non-pulmonary complications of mechanical ventilation
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Non-Pulmonary Complications of Mechanical Ventilation. Complications of Mechanical Ventilation. Complications related to Intubation Mechanical complications related to presence of ETT Pulmonary complications Cardiovascular complications Biomedical complications Neurological complications - PowerPoint PPT PresentationTRANSCRIPT
Non-Pulmonary Complications of Mechanical Ventilation
Complications of Mechanical Ventilation
• Complications related to Intubation• Mechanical complications related to presence
of ETT• Pulmonary complications• Cardiovascular complications• Biomedical complications• Neurological complications• Other complications
Four major concepts
• Know the patient• Know the ventilator• Put the ventilator between you and the patient• Alive ill patients
MV complications
MechanicalsBiophysical
Inflammatory Cytokines
Biochemical
MedicationModes
Disease
COMPLICATIONS RELATED TO AIRWAYS
CompetenceConfidence
Unable to Open Mouth• Trismus• Small mouth• Peri-oral scarring• Fascial swealling
Unable to insert laryngoscope• Short neck• Large chest• Prominent upper incisors• Small mandible• Edema
Unable to see glottis• Fixed position of the head• Small jaw• Anterior larynx• Obstructed by blood or vomit
Unable to pass tube into trachea• Fixed Unrecognizable glottis• Too small glottis or sub-
glottic diamete
Vulnerability to complications• Fixed Full stocmach• Hypovolemia• Hypotension• Hypoxemia• Hypercarbia• Agitation• Age and sex
• Trauma• Endobronchial
intubation• Esophageal
intubation• Severe hypoxia• Severe
hypotension• Death
Environment• No skilled help• No specialized equipments• Missing of defective
equipment• Poor positioning
Difficult Intubation
Injuries to Face, Lips and Oro-pharynx
• Trauma to the lips and cheeks from tube ties• Peri-oral herpes• Injuries to the tongue especially if entrapped
between the endotracheal tube and the lower teeth
• Pressure ulcers to the palate and oropharynx
Skin Avulsion
Tongue Injury
Lip Injury Periorbital herpes
Maxillary Sinus and Middle Ear Effusion
• Maxillary effusion – 20% in patients intubated for > 7 days.– 47% when the gastric tube is placed nasally– 95%
• Secondarily infected maxillary effusion (45-71% of effusions)
• Middle ear effusion (29%) with 22% of them become infected
• Hearing impairment that may contributes to the confusion and delirium in elderly population
Laryngeal Injuries
• Some degree of glottic injury is seen in 94% of patients intubated for 4 days or longer
• Erosive ulcers of vocal cords (posterior commissures)
• Swelling and edema of the vocal cords• Granulomas (7% in patients intubated for 4
days or more)
Vocal Cords Ulcers Granulomas
Vocal Cord Hematoma
Vocal Cord Edema
Pharyngo-laryngeal Dysfunction
• Post-extubation discomfort (40% regardless of the duration)
• Hoarsness : edema, injury, disarticulate– 52% in short-term intubation– 70% in patients with prolonged intubation
• Slowing of the reflex swallowing mechanism and risk of aspiration– 15.8% of patients who were intubated more than 4 days did
not have a gag reflex• Silent aspiration: Ventilator Associated Pneumonia
– 20% in young population– 36% in older population
Tracheal Injuries• Cuff pressure related tracheal mucosa ischemia• Cuff pressure tracheal damage: tracheal ulceration, edema and
sub-mucosal hemorrhage• Tracheal dilatation: tracheomalacia• Tracheal stenosis:
– At the site of the cuff (50%)– At the site of the tracheostomy (35%)– Unclear (15%)
Tracheal Stenosis Glottic Stenosis
Granuloma and Ulceration Tracheomalacia
Unplanned Extubation
• Self extubation (8%) and accidental extubation (1%)
• Longer ICU and hospital stay• Increased ICU and hospital mortality
CARDIOVASCULAR COMPLICATIONS OF MECHANICAL VENTILATION
Biomechanical effect
Exp InspCV
PPr
essu
re (m
mHg
)
Extra
thor
acic
vein
s
Righ
t atri
um
Exp Insp
CVP
Pres
sure
(mm
Hg)
Extra
thor
acic
vein
s
Righ
t atri
um
Decreased Cardiac Output.Decreased Pressure Gradient for venous return and decrease RV preload
PPVDecreased CO due to decreased RV filling
Volume due to decreased venousreturn
-2 mm Hg
3 mm Hg
5 mm Hg
6 mm Hg
8 mm Hg
2 mm Hg
Decreased Cardiac OutputDecreased Right Atrial Distension
PPVDecreased CO due to decreased RV fillingVolume due to decrease RA compliance
Decreased BPPPV vs. Spontaneous Ventilation
0
5
3
-3
120
0
10
Decreased BPPPV VS. Spontaneous Ventilation
0
5
3
-3
110
0
8
Hypotension following MV
PPV increase CO and BP
• Ventricular interdependence: decrease CO during spontaneous breathing due to : increase RV filling volume with shifting the intra ventricular septum causing mechanic impedance for LV decreasing its compliance causing decrease CO and BP
• PPV improve the dynamic shape of the septum providing better LV compliance, better preload and thus better Stroke Volume and BP.
• Increase in Trans mural pressure of the great arteries in the thorax.
Cyclic BP effects is related to Volume status
Ventilation on sick individual
Cyclic changes in Gas exchange and partial pressures
Effect of Changing Lung Volume on Pulmonary Vascular Resistance
Pulm
onar
y va
scul
ar R
esist
ance
Lung Volume
Total pulmonary vascular resistance
Intra-alveolar vaso-compressionHypoxic vasoconstriction
RV TLCFRC
Hemodynamic effects of mechanical Insuflation
.
End of inspirationMaximum of
SBP, PP, Aortic velocity
End of inspirationMinimum of
SBP, PP, Aortic velocity
Inc.LV ejection
Dec.LV ejection
Effect of Lung Volume
• No effect in Normal individual with PEEP less than 10 cmH2o
• Major effect in patients with Dynamic Hyperinflation such as asthmatic and COPD, and in pre-existing pulmonary hypertension
• Small changes in PVR can cause considerable hemodynamic compromise secondary to acute increase in PVR
• Avoid gas trapping in these patient
Know the patient, Know the ventilator
Alveolar pressure and Gas exchange
Dead Space
PaO2
Oxygen Transport
Pleural pressure
Venous Return
V/Q Matching
LV afterload
Work of Breathing
Fully Spontaneous
PartialVentilatorsupport
Fully Controlled
Effects of PPV on hemodynamicM
agni
tude
of E
ffect
Bradycardia and intra-arteriolar vasodilatation
Reflex Arrhythmias, Bradycardia
Intra arteriolar Vasodilatation
Effect of Preload on Cardiac Output
Left Ventricular Preload
Card
iac
Outp
utNormal cardiac function
Congestive heart failure
BIOCHEMICAL EFFECTOF MECHANICAL VENTILATION
Systemic inflammatory effect
Inflammatory Biochemical injury
Local and systemic Inflammation cascade
Micro vascular, Alveolar Fracture
Hotchkiss et allCritical care Med, 2002
Prot for Gas and Bacteria
Biochemical effect of MV
Pro- Inflammatory Cytokines during PPV
NEUROLOGICAL FUNCTIONS DURING MECHANICAL VENTILATION
Psychogenic effect
Acute Effects
• Vasoconstriction secondary to hypercapnia• Decreased intra-cerebral blood volume and
intracranial pressure• PEEP reduces cerebral perfusion pressure by
decreasing venous return and increasing intracranial pressure– 20-25% of is transmitted to the central venous
pressure in a normal compliant lung– >20% is transmitted in patients with decreased
lung compliance
0
100
200
300
100
Stage 1
Stage 2
Stage 3
Stage 4REM
Non REM
Age 40
Age 40
MV
Slee
p Ti
me
(min
utes
)
8 10
12
14
16
18
20
22
0 2 4 6 8
Stage 1Stage 2
Stage 3Stage 4
REM
Normal Sleep Pattern
8 10
12
14
16
18
20
22
0 2 4 6 8
Stage 1Stage 2
Stage 3Stage 4
REM
Hyponogram for a Patient on Mechanical Ventilation
Mechanisms by which mechanical Ventilation Disrupt Sleep
• Noise disruption– Ventilator alarm:
• inappropriate threshold• Delayed alarm inactivation
– Humidifier alarms• Disruption by nursing interventions
– Airway suction– Nebulizer delivery
• Ventilation-related pharmacological disruption– Benzodiazepines (↓REM, ↓deep NREM)– Oipoids (↓REM, ↓deep NREM)– Neuromuscular blocking drugs
• Ventilator mode– Pressure support ventilation
GASTROINTESTINAL EFFECTS OF MECHANICAL VENTILATION
Systemic inflammatory and low perfusion effects
GI Effects of PPV
GI Effects of MV
Esophagus, Stomach and Small Intestine
• Erosive esophagitis (30-50% of patients ventilated >48 hours)– NG tube– Poor lower esophageal sphincter tone and reflux– Opiates and adrenergic agonists– Duodenogastroesophageal reflux through the action of
trypsin• Upper gastrointestinal hemorrhage:
– Stress– Decreased gastric mucosal protection secondary to a fall in
splanchnic blood flow• Decreased motility of stomach and small intestine
Liver and Gallbladder• Reduction in portal venous flow secondary to
the fall in cardiac output• Increased hepatic arterial flow “ hepatic
arterial buffer response”• Normal total hepatic perfusion• Hepatic engorgement• Venous ischemia and elevation of serum
transaminases and hyperbilirubinemia• Reduction in drug clearance secondary to
reduction of hepatic blood flow
Large Bowel
• Constipation• Abdominal distension
RENAL FUNCTIONS DURING MECHANICAL VENTILATION
Systemic inflammatory and ischemic effects
Renal Effects of MV
• The usual renal response to reduction of cardiac output and mean arterial pressure
• Reduction in urine output secondary to a fall in the transmural pressure of the right atrium that results in reduction of the secretion of atrial naturitic peptide and the activation of renin-angiotensin-aldosterone system and pituitary vasopressin secretion
Acute Effects
• Vasoconstriction secondary to hypercapnia• Decreased intra-cerebral blood volume and
intracranial pressure• PEEP reduces cerebral perfusion pressure by
decreasing venous return and increasing intracranial pressure– 20-25% of is transmitted to the central venous
pressure in a normal compliant lung– >20% is transmitted in patients with decreased
lung compliance
ASYNCHRONY WITH MECHANICAL VENTILATION
Patient, Mode, and Operator effects
Asynchrony with the Ventiaitor
• Fighting the ventilators• Inconsistent tidal volume• Increase work of breathing• Barotraumas and thoracic air leak• Insufficient gas exchange• Disturbances in the cerebral blood flow
Ventilation complicationsMode specific
PCVPCV
What About New Modes?
Auto ModeAuto Mode
AutoFlowAutoFlow
PPSPPS
VSVS
Mode Specific Complications
Summery: MV complicationsProcedure
Mechanical Ventilation
Mechanical Ventilation and Disease
Mechanical Ventilation, Disease , and Operator