Full Text View

Diarrhoea and faecal incontinence occur frequently in critically ill patients. ^{1, 2, 3} Caring for patients with faecal incontinence is time-consuming. Furthermore, incontinence is a risk factor for skin breakdown, pressure ulcers and nosocomial infection. ^{4, 5, 6} To mitigate the adverse effects of faecal incontinence, faecal diversion systems can be implemented. Proprietary intrarectal faecal diversion and collection devices, so called rectal tubes, have been adopted by many intensive care units (ICUs). ^{5, 6, 7}


Case reports have described major adverse effects, such as massive bleeding, perforation or fistulas that occur with rectal tube placement. ^{7, 8, 9, 10, 11} However, there are limited epidemiological data on the frequency, indications and adverse events associated with the use of rectal tubes during usual clinical practice in the context of a general adult ICU. Our aim was to describe the epidemiology, with a focus on major adverse events.
 

Methods

We conducted an observational cohort study between November 2016 and January 2018 of all patients admitted to a single ICU. The research protocol was approved as a quality assurance project, with the need for informed consent waived (Royal Melbourne Hospital Research Ethics Committee).

All patients admitted to ICU during the 15-month research period were screened daily for the presence of a rectal tube. The decision to insert a rectal tube was made by bedside health care practitioners guided by a local protocol. The protocol included relative contraindications to insertion; for example, local anatomical abnormalities and systemic anticoagulation. All rectal tubes (Flexi-Seal SIGNAL FMS; ConvaTec) were inserted by ICU nursing staff who had received training in this procedure. Once inserted, ongoing protocol management by the primary nurse aimed to mitigate pressure injury by balloon deflation and volume checks once per shift, and completion twice per day of a checklist designed to confirm that the rectal tube was still clinically warranted and there were no signs of bleeding or excoriation. However, the protocol did not mandate removal for certain post-insertion events, such as commencement of systemic anticoagulation or fall in platelet count.

Adverse events associated with rectal tubes were identified by a manual review of ICU and hospital discharge summaries for documentation of indication for insertion and any complications perceived to be related to rectal tube placement. Finally, we linked data with the International Classification of Diseases (ICD-10) coding for potential complications related to rectal tubes and an electronic hospital-wide incident and complication management system (RiskMan; Datix Group, Melbourne, VIC, Australia) for complications related to rectal tubes. In particular, we conducted a key word and term search across all RiskMan submissions for the patient list during their ICU admission using “rectal”, “flexiseal”, “faecal” and “fecal”.

We categorised complications as major if insertion was associated with an outcome that we believed would be important to patients. ¹² We defined major complications as clinically important lower gastrointestinal bleeding, which was modified from the definition used to describe upper gastrointestinal bleeding by the Canadian Critical Care Trials Group and others; ^{13, 14, 15} rectal bleeding associated with anaemia (haemoglobin < 70 g/L) and transfusion of two or more units of packed red blood cells within 72 hours of first documentation of rectal bleeding; need for operation; or death.

We defined minor complications as reported dislodgement requiring repeat insertion, overinflation of the balloon without independently documented rectal pressure ulceration, or device dysfunction with skin or wound contamination. Identification of all complications required the agreement of two authors who had independently reviewed the clinical notes to clarify that the complication could be attributable to rectal device placement.

Each patient record was further reviewed by manual search for documentation of rectal tube output daily, where available.

Data were then extracted from the Australian and New Zealand Intensive Care Society Adult Patient Database (ANZICS-APD) on all patients admitted to the ICU during the study period, to allow direct comparison of demographics and outcomes. These data were merged with the rectal tube dataset using, as key variables, each patient’s unique identification number and ICU admission dates for those with more than one admission in the study period.
 

Statistical analyses

Data were merged within Stata version 16 (StataCorp, College Station, TX, USA) for further analyses. Day 1 was the first day of ICU admission and was therefore a partial day, with all others being full calendar days. Continuous data were summarised as mean with standard deviation (SD) for normally distributed variables. Data with skew distributions were otherwise summarised as median with interquartile range (IQR) or [range]. Binary data were summarised as proportions with associated 95% binomial confidence intervals, while comparisons of two proportions were reported as risk ratios (relative risks) with 95% confidence intervals (CIs). Proportions within levels of categorical data were compared using X² tests.

Results

Data were available for a total of 3418 ICU admission episodes for 3074 individual patients.

There were 111 episodes of rectal tube placement in 99 patients; that is, 3.2% of patients had a rectal tube inserted. These comprised 90 patients with only one episode of a rectal tube being inserted, another seven patients with rectal tubes inserted on two occasions (within the same ICU admission [n = 5] and across separate ICU admissions [n = 2]), and one subject with three and one subject with four episodes of rectal tubes inserted. At the time of rectal tube insertion, 79 patients (78%) were mechanically ventilated.

The median day of ICU admission for first rectal tube insertion was Day 6 (IQR, 4–9), with the most frequent indications being diarrhoea or excessive bowel motions (94/111, 85%), diversion after peri-anal surgery (4/111, 4%), prone ventilation (3/111, 3%), and peri-anal excoriation (2/111, 2%), with no indication recorded for eight episodes (7%).

The median of rectal tube use across the 111 episodes was 5 days [range, 1–23], with a mean of 5.8 days (SD, 4.6) for a total of 641 patient-days of exposure to the intervention. Data regarding stool output collected within the rectal tube diversion system were available from 74 cases. The median stool output was 350 mL (IQR, 200–706) on Day 1 and 238 mL (IQR, 100–600) on Day 2.
 

Comparison between patients who did and did not have rectal tube inserted

Patients who had a rectal tube inserted shared about the same age and sex distribution as patients for whom rectal tubes were not placed (Table 1) but had a substantially greater severity of illness with accompanying risk of death, as summarised by the Australian and New Zealand Risk of Death (ANZROD) score. ¹⁶

It was substantially more common for patients managed with rectal tubes to have a medical diagnosis (3.8%) rather than a trauma (3.0%) or surgical (1.8%) diagnosis (Table 2) (medical, trauma or surgical risk ratio, 1.7; 95% CI, 1.2–2.6).

There was also strong evidence for different proportions of rectal tube use across 20 Acute Physiology and Chronic Health Evaluation (APACHE) diagnostic groups (Table 2). In terms of absolute number of events, the most common ICU diagnostic categories of patients receiving rectal tubes in an episode of ICU care were cardiovascular medical (15/365, 4.1%), sepsis (13/322, 4%), cardiovascular surgical (15/609, 2.5%) and non-operative trauma (12/368, 3.3%). However, within ICU diagnostic groups, the highest proportional use of rectal tube devices was in 13% (5/39) of patients with medical haematological conditions and 12% (10/82) of medical gastrointestinal illness cases
 

Adverse events

There were 14/99 patients (14%) who had an adverse event attributable to rectal tube insertion or placement, corresponding to 2.2 events per 100 days of rectal tube insertion.

Three patients (3.0%) had a major adverse event, corresponding to an event rate of 0.5 per 100 days of rectal tube insertion (Table 3). In all three cases, patients were noted to have rectal bleeding and progressive anaemia, and subsequently found to have rectal mucosal ulceration causing blood loss clinically attributed to the rectal tube. These three patients received invasive surgical or endoscopic investigation as well as blood transfusion (Table 3).

Eleven patients (11%) had a minor adverse event (Online Appendix, table S1). Minor adverse events included balloon failure requiring reinsertion (n = 4), tube bypassing causing contamination of wound or soiling (n = 4), and tube being unintentionally dislodged (n = 3).
 

Other outcomes

Patients who received rectal tubes stayed on average more than four times longer in the ICU (mean, 14 days [SD, 14] v 2.8 days [SD, 3.7]). These patients had about double the mortality rate of patients in whom those devices were not used (Table 1) (mortality, 15% v 7.7%; risk ratio, 2.0; 95% CI, 1.2–3.4).

Discussion

Key findings

Based on observations at our centre, a considerable proportion of patients have a rectal tube inserted during their ICU admission. We recorded 111 insertions in 99 patients across a 15-month period. Most rectal tubes were inserted because the patient had diarrhoea or faecal incontinence, and we observed three major adverse events at a rate of 0.5 per 100 days of rectal tube insertion.

Moreover, the events we identified highlight the life-threatening nature of complications rectal tubes cause. All three cases of major rectal haemorrhage required transfusion of packed red blood cells and an invasive procedure. The frequency of rectal tube insertion and complication rate, and the magnitude of morbidity when a complication occurs, is concerning for a device that, to the best of our knowledge, has never been rigorously evaluated as to whether it has patient benefits. Our observations, if representative of other sites, suggest that rigorous evaluation of the benefits and harms of rectal tube placement is warranted.
 

Relationship to previous studies

To our knowledge, our observational study represents the first independent systematic study to provide epidemiological data on the frequency, indications and adverse events associated with the use of rectal tubes during usual clinical practice in ICU. Pre-existing data in this area are available either as manufacturer-supported research, analysis of an older generation of rectal tubes no longer used in ICU, or case reports. ^{7, 8, 10, 11} While the case series and case reports highlight the substantial harm that may occur with rectal tube use, they offer limited perspective on the frequency of these events. Our data suggest that adverse patient-centred outcomes may be more frequent than previously considered.
 

Limitations and strengths

Our study had a number of strengths. The use of thorough, multistep, manual review as well as database (RiskMan) analysis allowed greater detection of harm. It should also be noted that the minor complications detected by this study also represent a potential mechanism for genuine injury — dislodgement with balloon inflated causing tears, and cuff overinflation causing mucosal pressure injury.

Our study has a number of limitations. Despite being the largest study in the literature, there were still a relatively small number of rectal tubes inserted (n = 111) and the event rate of major complications was only three. Accordingly, our estimates of frequency of major complications are presented with considerable uncertainty. The identification of patients with tubes inserted, as well as complications, relied heavily on clinician documentation, and it is therefore possible that cases of rectal tube insertion and complications may have been underestimated. Our study was conducted as a single site and, during this study period, we did not document or audit compliance with the rectal tube protocol. Therefore, we cannot exclude the possibility that complications represent clinical practice rather than the device per se. Nonetheless, this is the first observational cohort study of the documented rates of rectal tube insertion, and subsequent injury or complication.
 

Clinical implications

During the study period, we observed that patients who have a rectal tube placed remain in ICU for much longer periods and have double the mortality rate than the overall ICU population. While severity of illness, as evident with higher ANZROD scores, is a confounding variable, these associations highlight that patients who have rectal tubes placed are a vulnerable population with poorer outcomes. We also observed that more than 80% of placements occurred because of diarrhoea, which remains a subjective diagnosis in critically ill patients, with prevalence varying widely depending on the definition used. ^{2, 3, 17} Diarrhoea and repetitive soiling are unpleasant, are likely to have an adverse impact on patient dignity, and are associated with local complications such as skin breakdown. ¹⁸ However, in the absence of risk of contamination of an existing wound, whether repetitive soiling is more unpleasant or more undignified than placement of a rectal tube remains a matter of opinion. Given the adverse outcomes with treatment of diarrhoea (ie, rectal tube placement) we observed, strategies to limit the frequency and magnitude of diarrhoea have merit. ¹⁹ Such strategies include delaying the commencement of laxative bowel regimens, ^{20, 21, 22} and possibly, manipulation of enteral nutrition formulae. ^{23, 24} Moreover, because of the outcomes associated with their use, it seems that clinicians should carefully balance the risk–benefit of rectal tube placement for each individual patient, and institutions should have systems to audit the placement, compliance with protocols, and outcomes with these devices.
 

Conclusion

Our prospective observational study suggests that, at least at our centre, a relatively large number of rectal tubes are inserted each year, and that complications resulting in adverse patient-centred outcomes occurred. Our observations support the concept that rigorous evaluation of these devices is required.