Celebration Week 2010
Abstracts for ADHB Young Investigator Award
Presentations
Contents
1
PARACETAMOL OVERDOSE: DETERMINANTS OF OUTCOME
FROM A SINGLE CENTRE, 10 YEAR EXPERIENCE
Tien Huey Lim – New Zealand
Liver Transplant Unit
2
COST BENEFIT ANALYSIS OF AMETHOCAINE (AMETOP)
COMPARED WITH EMLA FOR INTRAVENOUS CANNULATION
IN A CHILDREN'S EMERGENCY DEPARTMENT
Clinton Newbury – Children’s
Emergency Department,
Starship Hospital
3
A RETROSPECTIVE AUDIT OF CARDIAC WORKUP AND
OUTCOMES IN PATIENTS CONSIDERED FOR RENAL
TRANSPLANTATION AT AUCKLAND CITY HOSPITAL.
Elizabeth Curry – Department
of Renal Medicine
4
THE IMPACT OF MEASLES VIRUS IN THE AUCKLAND REGION
IN 2009
5
BACTERIAL MICRO-COLONIES EXIST WITHIN THE MUCOSA
OF PATIENTS WITH CHRONIC RHINOSINUSITIS AND EXERT
AN IMMUNOPARETIC EFFECT
Deborah Williamson –
Department of Microbiology,
LabPlus
Andrew Wood - Department of
Otolaryngology-Head & Neck
Surgery
Paracetamol overdose: Determinants of outcome from a single centre, 10 year
experience.
Lim TH, Gane E, Orr DW. NZ Liver Transplant Unit, Auckland City Hospital.
Paracetamol overdose (POD) is a leading cause of morbidity and mortality in western
countries. Prompt treatment with acetylcysteine can avert significant hepatic injury.
Aim: To evaluate the demographic and laboratory characteristics of patients with
POD at ACH and identify risk factors for severe hepatotoxicity and outcome.
Method: Patients with diagnosis of POD August 2000 - August 2010 at ACH were
identified (1731). Primary outcome: significant hepatotoxicity (peak serum AST or
ALT level >1000U/L). Secondary outcomes: death or referral for liver transplant.
1419 (82%) intentional overdose, 312 (18%) accidental. 65/1419 (4.6%) of
intentional group developed severe hepatitis, compared to 31/312 (10%) of
accidental group (p=0.003). Peak INR, transaminases and inpatient stay all
significantly higher in accidental group.
3/266 (0.3%) of those treated within 12 hours vs 41/133 (31%) for those treated
more than 12 hours had INR >2; (p<0.0001). Hepatotoxicity is also more common in
patients >40 years old: 16.5% vs 6.3% (p=0.002)
Only 1 patient with peak transaminases <1000U/L developed an INR >2.0 or had
evidence of liver failure.
Conclusions: Accidental overdose, delay of >12 hours from POD and receiving Nacetylcysteine; and age >40years are significant risk factors for severe hepatitis and
progression to liver failure. All patients presenting with a history of significant POD
should be commenced on N-acetylcysteine without delay.
Cost benefit analysis of amethocaine (Ametop) compared with EMLA for
intravenous cannulation in a children's emergency department.
Newbury C, Herd DW, Brown PM.
Children's Emergency Department, Starship Children's Hospital
AIM: To determine cost implications of introducing topical amethocaine into Starship
Hospital Children's Emergency Department practice.
METHODS: Data were obtained from a randomised controlled trial, quality assurance
project and an audit of topical anaesthetic use, with economic evaluation performed
from the District Health Board perspective in 2007 NZ dollars and Euros. Proportion
of children receiving topical anaesthetic cream during insertion of IVC was the
primary benefit measure, and cost per child presenting to the department was the
primary cost measure. Multiple clinical scenarios were modeled, and incremental
cost effectiveness ratios calculated compared to the baseline model.
RESULTS: Scenarios modeled include providing no topical anaesthesia, using
amethocaine exclusively or using a mixture of amethocaine and EMLA. The most cost
effective model provided EMLA at triage to those most likely to need IVC; then
amethocaine to other children later thought to require IVC. This model would cost
NZ$1.05 per child, down from NZ$1.47. Proportion of children receiving cream
during insertion of IVC would increase from 51% to 64%. The recommended model
dominated the current situation.
CONCLUSION: Use of amethocaine in a mixed model in the CED could reduce cost
and increase the proportion of children receiving topical anaesthetic during insertion
of IVC.
Retrospective audit of cardiac workup and outcomes in patients considered for
renal transplantation at Auckland City Hospital.
Curry E1, Webster M2, Pilmore H1.
1 Department of Renal Medicine, Auckland City Hospital
2 Department of Cardiology, Auckland City Hospital
Introduction: Cardiovascular disease is the most common cause of death among
patients with end-stage renal disease.
Renal transplantation improves
cardiovascular outcomes. Cardiovascular event rates in those who are considered
but not transplanted, are unknown as is the optimal cardiac screening test.
Methods: adult patients considered for renal transplant in Auckland January 2000 to
December 2007 were included.
Results: 878 patients were assessed, 819 were listed for transplantation. 658
patients underwent provocative cardiac testing (1123 tests) and 253 angiograms
were performed. Cardiac event rates per 100 patient years are presented in the
table below: Those never listed had an extremely high rate of cardiac events. Those
transplanted had the best outcome, with 8-fold fewer events. The negative and
positive predictive values of provocative cardiac tests were calculated against
subsequent cardiac events and significant disease on coronary angiogram:
Conclusion: The low event rates in those transplanted suggest that current screening
strategies are working. Transplant appears to reduce the risk of cardiac events,
compared with those listed and awaiting transplant. The predictive values of
screening investigations appear to be similar with the exception of ETTs. Larger
studies of cardiac screening processes in patients with end-stage renal disease are
needed.
The impact of Measles virus in the Auckland region in 2009
Deborah Williamson 1, Joshua Freeman 1, Kitty Croxson 2, Sally Roberts 1
1 Department of Microbiology, LabPlus, Auckland City Hospital
2 Department of Virology, LabPlus, Auckland City Hospital
The measles outbreak in Canterbury in 2009 was associated with a significant
disease burden. In Auckland, although the morbidity from measles was low, knockon effects were felt in many areas. We sought to assess the impact of measles on
various services within Auckland.
In the post-vaccine era, measles is an uncommon diagnosis. Although 70 patients
were tested for the presence of measles virus RNA, only 3 patients had laboratory
confirmation of infection. Fifty-four patients had specimens that were suitable for
further testing. A possible aetiology was established in 28/54 (52%) patients. Our
findings demonstrate the likelihood of alternative aetiological agents causing rashfever illnesses in a population where measles is non-endemic.
We also assessed the impact of measles on occupational health services and
healthcare workers (HCWs). In New Zealand, individuals born before 1969 are
assumed to be immune to measles. However, some studies suggest that this
predetermined age limit is not a reliable measure of immunity. In our local setting
however, we found that 893 (98%) of 912 HCWs more than 40 years old were
immune to measles. Future vaccination campaigns will be much improved if
assumptions can be made about immunity in HCWs. Our data support this
assumption in the epidemiologic setting of a hospital in New Zealand.
Bacterial micro-colonies exist within the mucosa of patients with chronic
rhinosinusitis and exert an immunoparetic effect
Andrew Wood1,2,3, John Fraser3, Emma Emanuelsson-Patterson4, Satya Amirapu5,
Simon Swift3, Richard Douglas1,2
1 Department of Otolaryngology-Head & Neck Surgery, Auckland District Health
Board
2 Department of Surgery, University of Auckland
3 Department of Molecular Medicine & Pathology, University of Auckland
4 Department of Chemical and Materials Engineering, University of Auckland
5 Department of Anatomy with Radiology, University of Auckland
Several species of bacteria have been identified within biofilms on the mucosal
surface of patients with chronic rhinosinusitis (CRS). To date only Staphylococcus
aureus has been reported within the mucosa.
Aims: 1. Determine whether species other than S. aureus exist within sinonasal
mucosa of CRS patients. 2. Quantify the inflammatory response provoked by intramucosal bacteria.
Methods: Mucosal samples were collected during endoscopic sinus surgery from 12
patients with CRS and 5 subjects with normal sinonasal mucosa. Samples were
sectioned and bacteria within the tissue identified by Gram’s and Giemsa stains and
fluorescence in situ hybridization (FISH). Immune cells were identified by
immunohistochemical techniques and light microscopy and quantified by counting
cell numbers per x63 field.
Results: Bacterial micro-colonies were identified in CRS patients (10/12) but only one
normal subject (1/5). S. aureus and Haemophilus influenzae were identified within
the mucosa by FISH. The mucosa immediately surrounding the microcolonies
demonstrated reduced numbers of T lymphocytes (p=0.021), B lymphocytes
(p=0.022) and eosinophils (p=0.034) compared to areas of mucosa without bacterial
microcolonies.
Conclusions: This is the first description of intra-mucosal bacteria other than
S.aureus in CRS. The apparent ability of the microcolonies to suppress the
inflammatory response may help explain why CRS often runs an intractable course.