UC Researching Why Patients Develop Pneumonia Following Surgery
May 1, 2013
A University of Canterbury (UC) researcher is seeking to better understand the relationship between the drugs given
during surgery and post-surgical chest infection.
UC Masters student Helana Kelly is researching the problem under supervision of Dr Maggie-Lee Huckabee.
A total of 297,440 New Zealand patients underwent acute or elective surgery in 2011-12. When patients undergo surgery,
painkillers are required to sedate and help relieve post-operative pain.
``Patients receive variable amounts of opioids to control pain and there are widespread variations in patient response.
Fentanyl is known to affect breathing and cough. A decreased cough response puts patients at risk of swallowed material
entering the airway, a condition referred to as aspiration. This can cause injury to the delicate air sacs in the lungs
and result in chest infection, or aspiration pneumonia.
``We want to find out the degree to which opiod pain-killers such as Fentanyl, impair airway protection (cough) in
surgical patients,’’ Kelly says.
``Potential risk factors for this include neurologic impairment, decreased level of consciousness, advancing age,
reflux, tube feeding and obesity.
``All patients undergoing surgery have a decreased level of consciousness due to anaesthesia. Material which may be
aspirated includes saliva, stomach contents, food and fluid.
``Aspiration is a costly complication in the acute hospital setting. A patient who has their surgical course complicated
by aspiration has an increased morbidity, increased length of hospital stay, and places greater demands on the health
system.
``Some of these patients require intensive care unit admission and intensive nursing care. If we could identify those
patients who are at risk of this complication, we may be able to apply a screening process to decrease risk and improve
health outcomes.
``We are assessing cough response through cough reflex testing at varying doses. Cough reflex testing is being used
clinically in New Zealand hospitals to identify patients at risk of silent aspiration due to an impaired cough
response,’’ Kelly says.
In the stroke population, cough reflex testing helps clinicians decide which patients require further investigation of
their airway protection prior to commencement of oral feeding.
UC researchers are investigating the effect of fentanyl cough response in healthy participants to see if any information
can be gained which will help reduce aspiration in the post-surgical population.
``Data from this study may add to our knowledge base to help us reduce aspiration in the post-surgical population.
``Our multi-disciplinary research includes investigators from the fields of speech-language therapy, medicine,
anaesthesia and nursing,’’ Kelly says.
Photo: Helana Kelly
ENDS