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