregular breathing pattern or use of accessory muscles
  5. Agitation or panic unrelieved by assurance
  6. Sudden deterioration of consciousness What Do I Do When I First Approach a Vented PT for Treatment? - *Prior to evaluate or treating a pt w/ mechanical vent, it is necessary to do the following:
  7. Check the medical records for trends in the pt's VS, blood gases, ventilators status, etc.
  8. Check with the nurse to determine if it is a good time for intervention. The staff may be getting ready to change settings or may have just changed them Situations that might contribute to a delay in providing therapy would include:
  1. Same day deterioration in medical status: this would include new difficulties in keeping a pt oxygenated as should by deteriorating blood gases with an increase in required oxygen (>60% or

12L), a change in the mode or settings. Check the chart for trends in O2 requirements

  1. New extubation: pts who are newly extubated require at least a few hours to rest and demonstrate stability before therapy is continued
  2. Newly intubated: if the pt has recently deteriorated to the point that they needed vent support, they may not be stable for therapy at this time
  3. Re-intubated: if it appears that apt has been re-intubated, ensure that the pt required new intubation vs. being on a night-time rest schedule before deciding to defer. Some pts can be on T-bar or CPAP during the day through their trach, but will rest at night on full vent support
  4. New tracheostomy placement: the pt may be sedated and new trachs tend to ooze blood, thus therapy should be deferred for 12-24hrs
  5. All other possible situation indicated in departmental competencies or special test precautions should be considered Treatment Guidelines: - Modes of Assistance: - PPS/PPV: Positive Pressure Support/Positive Support Ventilation
  • gives added support during inspiration to decreased the work of breathing
  • can the pt be on any MODE of the vent and have this MODE OF ASSISTANCE?: YES
  • can the pt be on PSV/PPS and PEEP at the same time: YES
  • can the pt be on a MODE OF ASSISTANCE and not be on the vent: NO
  • max setting for continued treatment?: AVERAGE ~6 PEEP: Positive End Expiratory Pressure
  • provides positive pressure JUST AT THE END OF EXHALATION to "pop" open the alveoli allowing them to be more available for gas exchange
  • can the pt be on any MODE of the vent and have this MODE OF ASSISTANCE?: YES
  • can the pt be on PSV/PPS and PEEP at the same time: YES
  • can the pt be on a MODE OF ASSISTANCE and not be on the vent: NO
  • max setting for continued treatment?: PEEP > 10 = NO TREATMENT AC/SIMV/CPAP - AC: Assist Control SIMV: Synchronized Intermittent Mechanical Ventilation CPAP: Continuous Positive Airway Pressure
  1. Pt initiated each breath?
  • AC: YES —> pt does not initiate each breath but machine can be set at such a low sensitivity that the pt doesn't have to do much to trigger the vent to take over
  • SIMVI: YES
  • CPAP: YES
  1. Pt can take their own breaths?
  • AC: YES —> the vent will deliver the min # of breaths but if the pt is getting stronger and can support a breath on their own, the vent will allow for that