3. The BASICS!!The BASICS!!
AnatomyAnatomy
• Upper Respiratory TractUpper Respiratory Tract
– Humidifies inhaled gasesHumidifies inhaled gases
– Site of most resistance to airflowSite of most resistance to airflow
• Lower Respiratory TractLower Respiratory Tract
– Conducting zone/airways (Anatomic deadConducting zone/airways (Anatomic dead
space)space)
– Respiratory zone/ bronchioles and alveoliRespiratory zone/ bronchioles and alveoli
(Gas exchange)(Gas exchange)
4. The BASICS!! (Cont’d)The BASICS!! (Cont’d)
PhysiologyPhysiology
Negative pressure circuitNegative pressure circuit
– Gradient between mouth and pleuralGradient between mouth and pleural
space is the driving pressurespace is the driving pressure
– need to overcome resistanceneed to overcome resistance
– maintain alveolus openmaintain alveolus open
6. DefinitionDefinition
Mechanical ventilator is anMechanical ventilator is an
apparatus which can replaceapparatus which can replace
normal mechanism of breathingnormal mechanism of breathing
either by providing intermittenteither by providing intermittent
or continuous flow of oxygen oror continuous flow of oxygen or
air under pressure, which isair under pressure, which is
connected to the patient by aconnected to the patient by a
tube inserted through mouth,tube inserted through mouth,
the nose or an opening in thethe nose or an opening in the
trachea.trachea.
7. Mechanical VentilationMechanical Ventilation
1.1. Indications for Intubation and VentilationIndications for Intubation and Ventilation
2.2. Principles of Mechanical VentilationPrinciples of Mechanical Ventilation
3.3. Modes & Patterns of VentilationModes & Patterns of Ventilation
4.4. Ventilator Dependence: ComplicationsVentilator Dependence: Complications
5.5. Liberation from Mechanical Ventilation: WeaningLiberation from Mechanical Ventilation: Weaning
6.6. TroubleshootingTroubleshooting
7.7. Arterial Blood GasesArterial Blood Gases
8. Indications for MechanicalIndications for Mechanical
VentilationVentilation
“….An opening must be attempted in the“….An opening must be attempted in the
trunk of the trachea, into which a tube ortrunk of the trachea, into which a tube or
cane should be put; You will then blow intocane should be put; You will then blow into
this so that lung may rise again….And thethis so that lung may rise again….And the
heart becomes strong….”heart becomes strong….”
Andreas Vesalius (1555)Andreas Vesalius (1555)
10. Primary IndicationsPrimary Indications
• Acute Respiratory Failure (66%)Acute Respiratory Failure (66%)
– Acute Respiratory Distress SyndromeAcute Respiratory Distress Syndrome
– Heart Failure (through pulmonary edema/hypertension)Heart Failure (through pulmonary edema/hypertension)
– PneumoniaPneumonia
– SepsisSepsis
– Complications of SurgeryComplications of Surgery
– TraumaTrauma
• Coma (15%)Coma (15%)
• A/c Exacerbation of COPD(13%)A/c Exacerbation of COPD(13%)
• Neuromuscular Disease (5%)Neuromuscular Disease (5%)
11. Prophylactic IndicationsProphylactic Indications
• ShockShock
• PostoperativelyPostoperatively
»Extreme obesityExtreme obesity
»Possibility of sepsisPossibility of sepsis
»COPD with upper abdominalCOPD with upper abdominal
surgerysurgery
»Cardiovascular and neurologicalCardiovascular and neurological
surgeriessurgeries
• Acid aspiration syndromeAcid aspiration syndrome
12. Therapeutic IndicationsTherapeutic Indications
• Resuscitation from cardio respiratoryResuscitation from cardio respiratory
arrestarrest
• Hypoventilation /ApneaHypoventilation /Apnea
• Drug over dosageDrug over dosage
• Neurological dysfunctionNeurological dysfunction
• Trauma to chest and laceratedTrauma to chest and lacerated
diaphragmdiaphragm
13. Objectives of MechanicalObjectives of Mechanical
VentilationVentilation
• Improves pulmonary gas exchangeImproves pulmonary gas exchange
• Relieves respiratory distressRelieves respiratory distress
• Alter pressure-volume relationsAlter pressure-volume relations
• Permit lung and airway healingPermit lung and airway healing
• Avoid complicationsAvoid complications
16. Modes of VentilatorModes of Ventilator
• Controlled modeControlled mode
RR and TV by VentilatorRR and TV by Ventilator
• Assist Control Mode (Mixed Mode)Assist Control Mode (Mixed Mode)
Both got their RoleBoth got their Role
• Spontaneous modeSpontaneous mode
RR and TV by PatientRR and TV by Patient
18. Pressure Controlled VentilationPressure Controlled Ventilation
• Pressure cycled breathing, fully ventilatorPressure cycled breathing, fully ventilator
controlledcontrolled
• Suited for patients with neuromuscularSuited for patients with neuromuscular
diseasesdiseases
• Inspiratory phase stops when presetInspiratory phase stops when preset
inspiratory pressure is reachedinspiratory pressure is reached
19. Volume Controlled VentilationVolume Controlled Ventilation
• Volume targeted VentilationVolume targeted Ventilation
• Inspiratory Cycle ends when TV isInspiratory Cycle ends when TV is
delivereddelivered
• Ventilator generates sufficient pressure toVentilator generates sufficient pressure to
deliver set volumedeliver set volume
20. Time Controlled VentilationTime Controlled Ventilation
• Normal I:E ratio -> 1:2Normal I:E ratio -> 1:2
• Prolonged Expiratory phase according toProlonged Expiratory phase according to
the underlying pathology i.e. up to 1:3 orthe underlying pathology i.e. up to 1:3 or
1:41:4
Inverse Ratio VentilationInverse Ratio Ventilation
• Helps prevent alveolar collapseHelps prevent alveolar collapse
• Hyperinflation, Auto-PEEP and decreasedHyperinflation, Auto-PEEP and decreased
cardiac outputcardiac output
• Use: ARDS with refractory hypoxemia orUse: ARDS with refractory hypoxemia or
hypercapniahypercapnia
21. ASSIST CONTROL MODE / MIXEDASSIST CONTROL MODE / MIXED
MODEMODE
• Intermittent Mandatory Ventilation (IMV)Intermittent Mandatory Ventilation (IMV)
-- Mandatory Breaths-- Mandatory Breaths
• Synchronized Intermittent MandatorySynchronized Intermittent Mandatory
Ventilation (SIMV)Ventilation (SIMV)
-- Synchronized Breaths-- Synchronized Breaths
• SIMV + Pressure SupportSIMV + Pressure Support
-- Pressure Support too along with-- Pressure Support too along with
22. SPONTANEOUS MODESPONTANEOUS MODE
• Pressure Support Ventilation (PSV)Pressure Support Ventilation (PSV)
-- Spontaneous inspiratory efforts trigger the-- Spontaneous inspiratory efforts trigger the
ventilator to provide a variable flow of gas in orderventilator to provide a variable flow of gas in order
to attain a preset airway pressure.to attain a preset airway pressure. Machine assistMachine assist
and augment the spontaneous breathing efforts ofand augment the spontaneous breathing efforts of
patientpatient
• Continuous Positive Airway Pressure (CPAP)Continuous Positive Airway Pressure (CPAP)
No machine breaths deliveredNo machine breaths delivered
Allows spontaneous breathing at elevated baselineAllows spontaneous breathing at elevated baseline
pressurepressure
Patient controls rate and tidal volumePatient controls rate and tidal volume
27. Setting a VentilatorSetting a Ventilator
Settings vary with Age, WeightSettings vary with Age, Weight
and underlying Pathology of theand underlying Pathology of the
patientpatient
30. FiOFiO22
FiOFiO22 (Oxygen concentration)(Oxygen concentration)
Expresses as percentage or decimalsExpresses as percentage or decimals
Settings from 21% to 100% (0.21 to 1.0)Settings from 21% to 100% (0.21 to 1.0)
FiOFiO22 of 0.5 or less –minimize oxygenof 0.5 or less –minimize oxygen
toxicitytoxicity
Target PaO2 isTarget PaO2 is
60mm of Hg or60mm of Hg or
SpO2 90% in ABG ,SpO2 90% in ABG ,
SpO2 95% in pulse oximeterSpO2 95% in pulse oximeter
With minimum possible FiOWith minimum possible FiO22
31. Respiratory Rate (RR)Respiratory Rate (RR)
Respiratory Rate (RR) or FrequencyRespiratory Rate (RR) or Frequency
> Set rate depends on age of patient> Set rate depends on age of patient
Newborn - 30-40/mtNewborn - 30-40/mt
Children - 20-30/mtChildren - 20-30/mt
Adult - 10-15/mtAdult - 10-15/mt
Reduce rate in patients with COPDReduce rate in patients with COPD
32. Minute Volume [MV]Minute Volume [MV]
Minute volume = Tidal volume X R.R.Minute volume = Tidal volume X R.R.
33. I:E RatioI:E Ratio
Inspiratory time and I:E ratioInspiratory time and I:E ratio
• Determines duration of inspirationDetermines duration of inspiration
and oxygenationand oxygenation
NewbornNewborn 0.3-0.5 sec0.3-0.5 sec
Infant and childrenInfant and children 0.5-0.8 sec0.5-0.8 sec
AdultAdult up to 1.5up to 1.5
secsec
34. I:E Ratio (Cont’d)I:E Ratio (Cont’d)
Normal I:E - 1:2 (is physiological)Normal I:E - 1:2 (is physiological)
COPDCOPD - 1:3 to 1:4- 1:3 to 1:4
1:1 or 2:1 or more is called1:1 or 2:1 or more is called
Inverse Ratio VentilationInverse Ratio Ventilation
Used in ARDS and inUsed in ARDS and in
Refractory HypoxemiaRefractory Hypoxemia
35. Trigger sensitivityTrigger sensitivity
• How does the Ventilator know when to give aHow does the Ventilator know when to give a
breath???breath??? “Trigger”“Trigger”
– Patient effortPatient effort
• The patient’s effort can be “sensed” as aThe patient’s effort can be “sensed” as a
change in pressure or a change in flow (in thechange in pressure or a change in flow (in the
circuit)circuit)
Helps to the initiation of breath by patientHelps to the initiation of breath by patient
- Ventilator sense the pressure drop in the- Ventilator sense the pressure drop in the
systemsystem
- Set between -2 to -20 cm of H- Set between -2 to -20 cm of H22OO
- Start from -2, incrementally increase- Start from -2, incrementally increase
36. Flow rateFlow rate
Flow rateFlow rate
Speed with which the Tidal Volume isSpeed with which the Tidal Volume is
delivereddelivered
An important determinant of patientAn important determinant of patient
comfortcomfort
Normal rateNormal rate - 40-60 L/ Mt- 40-60 L/ Mt
- 4X Minute Ventilation- 4X Minute Ventilation
37. End Expiratory PressuresEnd Expiratory Pressures
• PEEP (Positive End ExpiratoryPEEP (Positive End Expiratory
Pressure)Pressure)
• ZEEP (Zero End Expiratory Pressure)ZEEP (Zero End Expiratory Pressure)
• NEEP (Negative End ExpiratoryNEEP (Negative End Expiratory
Pressure)Pressure)
38. Initial Ventilatory settingInitial Ventilatory setting
for an adultfor an adult
ModeMode PCV/ VCVPCV/ VCV
FiO2FiO2 0.7-1 decrease to 0.5 or0.7-1 decrease to 0.5 or
lessless
Tidal Volume (VT) 10ml/KgTidal Volume (VT) 10ml/Kg
RRRR 10-15 breaths/mt10-15 breaths/mt
TriggerTrigger -2 cm of H2O-2 cm of H2O
Flow rateFlow rate 40-60 L/mt40-60 L/mt
I:EI:E 1:2 to 1:31:2 to 1:3
PEEPPEEP 5 cm of H2O5 cm of H2O
Analyze Arterial Blood Gas 20 minutes laterAnalyze Arterial Blood Gas 20 minutes later
and adjustand adjust
39. General rules ofGeneral rules of
Ventilator ManipulationVentilator Manipulation
To improve oxygenationTo improve oxygenation
Apply PEEPApply PEEP
Increase Insp. TimeIncrease Insp. Time
Increase FiOIncrease FiO22
To improve COTo improve CO22 removalremoval
Increase RateIncrease Rate
Increase Tidal VolumeIncrease Tidal Volume
40. Care during MechanicalCare during Mechanical
VentilationVentilation
- Sedation and muscle paralysis- Sedation and muscle paralysis
- Humidification- Humidification
- Chest physiotherapy- Chest physiotherapy
- Suctioning Event- Suctioning Event
- Nutritional support- Nutritional support
- Other general care- Other general care
- Prevention of infection- Prevention of infection
41. Sedation and MuscleSedation and Muscle
paralysisparalysis
Sedation and Muscle paralysisSedation and Muscle paralysis
• To relieveTo relieve
AwarenessAwareness
AnxietyAnxiety
Pain andPain and
Patient discomfortPatient discomfort
• Drugs for Analgesia, Sedation, and MuscleDrugs for Analgesia, Sedation, and Muscle
relaxationrelaxation
42. HumidificationHumidification
HumidificationHumidification
Process of addition of moisture and heat toProcess of addition of moisture and heat to
inspiratory gasesinspiratory gases
Methods of humidificationMethods of humidification
Heated humidifiersHeated humidifiers
NebulizersNebulizers
Heat and Moist Exchangers (HME’s)Heat and Moist Exchangers (HME’s)
In normal breathing humans,In normal breathing humans,
Temperature of upper trachea 30-33Temperature of upper trachea 30-33oo
CC
43. Chest PhysiotherapyChest Physiotherapy
Chest PhysiotherapyChest Physiotherapy
Used to mobilize the secretionUsed to mobilize the secretion
Techniques IncludesTechniques Includes
Postural drainagePostural drainage
PercussionPercussion
Rib SpringingRib Springing
Vibration etc.Vibration etc.
44. Suctioning EventSuctioning Event
Clearing of secretion (Suctioning)Clearing of secretion (Suctioning)
- Most common procedure done in ICU- Most common procedure done in ICU
- Should be done when needed, not on time- Should be done when needed, not on time
basisbasis
Suction cathetersSuction catheters
Should be made of clear materialsShould be made of clear materials
Size not greater than half the diameter of ETTSize not greater than half the diameter of ETT
Should be longer than ETTShould be longer than ETT
45. Suctioning Event (Cont’d)Suctioning Event (Cont’d)
Suction techniquesSuction techniques
• OpenOpen
Disconnecting the patient from theDisconnecting the patient from the
ventilatorsventilators
• ClosedClosed
Allow the catheter to suck withoutAllow the catheter to suck without
disconnecting from ventilatorsdisconnecting from ventilators
47. Nutritional supportNutritional support
• Nutritional support is very important inNutritional support is very important in
ventilator patientsventilator patients
• Acute loss of 30-40% Body weight is lethalAcute loss of 30-40% Body weight is lethal
• Poor nutrition leads to ventilator musclePoor nutrition leads to ventilator muscle
weakness and delay Weaningweakness and delay Weaning
48. Other General Care –Other General Care –
Mobilization of PatientMobilization of Patient
• Seven days bed rest leads to loss ofSeven days bed rest leads to loss of
muscle bulk up to 30%muscle bulk up to 30%
• Patient may require active, assistedPatient may require active, assisted
or passive movementor passive movement
• The joints should be maintained andThe joints should be maintained and
protected in neutral positionprotected in neutral position
49. Other General Care –Other General Care –
Pressure soresPressure sores
- Dependent areas of immobile patient- Dependent areas of immobile patient
- Tissues over the bony prominence- Tissues over the bony prominence
- Trauma, Diabetics Burn patients – High Risk- Trauma, Diabetics Burn patients – High Risk
Preventive measuresPreventive measures
• Regular turning and repositioning every 2-4Regular turning and repositioning every 2-4
hourshours
• Special mattress and beds should be used toSpecial mattress and beds should be used to
relieve pressure over susceptible areasrelieve pressure over susceptible areas
• Regular inspection of skin integrityRegular inspection of skin integrity
• Early nutritional supportEarly nutritional support
50. Other general care –Other general care –
Eyes and mouth careEyes and mouth care
- Commonest problems are Dry eyes and- Commonest problems are Dry eyes and
Exposure keratopathyExposure keratopathy
- Protective mechanisms are lost- Protective mechanisms are lost
- Decreased tear production- Decreased tear production
- Decreased resistance to infection- Decreased resistance to infection
PreventionPrevention
Artificial eye drops, hydrogel padsArtificial eye drops, hydrogel pads
51. Other general care -Other general care -
Oral hygieneOral hygiene
Oral Ulcers and Infection are commonOral Ulcers and Infection are common
Decreased Oral fluid intakeDecreased Oral fluid intake
Mucosal DehydrationMucosal Dehydration
Decreased saliva productionDecreased saliva production
Presence of Orotracheal tubePresence of Orotracheal tube
52. Prevention of InfectionPrevention of Infection
ICU patients are 4 times more prone toICU patients are 4 times more prone to
develop to nosocomial infectionsdevelop to nosocomial infections
Common sitesCommon sites
LungLung
Catheter sitesCatheter sites
Urinary tractsUrinary tracts
WoundWound
53. Prevention of InfectionPrevention of Infection
(Cont’d)(Cont’d)
• As many as 40% of infections areAs many as 40% of infections are
transmitted by the hands of Hospital stafftransmitted by the hands of Hospital staff
• Most important preventive measure againstMost important preventive measure against
the spread of infection is Hand Washingthe spread of infection is Hand Washing
Infections can be decreased byInfections can be decreased by
Using Antibiotics, Isolation techniquesUsing Antibiotics, Isolation techniques
Use of Disposable components-Use of Disposable components-
ETT, Catheters, Ventilator tubing andETT, Catheters, Ventilator tubing and
fittingsfittings
54. ALARMSALARMS
• Look from whereLook from where
• Do not switch alarm off until causeDo not switch alarm off until cause
of alarm trigger is identified andof alarm trigger is identified and
correctedcorrected
55. Discontinuing MechanicalDiscontinuing Mechanical
VentilationVentilation
• DeathDeath
• WeaningWeaning
– Up to 25% of patients have RespiratoryUp to 25% of patients have Respiratory
distress severe enough to requiredistress severe enough to require
reinstitution of ventilator.reinstitution of ventilator.
• ExtubationExtubation
– 10 - 20 % of Extubated patients who10 - 20 % of Extubated patients who
were successfully weaned requirewere successfully weaned require
reintubation.reintubation.
56. THE WEAN (Liberation fromTHE WEAN (Liberation from
MV)MV)
Weaning is the gradual withdrawal fromWeaning is the gradual withdrawal from
Mechanical Ventilation.Mechanical Ventilation.
• Hemodynamically stableHemodynamically stable
• Correction of underlying lung diseaseCorrection of underlying lung disease
• Correction of acid-base/electrolyte disordersCorrection of acid-base/electrolyte disorders
• Adequate nutritionAdequate nutrition
• Mentally alertMentally alert
• Avoidance of sedationAvoidance of sedation
57. THE WEAN (Cont’d)THE WEAN (Cont’d)
Techniques to Wean!!Techniques to Wean!!
• SIMV WeanSIMV Wean
• PS WeanPS Wean
• T- Piece TrialT- Piece Trial
58. TroubleshootingTroubleshooting
Is it working or not?Is it working or not?
– Look at the patient !!Look at the patient !!
– Listen to the patient !!Listen to the patient !!
– SaOSaO22, ABG, EtCO, ABG, EtCO22
– Chest X rayChest X ray
– Look at the Ventilator (PIP; Expired TV;Look at the Ventilator (PIP; Expired TV;
Alarms)Alarms)
59. TroubleshootingTroubleshooting (Cont’d)(Cont’d)
• When in doubt, DISCONNECT THE PATIENTWhen in doubt, DISCONNECT THE PATIENT
FROM THE VENTILATOR, and begin AMBUFROM THE VENTILATOR, and begin AMBU
Bag Ventilation.Bag Ventilation.
• Ensure you are bagging with 100% O2.Ensure you are bagging with 100% O2.
• This eliminates the Ventilator circuit as theThis eliminates the Ventilator circuit as the
source of the problem.source of the problem.
• Bagging by hand can also help you gaugeBagging by hand can also help you gauge
patient’s compliancepatient’s compliance
62. COMPLICATIONSCOMPLICATIONS (Cont’d)(Cont’d)
• Cardiovascular ComplicationsCardiovascular Complications
– Impaired venous return to RAImpaired venous return to RA
– Bowing of the Interventricular SeptumBowing of the Interventricular Septum
– Decreased left sided afterload (good)Decreased left sided afterload (good)
– Altered right sided afterloadAltered right sided afterload
• Sum Effect…..Sum Effect….. Decreased Cardiac OutputDecreased Cardiac Output
(usually, not always and often we don’t(usually, not always and often we don’t
even notice)even notice)
65. Please DoPlease Do
Remember!!Remember!!
WHEN IN ANY DOUBT ABOUTWHEN IN ANY DOUBT ABOUT
THE ADEQUACY OFTHE ADEQUACY OF
MECHANICAL VENTILATION...MECHANICAL VENTILATION...
MANUALLY VENTILATE THEMANUALLY VENTILATE THE
PATIENT WITH AN AMBU BAG,PATIENT WITH AN AMBU BAG,
WITH THE AVAILABLEWITH THE AVAILABLE
MAXIMUM OMAXIMUM O22
