Transcript Balloon Expulsion Test Normal Result

Constipation: an alternative
algorithm?
Katherine Clark
Conjoint Associate Professor, Newcastle University
CMN and HNE LHN
Contents
• Scope of the problem of constipation
• Current approaches to address the symptom a
palliative care population?
• An alternative approach for palliative care
based on a gastroenterology framework?
Prevalence of constipation
• Constipation is a distressing symptom, often
complicating the lives of people with specialist
supportive and palliative care needs.
• Prevalence reports vary between studies and stages
of illness, ranging from 50% at the time of referral
to palliative care services up to 90% of people at
the time of admission to an inpatient palliative care
unit.
Prevalence of constipation
• Other observational studies document that 60% of
people in a palliative care units were charted
regular laxatives, despite only 30% of people
having constipation listed as a problem on
admission*.
• More than 50% of this same group received more
than two laxatives simultaneously.
*Clark K, Currow DC, Talley NJ. The use of digital rectal examinations in palliative care
in-patients. Journal of Palliative Medicine 2010; 13(7): 797-797
Effectiveness of current
management?
• Despite the frequency with which constipation
complicates the lives of palliative care patients, the
current approach to management is most
remarkable for the number of people who fail to
achieve adequate symptom control.
• Reports suggest that 40-70% of palliative care
patients treated with laxatives (including peripheral
opioid antagonists) continue to experience
symptoms.
Effectiveness of current
management?
• Recently, the outcomes of 200 patients cared for by
specialist palliative care teams were examined.
• 19% of people treated with laxatives continue to
experience fewer than 3 bowel actions per week
regardless of which laxatives were prescribed.
• This group also noted that, in theory, any laxative
should be able to normalise bowel function but this
is clearly not the case in palliative care patients.
Effectiveness of current
management?
• Another case series of 211 palliative care patients
was undertaken to explore the relationship between
prescribed laxatives and the frequency of
documentation of bowel movements.
• However, bivariate analysis failed to identify any
relationship between any laxatives and the
frequency of bowel movements*.
*Clark K, Lam L, Currow DC. Exploring the relationship between the frequency of documented bowel
movements and prescribed laxatives in hospitalised palliative care patients. The American Journal of Hospice
and Palliative Medicine
Why is this concerning?
• Laxatives are prescribed with the aim of restoration
of regular, soft bowel actions, this does not seem to
be reliably the outcome for palliative care patients.
• This is worrying as the negative impacts of poorly
treated constipation may be serious.
• Aside from pain and discomfort, other associated
problems may include nausea, vomiting, anorexia,
urinary retention and bowel obstruction.
Why is this concerning?
• Constipation may equal or rival pain as a symptom
in terms of the distress and anxiety provoked.
• In both malignant and non-malignant life-limiting
illnesses, constipation has direct deleterious impacts
on reported quality of life, with recent data
suggesting the greater the number of laxatives
prescribed for a person, the more distressed the
person’s family is likely to be*.
*Clark K, Lam LT, Agar M, Chye R, Currow DC. Retrospective analysis of contributing factors to laxative
prescription in hospitalised palliative care patients. Palliative Medicine 2010:24(4):410-8
Why is this concerning?
• Aside from physical and personal costs, poorly
palliated constipation has societal costs.
• Constipated palliative care patients receive more
community nursing support and are 20% more
likely to be hospitalised.
• When hospitalised, severely constipated patients
receive more nursing time, with a recent study
suggesting that earlier and more effective
interventions for this group will result in significant
clinical and economic benefits.
Why is this concerning?
• Given the predicted rise in the demands for
palliative care over the next decade, the need
to identify more efficacious approaches to
managing constipation for this ever enlarging
cohort becomes even more pressing.
The currently accepted approaches
to palliating constipation in
advanced cancer and palliative care
populations?
Current clinical guidelines
• Palliative care patients are most likely to identify
themselves to be constipated when they experience
difficulties with ease of defecation.
• Palliative care consensus practise guidelines
recommend diagnosis and treatment based
predominantly on individuals' subjective reports
despite the fact that symptoms do not reliably
distinguish the site or cause of the problem.
• Physical examination is used to exclude rectal
impaction but little else.
Current clinical guidelines
• Investigations such as biochemistry are used to
identify potentially reversible factors;
• When further investigations are considered
necessary, practise guidelines recommend plain
abdominal radiographs with little consideration
paid to the fact that radiographs are most useful to
exclude bowel obstruction only*.
*Clark K, Currow DC. Plain radiographs to diagnose constipation in palliative care. Journal of Pain and
Symptom Management 2011.
Current clinical guidelines
• Once a bowel obstruction is excluded, patents are
commenced on laxatives with EAPC guidelines
recommending a combination of softer plus
stimulant;
• The actual guidelines suggest polyethylene glycol
and electrolytes or lactulose co-prescribed with a
stimulant with the recommended agents including
senna or sodium picosulphate.
• If not successful, the addition of rectal interventions
or agents such as methylnaltrexone is suggested.
Peripheral opioid antagonists
• Methylnaltrexone has been studied in palliative care patients
to manage the problem of opioid-induced constipation.
• However, even with well designed and performed trials,
problems remain with the routine use of this medication.
• There is little data to objectively define the magnitude of
individual contributing factors, including opioids, to the
severity of the symptom experienced.
• Given the number of contributing factors that may co-exist
in one individual at any one time, it is therefore difficult to
allocate blame to opioids alone.
• This observation is supported by the observation that this
medication is not universally effective for all people with
presumed predominantly opioid-induced constipation.
Assessing constipation in nonpalliative care?
• In contrast, the diagnostic approach recommended
by gastroenterology guidelines in resistant cases is
aimed at defining the underlying pathophysiology.
• Estimated to affect up to 30% of the general
population, gastroenterologists define idiopathic
constipation as:
– Disturbed neuro-muscular function of the colon,
– Disturbed neuro-muscular function of the structures of
defecation.
Assessing constipation in nonpalliative care?
• Gastroenterologists’ assessments begin at the
bedside where specialist guidelines recommend a
comprehensive digital rectal (DRE) examination.
• This is both to exclude rectal faecal impaction and
commence the process of screening for:
– Pelvic muscle weakness,
– Paradoxical anal sphincter contraction or an inability to
relax the anal sphincter appropriately.
Assessing constipation in nonpalliative care?
• Further investigations recommended by
gastroenterology practise guidelines include:
– Measurement of the time the contents of the
colon to transit through the colon with a colon
transit test (CTT),
– Assessment of the structures of defecation with:
• Anorectal manometry,
• Balloon expulsion tests.
Gastroenterology guidelines define four
sub-categories of chronic constipation
• Slow Transit Constipation where passage of colonic
contents is prolonged;
• Pelvic Dyssynergia where paradoxical contraction
of the external anal sphincter occurs;
• Irritable Bowel Syndrome where no dysfunction of
the colon or defecation structures is identified but a
person constantly perceives or experiences
symptoms of constipation;
• Combination slow transit plus outlet obstruction.
A non-palliative care approach to
constipation?
• Despite the subgroup people fall into initial
recommendations are conservative:
– Correction of under-hydration,
– Implementation of a regular gentle exercise program,
– Prescribing a dedicated time for toileting optimally in the
morning (the diurnal variation of colonic activity),
– Exploit the gastro colic reflex,
– Ensuring people know how to adopt a semi-squatting
position with their knees drawn up towards the chest.
Conservative recommendations?
• Recent observers have reported that combing
the conservative recommendations in a
severely non-palliative care constipated
population significantly improved:
– Symptoms as measured by the PAC-SYM,
– Quality of life as measured by the PAC-QOL.
A non-palliative care approach to
constipation?
• The diagnostic subgroups allow these conservative
recommendations to be supplemented with targeted
interventions.
• Specific initial recommendations for people with
slow transit problems include the prescription of the
oral laxatives with stimulant properties.
• In comparison, people with disordered defecation
may be better managed with general measures plus
prescription of regular enemas or suppositories.
Gastroenterology vs Palliative Care?
• Although the mechanisms that result in
disturbed bowel actions may be different, the
colon and pelvic structures are the same!
• Acknowledging this allows the problem of
constipation in palliative care to be
considered in an established framework ie
that developed and recommends by
gastroenterologists and colorectal surgeons.
Subcategorising constipation in
advanced cancer and palliative care?
•
•
•
The initial step is to define sub-categories
applicable to palliative care patients.
A logical approach to this is to examine the
factors that contribute to altered bowel habits this
population.
Based on this review, three physical subgroups are
proposed:
1. Slow transit of colonic contents;
2. Recto-sigmoid Outlet delay;
3. Overlap Syndrome with diagnostic features of both
slow transit and outlet delay.
Slow transit of colonic contents
• This category is based on the numerous factors in palliative
care that have been shown to slow colonic contents.
• Acquired factors know to slow transit commonly occurring
in palliative care include:
–
–
–
–
–
medications (anti-cholinergics, opioids),
reduced oral intake,
deteriorating performance status presenting as reduced mobility,
metabolic disturbances,
paraneoplastic syndromes.
• Ideopathic slow transit is likely to occur in 10% of the
general community, but how this impacts on the severity of
the constipation symptoms experienced during this time in
palliative care is not known.
Recto-sigmoid Outlet delay
• Rather than the label of pelvic floor dyssynergias
used in functional constipation, the category rectosigmoid outlet delay is suggested to accommodate
problems of the structures of defecation, both
functional and acquired.
• This term is used to include:
– The idiopathic constipation symptoms secondary to the
functional problems of inappropriate contraction of the
external anal sphincter on straining and inadequate
relaxation of the internal anal sphincter.
– The acquired problems of anal obstruction secondary to
myopathic or neuropathic processes.
Overlap Syndrome
• The third group proposed is that of a mixed
group of slow transit and outlet delay;
• This seems intuitively the most likely
scenario in palliative care patients given the
numerous pathologies likely to be present in
one individual, particularly as diseases
progress.
Is such an approach feasible in
palliative care?
Diagnosing Slow Transit ?
• Slow transit of colonic contents is easily and cheaply
diagnosed by combining capsules that continue radioopaque markers with plain abdominal radiographs;
• This investigation has been piloted in palliative care
inpatients and was found to be acceptable to this group.
• Furthermore, despite regular bowel actions, CTTs were
significantly impaired compared to control populations*.
*Clark K, Lam L, Chye R, Currow D. Pilot study to document colonic slow transit times in
palliative care inpatients. Asia-Pacific Journal of Clinical Oncology 2009;5(Suppl 2)
Measuring Colon Transit
Diagnosing Outlet Delay?
• Simple validated approaches exist that allow
the integrity of the structures that facilitate
defecation to be assessed at the bedside with:
– Rectal balloon expulsion,
– Hand-held anal manometers.
Diagnosing Outlet Delay?
Sample Report: Balloon Expulsion Test
Normal Result: With the patient seated on
a commode, he or she was able to expel
a 50-mL rectal balloon within ____
seconds.
Abnormal Result: With the patient seated
on a commode, he or she was unable to
expel a 50-mL rectal balloon in less than 2
minutes.
The clinical usefulness of subcategorising
constipation in palliative care patients?
• Undertaking comprehensive assessments
would, for the first time, allow clinicians to
knowledgably target constipation treatments
to the main pathology that have resulted in
the symptom of constipation.
• Such targeted strategies need to be applicable
to the palliative care population and to each
individual's stage of life.
E.g. Slow transit constipation
• Evidence in non-palliative care supports
stimulant laxatives as useful;
• In palliative care there is reluctance to
prescribe stimulants alone for fear of
provoking cramping abdominal pain;
• However, already data exists to suggest that
senna alone is likely to be more effective
than senna combined with docusate with no
increased cramping observed.
In summary
• Constipation remains a troubling symptom in the palliative
care population, with the underlying pathology still not well
defined.
• Sub-categorising constipation according to the precedents
set in gastroenterology would be the first attempt at
allowing structured epidemiological, aetiological,
pathophysiological and therapeutic enquiries.
• As ever, the investigations and interventions must be
tailored to the individual's capacity to tolerate them in the
context of their stage of life.