Transcript Slide 1
Nutrition Support In
Mechanical Ventilated
Patients
Pranithi Hongsprabhas MD.
Swallowing function
Oral phase
Preparation &movement of food
from oral cavity to pharynx
Pharyngeal phase
Soft palate rises to close nasal
cavity
Vocal cords adducts
Epiglottis tilts and shields larynx
Respiration is temporarily inhibited
Pharynx contracts
esophageal phase
upper esophageal sphincter relaxes
peristalsis
The most dreaded complication of tube
feedings is tracheobronchial aspiration
of gastric content
Tube feeding associated aspiration
The most serious complication of EN
Clinically unimportant to respiratory failure
Clinically
silent or cough, choking to ARDS
Aspiration categories
Oropharygeal bacteria
Inert fluid, particulate
Acidified gastric contents
Wynne JW et al. Ann Intern Med 1977, 87:486
Prevalence and mortality
Prevalence
Mortality
Varies
62% in witness
70% in depressed
consciousness
22% in ICU
50-75% in ET
intubation
0-40 % EN
associated
aspiration
40% with 1-lobe,
90% with 2 or
more
Gastric aspiration:
Risk factors for aspiration
Naso/oral enteral intubation
Tracheal intubation
Enteral tube feeding
Increased age with physiologic insult
Gastroparesis
Gastroesophageal reflux (GER)
Risk factors for aspiration
Decreased level of consciousness
(LOC)
Anesthesia
Neurological disorder
Seizure
Supine position
Impaired level of consciousness
Stroke
Head injury
Sedation
Anesthesia
Impaired ability to protect airway
Cough and gag
LES
GET
Regurgitation and dysphagia
Increased risk of aspiration
Cough and gag reflexes
Absence or presence of gag reflex: not
influence the risk of aspiration
Cough reflex may or may not prevent
aspiration
diminished cough or gag reflexes
are not reliable indicators or
aspiration risk
Nasal or oral feeding tubes
Increased oropharyngeal secretions
Impairment of laryngeal elevation
Disruption of UES, LES
Increased GER (75 vs. 35%)*, aspiration
*Ibanez J. et al.JPEN 1992;16:419
Gastric vs. small bowel feeding
Controversy
Early
study : SB feeding less aspiration
Later study : not confirm
ASPEN 2005
Acute brain injury
Impaired gastric function: delayed GET
Impaired LES: regurgitation
Post pyloric feeding: more preferred
Jejunal feeding
Better tolerate
Less reflux
Gleghon E. et al. Neurologic diseases in: ASPEN manual 2005: 246-255.
Size of NG-NE tube
Children:
Less
GER in Fr8 vs Fr10-12
Adult
No
significant different in GER,
aspiration rate
Ferrer M. et al.Ann Int Med 19992;130:991
Malposition of feeding tube
Faulty initial placement
Upward dislocation
Increased risk when tube ports in or
near esophagus
Need to confirm feeding tube position
Enteral feeding schedule
Bolus vs. continuous feeding
Bolus: higher aspiration risk
Decreased
LES
intragastric pressure
Intermittent vs. continuous
35
Aspiration rate (%)
30
Intermittent
Continuous
33.3%
25
20
15
16.67%
10
17.647%
5.89%
5
0
Ciocon study
Kocan study
Tracheal intubation /MV
Reduce upper airway defense
Cough
Desensitization of pharynx and larynx
Laryngeal m atrophy
Esophageal compression
Increase abdominal pressure: GER
Sedation
increased risk after 48 hr. and 1%/day in MV
Vomiting
Increased risk of aspiration
Forceful
entry of gastric content into
oropharynx
Displacement of feeding tube
Sedation increases risk of vomiting
Regurgitation and dysphagia
Increased risk of aspiration
Cough and gag reflexes
Absence or presence of gag reflex: not
influence the risk of aspiration
Cough reflex may or may not prevent
aspiration
diminished cough or gag reflexes
are not reliable indicators or
aspiration risk
Body position
Supine position: associated with more
aspiration
Less aspiration with elevation of head of
bed 30-45° during EN feeding
Position and GER/aspiration
Aspiration: supine vs. semirecumbent MV patients*
Semirecumbent decreases GER compare to supine#
70
60
50
68%
Supine
Semirecumbent
4154 cpm
40
32%
30
20
10
0
954 cpm
Radioactive
*Torres A et al: Ann Int Med 1992;116:540-3
#Orozco-Levi et al. Am J Respi Crit Care 1995;152:1387
Culture
Position and Pneumonia
25
Supine
20
Semirecumbent
15
10
5
0
Drakulovic et al
Kollef et al
Recognizing patients at risk of AP
Decreased LOC
Tracheal intubation
MV
NG, NE
Major abdominal and thoracic
trauma/surgery
DM
Advance age
Gastric residual volume (GRV)
History
Underlying rationale
Inherent flaws in the rationale
Inherent flaws in the practice
Clinical pattern of GRV
Evidence of correlation of GRV with EN
Evidence of GRV and aspiratiom
Gastric residual volume (GRV)
GRV >150-200 ml
Fluid in stomach:
3000/d
~125ml/hr
50 ml????
Use less GRV: receive
nutrient less
GRV and risk of aspiration:
controversy
GI
Secretion (ml)
Saliva
1000
Gastric
2000
Pancreatic
2000
Bile
1000
Small bowel
1000
Reach colon
600-1500
The Washington Manual of Surgery. Chapter14
Clinical pattern of GRV
GRV>100
GRV>150
GRV>200
Normal
volunteers
40%
15% (2.4%)
0%
Critically ill
NG
50% (27.4%) 50% (13.1%) 30% (4.3%)
Critically ill
PEG
25%
(11%)
(2.5%) 0%
McClave SA, et al. JPEN 1992;16:99
(0%) 0%
(0%)
(0%)
Correlation of GRV with ETF
Change in ETF rate change in GRV
GRV increases at the initial but decreases
as feeds continue
Bolus generate more GRV
GRV obtained from NG>gastrostomy
GRV and aspiration: Pro
P=0.020
50%50
P=0.01
P=0.018
40
40%
30
30%
20
20%
10
10%
0%
0
>2
GRV>=150ml,>2GRV>=200
GRV>500,
ml, 44.2
46.6
2
GRV<100 ml,
33.4
consecutive
GRV150500, or
vomiting,
43%
without
intolerace,
24%
Evidence of aspiration (gastric pepsin)
Metheney NA. JPEN2005;29:S10.
Mentec H. Critical Care Med 2001;29:1955-61.
Incidence of regurgitation by range of
GRV
GRV
0-50
GRV
51-100
GRV
101-150
GRV
151-200
GRV
201-299
GRV
300-399
GRV
400+
Pvalue
Regurgittion
28.7%
41.0%
29.4%
35.7%
33.3%
40.0%
37.5%
0.134
(439)
(39)
(17)
(14)
(9)
(5)
(8)
Aspiration
22.8%
23.7%
26.7%
20.0%
0.0%
40.0%
25.0%
(501
(38)
(15)
(10)
(10)
(5)
(8)
0.412
GRV and aspiration: Cons
Paracetamol absorption test (GET): no difference in GRV
McClave 2005: found no difference in aspiration (using yellow dye)
in GRV<150 ml vs.>150 ml, and >400 ml
GRV
0-50
GRV
51-100
GRV
101-150
GRV
151-200
GRV
201-299
GRV
300-399
GRV
400+
Pvalue
Regurgittion
28.7%
41.0%
29.4%
35.7%
33.3%
40.0%
37.5%
0.134
(439)
(39)
(17)
(14)
(9)
(5)
(8)
Aspiration
22.8%
23.7%
26.7%
20.0%
0.0%
40.0%
25.0%
(501
(38)
(15)
(10)
(10)
(5)
(8)
0.412
GRV and aspiration: Cons
35
30
GRV> 200 ml
GRV 400 ml
35%
25
20
27.80%
21.6%
15
22.6%
10
5
0
Regurgitation
Lukan JK. AJCN 2002;75:417S
Aspiration
Prevention
Head of bed elevation 30-45°
Verify tube placement
Gastric aspirate: GRV
Evaluate GI intolerance
GI intolerance
Abdominal discomfort
Bowel movement
Abdominal distention
Bowel sound
GRV
Trend to increased GRV Trend to increased
GRV
Radiography
Conclusion
Identify the risk patients
Prevention
Verify
tube placement position
Position: head of bed elevation
Avoid bolus feeding