Stratified outcome evaluation in peritonitis
Abstract
Background: The heterogeneity of disease severity in peritonitis often
makes outcome prediction and treatment planning problematic. Disease
severity stratification has been shown in studies elsewhere to relate with
outcome. Risk evaluation in secondary peritonitis is of value in treatment
planning, outcome prediction and conduction of surgical audits. This study
evaluated outcome in peritonitis by stratifying patients according to disease
severity using the Mannheim Peritonitis Index (MPI) at Kenyatta National
IIospital.
Objective: The main objective was to determine the usefulness of the MPI in
predicting outcome of secondary peritonitis at KNI--I.
Design: This was a prospective descriptive cross sectional survey.
Materials and methods: Seventy patients meeting the inclusion criteria and
admitted within the study period were consecutively enrolled into the study
within 24 hours of operation. Data encompassing the risk factors under
evaluation was collected comprising of age, sex, preoperative duration,
organ failure, sepsis source, malignancy, character and extent of exudate
from which the MPI was calculated. Patients were then followed up tiIJ
discharge or death to record outcome (complications, hospital stay or death).
Outcome evaluation was stratified in accordance with the MPI score. Data
analysis was done with the aid of the SPSS version 12 computer programme.
Results: A total of 56 males and 14 females (M:F =4:1) were recruited into
the study. The age range was 13-59 years with a mean of 32.17 years. Forty
six patients (65.7%) had generalised peritonitis, 15(21.4%) had 2-3 quadrant
peritonitis while 9(12.9%) had focal peritonitis. The commonest source of
sepsis was perforated appendicitis (31.4%), followed by perforated duodenal
ulcer (22.9%) and ileal perforation (18.6%). Ileus was the most frequent
organ dysfunction (48.6%). Source control was not achieved in 12.9% of
patients with an attendant 100% morbidity. Males had a lower mean MPI
score (23.17) compared to females (31). Patients with morbidity had a higher
mean MPI (26.9) compared to those without morbidity (22.8) (p=0.0 18).
Morbidity rates within group increased with rising MPI scores (31% for MPI
<21,54.2% MPI 21-29,64% MPI >29).
Nine (12.9%) patients died of which only 1(4.17%) had an MPI of<29. The
mean MPI for non survivor,s was 33.8 (23.4 for survivors). Females had a
higher mortality rate compared to males (21.43% vs 10.71%). The overall
mean hospital stay was 14 days but 22 days for those who developed
complications. Only 4 of 11(23.53%) patients with an MPI >29 had no
recorded adverse outcome at discharge. Those with an MPI :::::26had x2.1
risk of in hospital death. ROC curve analysis showed a mortality predictive
power of 0.916 with a sensitivity of88.9% and specificity of85.2% at MPl
of 29 points.
Conclusion: The findings of this study appear to be in keeping with others
elsewhere in showing that increasing MPI score does relate with outcome.
The MPI is therefore useful in prognosticating early outcome in patients
with surgical peritonitis at KNH
Citation
Master of Medicine (Surgery)Publisher
University of Nairobi Depatment of Surgery