Introduction
Materials and methods
Search strategy
Inclusion criteria
Data extraction and quality assessment
Data synthesis and analysis
Results
Trial identification
Trial characteristics
Trial | Population | Interventions | Definition of pneumonia |
---|---|---|---|
Montecalvo et al. 1992 [20] USA | Adult critically ill patients; mechanically ventilated patients in medical and surgical ICUs Mean age: 48 years Males: 60% Mean APACHE II score: 23 | NJ (n = 19) NG (n = 19) 12 French tube Endoscopic placement | New or persistent infiltrate on CXR for at least 5 days with any three of the following: a) purulent sputum with >25 WBC and <10 squamous epithelial cells on Gram stain and numerous bacteria b) purulent sputum with >25 WBC and <10 squamous epithelial cells on Gram stain and nosocomial or respiratory isolates on culture c) temperature > 38.6 ºC d) peripheral WBC >10,000 cells/mm3 |
Kortbeek et al. 1999 [21] Canada | Adult patients with major trauma and injury severity score ≥16 and mechanically ventilated for at least 48 hours Mean age: 34 years Male: 77.5% Mean APACHE II score: 18 Prokinetics not allowed for the first 24 hours | ND or OD (n = 37) NG or OG (n = 43) Fluoroscopic insertion | New infiltrate on radiograph (assessed by a blinded radiologist) of more than 48 hours' duration and at least two of the following: a) temperature >38.5 ºC or <35 ºC. b) blood WBC >10,000/cm3 or <3000/cm3. c) purulent sputum or isolation of pathogenic bacteria from endotracheal aspirate. A radiographic infiltrate and positive quantitative culture from BAL is also considered diagnostic of pneumonia |
Kearns et al. 2000 [22] USA | Adult patients admitted to medical ICU and mechanically ventilated Mean age: 51 years Male: 68% Mean APACHE II score: 21 All patients received H2 antagonists | Post pyloric (n = 21) NG (n = 23) Insertion was assisted using metoclopramide and tactile cues Location confirmed radioraphically (with or without barium) | Presence of a new infiltrate on a chest radiograph (assessed by 2 pulmonologists) in the presence of two of the following: a) WBC >10,000/mm3; b) temperature >38.5°C; and c) a positive glucose test or blue discoloration in the endotracheal secretions |
Boivin and Levy 2001 [29] | Adult patients who were admitted to ICU Mean age: 48 years Males: 45% Mean APACHE II score: 16.5 Mechanically ventilated: 79 (99%) | Post pyloric (n = 40) NG (n = 40) and erythromycin 200 mg iv every 8 hours for 96 hours Blind insertion/fluoroscopy in 4 patients | Pneumonia was not an outcome in this study |
Esparza et al. 2001 [24] USA | Adult patients in medical ICU Mean age: 47 years Male: 68% Mean APACHE II score: 16 All patients were mechanically ventilated except 1 patient in the post-pyloric feeding group and 2 patients in the gastric feeding group | ND (n = 27) NG (n = 27) Blind insertion or fluoroscopy (6 patients) Position confirmed with EMG and radiographs | Pneumonia was not an outcome in this study |
Day et al. 2001 [23] USA | Adult patients admitted to the neuro-ICU who are expected to receive enteral feeding for at least 72 hours Mean age: 57 years Male: 56% Mean APACHE III score: 47.8 | ND (n = 13) NG (n = 11) 10-French tube Blind insertion or fluoroscopy | Aspiration pneumonia was an outcome but no definition was provided |
Heyland et al. 2001 [25] Canada | Adult ICU patients expected to remain mechanically ventilated for > 72 hours Mean age: 59 years Male: 58% Mean APACHE II score: 22 | ND (n = 12) NG (n = 21) 12 French tubes Blind/endoscopic insertion Position confirmed radiologically with/without contrast | Pneumonia was not an outcome in this study |
Davies et al. 2002 [31] Australia | Adult ICU patients Mean age: 55 years Male: 70% Mean APACHE II score: 20 Mechanically ventilated patients: 90% | NJ (n = 34) NG (n = 39) Endoscopic insertion Location confirmed with contrast radiographs | Consensus conference definition. |
Montejo et al. 2002 [26] Spain | Adult mechanically ventilated patients in the ICU who are anticipated to require feeding >5 days Mean age: 57 years Male: 73% Mean APACHE II score: 18 | NJ (n = 50) NG (n = 51) Blind insertion/endoscopy/fluoroscopy/echography | CDC criteria for VAP, but no description of the criteria provided |
Neumann and DeLegge 2002 [27] USA | Adult patients in the ICU who are anticipated to require feeding >5 days Mean age: 57 years Male: 50% Mean APACHE II score: NR | Post pyloric (n = 30) NG (n = 30) 12 French tubes Blind insertion/fluoroscopy Location confirmed radiologically | Pneumonia not an outcome Clinically significant aspiration defined as new radiographic chest infiltrate that was empirically treated with antibiotics or the direct suctioning of feeding solution from oropharynx/airways |
Eatock et al. 2005 [32] Scotland | Adult patients with severe acute pancreatitis Median age: 60 years Male: 53% Median APACHE II score at day1: 11 Mechanically ventilated patients: 15 (31%) Patients admitted to ICU: 15 (31%) | NJ (n = 22) NG (n = 27) 7 or 8 French tubes Endoscopic insertion | Pneumonia was not an outcome in this study |
Kumar et al. 2006 [35] India | Adult patients with severe acute pancreatitis as defined by Atlanta criteria Admitted to ICU Mean age: 40 years Males: 83% Mean APACHE II score: 10 Respiratory failure: 19 (63%) | NJ (n = 14) NG (n = 16) Endoscopic insertion | Pneumonia was not reported as an outcome in this study |
Hsu et al. 2009 [33] Taiwan | Adult patient in medical ICU and mechanically ventilated Mean Age: 68 years Males: 70% Mean APACHE II score: 20 | ND (n = 59) NG (n = 62) 12 French tube Blind/endoscopic insertion | Not mentioned |
White et al. 009 [37] Australia | Adult mechanically ventilated patients in the ICU Median age: 52 years Males: 52% Median APACHE II score: 27 (APACHE II score were significantly different in both groups) | Post pyloric (n = 50) NG (n = 54) Blind insertion with erythromycin | Diagnosis of VAP was based on: new onset (after 48 hours) of fever, leukocytosis, new pulmonary infiltrates on chest radiograph, increased pulmonary secretions, and a clinical pulmonary infection score (CPIS) >6. |
Acosta-Escribano et al. 2010 [30] Spain | Adult patients with severe TBI requiring mechanical ventilation Mean age: 38 years Males: 86% Mean APACHE II score: 17 | NJ (n = 50) NG (n = 54) 12 French tube Radiologic placement | VAP defined as CPIS score >6 at 48 hours' post admission |
Zeng et al. 2010 [28] China | Adult patients with severe craniocerebral injury Mean age: 40 years Males: 63% Mean APACHE II score: NR | NJ (n = 20) NG (n = 20) | Pneumonia was not an outcome in this study |
Davies et al. 2012 [10] Australia and Canada | Adult >16 years old patients admitted to the ICU, mechanically ventilated >48 hours and receiving opioid infusion Mean age: 52 years Males: 74% Mean APACHE II score: 20 | NJ (n = 91) NG (n = 89) Spontaneously migrating frictional tube Location confirmed radiologically | |
Huang et al. 2012 [34] Taiwan | Adult patients in medical ICU, and requiring mechanical ventilation for more than 24 hours Mean age: 69 years Males: 71% Mean APACHE II score: 21 | ND (n = 50) NG (n = 51) 12 French tube Blind/endoscopic insertion Confirmation using pH measurement | VAP was diagnosed by two pulmonologists using a modified National Nosocomial Infections Surveillance system |
Singh et al. 2012 [36] India | Adult patients with severe acute pancreatitis as defined by: Atlanta criteria, APACHE II > 8 or CT severity index > 7 All patients were admitted to ICU. Mean age: 39 years Males: 68% Median APACHE II score: 8.2 | NJ (n = 39) NG (n = 39) Endoscopic placement | Pneumonia was not reported in this study |
Risk of bias
Pooled outcomes
Nosocomial pneumonia
Ventilator-associate pneumonia
Mortality
ICU length of stay
Duration of mechanical ventilation
Gastrointestinal bleeding
Aspiration
Nutritional requirements
Trial | Nutritional assessment outcomes | ||
---|---|---|---|
Outcome | Small bowel | Gastric | |
Montecalvo et al. 1992 [20] | Volume of feeding delivered (mean, SD) Mean calories delivered per day (Mean, SD) Daily goal caloric intake (Mean, SD) | (1209 +/- 344 ml/day) (1466 +/- 398 Kcal/day) (61 +/- 17%) | (963 +/- 525 ml/day)* (1182 +/- 603 Kcal/day)* (46.9 +/- 25.9%)* |
Kortbeek et al. 1999 [21] | Time to tolerate full feeds (mean, SD) | 34 +/- 7.1 hours | 43.8 +/- 22.6 hours* |
Kearns et al. 2000 [22] | Daily calories (mean, SEM) Daily calories (mean, SEM) Proportion of energy delivered (mean, SEM) | 18 +/- 1 kcal/Kg/day 1157 +/- 86 Kcal/day 69 +/- 7% | 12 +/- 2 kcal/Kg/day* 812 +/- 122 Kcal/day* 47 +/- 7% * |
Boivin and Levy 2001 [29] | Time to achieve goal rate (mean) | 33 hours | 32 hours |
Esparza et al. 2001 [24] | Average daily percentage of goal feeding | 66% | 64% |
Day et al. 2001 [23] | Protein intake (mean, SD) Delivered calories at day 10 (Mean, SD) Proportion of delivered calories (Mean, SD) | 105 +/- 22g 2147 +/- 625 Kcal 76 +/- 39% | 91 +/- 27g 1491 +/- 768 Kcal 86 +/- 23% |
Heyland et al. 2001 [25] | No nutritional outcomes reported | N/A | N/A |
Davies et al. 2002 [31] | Time to start feeds (mean, SEM) | 81.2 +/- 13.4 hours | 54.4 +/- 4.9 hours |
Montejo et al. 2002 [26] | Daily caloric intake (mean, SD) | 1286 +/- 344 kcal/day | 1237 +/- 342 kcal/day |
Neumann and DeLegge 2002 [27] | Time to start feeding from initial attempt (mean, SD) | 27 +/- 22.6 hours | 11.2 +/- 11 hours* |
Eatock et al. 2005 [32] | No difference in time to start feeding between groups | N/A | N/A |
Kumar et al. 2006 [35] | Serum pre-albumin (Mean, SD) All patients achieved the goal of 1800 Kcal within 7 days of feeding start (no difference) | 11.10 +/- 5.28 mg/dL | 17.55+/-4.50 mg/dL (P = 0.002) |
Hsu et al. 2009 [33] | Daily caloric intake (Mean, SD) Time to goal rate (Mean, SD) Proportion of daily goal calorie feeds (Mean, SD) | 27.1 +/- 7.6 Kcal/Kg/day 32.4 +/- 27.1 hours 95 +/- 5% | 23.5 +/- 8.8 Kcal/Kg/day* 54.5 +/- 51.4 hours* 83 +/- 6%* |
White et al. 2009 [37] | Average daily energy deficit (median, IQR) Time to reach goal from initiation of feeds (median, IQR) | 79 (2-340) Kcal 4.1 (3.8-5.4) hours | 149 (74-369) Kcal 4.1 (3.6-5.3) hours |
Acosta-Escribano et al. 2010 [30] | Proportion of mean efficacious volume | 92 +/- 7% | 84 +/- 15%* |
Zeng et al. 2010 [28] | No nutritional outcomes reported. | N/A | N/A |
Davies et al. 2012 [10] | Daily energy delivered, (mean, SD) Proportion of energy requirement delivered for study period (mean, SD) | 1497 +/- 521 Kcal 72% +/- 21% | 1444 +/- 485 Kcal 71% +/- 19% |
Huang et al. 2012 [34] | Proportion of energy intake (mean, SD) | 90.4 +/- 20.5% | 76.2 +/- 24.9%* |
Singh et al. 2012 [36] | No nutritional outcomes reported. | N/A | N/A |
Subgroup analyses
Sensitivity analyses
Overall summary of findings
Outcomes | Illustrative comparative risks* (95% CI) | Relative effect(95% CI) | Number of participants(studies) | Quality of the evidence(GRADE) | |
---|---|---|---|---|---|
Assumed risk | Corresponding risk | ||||
Gastric feeding
|
Small bowel feeding
| ||||
Pneumonia
|
228 per 1000
| 160 per 1000(116 to 221) | RR 0.70 (0.51 to 0.970) | 994(12 studies) | ⊕⊕⊝⊝low1,2 |
Mortality
|
239 per 1000
| 258 per 1000(1000 to 309) | RR 1.08 (90 to 1.29) | 1232(15 studies) | ⊕⊕⊕⊕high |
ICU length of stay
| N/A | The mean ICU length of stay in the intervention groups was 0.057 lower(1.79 lower to 0.66 higher) | N/A | 762(8 studies) | ⊕⊕⊕⊕high |
Duration of mechanical ventilation
| N/A | The mean duration of mechanical ventilation in the intervention groups was 1.01 lower(3.37 lower to 1.35 higher) | N/A | 263(3 studies) | ⊕⊕⊝⊝low1,3 |
GI bleeding
|
116 per 1000
| 103 per 1000(65 to 165) | RR 0.89 (0.56 to 1.42) | 546(6 studies) | ⊕⊕⊝⊝low1,2 |
Aspiration
|
94 per 1000
| 87 per 1000(49 to 156) | RR 0.92 (0.52 to 1.65) | 472(6 studies) | ⊕⊝⊝⊝very low1,4 |
Vomiting
|
228 per 1000
| 208 per 1000(121 to 351) | RR 0.91 (0.53 to 1.54) | 553(6 studies) | ⊕⊝⊝⊝very low1,5,6 |
Discussion
Heyland et al. [6] | Marik et al. [7] | Ho et al. [8] | Jiyong et al. [9] | Alhazzani et al. | |
---|---|---|---|---|---|
Total number of RCTs (patients)
| 10 (576) | 9 (522) | 11 (637) | 15 (966) | 19 (1394) |
Population
| Adult critically ill | Adult critically ill | Adult critically ill | Adults and pediatric critically ill | Adult critically ill |
Outcomes
(number of RCTs)
| Pneumonia (7) Mortality (9) Nutritional delivery (9) | Pneumonia (7) Nutritional delivery (6) ICU LoS (5) Mortality (7) | Pneumonia (7) Mortality (8) ICU LoS (5) Aspiration (2) Diarrhea (5) Complications (5) Nutritional delivery (7) | Pneumonia (11) Aspiration (7) Vomiting (6) | Pneumonia (12) Mortality (15) ICU LoS (8) DMV (3) GI bleeding (6) Aspiration (6) Vomiting (6) Nutritional delivery (15) |
Pneumonia
RR (95% CI)
| 0.76 (0.59, 0.99) | 1.44 (0.84, 2.46) a in favor of small bowel feeding | 1.28 (0.91, 1.80) b in favor of small bowel feeding | 0.63 (0.48, 0.83) | 0.70 (0.55, 0.90) |
Comments
| Different methods in data abstraction, and inclusion of studies with multiple interventions that should be excluded | Aspiration events was analyzed as pneumonia in one of the studies | Combined pneumonia and aspiration as a single outcome | Combined adult and pediatric studies. Did not include data from most recent RCTs |
Conclusions
Key messages
-
Literature surrounding small bowel feeding in critically ill patients is ambiguous, with few meta-analyses reaching opposing conclusions; there were variation in inclusion criteria, outcome detention, and methodology that lead to the discrepancy of results.
-
A recent RCT suggested that small bowel feeding does not reduce the risk of VAP in critically ill patients.
-
This systematic review and meta-analysis of RCTs suggests that small bowel feeding is associated with significant reduction in risk of pneumonia compared with gastric feeding. The effect on other clinically important outcomes was not statistically significant.