Temporary Abdominal Closure (TAC) has become standard surgical management of the open abdomen in the setting of septic shock, coagulopathy, and damage control laparotomy. Negative pressure wound therapy (NPWT) evacuates intraabdominal fluid and purulent drainage during resuscitative measures and protects the exposed viscera for critically ill patients with open abdomens [1] [2] [3] [4] . New uses for NPWT include irrigation or washout TAC methods to reduce microbial contamination and promote healing [5] .

In 1916, Fraser and Bates published successful treatment of appendiceal abscesses, viscus-perforating bullet wounds, and peritonitis with an antiseptic intra-abdominal washout using a 0.5% hypochlorous acid in normal saline (EUSOL) [6] .

In their 6-month war experience, they were able to decontaminate wounds of gas gangrene, compound fractures, joints, skull fractures, chest, and abdominal surgery with EUSOL. Their report noted that hypochlorous acid as “Eusol” was a potent disinfectant in their experience, and helped their soldiers to survive. They performed rabbit experiments to confirm that a hypochlorous acid solution washout, (leaving some solution in situ upon closure), was without deleterious effect (such as adhesions) [6] . Hypochlorous (HOCL) acid is a beneficial wound cleanser. It reduces the prokaryotic organism burden to 10⁻² power, while normal saline only reduces it to the 10⁻⁵ power [7] . One hundred three years later, it was used intra-abdominally again as an irrigant with NPWT-I documented in the literature as a case report [8] . This study aimed to evaluate the use of Vashe^Ò, (SteadMed. Inc., Fort Worth, TX) (V-HOCL) as a simple washout or irrigant, utilizing NPWT-i: Abthera^TM (Acelity, Inc, San Antonio, TX) and V.A.C. Dressing System^TM (Acelity, Inc, San Antonio, TX) in acutely ill patients with septic open abdomens. We hypothesized that the use of V-HOCL would be safe to use as an intra-abdominal washout and irrigation in the short and long term open septic abdomens. In addition, we hypothesize that V-HOCL is not hazardous to the peritoneum or serosal surfaces of the abdominal organs.

Table 1 describes the demographic characteristics of Group A (NPWT-i compared

Mean ± sd, (Range, Median); M/F = Male/Female. *Toxic Epidermal Necrolysis, Thermal Injury, Necrotizing Fasciitis; ^Septic or Hemorrhagic; NPWT-i = Negative Pressure Wound Therapy-Irrigation.

to Group B (Washout). Both groups tolerated V-HOCL washout/irrigations. Fifty percent of both groups were in either septic or hemorrhagic shock on admission. Group A had more severely ill patients (burns, necrotizing fasciitis, acute renal injury) versus mainly perforated viscus in Group B (Washout). Compared to Group B patients, Group A were older (median 50 vs 37 years), had a median hospitalization of 28 vs 8 days, 4 times as many operations, an increased frequency of acute renal failure (75% vs 11%), 63% required continuous renal replacement therapy, and an overall increase in co-morbidities. Diabetes, cardiac disease, COPD, renal failure, psychiatric disease, and heroin abuse were the most common co-morbidities. The patients tolerated the procedure well and did not undergo episodes of hypotension, hypertension, anaphylaxis, or systemic toxicity. There were four mortalities in Group A that were attributed to the initial diagnosis and not to the NPWT-i treatment, which was an incidental confounding factor regarding these deaths. Of significance, the two anastomotic breakdowns in Group A did not occur during the V-HOCL irrigations.

In Table 2, as expected, Group A had a longer irrigation exposure to V-HOCL with the intraabdominal NPWT-i, median 23 liters (range 7 to 47 liters), compared to Group B, median 3 liters (range 1 to 3 liters). Table 3 shows the laboratory values pre- and post-washouts and irrigations. There were no statistically significant differences between the two treatment methods with V-HOCL delivery and removal. In both groups, the white blood cell count was decreased post-treatment, and serum chloride levels were slightly increased but within normal limits. Comparing Group A with Group B, pre-treatment hemoglobin was significantly decreased, (median 9.8 vs 12.6 g/dl, p < 0.01) as were the platelets, (median 166 vs 312, p < 0.047). There were no statistically significant differences between the two groups in lactate, pH, and CO₂ or HCO₃ pre- and post-washout and irrigation procedures.

Mean ± sd, (range, Median); no hemodialysis or anaphylaxis; NPWT-I = Negative pressure wound therapy-irrigation; Tx Time = Treatment Time; *the other 6 patients had their abdomens closed within 24 - 48 hours.

Mean ± sd, (range, Median); NPWT-I = Negative pressure wound therapy-irrigation; PreOp = Before procedure; PostOp = After procedure; Hgb = Hemoglobin; Hct = Hematocrit; Plt = Platelets.

In this retrospective observational pilot study, both short term and prolonged care with V-HOCL as an intraabdominal disinfectant for the open septic abdomen was safe and beneficial to use in the setting of trauma, burn and general surgery. In addition, V-HOCL was not hazardous to the peritoneum or serosal surfaces of the abdominal organs as a washout solution or irrigant with NPWT-i. This study confirmed the findings and recommendations of Fraser and Bates in 1916 for the use of HOCL acid in septic open abdomens [6] . There were no systemic toxicities noted or attributed to utilizing V-HOCL in a protocol requiring intermittent fluid irrigation and drainage for a period of days (Group A) or as an open abdomen surgical washout solution (Group B).

Except for documentation by Fraser and Bates [6] (over a century ago), and Matthews [8] , we were unable to find the use of any HOCL acid solution as an irrigant or washout of the open septic abdomen in the literature. HOCL acid solutions have been reported mainly as disinfectants for wounds at a risk for healing [12] [13] . Currently, NPWT has been a major player in the healing of surgical wounds.

Besides Matthews et al., there have been 3 reported studies between 2012 and 2017 utilizing NPWT-i for wounds at risk for healing, or septic abdomens [8] . Gabriel et al. reported 2 cases of deep wounds which benefited from V.A.C. VeraFlo^TM Therapy with Prontosan^Ò (B. Braun Medical, Inc. Bethlehem, PA) and another case with normal saline [14] . Brinkert et al. used NPWT-i with normal saline on 131 diabetic and orthopedic wounds successfully [15] . Sibaja et al. documented normal saline irrigation in 48 patients with septic open abdomens in a controlled fashion in trauma and general surgery patients using NPWT-i [16] .

Limitations of this retrospective observational study were the small number of patients. Although there was a protocol for the use of V-HOCL with NPWT-i in Group A, Group B patients obtained standard abdominal washout procedures with V-HOCL at the discretion of the operating surgeon. Neither Group A nor B procedures provided information as to the distribution of the irrigant or washout into all abdominal quadrants. There was no protocol in place for a standardized collection of abdominal fluid or intraabdominal cultures at baseline, during treatment or post treatment. Ongoing studies in the medical center are using V-HOCL and assessing the microbiology of the peritoneal cavity before and after washout or irrigation with V-HOCL.

This pilot study has shown that Vashe^Ò, a 0.033% hypochlorous acid in normal saline solution is safe as a standard surgical intra-abdominal washout or NPWT-i irrigant using the combination of the Abthera^TM device and V.A.C. Dressing System^TM for septic open abdomens. In patients requiring an exploratory laparotomy and possibly an open abdomen for continuous irrigation or a single washout of the abdomen, these interventions may provide a benefit to the patient with a septic open abdomen.

There was no funding for this Pilot Study.

Each of the above listed authors declare that there are no conflicts of interest related to this manuscript, except for Marc R. Matthews, MD, Luis G. Fernandez, MD, who are surgical consultants for both Acelity, Inc., and SteadMed Medical, LLC.

Matthews, M.R., Quan, A.N., Shah, A.R., Tugulan, C.I., Nashed, B.A., Goldberg, R.F., Pieri, P.G., Fernandez, L.G., Kowal-Vern, A. and Foster, K.N. (2018) Hypochlorous Acid for Septic Abdominal Processes Using a Unique Negative Pressure Wound Therapy System: A Pilot Study. Surgical Science, 9, 412-421. https://doi.org/10.4236/ss.2018.911048