Management of small bowel perforation with intra- and post-operative lavages with povidone iodine. (A prospective study).
Diffuse septic peritonitis resulting: from small bowel perforations is a frequently encountered problem in tropics and continues to be associated with a high mortality -rate even though. diagnostic facilities have improved, surgical procedures have been standardised and post-operative intensive care has reached a sophisticated level. Various antibiotics and operative procedures have been tried. In a systematic attempt to eradicate infection from the peritoneal cavity in cases of fulminating peritonitis, local therapy, which is an important factor does not appear to have attracted the attention it deserves.
The aim of the present study is to reduce the bacterial toxaemia by using a potent and broad spectrum antibacterial agent such as povidone iodine for peritoneal lavage.
Twenty-five patients of ileal perforations presented to a surgical unit of the K.E.M. Hospital, Bombay, India, were studied. The ages of the patients varied from 16 to 50 years with a mean of 29.6 years. There were 21 males and 4 females in the study group.
All the patients presented with a history of fever of varying duration, abdominal pain, vomiting and abdominal distension. The average duration of acute abdominal symptoms prior to admission varied from 12 hours to 6 days (mean 2.1 days).
On clinical examination of these patients all had evidence of peritonitis with paralytic ileus, dehydration and septicaemic shock. The plain X-ray of the abdomen revealed gas under the diaphragm in all the patients. Abdominal paracentesis done in both iliac fossae was positive in all cases. The fluid obtained, was examined for microbiological assessment.
The patients were pre-operatively prepared by correcting the dehydration and acidosis. The temperature, pulse, respiratory rate, blood pressure and CVP and urine output were monitored carefully.
The patients were explored through a right paramedian incision. All the patients had gross peritonitis. Twenty one patients had ileal perforation and four patients had tuberculous strictures with proximal ileal perforation.
The ileal perforations were sutured in two layers of interrupted unabsorbable linen sutures after excising the edge of the ulcer for histopathological examination. The suture line was extraperitonealised by suturing the affected loop to the lower end of the peritoneal incision. A thorough peritoneal lavage was given with normal saline. The tube drains were placed in both the flanks, one tube pointing upwards and the other in the pelvis.
Prior to the closure of the abdomen, 500 ml of povidone-iodine containing 312.5 µg/ml of available iodine was instilled in the peritoneal cavity (see results). This was drained out through the drainage tubes after 30 minutes. In the post-operative period, the antibiotics used were inj. gentamicin 60 mg, 8 hourly and/or crystalline penicillin 10 lac units 6 hourly. From the second postoperative day the peritoneal lavage was given by instilling 500 ml of povidone-iodine solution through one tube, and the fluid was drained through the other tube after 30 minutes. The returning fluid was examined microbiologically. The lavage was given every day till the peristalsis returned.
Patients were maintained on intravenous fluids till peristaltic activity returned. They were then gradually converted to full diet. Systemic antibiotics were given for 7 days. In patients with serological or histological evidence of typhoid, a full course of chloramphenicol was given. In tuberculous patients antitubercular chemotherapy was advised.
In vitro studies in our laboratory showed that povidone iodine containing 156.25 µg/ml of available iodine (3% of the original stock solution) has bactericidal activity when kept in contact for a period of 15 minutes. However, in clinical application, we have used double the concentration and time.
The bacterial count of the peritoneal fluid rapidly decreased with serial lavages. Pre-operatively, the bacterial count varied between 10 and 10 organisms/ml. On the 2nd and 4th postoperative days it varied between 10 and 10 and 10 to 10 organisms/ml respectively. On the 6th post-operative day the count varied from no growth to hardly 10 organisms/ml.
Type of bacterial growth
This is presented in [Table 1] below and is self-explanatory.
Post-operative hospital stay
Eight patients (32%) remained in the hospital for a period of only 10-13 days, 9 patients (36%) for a period of 14-17 days, 5 patients (20%) for a period of 17-21 days and only 2 patients were in the hospital for more than 21 days. One patient of the series died on the 10th postoperative day.
Iodine absorption as studied by the PBI levels in three patients was found to be insignificant. Widal test and the histopathological examination was found to be positive in 3 cases of typhoid while histopathology was positive for tuberculosis in another 4 cases. Eighteen patients showed only non-specific inflammation.
The antibiotic combination used in all patients was gentamicin and crystalline penicillin. It was noteworthy that in two patients, the organisms were resistant to these antibiotics; yet, the patients progressed well. This could be possible because of local bactericidal effect of povidone iodine.
Complications and mortality
Ten patients in the series had no complications at all. Fourteen patients developed superficial wound infection which was treated with repeated dressings. There was no leak from the extra peritonealised bowel. Only one patient (4%), who had non-specific ileal perforation, developed endotoxaemia. He could not be given povidone iodine irrigation as the catheter got blocked on the second postoperative day. He died on the 10th day of endotoxaemia inspite of all measures. The overall mortality was 1/25 i.e., 4%.
Small bowel perforation is a common emergency having an extremely high mortality. However, this has been reduced over years with a better understanding and management of shock and septicaemia, improved surgical technique and the use of appropriate antibiotics. Inspite of all these measures, the mortality still hovors between 10 and 36.5%. Dickson and Cole recorded 56% mortality in a study of 38 cases. Mehendale and Samsi reported 31.5% mortality in a study of 32 cases. Nadkarni et al reported only 12.57% mortality.
The toxaemia after bowel perforation is probably due to the absorption of toxins by the lymphatics and the capillaries which form a rich network in the peritoneum. Though the peritoneal fluid has a large number of mononuclear cells providing an excellent barrier against infective processes, this barrier crumbles against the onslought of the toxic material pouring out of the perforation.
It was believed that peritoneal irrigation with either normal saline or an antibiotic solution during the intra-operative phase would reduce this toxaemia. However, this could lead to the emergence of resistant strains of bacteria. Further the absorption of toxins continues for several days; thus the attempt at effective reduction of absorption of toxins would have to aim at daily peritoneal lavage till toxaemia is controlled; this was the "raison d'etre." of the present study.
Various surgical techniques have been tried to reduce the high mortality resulting from bowel perforations;  however, these did not significantly alter the mortality rate. The cause of death in a majority of such patients was toxaemia.
A potent and broad spectrum microbicidal agent, povidone iodine was selected for peritoneal irrigation as no other single antibiotic is capable of controlling a large spectrum of gastro-intestinal flora of organisms. The dose of povidone iodine and the duration of contact was based on our in vitro studies. It did not have any deleterious effect. In experimental mice, Gilmore had shown that povidone iodine (6-7.5 mg of available iodine per kg) significantly reduced the mortality in mice with bacterial peritonitis when compared to an identical control group (p < 0.001) .
The therapeutic dose of povidone iodine was almost ten times less than the LD50 dose in mice. It was also found that the new povidone iodine solution containing increased povidone had a highly significant effect in reducing the mean number of adhesions formed (p < 0.001) and also their mean lengths of attachments (p < 0.001). Iodine absorption as studied by the PBI levels is insignificant.
Suturing with exteriorisation of the perforation has a mortality of 12.5%. The reduced mortality of 4% in the present series shows that better results can be obtained by extraperitonealisation of the affected bowel and daily peritoneal lavages with 5% povidone iodine than with exteriorisation only.
In our series, clinically the postoperative recovery was much faster and satisfactory. Patients had no discomfort with the irrigation. The post-operative hospital stay was also reduced. Bacteriological reports themselves reveal that the colony counts were markedly decreased. because of direct local action of povidone iodine.