Name
University of Phoenix
NSG/302 Professional Contemporary Nursing Role and Practice
Prof. Name
Date
Current evidence indicates that routine normal saline instillation (NSI) before endotracheal suctioning is not recommended for mechanically ventilated adult patients. High-quality research shows that saline instillation does not significantly improve secretion clearance and may increase the risk of ventilator-associated pneumonia (VAP), reduce oxygenation, and trigger unnecessary physiological stress. Modern evidence-based critical care guidelines recommend performing endotracheal suctioning without routine saline instillation, unless there is a clear clinical indication based on patient assessment.
Endotracheal suctioning is a common intervention in intensive care units (ICUs) that helps maintain airway patency and remove respiratory secretions. However, because suctioning itself can cause complications, every step of the procedure should be supported by the best available evidence. This review summarizes current research, clinical recommendations, and nursing implications regarding the use of normal saline before endotracheal suctioning.
A systematic literature search was performed to identify the highest-quality evidence on normal saline instillation before endotracheal suctioning in mechanically ventilated adults.
The following databases were searched:
University of Phoenix Library
CINAHL
MEDLINE
Cochrane Library
PsycINFO
Google Scholar (secondary source)
Priority was given to:
Peer-reviewed journal articles
Evidence-based clinical practice guidelines
Systematic reviews
Randomized controlled trials
Studies involving mechanically ventilated adult ICU patients
The search aimed to determine whether saline instillation improves secretion removal or contributes to adverse outcomes such as ventilator-associated pneumonia, impaired oxygenation, prolonged hospitalization, or increased mortality.
Endotracheal suctioning is an essential nursing and respiratory therapy procedure for patients receiving mechanical ventilation. The primary purpose is to remove airway secretions, maintain a patent airway, and support effective oxygenation.
Although necessary, suctioning is an invasive procedure associated with several potential complications, including:
Hypoxemia
Cardiac dysrhythmias
Increased intracranial pressure
Airway trauma
Infection
Because of these risks, healthcare providers continually evaluate whether additional interventions, including saline instillation, improve patient outcomes or introduce unnecessary harm.
Normal saline instillation involves introducing approximately 1–5 mL of sterile normal saline into an endotracheal tube immediately before suctioning.
Historically, clinicians believed this practice could:
Thin thick respiratory secretions
Improve mucus removal
Stimulate coughing
Make suctioning easier
While this practice became common in many ICUs, contemporary research has challenged both its effectiveness and safety.
Caparros (2014) conducted a comprehensive review of studies examining saline instillation during endotracheal suctioning in mechanically ventilated adult ICU patients. The review included adults older than 18 years who were intubated or had tracheostomies and required mechanical ventilation.
Evidence from CINAHL, MEDLINE, the Cochrane Library, PsycINFO, and national clinical guidelines was analyzed.
The review concluded that routine saline instillation does not improve clinical outcomes. Instead, multiple studies demonstrated an association between saline instillation and higher rates of ventilator-associated pneumonia.
Patients who underwent suctioning without saline instillation experienced:
Lower rates of ventilator-associated pneumonia
Significant reductions in VAP after eliminating routine saline use
Better adherence to evidence-based suctioning practices
These findings support discontinuing routine saline instillation during endotracheal suctioning.
Ayhan et al. (2015) explored both the available scientific evidence and ICU nurses’ perspectives regarding saline instillation before suctioning.
Although research questioning saline use has existed since the 1970s, the study found that the practice remained widespread.
Key survey findings included:
Nearly 88% of ICU nurses routinely instilled saline before suctioning.
Most nurses believed saline helped liquefy thick secretions.
Approximately 77% based saline use on secretion consistency.
Most administered 1–4 mL of sterile normal saline.
Despite this routine practice, many nurses also acknowledged possible risks.
Among nurses who routinely used saline:
42% believed the practice could be harmful.
92% identified increased lung infection risk as the greatest concern.
Many also reported concerns about reduced oxygen saturation.
Nurses who chose not to use saline primarily cited:
Lack of proven clinical benefit
Potential patient harm
The study highlighted a significant gap between traditional nursing practice and current evidence-based recommendations.
Akgül and Akyolcu (2002) evaluated physiological responses following endotracheal suctioning with and without saline instillation.
Researchers monitored:
Heart rate
Oxygen saturation (SpO₂)
Arterial blood gases
Blood pH
Patients were observed for five minutes after suctioning.
The study found:
Small decreases in oxygenation following saline instillation
Minor changes in arterial blood gases
Significant increases in heart rate after saline-assisted suctioning
No meaningful improvement in oxygen saturation
Although several physiological changes were not statistically significant, saline instillation produced undesirable responses without measurable clinical benefits. The researchers concluded that routine saline instillation should be reconsidered because its risks outweigh its limited value.
Current evidence consistently suggests that routine saline instillation may increase the likelihood of ventilator-associated pneumonia (VAP).
Several mechanisms may explain this association.
Research suggests that saline may transport bacteria deeper into the lower respiratory tract during suctioning, increasing the risk of infection.
Residual saline remaining within the lungs can interfere with gas exchange and temporarily worsen oxygenation after suctioning.
Studies have shown that only a small proportion of instilled saline is removed during suctioning, leaving fluid within the airway that may contribute to respiratory complications.
These findings explain why many current critical care guidelines discourage routine saline instillation before endotracheal suctioning.
Modern critical care emphasizes interventions supported by high-quality evidence. Current research recommends that clinicians:
Perform suctioning only when clinically indicated.
Avoid routine saline instillation before suctioning.
Maintain sterile suctioning techniques.
Monitor oxygenation before, during, and after suctioning.
Use humidification and adequate hydration to manage thick secretions.
Critical care nurses and respiratory therapists play a key role in implementing these recommendations and ensuring evidence-based respiratory care.
In older adult patients with chronic obstructive pulmonary disease (COPD) receiving mechanical ventilation through an endotracheal tube (P), does the use of normal saline instillation during endotracheal suctioning (I), compared with suctioning without saline instillation (C), increase the risk of ventilator-associated pneumonia, mortality, and prolonged hospital stay (O)?
Evidence-based practice combines the best available research with clinical expertise and patient preferences to improve healthcare outcomes.
The literature consistently indicates that routine saline instillation before suctioning provides little clinical benefit while increasing the risk of complications.
Healthcare organizations should consider:
Updating endotracheal suctioning protocols.
Educating nurses on current evidence-based recommendations.
Reducing unnecessary saline instillation.
Promoting guideline-based respiratory care.
Implementing evidence-based suctioning practices can improve patient safety, reduce preventable infections, and enhance the quality of critical care.
Developing focused PICO questions also enables nurses to evaluate interventions across multiple clinical settings. For example:
In older adults with diabetes living in long-term care facilities, does scheduled subcutaneous insulin therapy compared with oral metformin improve blood glucose control while reducing complications?
Using structured clinical questions supports informed decision-making and strengthens evidence-based nursing practice.
Clinical Question: Should normal saline be routinely instilled before endotracheal suctioning?
Evidence-Based Answer: No. Current evidence does not support routine saline instillation because it fails to improve secretion clearance and may increase the risk of ventilator-associated pneumonia and other complications.
Routine saline instillation does not improve secretion removal.
Evidence links saline instillation with higher rates of ventilator-associated pneumonia.
Saline may temporarily reduce oxygenation after suctioning.
Increased heart rate has been observed following saline-assisted suctioning.
Current guidelines recommend suctioning without routine saline instillation unless clinically indicated.
Endotracheal suctioning remains an essential intervention for mechanically ventilated patients, but routine normal saline instillation is no longer considered best practice in adult critical care.
Current research demonstrates that saline instillation offers minimal clinical benefit while increasing the risk of respiratory complications, including ventilator-associated pneumonia. Evidence-based guidelines recommend individualized suctioning decisions based on patient assessment rather than routine saline use. Ongoing education and protocol updates are essential to bridge the gap between traditional practice and current evidence.
No. Current evidence-based guidelines do not recommend routine saline instillation because it has not been shown to improve secretion clearance and may increase complications such as ventilator-associated pneumonia.
Clinicians historically believed saline would loosen thick secretions, stimulate coughing, and make suctioning easier. However, research has not consistently supported these assumptions.
Yes. Multiple studies suggest that saline may facilitate bacterial migration into the lower respiratory tract, increasing the risk of ventilator-associated pneumonia.
No. Most research shows no significant improvement in oxygen levels. Some studies report temporary reductions in oxygenation following saline instillation.
Healthcare professionals should suction only when clinically indicated, use sterile technique, optimize humidification, maintain adequate hydration, and avoid routine saline instillation unless there is a specific clinical indication.
Akgül, S., & Akyolcu, N. (2002). Effects of normal saline on endotracheal suctioning. Journal of Clinical Nursing, 11(6), 826–830. https://doi.org/10.1046/j.1365-2702.2002.00714.x
Ayhan, H., Taştan, S., İyigün, E., Akamca, Y., Arıkan, E., & Sevim, Z. (2015). Normal saline instillation before endotracheal suctioning: What does the evidence say? What do nurses think? Journal of Critical Care, 30(4), 762–767. https://doi.org/10.1016/j.jcrc.2015.02.019
Caparros, A. C. S. (2014). Mechanical ventilation and the role of saline instillation in suctioning adult intensive care unit patients. Dimensions of Critical Care Nursing, 33(4), 246–253. https://doi.org/10.1097/DCC.0000000000000049
Klompas, M., Branson, R., Eichenwald, E. C., Greene, L. R., Howell, M. D., Lee, G., Magill, S. S., Maragakis, L. L., Priebe, G. P., Speck, K., Yokoe, D. S., Berenholtz, S. M., & Society for Healthcare Epidemiology of America. (2014). Strategies to prevent ventilator-associated pneumonia in acute care hospitals: 2014 update. Infection Control & Hospital Epidemiology, 35(8), 915–936. https://doi.org/10.1086/677144
American Association for Respiratory Care. (2010). AARC clinical practice guideline: Endotracheal suctioning of mechanically ventilated patients with artificial airways 2010. Respiratory Care, 55(6), 758–764. https://rc.rcjournal.com/content/55/6/758
