Classification of Irrigation Solutions

Classification of Irrigation Solutions

1. Normal Saline (NS)
   – Considered the gold standard due to safety, low cost, and minimal cytotoxicity.
   – Mechanism: Dilutes and mechanically removes bacteria, necrotic tissue, and foreign debris.

Studies Supporting NS Use:
– FLOW Trial (2011): Involved 2,447 patients with open fractures. NS showed a significantly lower reoperation rate (11.6%) than castile soap (14.8%).
– Owens et al. (2009): NS showed better performance in bacterial regrowth reduction at 48 hours than castile soap.
– Capito et al. (2017): Hyperosmolar saline led to lower postoperative pain and swelling in shoulder arthroscopy.

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2. Normal Saline with Antibiotic Additives
   – Common antibiotics: Bacitracin, Polymyxin, Neomycin, Vancomycin.
   – Mechanism: Bactericidal or bacteriostatic, disrupting bacterial membranes.

Supporting Studies:
– Almaawi et al. (2022): Vancomycin lavage in TKA reduced postoperative infections, though not statistically significant.
– Anglen (2005): Castile soap was found equivalent to bacitracin in bacterial reduction in open fractures.

3. Saline with Surfactants
   – Surfactants like Castile soap and benzalkonium chloride act by emulsifying debris and microbes.

Studies & Trials:
– Bhandari et al. (2001): Soaps reduced microbial count without affecting fracture union.
– Conroy et al. (1999): Castile soap had lower wound culture positivity than NS.
– FLOW Trial (2011): Showed no added benefit of castile soap over NS.

 

Newer Irrigation Agents

4. Povidone-Iodine
   – Strong oxidizer with proven antimicrobial properties.
   – Recommended by WHO, CDC, and AAOS.

Key Studies:
– Premkumar et al. (2021): 10% solution more effective than 0.35% in MSSA biofilm eradication.
– Goswami & Austin (2019): 0.3% solution effective with minimal cytotoxicity.
– Riesgo et al. (2018): 83.3% success in PJI with povidone-iodine+vancomycin vs. 63.2% in NS controls.
– De Luna et al. (2017): 3% povidone-iodine with pulse lavage reduced deep infection in spine surgery.

 

5. Chlorhexidine Gluconate (CHG)
   – Cationic antiseptic that disrupts microbial cell walls.
   – FDA-approved 0.05% formulation

Supporting Evidence:
– Schwechter et al. (2011), Frisch et al. (2017): Decreased MRSA and biofilm load on implants.
– Moore et al. (2022): CHG showed high cytotoxicity in tumour models.
– Barros et al. (2019), Byren et al. (2009): Successful outcomes in TKA/THA PJI treatment using CHG vs NS

 

6. Hydrogen Peroxide
   – Generates reactive oxygen species to damage cellular components.
   – Mechanical foam action helps with wound debridement.

Key Findings:
– Glynn et al. (2009): Effective in biofilm inhibition.
– Shigematsu et al. (2005): Minimal implant surface degradation.
– Ulivieri et al. (2011): No deep infections in 490 spine surgery patients using peroxide + povidone protocol.
– George et al. (2015): 1% povidone + 50:50 3% hydrogen peroxide used successfully in single-stage PJI.

 

7. Sodium Hypochlorite (Dakin’s Solution)
   – Active against bacteria, fungi, and viruses.- Röhner et al. (2020): Superior biofilm penetration vs. CHG on polyethylene.
8. Acetic Acid
   – Disrupts microbial membranes by acidifying the intracellular environment.

Evidence:
– Tsang et al. (2018): 5% acetic acid eradicated 96.1% MSSA biofilms.
– Williams et al. (2017): 87% success in TKA PJI when 3% acetic acid was used intraoperatively for P. aeurenginosa, S.aureus

 

9. Hypochlorous Acid
   – Produced by neutrophils; acts similarly to sodium hypochlorite – residual chlorine ion act as ionisers, pH lowering effect .

Clinical Insights:
– Kubacki & Gilbert (2018): Potential implant corrosion on cobalt/titanium.
– Clayman et al. (2023): 2 cases of successful hardware salvage with intra- and post-operative instillation.

 Conclusion
Normal saline remains the safest default.

Povidone-iodine is the only adjunct currently endorsed by AAOS, CDC, and WHO.

There is growing evidence supporting the use of antiseptics like CHG, hydrogen peroxide, acetic acid, and hypochlorous acid in specific contexts (e.g., PJI, spine, oncology), though cytotoxicity and standardization of protocols remain unresolved issues.