HOB Literature Review

Ver 12.03.12

Head of Bed (HOB) Elevation or Semi-Recumbent Positioning Literature Review

Ventilator Associated Pneumonia Prevention Bundle

The elevation of the head of bed (HOB) to a semi-recumbent position (30 degrees) is associated with a decreased incidence of aspiration and Ventilator- Associated Pneumonia (VAP). The intervention is supported unanimously by all four leading guidelines, and newer publications in the field accept the head of bed as an effective, low cost and low risk intervention.

Since the last guideline was written (2007), the majority of studies have been focused on determining the appropriate angle for the HOB elevation.

*Article referencing effects of HOB elevation or semi-recumbent positioning in cardiosurgical population.

2008 -Society for Healthcare Epidemiology of America Guidelines: A guideline of practical recommendations to assist acute care hospitals in implementing and prioritizing their ventilator-associated pneumonia (VAP) prevention efforts. 1

ü  Recommends the semi-recumbent position (30-45 degrees) as a strategy to prevent aspiration.

Articles Cited in Guideline
Study Type and Author / Results - Details in Annotated Bibliography
Quasi-Experimental Study
(Resar, 2005) 2 / Pro-This study did not specifically focus on HOB intervention, but implemented the use of the IHI ventilator bundle. Findings showed that adherence to the bundle led to a significant reduction of VAP. One of the four implemented items was head of bed elevation to 30-45 degrees.
Review
(Kollef, 2004) 3 / Pro - This review did not specifically focus on the HOB intervention, but rather on clinical methods used for prevention of HAP/VAP. Review recommends the implementation and use of semi-erect head of bed positioning based on the findings of 4 RCTs.
CDC Guideline
(Tablan, 2003 ) 4 / Pro- In the absence of medical contraindication(s), for patients with a high risk for aspiration, elevate the HOB at an angle of 30–45 degrees e.g., a person receiving mechanically assisted ventilation and/or who has an enteral tube in place. (See CDC below)
Systematic Review
(Collard, 2003) 5 / Pro- This review did not focus on the HOB elevation, but rather on all interventions that are beneficial to the prevention of VAP. Review recommends the use of semi-recumbent position based on findings of 3 RCTs.
Supine vs. Semi-recumbent Position
(Drakulovic, 1999) 6 / Pro- Study focused on medical and respiratory patients who required mechanical ventilation in the ICU. Findings showed the semi-recumbentbodyposition reduces frequency and risk of nosocomial pneumonia, especially inpatientswho receive enteral nutrition.
Supine vs. Semi-recumbent Position
(Orozco-Levi-1995) 7 / Pro- Study focused on adult, critically ill patients requiring mechanical ventilation and nasogastric intubation. Study findings showed that irrespective of body position (supine or semi-recumbent), patients with gastroesophageal reflex (GER) are at risk for gastric content aspiration. Additionally, the study concludes that while the semi-recumbent position doesn’t completely protect from GER, it does protect against pulmonary aspiration of gastric contents.
*Supine vs. Semi-recumbent Position
(Kollef 1993) 8 / Pro- Study focused on medical, surgical, and cardiothoracic patients that required mechanical ventilation for longer than 24 hours. Study findings showed a significantly lower mortality rate in semi-recumbent vs. supine head positioning.
Supine vs. Semi-recumbent Position, crossover trial
(Torres, 1992) 9 / Pro- Study focused on patients requiring mechanical ventilation and intubation. Study findings conclude that the supine position and length of time the patient is kept in this position are potential risk factors for aspiration of gastric contents.9

2008-Canadian VAP Prevention Guidelines: Evidence-based, clinical practice guidelines for the prevention of ventilator-associated pneumonia10

ü  Recommends the head of bed to be elevated to 45 degrees or as much as possible when not possible.

Articles Cited in Guideline
Study Type and Author / Results - Details in Annotated Bibliography
Supine vs. Semi-recumbent Position
(van Nieuwenhoven, 2006) 11 / Con- Study focused on adult patients who were intubated within 24 hr of ICU admission and required mechanical ventilation for >48 hours. This study looked at the feasibility of achieving an elevation of 45 degrees in the HOB intervention. Unfortunately, study failed to meet the target elevation of 45 degrees, and compared 10 degree elevation vs. 30 degree elevation- comparison failed to show VAP reduction.
Supine vs. Semi-recumbent Position
(Drakulovic, 1999) 6 / Pro- Study focused on medical and respiratory patients who required mechanical ventilation in the ICU. Findings showed the semi-recumbentbodyposition reduces frequency and risk of nosocomial pneumonia, especially inpatientswho receive enteral nutrition. (See SHEA, above)
Supine vs. Semi-recumbent Position
(Orozco – Levi, 1995) 7 / Pro- Study focused on adult, critically ill patients requiring mechanical ventilation and nasogastric intubation. Study findings showed that irrespective of body position (supine or semi-recumbent), patients with GER are at risk for gastric content aspiration. Additionally, the study concludes that while the semi-recumbent position doesn’t completely protect from GER, it does protect against pulmonary aspiration of gastric contents. (See SHEA, above)
Supine vs. Semi-recumbent Position, crossover trial
(Torres, 1992) 9 / Pro- Study focused on patients requiring mechanical ventilation and intubation. Study showed that both the supine position and length of time the patient is kept in this position are potential risk factors for aspiration of gastric contents.9 (See SHEA, above)

2004-Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia.12

ü  Recommends the semi-recumbent position (30-45degrees) to reduce aspiration and ventilator associated pneumonia.

Articles Cited in Guideline
Study Type and Author / Results - Details in Annotated Bibliography
CDC Guidelines
(Tablan, 2003 ) 4 / Pro- In the absence of medical contraindication(s), elevate at an angle of 30–45 degrees of the head of the bed of a patient at high risk for aspiration (e.g., a person receiving mechanically assisted ventilation and/or who has an enteral tube in place) (See CDC below)
Supine vs. Semi-recumbent Position
(Drakulovic, 1999) 6 / Pro- Study focused on medical and respiratory patients who required mechanical ventilation in the ICU. Findings showed the semi-recumbentbodyposition reduces frequency and risk of nosocomial pneumonia, especially inpatientswho receive enteral nutrition. (See SHEA and ZAP, above)
Supine vs. Semi-recumbent Position
(Orozco – Levi, 1995) 7 / Pro- Study focused on adult, critically ill patients requiring mechanical ventilation and nasogastric intubation. Study findings showed that irrespective of body position (supine or semi-recumbent), patients with GER are at risk for gastric content aspiration. Additionally, the study concludes that while the semi-recumbent position doesn’t completely protect from GER, it does protect against pulmonary aspiration of gastric contents. (See SHEA and ZAP, above)
Supine vs. Semi-recumbent Position, crossover trial
(Torres, 1992) 9 / Pro- Study focused on patients requiring mechanical ventilation and intubation. Study findings conclude that the supine position and length of time the patient is kept in this position are potential risk factors for aspiration of gastric contents.9 (See SHEA and ZAP, above)

2003- CDC Guidelines for preventing Health-Care-Associated Pneumonia; Evidence-based, clinical practice guidelines for the prevention of healthcare-associated pneumonia, including VAP. 4

ü  Recommends semi-recumbent position (30-45 degrees) for prevention of aspiration.

Articles Cited in Guideline
Study Type and Author / Results - Details in Annotated Bibliography
Supine vs. Semi-recumbent Position, crossover trial
(Torres, 1992) 9 / Pro- Study focused on patients requiring mechanical ventilation and intubation. Study finding showed that both the supine position and length of time the patient is kept in this position are potential risk factors for aspiration of gastric contents. (See SHEA, ZAP and ATS, above)
Supine vs. Semi-recumbent Position
( Orozco-Levi, 1995) 7 / Pro- Study focused on adult, critically ill patients requiring mechanical ventilation and nasogastric intubation. Study findings showed that irrespective of body position (supine or semi-recumbent), patients with GER are at risk for gastric content aspiration. Additionally, the study concludes that while the semi-recumbent position doesn’t completely protect from GER, it does protect against pulmonary aspiration of gastric contents. (See SHEA, ZAP and ATS, above)
Supine vs. Semi-recumbent Position
(Drakulovic, 1999) 6 / Pro- Study focused on medical and respiratory patients who required mechanical ventilation in the ICU. Findings showed the semi-recumbentbodyposition reduces frequency and risk of nosocomial pneumonia, especially inpatientswho receive enteral nutrition. (See SHEA, ZAP and ATS above)

Post Guideline Publications:

Post Guideline Publications, 2007-2012
Study Type and Author / Results - Details in Annotated Bibliography
Systematic Review
(Niel-Weise, 2011 ) 13 / Pro – Analyzed 3 RCTs evaluating the benefits and disadvantages of the semi-upright position. Review of literature failed to show clinical benefit of head of bed intervention, however expert panel of 22 clinicians supported treatment for mechanical ventilated patients between 20-45 degree elevation - based on clinical determinates.
Literature Review
(Li Bassi,2011)14 / Pro- Reviewed 9 RCTs and 2 animal studies to evaluate the role of body positioning on VAP. Findings showed a decrease in VAP due to semi-recumbent position and reduction in gastric aspiration.
Clinical Review
(Grap, 2010 ) 15 / Pro- This review summarizes the epidemiology, pathophysiology, and risk factors associated with VAP and provides evidence-based recommendations for preventions. Review recommends the use continuous backrest elevation of 30-45 degrees an early prevention measure for VAP in the Emergency Department.
Observational Trial
(Rose, 2010) 16 / Con- Study focused on adult patients requiring mechanical ventilation in Australia and New Zealand ICU’s. Findings showed that actual backrest elevation was less than recommended and predominantly influenced by clinical and patient condition, where more acute patients had a lower HOB. Authors felt that more study is warranted to determine if the perceived difference in VAP rates is due to this phenomena.
Meta-Analysis
(Alexiou, 2009)17 / Pro- Study analyzed 7 RCTs to evaluate the effect of body position of patients requiring mechanical ventilation. Study findings showed that patients in the semi-recumbent position have a significantly lower rate of clinically diagnoses of VAP than patients positioned supinely.
Survey of Infection Control Leaders
(Krein, 2008)18
/ Pro- Study surveyed 719 US hospital infection control leaders to determine what practices are used by hospitals to prevent VAP. Survey response showed that semi-recumbent positioning was one of the most used VAP prevention.
HOB position 45 degrees vs. 20 degrees
(Keeley,2007)19 / Pro- Study focused on adult mechanically ventilated patients with HOB position at the two different degrees of head of bed elevation. Findings showed that there was a trend towards a reduction in VAP in the patients with HOB at an angle of 45 degrees.

Annotated Bibliography

1. Coffin S, MD, Klompas M, MD, Classen D, MD, et al. Strategies to prevent Ventilator‐Associated pneumonia in acute care hospitals•. Infection Control and Hospital Epidemiology. 2008;29(S1, A Compendium of Strategies to Prevent Healthcare‐Associated Infections in Acute Care Hospitals):pp. S31-S40. Available from: http://www.jstor.org/stable/10.1086/591062.

2. Resar R, Pronovost P, Haraden C, Simmonds T, Rainey T, Nolan T. Using a bundle approach to improve ventilator care processes and reduce ventilator-associated pneumonia. Jt Comm J Qual Patient Saf. 2005;31(5):243-248.

Pro-Systematic review - This review did not specifically focus on HOB elevation, but reviewed implemented the use of the IHI ventilator bundle. Review focused on 21 teaching hospitals 40 community hospitals thatwere made up 44 medical ICU's and 12 surgical ICU's. Data from 35 units showed a decrease in VAP rated with increased adherence to ventilator bundle. One of four bundle items was head of bed elevation to 30-45degrees.

3. Kollef MH. Prevention of hospital-associated pneumonia and ventilator-associated pneumonia. Crit Care Med. 2004;32(6):1396-1405.

Pro- Systematic review - Synthesizes the available clinical data for the prevention of hospital-associated pneumonia (HAP) and ventilator- associated pneumonia (VAP) This review did not specifically address head of bed elevation , but recommends the use of semirecumbent positioning based on 4 RCTs that showed beneficial effect.

4. Tablan OC, Anderson LJ, Besser R, Bridges C, Hajjeh R. Guidleines for preventing healthcare-associated pneumonia, 2003: Recommendations of CDC and the healthcare infection control practices advisory committee. MMWR Recomm Rep. 2004;53:1-36.

5. Collard HR, Saint S, Matthay MA. Prevention of ventilator-associated pneumonia: An evidence-based systematic review. Ann Intern Med. 2003;138(6):494-501.

Pro- Systematic review - The preventive practices with the strongest supportive evidence were semi-recumbent positioning, sucralfate instead of H2-antagonists for stress ulcer prophylaxis, and selective digestive tract decontamination. Aspiration of subglottic secretions and oscillating beds may be useful in select populations. There is no evidence to support specific methods of enteral feeding or increased frequency of ventilator circuitry changes. After evaluation of potential benefits and risks, the authors recommend considering several specific interventions to reduce the incidence of ventilator-associated pneumonia: semi-recumbent positioning in all eligible patients, sucralfate rather than H2-antagonists in patients at low to moderate risk for gastrointestinal tract bleeding, and aspiration of subglottic secretions and oscillating beds in select patient populations. Semi-recumbent patient positioning is a low-cost, lowrisk approach to preventing ventilator-associated pneumonia, and all three trials suggested that it is effective (grade IIa) (14–16). Semi-recumbent patient positioning should be considered in all eligible patients. Of importance, only one trial has looked at the clinical outcome of ventilator associated pneumonia (14). These findings should be confirmed by additional randomized clinical trials.

6. Drakulovic MB, Torres A, Bauer TT, Nicolas JM, Nogue S, Ferrer M. Supine body position as a risk factor for nosocomial pneumonia in mechanically ventilated patients: A randomised trial. Lancet. 1999;354(9193):1851-1858.

Pro- Supine vs. semi-recumbent postion - Study focused on 86 intubated and mechanical ventilated patients in the Respiratory and Medical ICU's. The frequency of clinically suspected nosocomial pneumonia was lower in the semirecumbent group than in the supine group (three of 39 [8%] vs 16 of 47 [34%]; 95% CI for difference 10·0–42·0, p=0·003). This was also true for microbiologically confirmed pneumonia (semirecumbent 2/39 [5%] vs supine 11/47 [23%]; 4·2–31·8, p=0·018). Supine body position (odds ratio 6·8 [1·7–26·7], p=0·006) and enteral nutrition (5·7 [1·5–22·8], p=0·013) were independent risk factors for nosocomial pneumonia and the frequency was highest for patients receiving enteral nutrition in the supine body position (14/28, 50%). Mechanical ventilation for 7 days or more (10·9 [3·0–40·4], p=0·001) and a Glasgow coma scale score of less than 9 were additional risk factors. The semirecumbent body position reduces frequency and risk of nosocomial pneumonia, especially in patients who receive enteral nutrition. The risk of nosocomial pneumonia is increased by long-duration mechanical ventilation and decreased consciousness.