Volume 24 - The Society for the Advancement of Anaesthesia in ...

SAAD DENTAL NURSE PRIZE WINNER
POST-OPERATIVE
NAUSEA AND
VOMITING IN
DENTAL PATIENTS
A Nurse’s View
Sharon Williams RDN DAN DSN Cert Ed
Senior Dental Anaesthetic Nurse
Royal Albert Edward Infirmary, Wigan
Aims and intended learning
outcomes
In the study presented in this article, the aim is to provide
an overview of the management of post-operative
nausea and vomiting within dentistry, emphasising the
nurse’s role.
After reading this article, one should be able to:
• describe the physical and psychological complications
associated with post-operative nausea and vomiting
• discuss how vomiting is triggered by the brain
• explain the risk factors and how the risk assessment tool
works
• look at areas for improvement within nurse education in
the management of post-operative nausea and vomiting.
Introduction
Post-operative nausea and vomiting (PONV) was first
described in 1848 by John Snow (1) , within 18 months
of the introduction of anaesthesia to Britain. The belief
that anaesthetics alone were responsible for most cases of
post-operative nausea and vomiting persisted until 1916
when Flagg reported that it may result from other causes
including pain, reflex responses and the use of opioids (1) .
PONV is one of the most common post-operative
complications and can affect as many as 40% of patients (2) .
It can cause patient distress, medical complications and has
financial implications. The aetiology is multi-factoral (1) ,
occurring in all types of patients and with all types of
surgery and anaesthetics (3) .
Nurses, therefore, spend a lot of time comforting and
supporting patients. They assess and treat the symptoms
caused by PONV, including clearing up after episodes of
sickness and explaining the problem to patients. It can
delay a patient’s discharge from the recovery room and
increases the nurse’s workload. Although less than 1%
of day surgery patients have to stay in hospital overnight
because of uncontrollable nausea and vomiting, this
makes it an expensive complication (3) .
Physical complications of PONV in dental patients
can vary from minor episodes through to more serious
problems, such as (4) :
• general delay in mobilisation and recovery
• possible disruption of tooth sockets leading to ongoing
bleeding
• delay in giving oral analgesia and other medication
• increased pain, discomfort and distress
• dehydration
• aspiration of vomit with the risk of aspiration
pneumonia
• obstruction of airway.
Psychological effects can also affect the patient’s recovery
following surgery in the following ways (4) :
• discomfort
• shame and embarrassment
• dissatisfaction with the outcome of dental surgery
• fear of further dental surgery under general anaesthetic.
Nausea and vomiting
Nausea is an unpleasant sensation commonly preceding
vomiting (4) . The vomiting reflex is an important defence
mechanism for the expulsion of toxins. There are three
components to the vomiting reflex: emetic detectors,
coordinating centres and motor outputs (3) .
• Emetic detectors: these are receptors in the gut wall
that respond to distension, receptors in the mucosa of
the stomach and the duodenum, monitor the internal
environment. The stimulus is carried by the vagus nerve
to the brain stem (3) .
• Coordinating centres: the vomiting centre lies inside the
blood brain barrier in the medulla. It coordinates the
control of the vomiting reflex receiving signals from the
pharynx, gastrointestinal tract and mediastinum via the
vagus nerve. It also receives signals from a portion of
the eighth cranial nerve and the chemoreceptor trigger
zone. The chemoreceptor trigger zone e (CTZ) lies on
the outside of the blood brain barrier in the medulla
where it is exposed to circulating toxins. Stimulation of
SAAD DIGEST | VOL.24 | JANUARY 2008 13