Mechanical Ventilation: Pressure Support, Pressure Control .
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)ALERTNever disable ventilator alarms.Always plug a ventilator into a power outlet that is supplied by an emergencygenerator.OVERVIEWPositive pressure ventilation (PPV) through an artificial airway is used to maintain orimprove oxygenation and ventilation. Respiratory insufficiency or failure, evidenced byapnea, hypoxia, hypercarbia, and increased work of breathing, are indications formechanical ventilation. Selection of volume or pressure modes is dependent on the availableevidence, clinical goals, availability of modes, and the practitioner’s preference. There isvery little evidence indicating that one mode of ventilation is more effective than another interms of clinical outcomes (i.e., mortality) and ventilator hours needed.Positive pressure modes of ventilation have traditionally been categorized into volume modeand pressure mode. However, with the advent of microprocessor technology, sophisticatediterations of traditional volume and pressure modes of ventilation have evolved. Ventilatormanufacturers have created different names for the modes, and parameters that requireadjustment vary somewhat among the ventilators. Although many of the modes havenames that are different from traditional volume and pressure modes, they are similar infunction in many cases. There is little evidence that the newer modes improve outcomes.With traditional pressure ventilation, the practitioner selects the desired pressure level, andthe inspired tidal volume (VT) is determined by the selected pressure level and the patient’sresistance and compliance. This is an important characteristic to note when caring for anunstable patient on a pressure mode of ventilation. Careful attention to exhaled VT isnecessary to prevent inadvertent hyperventilation or hypoventilation. Permissivehypercapnia should not be attempted in patients with elevated intracranial pressure (ICP) orpatients with myocardial ischemia, injury, or arrhythmias. Some patients receiving lowpressure ventilation, leading to permissive hypercapnia, require sedation to decreasespontaneous effort.Many modes of pressure ventilation are available. Those modes include assist-control (A/C),synchronized intermittent mandatory ventilation (SIMV), pressure support ventilation (PSV),positive end-expiratory pressure (PEEP) and continuous positive airway pressure (CPAP),pressure-control/inverse ratio ventilation (PC/IRV), proportional assist ventilation (PAV),adaptive support ventilation (ASV), airway pressure release ventilation (APRV), and biphasic(Table 1).Table 1 Volume and Pressure Modes and Corresponding Ventilator ParametersMode nameMain parametersCommentsanddescriptionAssist controlVTGenerally considered a support mode. Must(A/C)Rateswitch to another mode or method forTIweaning.Copyright 2020, Elsevier, Inc. All rights reserved.1 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory lation(PCV)Pressurecontrolledinverse vel itivityFIO2PEEPVTRateTISensitivityFIO2PEEPPressure support (PS)levelSensitivityFIO2PEEPInspiratory pressure limit(IPL)RateTISensitivityFIO2PEEPAs for PCV, but aninverse inspiratory-toexpiratory (I:E) ratio isattained by lengtheningthe TI. Inverse ratiosinclude 1:1, 2:1, 3:1,and 4:1.PHIGHPLOWTHIGH (similar toinspiratory time in PC)TLOW (similar toexpiratory time in PC)orSet THIGH/TLOW ratioRateFIO2PHIGH: high CPAP levelPLOW is generally 0–5H2O.THIGHTLOWFIO2Originally used as a weaning mode; however,work of breathing is high at low SIMV rates.Often used in conjunction with PSV.Often pressure is arbitrarily selected (e.g.,10–20 cm H2O) then adjusted up or down toattain the desired tidal volume. Some use theplateau pressure if transitioning from volumeventilation as a starting point.Variants of PCV include volume-assuredpressure options and some other modes, suchas airway pressure release ventilation andbilevel ventilation.Some ventilators allow for the I:E ratio to beselected.Similar in many ways to PCV in that aninspiratory pressure (PHIGH) and PEEP (PLOW)are set. However, unlike PCV, the patient maytake spontaneous breaths as well. Ifadditional support is desired for patientinitiated breathing, pressure support in bilevelmode (PSUPP) may be selected as well.Attention to VT is important because thepatient can augment VT significantly withsupported spontaneous breaths.APRV is a form of biphasic ventilation with avery short expiratory time. Generally, theCPAP level is adjusted to ensure adequateoxygenation while the rate of the releases isincreased or decreased to meet ventilationgoals. VT is variably dependent on the CPAPlevel, compliance and resistance of thepatient, and patient spontaneous effort.Copyright 2020, Elsevier, Inc. All rights reserved.2 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)Dual controlor volumeassuredpressuresmodes (1–5listed below)These modes providepressure breaths with aminimum tidal volumeassurance.1. Volumesupport (VS)VTSensitivityFIO2PEEPRate and TI set inaddition to those set forVS.Rate and TI are set inaddition to those set forVS.2. Pressureregulatedcontrol (PRVC)3. Volumecontrol plus(VC )4. Adaptivesupportventilation(ASV)Body weight%MinVolHigh pressure limit5. Proportionalassistventilation(PAV)Proportional pressuresupport (PPS): PEEP,FIO2, percent volumeassist and flow assistProportional assist plus:PEEP, FIO2, percentsupportEndotracheal tubeinternal diameterPercent compensation6. Automatictubecompensation(ATC)These modes are ventilator-specific. Althoughthe similarities are greater than thedifferences, they are called different names.Often the names suggest that the mode is avolume mode, yet a decelerating flow pattern(associated with pressure ventilation) isalways provided.The pressure level is automatically adjustedto attain the desired VT. If control of pressureis desired, it must be carefully monitored.As with VS. The difference is that this is acontrol mode. Spontaneous breaths, however,may also occur.This is a mode option listed in the categorycalled Volume and Ventilation Plus. To accessthis mode, the RT selects the SIMV or A/C(both control modes), then selects VC . Forsome clinicians, this is confusing because itappears that the patient is on two differentmodes versus VC .Once basic settings are selected, ASV isstarted and %MinVol is adjusted if indicated.Spontaneous breathing is automaticallyencouraged, and when the inspiratorypressure (PINSP) is consistently 0 and rate is 0,extubation may be considered.Depending on the ventilator, the amount ofassistance that is provided is determined bythe clinician, and different parameters areselected to do so. Default percent supportnumbers are recommended, but the clinicianmust determine the timing of reductions ofsame.This is not an independent mode, but rather apressure option to offset the work associatedwith tube resistance. It can be combined withother modes or used alone, as in a CPAPweaning trial.%MinVol, minute volume; A/C, assist control; APRV, airway pressure release ventilation; ASV, adaptive supportventilation; ATC, automatic tube compensation; BiPAP, bilevel positive airway pressure; CPAP, continuous positiveairway pressure; FIO2, fraction of inspired oxygen; I:E, inspiratory-to-expiratory; PAV, proportional assistventilation; PAV , proportional assist plus; PC, pressure control; PCV, pressure-controlled ventilation; PEEP,positive end-expiratory pressure; PHIGH, pressure high; PINSP, inspiratory pressure; PLOW, pressure low; PPS,proportional pressure support; PRVC, pressure-regulated control; PSUPP, pressure support; PSV, pressure supportventilation; SIMV, synchronized mandatory ventilation; THIGH, time high; TI, inspiratory time; TLOW, time low; VC ,volume control plus; VS, volume support; VT, tidal volume(Adapted from Burns, S.M. [2008]. Pressure modes of mechanical ventilation: The good, the bad, and the ugly.AACN Advanced Critical Care, 19[4], 399-411.)Copyright 2020, Elsevier, Inc. All rights reserved.3 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)Summary descriptions of modes, mode parameters, and ventilator alarms are providedwithin this procedure (Table 1) (Table 2).Table 2 Alarms and Backup Ventilation Setting of Initial Ventilatory Setup(Adults)AlarmSettingLow pressure5–10 cm H2O below PIPLow PEEP/CPAP3–5 cm H2O below PEEPHigh pressure limit50 cm H2O, which is adjusted to 10–15cm H2O above PIPLow exhaled VT100 ml or 50% below set VTLow exhaled MV2–5 L/min or 50% below minimum SIMVor A/C backup MVHigh MV50% above baseline MVOxygen percentage (FIO2)5% above and below set oxygenpercentageTemperature2 C (3.6 F) above and below settemperature, high temperature not toexceed 37 C (98.6 F)Apnea delay20 secApnea valuesVT and rate set to achieve full ventilatorysupport (VT 6–8 ml/kg, rate 10–12breaths/min) with 100% oxygenA/C, assist-control; CPAP, continuous positive airway pressure; FIO2, fraction of inspired oxygen; MV, minutevolume; PEEP, positive end-expiratory pressure; PIP, positive inspiratory pressure; SIMV, synchronized intermittentmandatory ventilation; VT, tidal volume(From R.M. Kacmarek, J.K. Stoller, A.J. Heuer. [2017]. Egan’s fundamentals of respiratory care [11th ed.]. St.Louis: Elsevier.)HumidityHumidity is essential to prevent the drying effect of the gases provided by the ventilator.Inspired gases may be humidified with the use of standard cascade or high-volumehumidifiers. Many organizations use disposable heat-moisture exchangers (HMEs) in placeof conventional humidifiers because HMEs decrease the risk of infection and areinexpensive. HMEs prevent hypothermia, evaporation and thickening of secretions,atelectasis, and destruction of the epithelium in the airway. 1 The use of HMEs has beenassociated with decreased incidence of ventilator-associated pneumonia (VAP) in ventilatedpatients.5ComplicationsComplications of PPV include pulmonary barotrauma, volume-pressure trauma,hemodynamic changes, and VAP. Pulmonary barotrauma is manifested by pneumothorax, pneumomediastinum,pneumopericardium, pneumoperitoneum, and subcutaneous emphysema. Volume-pressure trauma is evidenced by large volumes being translated into highplateau pressures and subsequent acute lung injury.Copyright 2020, Elsevier, Inc. All rights reserved.4 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy) Hemodynamic changes can be caused by PPV, which can reduce venous return anddecrease cardiac output. Auto-PEEP is a common complication of mechanical ventilationthat can result in hemodynamic compromise and even death.EDUCATION Clarify advance directives with the patient and family.During a life-threatening emergency, mechanical ventilation may need to be initiatedquickly, with no time for staff to speak with the patient or family members beforehand.As soon as possible, educate the patient and family about mechanical ventilation.Ensure that the patient and family understand the implications of intubation andmechanical ventilation specific to the situation, including why a ventilator is being used.Communicate in a way they understand; “respirator” and “life support” are commonlyunderstood terms.Explain the procedure to the patient and family.Discuss the potential benefits of mechanical ventilation that the patient may experience(e.g., less shortness of breath, less difficulty with the breathing process).Discuss the unpleasant sensations that the patient may experience (e.g., gagging,anxiety). Explain to the patient that medications are given to promote relaxation andtolerance of the treatment. Explain that some patients may require sedation duringmechanical ventilation.Explain that the patient will be unable to speak. Establish a method of communication inconjunction with the patient and family before initiating mechanical ventilation, ifnecessary.Explain to the patient and family what they should expect while the patient is ventilated.Educate the patient and family about ventilator alarms and their meanings. Assure themthat staff do hear the alarms and will respond accordingly.Encourage questions and answer them as they arise.ASSESSMENT AND PREPARATIONAssessment1. Perform hand hygiene before patient contact.2. Introduce yourself to the patient.3. Verify the correct patient using two identifiers.4. Assess the need for mechanical ventilation before initiating ventilator support.a. Signs and symptoms of respiratory insufficiency or failure (e.g., hypercapnia secondaryto hypoventilation, hypoxia)b. Decreased peripheral oxygen saturation (SpO2) and arterial oxygen saturation (SaO2)c. Altered level of consciousnessd. Adventitious breath soundse. Acid-base imbalancef. Cyanosisg. Hypotension or hypertensionh. Increased work of breathingi. Hemodynamic instabilityCopyright 2020, Elsevier, Inc. All rights reserved.5 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)Preparation1. Before initiating mechanical ventilation, ensure that the ventilator and associatedequipment are functioning properly per the manufacturers’ specifications and theorganization’s practice. Check the system microprocessor or ventilation system, circuitcompliance, HME or humidifier, and filters, and perform a circuit leak test.2. Ensure that the patient is positioned with the head of the bed elevated 30 to 45 degrees,unless contraindicated.3PROCEDUREPressure Support Ventilation (PSV)1. Perform hand hygiene and don gloves.2. Verify the correct patient using two identifiers.3. Explain the procedure to the patient and ensure that he or she agrees to treatment.4. Select the PSV level to lower the spontaneous respiratory rate to less than or equal to20 breaths/min and to attain a VT of 6 to 8 ml/kg ideal body weight (IBW).3 Ifnecessary, increase the VT if the partial pressure of carbon dioxide (PaCO2) increases ordecreases below the normal values, causing the patient to become hypercarbic oralkalotic.Rationale: Increasing the pressure support (PS) allows for larger VTs, todecrease the risk for hypercarbia. Decreasing the PS leads to increasedacidosis and smaller VTs.5. Set the trigger sensitivity between –1 and –2 cm H2O pressure.3Rationale: If the sensitivity is set too low, increased patient effort isnecessary to initiate a ventilator breath. Dyssynchrony can result.6. Select the PEEP level. In many cases, the initial setting is 5 cm H2O.3a. Adjust PEEP as needed after evaluation of tolerance (e.g., SaO2, arterial partial pressureof oxygen [PaO2], physical assessment).b. Increase PEEP levels to restore functional residual capacity (FRC) and allow reduction offraction of inspired oxygen (FIO2) to safe levels (i.e., less than or equal to 0.5).3Rationale: A PEEP level of 5 cm H2O is considered physiologic.3 High levels ofPEEP rarely should be interrupted because reestablishing FRC (and PaO2) maytake hours, especially in a patient with acute respiratory distress syndrome(ARDS).7. Place the patient on 100% oxygen unless information is available that identifies aprecise FIO2.3 Adjust the FIO2 downward, as tolerated, using SaO2 and arterial blood gas(ABG) values to guide level selection. Titrate the FIO2 to obtain a PaO2 of 60 to 80 mm Hgand an SpO2 or SaO2 of 90% or greater.3Rationale: Most patients in the acute care setting should be placed on 100%oxygen unless information is available identifying a precise FIO2.3 High levelsof FIO2 result in increased risk of oxygen toxicity, absorption atelectasis, andCopyright 2020, Elsevier, Inc. All rights reserved.6 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)reduction of surfactant synthesis. By initiating PPV with maximum oxygenconcentration, hypoxemia can be avoided while optimal ventilator settings arebeing determined and evaluated. This also permits measurement of thepercentage of venous admixture (shunt), which provides an estimate of theseverity of the gas-exchange abnormality.8. Ensure that the ventilator alarms are set appropriately (Table 2).9. Provide circuit humidification.a. For conventional humidifiers, make sure the humidifier has adequate fluid (steriledistilled water) and that the thermostat setting is adjusted according to themanufacturer’s recommendations.b. When using a humidifier, maintain the gas temperature between 34 C and 41 C (93.2 Fand 105.8 F) at the circuit Y-piece with a relative humidity of 100%.1Rationale: Gases are generally humidified before entering the artificial airway.In a patient with thick or tenacious secretions, pay attention to theinspired temperature to prevent mucus plugging. In this situation,circuit temperature may need to be closer to body temperature.c. Place an HME between the patient’s airway and the ventilator circuit.Rationale: The moisture in warmed, exhaled gases passes through the vastsurface area of the HME and condenses. With inspiration, dry gases passthrough the HME and become humidified.i.Change the HME per the manufacturer’s instruction. In many cases, an HME can be usedfor at least 48 hours; in some patients, it can be used for up to 1 week.1Rationale: The longer the HME is inline, the more efficient the humidification;however, inspiratory resistance increases over time. In weaning patients, theadditional resistive load added by these humidifiers may preclude their use.ii. Do not use an HME if secretions are copious or bloody.Rationale: Secretions may cause obstruction; an HME is contraindicated whensecretions are copious or bloody.10. Place the capnography device and appropriate adapter in the ventilator circuit, ifordered, or per the organization’s practice.11. Discard supplies, remove gloves, and perform hand hygiene.12. Document the procedure in the patient’s record.Pressure Control (PC)1. Perform hand hygiene and don gloves.2. Verify the correct patient using two identifiers.3. Explain the procedure to the patient and ensure that he or she agrees to treatment.Copyright 2020, Elsevier, Inc. All rights reserved.7 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)4.5.6.7.Select PC.Select the inspiratory pressure level (IPL).Select the respiratory rate.Select the inspiratory time (TI) or inverse inspiratory-to-expiratory (I:E) ratio(ventilators vary). The patient likely will not tolerate the prolonged TI in inverse ratioventilation (IRV) without sedation and paralysis.Rationale: Because IRV may result in auto-PEEP, evaluating the total amountof PEEP present is important.8. Select the PEEP level. When transitioning from volume ventilation to PC/IRV, initiallymaintain PEEP at the level used previously until the IRV’s effect is assessed.Rationale: The goal of PC/IRV is to improve oxygenation. This is done inconjunction with PEEP.IRV may result in auto-PEEP (which may be a desirable outcome ofthe mode); regardless, anticipate and measure auto-PEEP regularly.9. Set the trigger sensitivity to between –0.5 and –1.5 cm H2O pressure.4Rationale: If the sensitivity is set too low, increased patient effort isnecessary to initiate a ventilator breath. Dyssynchrony can result.10. Place the patient on 100% oxygen unless information is available that identifies aprecise FIO2.3 Adjust the FIO2 downward, as tolerated, using SaO2 and ABG values toguide level selection. Titrate the FIO2 to obtain a PaO2 of 60 to 80 mm Hg and an SaO2 orSpO2 of 90% or greater.3Rationale: Most patients in the acute care setting should be placed on 100%oxygen unless information is available identifying a precise F IO2.3 High levelsof FIO2 result in increased risk of oxygen toxicity, absorption atelectasis, andreduction of surfactant synthesis. By initiating PPV with maximum oxygenconcentration, hypoxemia can be avoided while optimal ventilator settings arebeing determined and evaluated. This also permits measurement of thepercentage of venous admixture (shunt), which provides an estimate of theseverity of the gas-exchange abnormality.11. Ensure that the ventilator alarms are set appropriately (Table 2).12. Provide humidification of the circuit.a. For conventional humidifiers, make sure the humidifier has adequate fluid (steriledistilled water) and that the thermostat setting is adjusted according to themanufacturer’s recommendations.b. When using a humidifier, maintain the gas temperature between 34 C and 41 C (93.2 Fand 105.8 F) at the circuit Y-piece with a relative humidity of 100%.1Rationale: Gases are generally humidified before entering the artificial airway.Copyright 2020, Elsevier, Inc. All rights reserved.8 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)In a patient with thick or tenacious secretions, pay attention toinspired temperature to prevent mucus plugging. In this situation,circuit temperature may need to be closer to body temperature.c. Place an HME between the patient’s airway and the ventilator circuit.Rationale: The moisture in warmed, exhaled gases passes through the vastsurface area of the HME and condenses. With inspiration, dry gases passthrough the HME and become humidified.i.Change the HME per the manufacturer’s instruction. In many cases, an HME can be usedfor at least 48 hours; in some patients, it can be used for up to 1 week.1Rationale: The longer the HME is inline, the more efficient the humidification;however, inspiratory resistance increases over time. In weaning patients, theadditional resistive load added by these humidifiers may preclude their use.ii. Do not use an HME if secretions are copious or bloody.Rationale: Secretions may cause obstruction; an HME is contraindicated whensecretions are copious or bloody.13. Place the capnography device and appropriate adapter within the ventilator circuit, ifordered, or per the organization’s practice.14. Discard supplies, remove gloves, and perform hand hygiene.15. Document the procedure in the patient’s record.Volume-Assured Pressure Support (VAPS)1. Perform hand hygiene and don gloves.2. Verify the correct patient using two identifiers.3. Explain the procedure to the patient and ensure that he or she agrees to treatment.4. Select VAPS.5. Select the desired VT.6. Select the parameters (pressure, volume, rate). Consult the specific ventilator manualas needed for additional parameter settings.Rationale: Volume-guaranteed pressure modes require that the practitionerselect the desired VT; some ventilators also require selection of the pressurelevel. Spontaneous breathing modes and controlled modes are available.7. Place the patient on 100% oxygen unless information is available that identifies aprecise FIO2.3 Adjust the FIO2 downward as tolerated using SaO2 and ABG values to guidelevel selection. Titrate the FIO2 to obtain a PaO2 of 60 to 80 mm Hg and an SaO2 or SpO2of 90% or greater.3Rationale: Most patients in the acute care setting should be placed on 100%oxygen unless information is available identifying a precise F IO2.3 High levelsCopyright 2020, Elsevier, Inc. All rights reserved.9 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)of FIO2 result in increased risk of oxygen toxicity, absorption atelectasis, andreduction of surfactant synthesis. By initiating PPV with maximum oxygenconcentration, hypoxemia can be avoided while optimal ventilator settings arebeing determined and evaluated. This also permits measurement of thepercentage of venous admixture (shunt), which provides an estimate of theseverity of the gas-exchange abnormality.8. Ensure that the ventilator alarms are set appropriately (Table 2).9. Provide circuit humidification.a. For conventional humidifiers, make sure the humidifier has adequate fluid (steriledistilled water) and that the thermostat setting is adjusted according to themanufacturer’s recommendations.b. When using a humidifier, maintain the gas temperature between 34 C and 41 C (93.2 Fand 105.8 F) at the circuit Y-piece with a relative humidity of 100%.1Rationale: Gases are generally humidified before entering the artificial airway.In a patient with thick or tenacious secretions, pay attention toinspired temperature to prevent mucus plugging. In this situation,circuit temperature may need to be closer to body temperature.c. Place an HME between the patient’s airway and the ventilator circuit.Rationale: The moisture in warmed, exhaled gases passes through the vastsurface area of the HME and condenses. With inspiration, dry gases passthrough the HME and become humidified.i.Change the HME per the manufacturer’s instruction. In many cases, an HME can be usedfor at least 48 hours; in some patients, it can be used for up to 1 week.1Rationale: The longer the HME is inline, the more efficient the humidification;however, inspiratory resistance increases over time. In weaning patients, theadditional resistive load added by these humidifiers may preclude their use.ii. Do not use an HME if secretions are copious or bloody.iii. Rationale: Secretions may cause obstruction; an HME is contraindicated when secretionsare copious or bloody.10. Place the capnography device and appropriate adapter within the ventilator circuit, ifordered, or per the organization’s practice.11. Discard supplies, remove gloves, and perform hand hygiene.12. Document the procedure in the patient’s record.MONITORING AND CARE1. Check for secure stabilization and maintenance of the endotracheal (ET) tube.(Commercial ET tube holders are available.)Copyright 2020, Elsevier, Inc. All rights reserved.10 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)2. Confirm ET tube placement, ideally by clinical assessment and continuous waveformcapnography. If continuous waveform capnography is not available, use a nonwaveformnumeric exhaled carbon dioxide monitor.3. Monitor SpO2 continuously.4. Monitor the inline thermometer to maintain inspired gas temperature between 34 C and41 C (93.2 F and 105.8 F).1Rationale: There is the risk of thermal injury from overheated inspired gasand risk of poor humidity from underheated inspired gas.5. Keep the ventilator tubing clear of condensation. Drain tubing from the patient towardthe expiratory limb.Rationale: Condensation in the tube that is drained toward the patient maycause a respiratory infection if the patient inhales the contaminated waterdroplets.6. Ensure the availability of a self-inflating manual resuscitation bag (MRB) andappropriate-size face mask attached to supplemental oxygen at the head of the bed.Attach or adjust the PEEP valve if the patient is on PEEP.Rationale: Ventilation and oxygen may be needed immediately to relieveacute respiratory distress caused by hypoxemia or acidosis.7. Check the ventilator settings on a routine basis to ensure that they match theprescribing order.8. Explore any change in peak inspiratory pressure (PIP) or decreased (sustained) V T onPSV. Immediately explore the cause of high-pressure alarms.Rationale: Acute changes in PIP or VT may indicate mechanical malfunction,such as tubing disconnection, cuff or connector leaks, tubing or airway kinks,or changes in resistance and compliance.Always consider the possibility of a tension pneumothorax if thepatient has a shift in the trachea, decreased breath sounds on oneside, and increased peak pressures. If a tension pneumothoraxoccurs, perform a needle thoracotomy.9. Place a bite block between the teeth if the patient is biting on the oral ET tube. If a biteblock is unavailable, an oral airway may be used.Rationale: An oral airway serves the same purpose as a bite block.An oral airway may not be tolerated as well as the bite block becauseit may induce gagging.10. Change the patient’s body position as often as possible. Maintain the head of the bed orbackrest elevation at 30 to 45 degrees.4Copyright 2020, Elsevier, Inc. All rights reserved.11 of 14
Mechanical Ventilation: Pressure Support,Pressure Control, and Volume-AssuredPressure Support (Respiratory Therapy)Rationale: Continuous lateral rotation therapy may be helpful in improvingoxygenation. Elevation is one of the most modifiable factors related to VAP.11. Evaluate for patient–ventilator dyssynchrony.Rationale: Dyssynchrony occurs when the patient’s intrinsic breaths oppose orchallenge the ventilator and may occur because of patient fatigue orrestlessness.12. Observe for hemodynamic changes associated with increased VT, PEEP, or decreasedcardiac output.Rationale: Hemodynamic changes may indicate functional changes incirculating volume caused by positive intrathoracic pressure.Always consider the potential for pneumothorax with acute changes,such as a tracheal shift, decreased breath sounds, and increased PIPreadings on the ventilator.13. Suction the patient, using the closed technique if possible, only when needed (i.e., notroutinely).14. On an ongoing basis, monitor the patient for complications of mechanical ventilation,such as barotrauma, volutrauma, VAP, pneumothorax, or accidental extubation.15. Observe the patient for signs or symptoms of pain. If pain is suspected, report it to theauthorized practitioner.EXPECTED OUTCOMES Maintenance of adequate pH, PaCO2, and PaO2Maintenance of adequate breathing patternRespiratory muscle restUNEXPECTED OUTCOMES Unacceptable pH, PaCO2, or PaO2Hemodynamic instabilityPulmonary barotraumas or volutraumaInad
synchronized intermittent mandatory ventilation (SIMV), pressure support ventilation (PSV), positive end-expiratory pressure (PEEP) and continuous positive airway pressure (CPAP), pressure-control/inverse ratio ventilation (PC/IRV)
Pressure support Pressure control ventilation Pressure-controlled inverse-ratio ventilation Airway pressure release ventilation Volume-assured pressure modes (1-5 below) 1. Pressure augmentation (Bear 1000) 2. Volume Support (Siemens) 3. Pressure Regulated Control (Siemens) Main Parameters Pressure support level, sensitivity, FIO 2, and PEEP
Mechanical Ventilation: Schedule History, Concepts and Basic Physiology - Nader Volume Control Ventilation (CMV, ACV) - Nader Intermittent Mandatory Ventilation (SIMV) - Nader Pressure Support Ventilation (PSV) - Nader Pressure Control Ventilation (PCV) - Junker Pressure Regulated Volume Control (PRVC) - Junker
Mechanical Ventilation: Schedule History, Concepts and Basic Physiology – Nader Volume Control Ventilation (CMV, ACV) – Nader Intermittent Mandatory Ventilation (SIMV) – Nader Pressure Support Ventilation (PSV) – Nader Pressure Control Ventilation (PCV) –
(10) A mode of ventilation is classified according to its control variable, breath sequence, and targeting schemes. CMV continuous mandatory ventilation IMV intermittent mandatory ventilation CSV continuous spontaneous ventilation VC volume control PC pressure control TAXONOMY FOR MECHANICAL
Mechanical Ventilation is indicated in pandemic flu for acute respiratory failure, defined as insufficient oxygenation, insufficient alveolar ventilation, or both. The principal benefits of mechanical ventilation are improved gas exchange and decreased work of breathing. Mechanical ventilation can be volume, pressure, flow or time-limited.
ventilation à haute fréquence aboutirent à la mise au point de deux types très différents d'appareils : ceux délivrant la ventilation par percussions à haute fréquence ou high frequency percussive ventilation (HFPV) et ceux délivrant la ventilation à percussions intrapulmonaires ou intra-pulmonary percussive ventilation (IPV).
tent Mandatory Ventilation) * * * * APRV (Airway Pressure Release Ventilation) * * * * BIPHASIC (Biphasic Positive Pressure Ventilation) * * * * PC-MMV (Pressure Control Mandato-ry Minute Ventilation) * * CPAP-PSV (Continuous Positive Air-way Pressure with Pressure Support and Apnea Backup) * *
Welcome to the ASME/Bath 2019 Symposium on Fluid Power and Motion Control (FPMC 2019) held at the Zota Beach Resort, on the powdery white sands and brilliant turquoise waters of Sarasota’s Longboat Key, Florida. I hope you will find the technical program of the symposium engaging. I also hope that you will enjoy the social events and further develop your network with colleagues. The .
