Selective digestive decontamination, a seemingly effective regimen with individual benefit or a flawed concept with population harm?

James C Hurley

doi:10.1186/s13054-021-03744-w

Abstract

Selective digestive decontamination (SDD) regimens, variously constituted with topical antibiotic prophylaxis (TAP) and protocolized parenteral antibiotic prophylaxis (PPAP), appear highly effective for preventing ICU-acquired infections but only within randomized concurrent control trials (RCCT’s). Confusingly, SDD is also a concept which, if true, implies population benefit. The SDD concept can finally be reified in humans using the broad accumulated evidence base, including studies of TAP and PPAP that used non-concurrent controls (NCC), as a natural experiment. However, this test implicates overall population harm with higher event rates associated with SDD use within the ICU context.

Highlights

Selective digestive decontamination (SDD) is both a variously constituted antibiotic regimen and an unreified concept
The SDD concept arose from studies using irradiated chimeric mice transplanted with leukemic cells which were at high risk of lethal blood stream infection arising from the digestive tract [5,6,7]
This evidence, recently updated with results from 41 Randomized Concurrent Control trial (RCCT)’s (11,004 Intensive care unit (ICU) patients) [1], enables topical antibiotic prophylaxis (TAP) to be compared versus five other ventilator-associated pneumonia (VAP) prevention interventions (Table 1) [20,21,22,23] using summary data as tabulated within recent Cochrane reviews

Summary

Introduction

Selective digestive decontamination (SDD) is both a variously constituted antibiotic regimen and an unreified concept. SDD regimens appear highly effective for preventing ICU-acquired infections [1,2,3,4]. The applications and composition of SDD regimens have drifted far from that originally conceived. The mode of action, benefits and associated risks remain unclear despite extensive study among various ICU, haematology and other immunocompromised This breadth of study findings, within studies of regimens using one or both of the two main SDD components, ‘TAP’ and ‘PPAP’, provides a unique and valuable natural experiment with which to test the SDD concept and its implications to the ‘whole of ICU’ population. Pseudomonas and other Gram-negative (GN) bacteremias complicating chemotherapy-associated neutropenia were associated with high mortality In this era, with few effective antipseudomonal antibiotics, preventing acquired infections. Hurley Crit Care (2021) 25:323 a Randomized Concurrent Control trial (RCCT) Control vs SOD b Randomized Concurrent Control trial (RCCT) Control vs SDD

Physical barrier

Observational control TAP study intervention

ICU mortality

Mean age

Findings

Conclusion