In Adult Horses With Septic Peritonitis , Does Peritoneal Lavage Combined With Antibiotic Therapy Compared to Antibiotic Therapy Alone Improve Survival Rates ?

The quality of evidence in equids is insufficient to direct clinical practice aside from the following: The use of antiseptic solution to lavage the abdomen causes inflammation and is detrimental to the patient. For peritonitis caused by Actinobacillus equuli, treatment with antibiotics alone may be sufficient. A variety of antibiotics were used in the two reported studies.


Appraisal, application and reflection
Only low-quality evidence is available comparing the use of antibiotics with the combined use of antibiotics and peritoneal lavage to treat horses with peritonitis.There are many likely confounding factors in the case series reported which are inherent to use of case series.This includes unblinded treatment selection; it is likely that more severely affected cases or those where the abdomen is contaminated with gastrointestinal or uterine contents are treated with peritoneal lavage and antibiotics whereas those thought to be less severely affected are treated with antibiotics alone.There is also significant variation in the treatments used between cases within studies and between studies, including the use of treatment protocols which are now outdated, in particular, aminoglycoside choice, dose and frequency, (Golland et al., 1994, Hawkins et al., 1993).There is variation in the class of antibiotics, doses and frequency used and duration of treatment for cases within and between studies.A single study (Nieto et al., 1993) included patients in which abdominal lavage was performed using povidone-iodine solution, which has been shown to cause peritoneal inflammation (Schneider et al., 1988) and several studies do not describe the fluid used for lavage the abdomen (Hawkins et al., 1993, Henderson et al., 2008, Javsicas et al., 2010, Matthews et al., 2001).Financial constraints may have influenced the choice of treatment and the survival of patients reported.Patients in all the case series studies described received additional treatments including intravenous fluid therapy, non-steroidal antiinflammatory medication, gastroprotectants, anti-endotoxic medication and prokinetics.The impact of these treatments was not analysed in most studies and is not described in this summary.

Conclusion:
There is no evidence in equids that there is a difference in survival when the use of antibiotics is compared to the use of antibiotics combined with peritoneal lavage.However, the quality of data available is insufficient to direct clinical practice apart from two areas; in peritonitis caused by Actinobacillus equuli, treatment with antibiotics alone is sufficient, and the use of antiseptic solutions such as povidone iodine to lavage the abdomen causes inflammation and is detrimental to the patient.More definitive conclusions cannot be drawn until higher quality evidence on this topic is available.

Main findings: (relevant to PICO question):
All ponies undergoing abdominal lavage showed signs of discomfort Lavage with 10% povidone-iodine [n=3]:  All ponies treated showed severe abdominal pain, tachycardia and pyrexia. 1 pony died after 30h and another was euthanised after 36h  1 pony survived to 96h

5 total pages: 11 Intervention details:
Medical [n=15]; antibiotic therapy Surgical [n=34]; ventral midline coeliotomy Abdominal lavage was performed in both groups and frequency of abdominal lavage was not different between the treatment groups Study

7 total pages: 11 Main findings: (relevant to PICO question):
Veterinary Evidence ISSN:2396-9776 Vol 2, Issue 4 DOI: http://dx.doi.org/10.18849/ve.v2i4.135next review date: 13 Nov 2019 p a g e | 8 total pages: 11 CAB Abstracts on OVID Platform 1973-Week 17 2017 PubMed accessed via the NCBI website 1973-Week 17 2017 Search terms: 1. (equine or horse or equus or colt or equid) and peritonitis) 2. (antibiotic or antimicrobial or antibacterial or anti-microbial) 3. (lavage OR surgery OR exploratory laparotomy OR laparotomy OR coeliotomy OR celiotomy) 4. 1 and (2 or 3) Dates searches performed: 11 th May 2017 Exclusion / Inclusion Criteria Exclusion: Non-English language papers Single case reports Book chapters and literature reviews without novel information Not relevant to the question Inclusion: Papers comparing the use of antimicrobials with the combination of antimicrobials and peritoneal lavage were included.Due to the very limited available literature papers describing the use of antimicrobials or antimicrobials and peritoneal lavage or peritoneal lavage were included even when there was not a direct comparison of treatment modalities.