Can Sodium Bicarbonate Rinse Reduce Pneumonia in Ventilated Patients With TBI?

In patients with traumatic brain injury (TBI) who are mechanically ventilated, the addition of 0.9% sodium bicarbonate oral rinse to a 2% chlorhexidine mouthwash treatment regimen did not show statistical significance in lowering the incidence of ventilator-associated pneumonia (VAP). Likewise, the use of 0.9% sodium bicarbonate oral rinse showed only a minimal advantage in lowering the quantitative bacterial load. These were among study findings reported in Trends in Anaesthesia and Critical Care.

Patients with TBI in the intensive care unit (ICU) often require mechanical ventilation (MV), which makes oral hygiene difficult. This, along with the lowered immunity of patients with TBI, likely contributes the finding that up to 28% of patients with TBI on MV may develop pneumonia from aspirating pathologic flora in oral secretions. Although oral chlorhexidine has been shown to help prevent VAP, it has been unclear whether adding sodium bicarbonate to this oral rinse would be advantageous. Researchers therefore sought to determine how adding sodium bicarbonate to the oral chlorhexidine rinse used in patients with TBI on MV would affect their incidence of pneumonia.

The researchers conducted a prospective, randomized controlled, interventional study in the 27-bed ICU of Banaras Hindu University Trauma Care Centre, Varanasi, India, between December 2019 and August 2021. The primary study outcome was the incidence of VAP, as determined by the Clinical Pulmonary Infection Score (CPIS) score from day 1 to day 5. The score is considered positive in patients with a CPIS of more than 6. The secondary outcomes included oral acidity/alkalinity (pH) and endotracheal tube aspirate quantitative bacterial load. Oral pH is measured with the use of pH strips. In patients in whom the endotracheal tube quantitative bacterial load is more than10⁵ CFU/mL, this is considered a significant finding.

The final study analysis included 88 patients between 18 and 65 years of age with evidence of head injury who were intubated in the ICU within 24 hours of their injury and were kept on MV thereafter. Patients were divided into 2 groups: 44 patients who received 0.9 sodium bicarbonate oral rinse once daily along with 2% chlorhexidine mouthwash 2 times daily (SBC group); and 44 patients receiving 2% chlorhexidine mouthwash 3 times daily (control group). The groups were well matched for sex, age, comorbidities, and acute physiology and chronic health evaluation (APACHE) score upon admission (mean scores were 21.28±7.0 for SBC group vs 21.21±7.0 for control group).

Results of the analysis showed no statistically significant difference in the incidence of VAP among both of the groups from day 1 to day 5 (P >.05). Further, no difference was reported in quantitative bacterial load among both groups on days 1, 3, and 5 (P >.05).

A statistically significant difference was reported, however, between both groups in oral pH on days 3 and 5, with SBC group having higher oral pH levels than the control group (P =.03 on day 3; P =.01 on day 5).

There are several limitations apparent in the current study. First, the CPIS scoring system used in the study has few subjective parameters and few objective parameters. Second, the staff nurse who provided the oral care was not the same individual for all of the patients all of the time, based on availability and shifts. Additionally, the sample size in the study was small.

The researchers concluded that “The alkalinization of [the] oral cavity with 0.9% sodium bicarbonate oral rinse along with 2% chlorhexidine [mouthwash] lowered the incidence of VAP as compared [with] 2% chlorhexidine [mouthwash] alone but the difference was not statistically significant.” Additional studies with a larger sample size are warranted, said the researchers.

This article originally appeared on Pulmonology Advisor