Surgery · Medical Literature
Preoperative chlorhexidine mouthwash to prevent postoperative infections in low-risk elective abdominal surgeries: a double-blind RCT from North India among patients with poor oral hygiene.
Abstract
Postoperative respiratory complications, particularly in patients with poor oral hygiene, contribute significantly to morbidity and healthcare burden. The oral cavity serves as a reservoir of pathogenic micro-organisms that, when aspirated during or after surgery, can lead to respiratory infections. While chlorhexidine mouthwash has shown promise in high-risk surgeries, its role in short-duration elective abdominal surgeries remains unexplored, especially in low-resource settings. This double-blind, randomised controlledrial included 228 patients (American Society of Anaesthesiologists I/II, aged 18-65 years, Oral Hygiene Index (OHI) >6) undergoing elective abdominal surgery under general anaesthesia lasting <4 hours. Patients were randomised to receive either 0.2% chlorhexidine (group A) or normal saline (group B) mouthwash two times before surgery. Outcomes measured included postoperative sore throat, fever, pneumonia, surgical site infections (SSI) and length of hospital stay. Microbiological cultures, complete blood count, C-reactive protein (CRP) and chest X-rays were evaluated on postoperative days 1, 3 and 7. Chlorhexidine significantly reduced sore throat (18.42% vs 47.37%, p<0.001), positive bacterial cultures (21.05% vs 62.28%, p<0.001), CRP elevation and SSI (4.39% vs 21.93%, p<0.001). Length of hospital stay was also shorter in the chlorhexidine group (p<0.001). Pneumonia rates were low and comparable. This double-blind randomised controlled trial demonstrates that preoperative use of chlorhexidine mouthwash significantly reduces postoperative sore throat, bacterial colonisation, SSI and length of hospital stay in patients with poor oral hygiene undergoing short-duration elective abdominal surgeries. These findings highlight the utility of a simple, low-cost oral hygiene intervention in improving surgical outcomes, particularly in low-resource settings and support its incorporation into standard perioperative protocols, even for lower risk procedures. CTRI/2024/06/069511).
Clinical relevance
This RCT addresses a critical gap in perioperative care by evaluating the efficacy of preoperative chlorhexidine mouthwash in low-risk elective abdominal surgeries among patients with poor oral hygiene (OHI >6) — a population and procedural category largely excluded from prior decontamination literature. The oral cavity represents a significant reservoir of pathogenic microorganisms capable of causing postoperative respiratory and surgical site infections, particularly in low-resource settings where baseline oral hygiene is poor. Given the scalability and minimal cost of this intervention, these findings are immediately relevant to surgeons and anesthesiologists seeking to reduce preventable postoperative morbidity across resource-constrained environments.
Key findings
1. Postoperative sore throat was significantly reduced in the chlorhexidine group versus placebo (18.42% vs 47.37%; p<0.001), representing a clinically meaningful reduction of approximately 29 percentage points. 2. Positive postoperative bacterial cultures were markedly lower in the chlorhexidine arm (21.05% vs 62.28%; p<0.001), indicating substantial suppression of oropharyngeal microbial colonisation with a reduction of ~41 percentage points. 3. Surgical site infection (SSI) rates were significantly lower in the chlorhexidine group (4.39% vs 21.93%; p<0.001), yielding an absolute risk reduction of ~17.5 percentage points and an estimated NNT of approximately 6 to prevent one SSI. 4. C-reactive protein (CRP) elevation was significantly attenuated in the chlorhexidine group versus saline on postoperative days 1, 3, and 7 (p<0.001), corroborating reduced systemic inflammatory burden. 5. Length of hospital stay was significantly shorter in the chlorhexidine group compared to placebo (p<0.001), though specific mean duration values were not reported in the abstract. 6. Postoperative pneumonia rates were low and statistically comparable between both groups, suggesting that short-duration (<4 hours) general anaesthesia carries limited aspiration pneumonia risk regardless of oral decontamination status in ASA I/II patients.
Practice implications
Perioperative teams should consider incorporating two preoperative rinses of 0.2% chlorhexidine mouthwash into standard surgical preparation protocols for ASA I/II patients aged 18–65 with documented poor oral hygiene (OHI >6) undergoing elective abdominal procedures under general anaesthesia lasting less than 4 hours, particularly in low-resource or high-volume surgical settings. Given the significant reductions in SSI and bacterial colonisation, this intervention is especially actionable in institutions where baseline postoperative infection rates are high and access to advanced prophylactic measures is limited. The simplicity, low cost, and non-invasive nature of this intervention support its immediate integration into existing WHO Surgical Safety Checklist-aligned perioperative bundles without the need for additional infrastructure or specialist input.