Transcript OTDNET webinar

OTDNET webinar
8th May 2013
Today’s session
08:30 Joanne 12yo
08:45 Ruby 8yo
09:00 Jeremy 57yo
09:15 Haviva 62yo
09:30 Ally 3yo
10:00 Eric 57yo
12 yr old Joanne
It is Monday afternoon. She is brought by her mother
Susan. Both are patients of the practice, though Joanne
has not been seen for some years.
Joanne had a cold 2 weeks ago and missed a couple of
days at school. Over the weekend Joanne felt quite
unwell and Susan was concerned enough to take her to
an after hours GP. The GP diagnosed asthma,
prescribed Seretide MDI 250/25 1 puff bd and advised
Susan to follow-up with her GP in a couple of weeks.
12 yr old Joanne
Susan tells you that she was not impressed with the service
from the after hours GP. He asked very few questions,
performed a cursory examination and then stated the
problem was asthma while writing the prescription. She
states the consultation lasted less than 5 minutes. She has
used the internet to research the medication and cannot
understand why the Seretide inhaler was prescribed. She is
particularly concerned about the product containing
‘steroids’.
In order to make a judgement as to whether Joanne has
asthma, what key features in her history do you look for?
History of present episode
• Episodes of wheeze with or without shortness or breath, chest
tightness, cough, breathlessness or wheeze at night
• Chest pain associated with the symptoms
• Previous inhaler use. If used, what happened?
Past history
• Recurring episodes of wheeze with or without shortness of breast,
chest tightness and/or the symptoms occurring with other triggers
such as season, air temperature, URTIs, exposure to cigarette
smoke, exposure to aeroallergens
• History of allergic rhinitis and/or atopic dermatitis.
• History suggesting a cause for the shortness of breath other than
that associated with the respiratory system
• Have any medications been taken?
Family history
• Asthma or atopic disease in siblings
• Exposure to environmental tobacco smoke
12 yr old Joanne
Using the National Asthma Council Australia’s Asthma
Management Handbook approach, describe the
patterns of asthma in children.
12 yr old Joanne
Joanne confirms she has wheeze with her cold, felt chest
tightness and was short of breath. She has noticed this
several times over the past couple of years, usually but not
always, in the context of a cold. Sometimes it occurred at
night. The frequency of these episodes were more than 6
weeks apart.
She had eczema in the first 6 months of life. She is fully
immunised and has had no major illness. Her growth and
development are normal. She is not taking any medication.
Her physical examination today is normal.
What is your diagnosis? List in note form only, up to four (4)
key elements of management?
The most likely diagnosis is infrequent episodic asthma.
Key components of asthma management include;
• Education about the condition and its management
• A written asthma action plan
• Appropriate use of medications
• Regular review
12 yr old Joanne
Describe the drug treatment options for episodic
asthma in children.
Infrequent episodic asthma is treated with inhaled
short-acting beta2 agonists as required.
Frequent episodic asthma can often be well controlled
with low-dose inhaled corticosteroids or montelukast
or sodium cromoglycate. Treatment is identical to the
initial treatment for persistent asthma. However,
children with frequent episodic asthma are often
affected only during winter and may require preventive
therapy only during those months.
12 yr old Joanne
Describe the drug treatment options for persistent
asthma in children.
Inhaled corticosteroids are the most effective
preventive therapy in children with asthma.
Montelukast or sodium cromoglycate are alternatives
to inhaled corticosteroids. If control is not achieved
after a 4-week trial of montelukast, low-dose inhaled
corticosteroids should be trialled instead. In addition,
use a short-acting beta agonist for symptomatic relief,
as required.
If inhaled corticosteroids are initiated but improvement
does not occur over 4-8 weeks, then review the
diagnosis, inhaler technique and adherence. If all are
satisfactory but symptoms persist, add montelukast or
a long-acting beta agonist. If frequent short-acting beta
agonist use is still required, review the diagnosis.
12 yr old Joanne
What is asthma severity? What is asthma control?
How would you assess asthma control?
Severity is classified according to the minimum amount
of medication and intensity of interventions required to
achieve and sustain good asthma control.
Control is assessed as good, fair or poor according to
recent reliever requirement, recent symptom
frequency, nocturnal asthma, recent exacerbations,
unplanned visits, current lung function (in adults and
older children), and sometimes airway
hyperresponsiveness.
In practice, severity and control interact. Of the two
concepts, control is most relevant to the day-to-day
care of a patient with asthma.
Ruby is having an asthma attack
You are a GP at a small rural hospital. Ruby, aged 8 yrs,
arrives at the hospital in a car driven by her mother
Maria. She says that Ruby, who has a past history of
asthma, has had a runny nose and a cough for 3 days.
Her asthma has been worse over the last 2 days, and
she has been requiring frequent salbutamol (12 puffs
via spacer hourly for the last 2 hours). Despite
salbutamol, Ruby has deteriorated.
Maria noticed on the way to hospital that Ruby stopped
talking and her breathing became more laboured.
Ruby is having an asthma attack
Ruby was born at 40 wks gestation and the delivery was
uneventful. She was first diagnosed with asthma at the age of 3
yrs. She usually takes flixotide twice a day, and for her
exacerbations of asthma needs salbutamol and oral
prednisolone. On average, she has two to three exacerbations
per year and has had five ward admissions since she was 3 years
of age. Ruby's immunisations are up to date. She is allergic to
penicillin.
On examination Ruby is pale, has a tracheal tug, marked use of
the accessory muscles of respiration and pronounced intercostal
recession. She is unable to communicate with words. Her heart
rate is 150 beats per minute, her respiratory rate is 30 breaths
per minute, oxygen saturation is 84% in room air, she has a
temperature of 36.8oC (tympanic), Glasgow coma score of 14,
and her weight is 25 kg. Her chest is silent with the occasional
expiratory wheeze.
Ruby is having an asthma attack
What are the most important elements of physical
examination when assessing the severity of acute
asthma in children? List up to five (5) elements of
physical examination.
In the assessment of severity of acute childhood asthma
it is important to note the following primary features
• general appearance/mental state
• work of breathing (accessory muscle use, intercostal
recession, tracheal tug)
The following secondary features should also be noted:
• initial SaO2 in room air
• heart rate (tachycardia can be a sign of severity, but is
also a side effect of beta agonists)
• ability to speak
Change in mental status is viewed as heralding an
impending catastrophe. Initial SaO2 in room air, heart
rate and ability to speak are helpful but less reliable
features. Pulsus paradoxus and peak expiratory flow rate
are not reliable indicators of severity. Wheeze is also not
a good marker of severity.
Ruby is having an asthma attack
What are the risk factors for Ruby requiring admission
to ICU?
Patients at risk of requiring ICU management for
asthma include those who have a history of:
• ICU admissions, mechanical ventilation, or rapidly
progressive and sudden respiratory deterioration
• seizures or syncope during an asthma
exacerbation
• exacerbations precipitated by food
• use of more than two beta-agonist metered dose
inhaler (MDI) canisters per month
• insufficient preventer therapy or poor adherence
to preventer therapy
• inability to recognise the severity of illness
• associated depression or other psychiatric
disorder.
Ruby is having an asthma attack
What investigations are needed?
A CXR is not routinely indicated in the unintubated
asthmatic child, as unexpected radiographic
abnormalities are very rare. Exceptions are situations in
which the clinical examination suggests the possibility of
barotrauma or pneumonia.
Arterial blood gases are not usually required. They are
distressing and can cause a child with respiratory
compromise to deteriorate further. Typical findings during
the early phase of severe asthma are hypoxaemia and
hypocapnia. With increasing airflow obstruction,
hypercapnia will develop and indicate impending
respiratory failure. However, the decision to intubate an
asthmatic child should not depend on blood gas
determination, but should be made on clinical grounds.
The intubated patient, however, requires frequent blood
gas determination, ideally from an indwelling arterial line,
to assess adequacy of ventilatory support and
progression of illness.
Ruby is having an asthma attack
How would you manage Ruby?
Your initial management of Ruby is to:
• transfer her and her mother to a resuscitation cubicle
• aim for minimal handling and allow her to adopt the most
comfortable position
• ask for help from other medical staff within the hospital or in close
proximity
• administer oxygen to maintain SaO2 >92%
• administer continuous nebulised salbutamol (0.5% undiluted)
• administer nebulised ipratropium (3 doses x 250 mcg, 20 minutes
apart, added to salbutamol)
• obtain intravenous access – use comfort techniques such as dermal
anaesthetic cream or patch, or distract her
• take blood for FBC, UEC, lactate and venous blood gases as needed.
Arterial blood gases are usually not needed unless intubated
• administer methylprednisolone 1 mg/kg intravenously (IV) 6 hourly
or hydrocortisone 2–4 mg/kg IV 4–6 hourly
If Ruby is not responding to initial treatment or deteriorating further,
contact the nearest tertiary paediatric hospital or paediatric retrieval
service to arrange retrieval and transfer of Ruby to a paediatric ICU
facility and commence drug infusions as shown below.
Aminophylline
• Loading dose: 10 mg/kg IV (maximum dose 500 mg) over 60
minutes. If Ruby were taking oral theophylline, do not give IV
aminophylline – obtain a serum level. Administer a continuous
infusion unless marked improvement has occurred following a
loading dose.
Magnesium sulphate
• Dose: 50% magnesium sulphate – 0.1 ml/kg (50 mg/kg) over 20
minutes, then 0.06 ml/kg/hr (30 mg/kg/hour) by infusion. Aim to
keep serum magnesium between 1.5 and 2.5 mmol/L.
IV salbutamol
• IV salbutamol may also be considered. However, there is limited
evidence that it is beneficial. It does not appear to provide any
benefits over nebulised salbutamol even in severe cases. Loading
dose: 5 mcg/kg/min for 1 hour. This should be followed by an
infusion in a dose of 1–2 mcg/kg/min.
Ruby is having an asthma attack
What potential treatment options exist if there is no
improvement despite pharmacological treatment? List,
in note form only, up to two (2) options.
If there is no improvement despite
pharmacological treatment, further treatment
options include:
• Non-invasive positive pressure ventilation
(NPPV)
• Intubation
Ruby is having an asthma attack
Where should Ruby be admitted?
Despite whether Ruby requires intubation, she
should be retrieved and transferred to a
paediatric ICU by a paediatric retrieval service.
Transfer should be considered in children with:
• severe or critical asthma requiring intravenous
therapy or respiratory support
• escalating oxygen requirement
• poor response to salbutamol or inability to
wean salbutamol
• a requirement for care above the level of that
provided by the local hospital.
Jeremy has chest pain and is breathless
Jeremy, aged 57 yrs, is a storeman who lives alone. He presents
to the local rural hospital where you are on call with sharp leftsided chest pain, shortness of breath and rigors. He has been
unwell for 5 days with increasing shortness of breath. Five days
ago he presented to another doctor who prescribed amoxycillin,
which he has taken with no improvement in symptoms. He
coughed up copious amounts of yellow sputum last night.
Jeremy has a past history of ischaemic heart disease with an
acute myocardial infarction and stent inserted into a coronary
artery 2 yrs ago. He also has a past history of hypertension,
GORD and excision of multiple melanomas. Jeremy was
vaccinated against influenza 3 weeks ago. His current
medications are aspirin, ramipril, atorvastatin and pantoprazole.
Jeremy has chest pain and is breathless
On examination, Jeremy is anxious with laboured
breathing. He has reduced breath sounds at the right
lung base. His temperature is 38.2ºC (tympanic), his
pulse rate is 84 beats per minute (regular), blood
pressure is 130/70 mmHg, respiratory rate is 24 breaths
per minute and his oxygen saturation (Sa02) is 98% in
room air. You decide it's likely Jeremy has community
acquired pneumonia (CAP).
How would you assess the severity of community
acquired pneumonia? What clinical scoring tools are
available to do this?
It is important to assess the severity of pneumonia in
order to make a decision on appropriate treatment and
the need for hospital admission.
Various scoring systems can also be used to assess the
severity of pneumonia and include
• Pneumonia Severity Index (PSI) (this uses
information such as the patient's age, comorbidities,
vital signs and blood tests)
• CURB-65 (this uses information such as presence of
confusion, urea level, respiratory rate, blood
pressure and age >65 years)
• CRB-65 (this uses similar information to CURB with
the exception of urea)
• SMART-COP
There is no evidence supporting one scoring system
over another. None can replace clinical assessment.
Jeremy has chest pain and is breathless
What investigations would you request?
A CXR should be performed in all patients with
presumed pneumonia. Investigations for the causal
pathogen should also be done. This may include
sputum gram stain and culture, and blood cultures in
patients who require hospital admission. Arterial blood
gases should be done on severely ill patients.
Other investigations may be appropriate depending on
the clinical circumstances. These include sputum for
mycobacterium tuberculosis, urine antigen testing for
pneumococcus, upper respiratory tract samples for
polymerase chain reaction for respiratory tract viruses,
and serological tests can be performed for Legionella
spp. or mycoplasma pneumoniae if epidemiological
reasons exist. Haematology and electrolytes may also
be appropriate.
Jeremy has chest pain and is breathless
What are the organisms most likely to cause CAP in
Australia?
Streptococcus pneumoniae, mycoplasma pneumoniae
and respiratory viruses are the most common
aetiological agents for CAP in Australia.
Atypical pneumonia (about one in five cases of CAP) is
caused by organisms such as mycoplasma pneumoniae,
chlamydia pneumoniae and Legionella spp. In one
study, over 30% of culture positive CAP had co-infection
with either a virus or atypical pathogen.
Jeremy has chest pain and is breathless
What organisms are most likely to cause CAP in
immunocompromised patients?
In immunocompromised patients, organisms may be
atypical such as Klebsiella pneumoniae, Haemophilus
influenzae or Morexella catarrhalis, or typical organisms
can present atypically. For example, pneumonia due to
Streptococcus pneumoniae may rapidly progress to
septic shock, organ dysfunction and death.
Jeremy has chest pain and is breathless
Which antibiotic(s) would you prescribe for Jeremy and
for how long?
There are several antibiotic guidelines for CAP. For patients
managed as an outpatient, Therapeutic Guidelines recommends
the following:
• amoxycillin 1g 8 hourly for 5–7 days OR
• doxycycline 200mg for the first dose then 100mg doxycycline
daily for a further 5 days OR
• clarithromycin 250mg 12 hourly for 5–7 days
Patients should be reviewed at 24–48 hours and if there is no
improvement, combination therapy with amoxycillin plus either
doxycycline or clarithromycin may be appropriate.
Broad spectrum antibiotics and antibiotics not conforming with
current guidelines risk Clostridium difficile associated diarrhoea
and methicillin resistant Staphylococcus aureus (MRSA). They also
have significantly higher rates of treatment failure and mortality.
Studies on the aetiology of CAP in Australia show that less than
5% of identifiable pathogens are resistant to standard therapy.
In Jeremy's case, it would be appropriate to continue amoxycillin
and add either doxycycline or clarithromycin. Duration of
treatment depends on his response.
Jeremy has chest pain and is breathless
You continue Jeremy's amoxycillin and add doxycycline.
He responds well to treatment when reviewed 2 days
later. Jeremy returns to see you 2 weeks later. He is
feeling much better.
Is immunisation useful in preventing CAP?
Influenza vaccination prevents hospitalisation for
influenza and pneumonia. It also prevents deaths from
influenza-related conditions among the elderly.
Pneumococcal immunisation of at-risk individuals and
children has reduced morbidity and mortality. However,
there has been an increase in non-vaccine strains,
recombinants and increased antibiotic resistance.
Haviva needs to lie down during class
Haviva, aged 62 yrs, is a teacher at the local high school.
She has a past history of diet-controlled type 2 diabetes,
hypothyroidism, reflux oesophagitis, hypertension and
hypercholesterolaemia. Her medications include thyroxine,
pantoprazole, perindopril and atorvastatin. She is allergic to
penicillin.
It is early afternoon, and she presents after suddenly feeling
‘all light-headed’ during a class just after lunch. She was
standing at the whiteboard when she felt unwell, sat down,
then ended up lying down on the floor. After a few minutes
the feeling resolved, but she continued to feel ‘not quite
right’ and was having a little trouble catching her breath.
The school principal drove her to your practice.
Haviva needs to lie down during class
Further history reveals that Haviva has been well up until
today. She now complains of mild left-sided pleuritic chest
discomfort and mild breathlessness. She has not had any
fever, or cough, is not taking any hormonal therapy, and has
not had any unintended weight loss, calf pain or swelling.
Examination demonstrates a pulse of 85 beats per minute
(regular), a BP of 130/70 mmHg, and a respiratory rate of
20 breaths per minute. She is afebrile. Haviva‘s chest is clear
to auscultation and resonant to percussion. She has an
otherwise normal examination.
What is the likely diagnosis? What are your differential
diagnoses?
Haviva’s presentation with pleuritic chest pain and
breathlessness raises the possibility of PE. Other
important differential diagnoses for chest discomfort
and breathlessness include cardiac causes (acute
ischaemia, arrhythmia, pulmonary oedema and
pericarditis) and respiratory causes (pleural effusion,
pneumonia and pneumothorax).
Haviva needs to lie down during class
What investigations are available to confirm or exclude
the likely diagnosis and where should these
investigations be performed?
Given the serious and possibly time-critical nature of many
of the differential diagnoses, Haviva should be evaluated in
an emergency department.
Appropriate investigations include:
• ECG and CXR to help assess for the presence of
differential diagnoses, and to guide the choice of further
investigations
• Blood tests that may be useful include a FBC (to assess
platelet numbers prior to commencing anticoagulation),
estimation of renal function (prior to intravenous
contrast administration), and a D-dimer in selected cases.
D-dimer is a breakdown product of thrombin and
elevated levels suggest the presence of thrombus. In the
setting of a patient with a low pretest probability for PE,
a negative D-dimer can be used to exclude the diagnosis
of PE.
Specific imaging tests to confirm a diagnosis of PE
include
• A VQ scan which uses lower doses of radiation
(approx. 1.3 mSv), and is therefore preferred in
younger patients. However, there is a significant
possibility of a non-diagnostic scan, which would
necessitate further testing, particularly in patients
with a history of COPD or an abnormal initial CXR.
• A CTPA is more sensitive and cost-effective than VQ
scanning, however, risks include contrast reactions,
renal impairment and a much higher radiation
exposure (approx. 8–10 mSv). The latter is an
important consideration in young women, where
breast tissues receive a significant radiation dose.
Haviva needs to lie down during class
How do you determine the pre-test probability of your
working diagnosis? How does this affect the choice of
investigations?
Most patients evaluated for a PE do not have a PE.
Many investigations are time-consuming and involve
exposure to contrast and radiation. Identification of
patients with a low pre-test probability allows further
risk-stratification with D-dimer testing to reduce the
number of unnecessary imaging tests.
Various clinical decision rules have been developed for
the determination of the pre-test probability for PE.
These include the Wells rule, the simplified Wells rule,
the Geneva rule, the Charlotte rule and PERC
(Pulmonary Embolism Rule out Criteria) rule.
Haviva needs to lie down during class
Haviva is transferred to hospital by ambulance, and is
evaluated in the local emergency department. She has
a CXR showing bibasal atelectasis, and a positive Ddimer. Subsequent CT pulmonary angiography confirms
multiple small pulmonary emboli in subsegmental
vessels throughout both lungs.
What treatment is likely to be instituted for Haviva?
Haviva is likely to have traditional management, which
includes hospital admission and treatment with
subcutaneous low molecular weight heparin (LMWH).
Warfarin is likely to be commenced, and the LMWH
continued until her INR is in the target range of 2–3.
Haviva needs to lie down during class
Three weeks later, Haviva’s daughter Naomi, who is 35
yrs old and 28 weeks pregnant, presents with pleuritic
chest pain and mild breathlessness. You consider the
diagnosis of pulmonary embolism (PE).
How does diagnosis and management of suspected PE
alter in the setting of pregnancy?
Plasma D-dimer is more likely to be elevated in pregnancy than
in the non-pregnant state. However, a negative D-dimer is still
useful in a patient with low pre-test probability for PE, as further
testing is not necessary. An elevated D-dimer should prompt
lower limb ultrasonography, which may demonstrate a reason
for anticoagulation without the use of ionising radiation.
If an ultrasound of the lower limbs reveals no thrombus and a PE
still needs to be excluded, then definitive imaging (VQ or CTPA)
should occur. The estimated radiation absorbed by the fetus
depends on the modality chosen and gestational. Appropriate
initial chest imaging should be either a CTPA or perfusion-only
lung scanning.
If a PE is confirmed, then LMWH is recommended in the
pregnant patient. Warfarin is not recommended during the first
or third trimesters, and caution should be used if given in the
second trimester. Anticoagulation should be continued for 3
months after delivery, and warfarin is safe in breastfeeding.
Ally can’t stop coughing
Terri has brought her child Ally, aged 3 yrs, in to see you.
Ally has been coughing for 2 wks and Terri is concerned
because last night ‘Ally couldn’t stop coughing.’ For 1 week
prior to the onset of her cough, Ally had a clear runny nose
and was ‘off her food’. Ally has no siblings and attends
kindergarten on two mornings each week. On examination,
Ally’s temperature is 37.2°C, her throat is not inflamed, her
eardrums appear normal, there is no lymphadenopathy and
her chest is clear. While sitting in your examination room,
Ally has a prolonged bout of coughing followed by gagging.
What is the most likely underling diagnosis? Write in note
form your single (1) diagnosis. What are your differential
diagnoses?
Given the prolonged bout of coughing followed by
gagging, pertussis is likely to be the working diagnosis.
Infection with the Bordetella pertussis bacterium
causes an acute respiratory illness characterised by a
catarrhal phase, which is followed by a paroxysmal
cough with or without the characteristic ‘whoop’ or
post-tussive vomiting.
Your differential diagnosis includes pertussis, infection
due to respiratory syncytial virus or adenovirus and
croup.
Ally can’t stop coughing
What investigation(s) would you order to confirm your
working diagnosis?
It would be appropriate to request a PCR and culture for
pertussis (and respiratory viruses) on a nasopharyngeal swab
given Ally’s history of 2 weeks of (nonparoxysmal) cough.
Serology for pertussis could also be requested.
Ally can’t stop coughing
What treatment would you give Ally? What would you
advise Terri about excluding Ally from other people?
Ally has clinical features of pertussis and should be treated with
antibiotics. Once symptoms are established antibiotics have little
impact on the progression of the illness in the individual. However,
for public health purposes the aim of antibiotic treatment is to
reduce the patient’s infectious period to others. Antibiotics should
be commenced within 3 weeks of the onset of cough.
Ally should be excluded from kindergarten until she has received 5
days of antibiotic. In general, all cases with an association with
childcare, family daycare, preschools, schools or other settings
where there are susceptible individuals such as young children
and infants should be excluded from those settings for 21 days
after the onset of illness, or until they have received 5 days of a 7
day course of appropriate antibiotics (or the full 5 day course if
using azithromycin).
Ally’s suspected pertussis should be notified to the local public
health unit or health department and advice sought on
prophylaxis for contacts. In general, confirmed or probable cases
of pertussis should be notified to your public health unit or health
department as per the Australian National Notifiable Diseases
case definition.
Ally can’t stop coughing
Ally’s nasopharyngeal swab result comes back pertussis
PCR positive. You note that Ally is up to date with her
childhood vaccinations. Terry is angry that her child has
developed pertussis despite being fully vaccinated and
wants to know how this was possible.
What would you say to Terri?
You could explain to Terri that pertussis vaccination is
approximately 84–89% effective in preventing pertussis
infection. Furthermore, protection from the vaccine
does wane over time and booster doses are necessary.
Consequently, it is not uncommon to see an older
vaccinated child with pertussis infection. However,
vaccination is very effective in preventing death or
serious illness from pertussis in young children. You
could commend Terri for having Ally fully vaccinated
and reassure her that it is highly unlikely that Ally will
develop severe disease.
Ally can’t stop coughing
In general, what contacts of a case of pertussis should
receive chemoprophylaxis?
In general, chemoprophylaxis is limited to a narrow
range of contacts who have been exposed to an
infectious case of pertussis in the previous 3 weeks and
depends on the risk that it poses to young or
unvaccinated infants. The definitions of eligible
contacts (other than household contacts) for pertussis
chemoprophylaxis are complex and best discussed with
your local public health unit, which will follow up
contacts.
http://www.health.gov.au/internet/main/publishing.ns
f/Content/cdna-song-pertussis.htm
Ally can’t stop coughing
Ally and Terri shared a household with David and Faith
and their new baby while infectious with pertussis.
David and Faith had received adult pertussis
vaccination from their GP shortly after their baby was
born.
Should David and Faith receive chemoprophylaxis?
Yes. While David and Faith are most likely to be
protected by their recent vaccinations, the setting and
potential for them to acquire infection from Ally and
transmit it to their unimmunised newborn would
warrant provision of chemoprophylaxis to ‘all family
members when there is an unvaccinated infant in the
household’.
Eric is sleepy
Eric, aged 57 yrs, is a truck driver who presents with sleepiness.
He has a past history of ischaemic heart disease, type 2 diabetes,
hypertension and hyperlipidaemia and he is on metformin,
irbesartan, atorvastatin and aspirin. Eric smokes 25 cigarettes a
day, and consumes 6 standard drinks of alcohol most nights of
the week.
Eric describes increasing sleepiness during the day that has been
getting worse over the past 12 months. He will often fall asleep
inappropriately. He is a loud snorer and his wife says she often
stays awake at night because Eric stops breathing and she is
worried that he won’t wake up. Recently, he has been more
irritable and had a number of arguments with his daughters. On
further questioning, Eric describes falling asleep at the traffic
lights, although he says he has not been involved in any road
traffic accidents.
Eric is sleepy
What is the most likely diagnosis? Write in note form,
your single (1) diagnosis.
Eric has symptoms suggestive of obstructive sleep
apnoea (OSA). This is a common problem, affecting up
to 25% of adult males in Australia. Common night-time
clinical features include snoring, observed apnoeas,
nocturnal choking and nocturia. Daytime sleepiness, or
fatigue, is the most common daytime symptom with
irritability or mood changes also commonly noted.
Eric is sleepy
What would you look for on physical examination? List
up to four (4) suggestions. What clinical tools might
help in your assessment?
There are several examination findings that are useful in the
assessment of suspected OSA. These include an elevated
BMI, a crowded oropharynx (ie. large tonsils, a thick stumpy
uvula and a large set back tongue), increased neck
circumference and retrognathia.
The most commonly used tool for assessment of the
oropharynx is the modified mallampati (MMP) score, which
strongly correlates with OSA.
A neck circumference of greater than 40 cm has been found
to have a sensitivity of 60% and a specificity of 93% for OSA
independent of gender. However, clinical examination and
history alone are able to predict only approximately 50% of
cases of obstructive sleep apnoea, so further investigation
is required.
The Epworth Sleepiness Scale (ESS) is a useful tool that
evaluates sleepiness by estimating the likelihood of dozing.
A score of >10 is considered abnormal, with increasing
scores reflecting increasing sleepiness.
Eric is sleepy
On examination Eric is obese, with a body mass index
(BMI) of 38 kg/m2. He has a Modified Mallampati
(MMP) score of 3 and a neck circumference of 45 cm.
The remainder of his physical examination is normal.
His score on the Epworth Sleepiness Scale (ESS) is
18/24.
Eric is sleepy
What investigations would you consider requesting to
confirm your working diagnosis?
The Australian Sleep Association divide investigations for OSA
into four categories based on the level of evidence for their use.
They range from a level one study, which consists of an inlaboratory polysomnography (PSG) undertaken with overnight
observation, to a level four study, which consists of overnight
pulse oximetry.
In-laboratory PSG is the gold standard for the diagnosis of OSA
and involves multiple channels to assess sleep quality, adequacy
of ventilation, brain function, eye movements and heart rhythm,
as well as chest wall and abdominal wall movements.
Intermediate tests involve non-supervised home-based sleep
studies with fewer monitoring channels. The use of home testing
with portable monitors is limited to patients with a high pre-test
probability of moderate to severe OSA. These studies are not
recommended when there are comorbid conditions including
moderate to severe pulmonary disease, cardiac failure or
neuromuscular disease and should be avoided when diagnoses
other than OSA are being considered.
Eric is sleepy
What advice would you give Eric regarding his work
while he is being investigated?
Austroads’ Assessing Fitness to Drive for commercial and private
vehicle drivers provides information on OSA and driving. Patients
suspected of having sleep apnoea should be warned about the
potential effect on driving, and it is then their responsibility to
avoid driving if sleepy.
A person is not fit to hold an unconditional licence if they have
self-reported episodes of sleepiness, drowsiness while driving,
motor vehicle accident(s) caused by sleepiness or inattention. If
they pose a significant driving risk in the opinion of the treating
doctor they are also not fit to hold an unconditional licence.
The legal responsibility for notifying the relevant state or
territory authority regarding medical conditions, which may
affect driving, lies with the driver once they are aware of the
impact that their condition may have on driving. However, if
there are concerns that the patient continues to drive despite
appropriate advice and poses a public safety risk then direct
reporting to the licensing authority should be considered. In
New South Wales reporting is not mandatory. However, there
are statutes that may protect health professionals who report
without patient consent from litigation.
Eric is sleepy
Eric undergoes a sleep study.
What is the diagnosis?
Eric is sleepy
Eric has severe OSA. The hypnogram shows frequent obstructive
apnoeas in all sleep stages associated with profound arterial oxygen
desaturations. There are frequent cortical arousals associated with
these respiratory events, with resulting fragmented sleep. Consensus
guidelines suggest that if respiratory events (obstructive apnoeas,
hypopnoeas or respiratory event related arousals) on PSG occur at a
frequency of >15 events/hour (also called the apnoea-hypopnoea
index, or AHI) then a diagnosis of OSA is confirmed. OSA can also be
confirmed in patients with >5 events/hour if there are associated
symptoms. OSA severity is considered mild if the AHI is >5 events/hour
but <15 events/hour, moderate if the AHI is ≥15 events/hour but <30
events/hour, and severe if the AHI is ≥30 events/hour.
The significance of mild or moderate OSA is controversial and current
practice in managing milder forms of OSA is variable. In many facilities,
mild or moderate OSA is generally managed conservatively unless the
patient wishes to commence active treatment, has significant
comorbidities such as difficult to control hypertension or ischaemic
heart disease, or if a patient has symptoms such as hypersomnolence
that are clearly due to their OSA. Consider excluding non-sleep apnoea
causes of hypersomnolence such as chronic sleep deprivation in a
patient with mild to moderate sleep apnoea on PSG before offering
active treatment.
Eric is sleepy
How would you treat this condition?
OSA is a chronic condition requiring long-term collaborative
management.
• Treatment for OSA should be multimodal and include
weight loss, exercise, avoidance of alcohol and sedatives
and positional therapy (strategies to encourage lying on
the side rather than the back).
• Continuous positive airway pressure (CPAP) with heated
humidification is the treatment of choice and should be
offered to all patients with severe OSA.
• Oral appliances (ie. mandibular advancement splints) are
not as efficacious as CPAP, however, they may have a role
in patients with mild to moderate OSA based on patient
preference or intolerance of other management
strategies including CPAP.
• There is limited evidence to support the use of surgical
techniques for OSA as first line treatment – they may be
considered in patients with severe OSA who do not
tolerate other treatments and have correctable anatomy.
Eric is sleepy
When would you advise Eric that he is able to return to
work?
A sleep specialist may grant a conditional commercial
licence after review where there has been a satisfactory
response to treatment and the patient has
demonstrated treatment compliance. Annual review is
recommended.