Perioperative oxygen administration in patients undergoing major non-cardiac surgery under general anaesthesia in Australia and New Zealand

The practice of anaesthetists relating to the administration of intraoperative oxygen has not been previously quantified in Australia and New Zealand. The optimal regimen of intraoperative oxygen administration to patients undergoing surgery under general anaesthesia is not known, and international recommendations for oxygen therapy are contradictory; the World Health Organization (WHO) recommend administering an intraoperative fraction of inspired oxygen of at least 0.8, while the World Federation of Societies of Anaesthesiologists, British Thoracic Society, and Thoracic Society of Australia and New Zealand recommend a more restrictive approach. We conducted a prospective observational study to describe the pattern of intraoperative oxygen administration among anaesthetists in Australia and New Zealand and, second, to determine the proportion of anaesthetists who administer intraoperative inspired oxygen in accordance with the WHO recommendations. We identified 150 anaesthetists from ten metropolitan hospitals in Australia and New Zealand and observed the patterns of intraoperative oxygen administration to American Society of Anesthesiologists physical status classification (ASA) 3 or 4 patients undergoing prolonged surgery under general anaesthesia. The median (interquartile range) intraoperative time-weighted mean fraction of inspired oxygen (FiO₂) for all participants in the study was 0.47 (0.40-0.55). Three out of 150 anaesthetists (2%, 95% confidence interval 0.4 to 5.7) administered an average intraoperative FiO₂ of at least 0.8. These findings indicate that most anaesthetists routinely administer an intermediate level of oxygen for ASA 3 or 4 adult patients undergoing prolonged surgery in Australia and New Zealand, rather than down-titrating inspired oxygen to a target pulse oximetry reading (SpO₂) or administering liberal perioperative oxygen therapy in line with the current WHO recommendation.

He Tamariki Kokoti Tau: Tackling preterm incidence and outcomes of preterm births by ethnicity in Aotearoa New Zealand 2010-2014

OBJECTIVE

To explore preterm birth among Māori indigenous peoples through Kaupapa Māori research of preterm birth in Aotearoa New Zealand.

METHODS

Linked maternity, mortality, and hospital data were analyzed for women and their infants born between January 1, 2010 and December 31, 2014. Relative risks (RR) were calculated for each ethnic group for preterm birth, small for gestational age (SGA), and mortality.

RESULTS

Adjusted rates showed that compared with Māori women, European women were at significantly less risk of having extremely and very preterm infants (RR 0.86, 95% confidence interval [CI] 0.76-0.95). Preterm infants of European women had a significantly lower adjusted RR of early neonatal death (RR 0.65, 95% CI 0.45-0.93) or post-neonatal death (RR 0.41, 95% CI 0.26-0.64). In addition to ethnicity, preterm rates were influenced by maternal age, body mass index, smoking status, and SGA status.

CONCLUSION

This study demonstrates that the Aotearoa New Zealand maternity system privileges whiteness, suggesting that clinical pathways for evidence-based medical care are not delivered systemically and equitably for all. Health pathways that focus on equity as a fundamental right will enhance health outcomes for Māori women and their infants.

A call for action that cannot go to voicemail: Research activism to urgently improve Indigenous perinatal health and wellbeing

In this call to action, a coalition of Indigenous and non-Indigenous researchers from Australia, Aotearoa New Zealand, United States and Canada argue for the urgent need for adequately funded Indigenous-led solutions to perinatal health inequities for Indigenous families in well-resourced settler-colonial countries. Authors describe examples of successful community-driven programs making a difference and call on all peoples to support and resource Indigenous-led perinatal health services by providing practical actions for individuals and different groups.

He Korowai Manaaki (Pregnancy Wraparound Care): Protocol for a Cluster Randomized Clinical Trial

Background

Maternal and infant health inequities between Māori (the Indigenous peoples of Aotearoa New Zealand) and New Zealand European women are well documented and cannot be explained solely by socioeconomic status. A research center-iwi (tribal group) partnership aims to address these disparities and improve maternal and infant health outcomes by implementing an augmented maternity care pathway (He Korowai Manaaki) to improve access to services and evidence-informed care.

Objective

The objective of this study is to test whether an augmented maternity care pathway improves Māori infant health outcomes.

Methods

This is a Kaupapa Māori (by, with, and for Māori) cluster randomized clinical trial involving 8 primary care practices allocated to either an intervention arm or control arm. The intervention arm comprises an augmented maternity care pathway (He Korowai Manaaki) offering clinical care through additional paid health care appointments and improved access to social support (eg, housing, transport). The control arm is usual care. The primary outcome is increased timely vaccination for Māori infants, defined as all age-appropriate vaccinations completed by 6 months of age.

Results

Recruitment commenced in November 2018 and was completed in June 2020, with 251 enrolled women recruited in intervention primary care practices before 20 weeks of pregnancy. Publication of results is anticipated in late 2023.

Conclusions

The results will inform primary health care policy including whether the provision of augmented maternal care pathways reduces disparities in the structural determinants of health. If effective, He Korowai Manaaki will strengthen the health and well-being of pregnant Māori women and their babies and improve their health outcomes, laying a strong foundation for lifelong health and well-being.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12619001155189; https://tinyurl.com/yypbef8q

International Registered Report Identifier (IRRID)

DERR1-10.2196/18154

Reaching under-screened/never-screened indigenous peoples with human papilloma virus self-testing: A community-based cluster randomised controlled trial

BACKGROUND

Indigenous women in the high-income countries of Canada, Australia, New Zealand and USA, have a higher incidence and mortality from cervical cancer than non-Indigenous women. Increasing cervical screening coverage could ultimately decrease cervical cancer disparities.

AIMS

To increase cervical screening for under-screened/never-screened Māori women.

MATERIALS AND METHODS

This study was a cluster randomised controlled trial. Inclusion criteria were women aged 25-69, last screened ≥4 years ago, in Northland, New Zealand. The intervention arm was the offer of a human papilloma virus (HPV) self-test and the control arm was the usual offer of standard care - a cervical smear. The primary outcome was rate of cervical screening in the intervention group compared to control in Māori, the Indigenous peoples of New Zealand. Six primary care clinics were randomly allocated to intervention or control.

RESULTS

Of 500 eligible Māori women in the intervention arm, 295 (59.0%) were screened. Of 431 eligible Māori women in the control arm, 94 (21.8%) were screened. Adjusting for age, time since last screen, deprivation index, Māori women in the intervention arm were 2.8 times more likely to be screened than women in the control arm (95% CI: 2.4-3.1, P-value <0.0001).

CONCLUSIONS

Offer of HPV self-testing could potentially halve the number of under-screened/never-screened Māori women and decrease cervical morbidity and mortality. These results may be generalisable to benefit Indigenous peoples facing similar barriers in other high-income countries.

Creating functional groups of marine fish from categorical traits

Background

Functional groups serve two important functions in ecology: they allow for simplification of ecosystem models and can aid in understanding diversity. Despite their important applications, there has not been a universally accepted method of how to define them. A common approach is to cluster species on a set of traits, validated through visual confirmation of resulting groups based primarily on expert opinion. The goal of this research is to determine a suitable procedure for creating and evaluating functional groups that arise from clustering nominal traits.

Methods

To do so, we produced a species by trait matrix of 22 traits from 116 fish species from Tasman Bay and Golden Bay, New Zealand. Data collected from photographs and published literature were predominantly nominal, and a small number of continuous traits were discretized. Some data were missing, so the benefit of imputing data was assessed using four approaches on data with known missing values. Hierarchical clustering is utilised to search for underlying data structure in the data that may represent functional groups. Within this clustering paradigm there are a number of distance matrices and linkage methods available, several combinations of which we test. The resulting clusters are evaluated using internal metrics developed specifically for nominal clustering. This revealed the choice of number of clusters, distance matrix and linkage method greatly affected the overall within- and between- cluster variability. We visualise the clustering in two dimensions and the stability of clusters is assessed through bootstrapping.

Results

Missing data imputation showed up to 90% accuracy using polytomous imputation, so was used to impute the real missing data. A division of the species information into three functional groups was the most separated, compact and stable result. Increasing the number of clusters increased the inconsistency of group membership, and selection of the appropriate distance matrix and linkage method improved the fit.

Discussion

We show that the commonly used methodologies used for the creation of functional groups are fraught with subjectivity, ultimately causing significant variation in the composition of resulting groups. Depending on the research goal dictates the appropriate strategy for selecting number of groups, distance matrix and clustering algorithm combination.

Evidence of separate subgroups of juvenile southern bluefin tuna

Archival tagging studies of southern bluefin tuna (SBT , Thunnus maccoyii) have revealed that juveniles residing in the Great Australian Bight (GAB) over the austral summer undertake seasonal cyclic migrations to the southeast Indian Ocean and the Tasman Sea during winter. However, there remains disagreement about the extent of mixing between juvenile SBT regularly caught by longline fleets south of Africa and those observed in the GAB. Some researchers have argued that archival tag recoveries indicate most juveniles reside in the GAB over the austral summer. Others have suggested that recoveries of conventional and archival tags are better explained by a juvenile population consisting of separate groups on the eastern and western sides of the Indian Ocean with limited intermixing. We present analyses of catch and tag recovery data and re-examine archival tagging studies. The evidence provided strongly favors the hypothesis of separate juvenile subgroups, or contingents, with limited intermixing. We draw some tentative conclusions about the nature of the putative contingents and discuss some implications of these findings for the interpretation of existing datasets and future research priorities. We also provide the first evidence that the migration choices of juveniles that summer in the GAB are influenced by fidelity to winter feeding grounds and suggest this helps explain the collapse of the surface fishery off New South Wales in the 1980s.

Graphical model-based O/E control chart for monitoring multiple outcomes from a multi-stage healthcare procedure

Most statistical process control programmes in healthcare focus on surveillance of outcomes at the final stage of a procedure, such as mortality or failure rates. Such an approach ignores the multi-stage nature of these procedures, in which a patient progresses through several stages prior to the final stage. In this paper, we introduce a novel approach to statistical process control programmes in healthcare. Our proposed approach is based on the regression adjustment and multi-stage control charts that have been in use in industrial applications for decades. Three advantages of the approach are: better understanding of how outcomes at different stages relate to each other, explicit monitoring of upstream stage outcomes may help curtail trends that lead to poorer end-stage outcomes and understanding the impact of each stage can help determine the most effective allocation of quality improvement resources. A test statistic for the control charts is proposed. Simulations are performed to test the control charts, and the results are summarised using an empirical probability of true detection. An illustrative example using data from a maternity unit is included. A main result from the simulation study is that taking a multi-stage approach makes it easer to explicitly identify shifts in upstream stage outcomes that might otherwise be signalled in final stage outcomes if dependence between stages is ignored.

Men's preferences for women's breast morphology in New Zealand, Samoa, and Papua New Guinea

Sexual selection via mate choice may have influenced the evolution of women's breast morphology. We conducted an image-based questionnaire quantifying and comparing the preferences of men from Papua New Guinea (PNG), Samoa, and New Zealand (NZ) for images of women's breast size, breast symmetry, areola size, and areolar pigmentation. Results showed that men from PNG preferred larger breasts to a greater extent than men from Samoa and NZ, providing some support for the hypothesis that men from subsistence living cultures have a greater preference for morphological cues indicative of caloric reserves. Symmetrical breasts were most attractive to men in each culture. However, preferences were highest among NZ men, followed by men from Samoa, and were lowest among men from PNG. These results did not support the hypothesis that people living in higher pathogen environments have a greater preference for traits indicative of pathogen resistance and developmental stability. Large areolae were preferred among men from PNG, and to a lesser extent in Samoa, while in NZ men preferred medium-sized areolae. Thus, men's preferences for women's areolar size appear to be highly culturally specific. Darkly pigmented areolae were most attractive to men from Samoa and PNG, whereas men from NZ preferred areolae with medium pigmentation. These findings suggest that areolar pigmentation indicative of sexual maturity is preferred by men rather than lighter pigmentation, which may signal that a woman is in the early years of reproductive maturity. This study highlights the importance of cross-cultural research when testing the role of morphological cues in mate choice.

Prospective evaluation of a continuous monitoring and quality-improvement system for reducing adverse neonatal outcomes

OBJECTIVE

Our objective was to evaluate a prospective monitoring and quality improvement system for studying trends in the rates of an adverse neonatal outcome, the low Apgar scores (Apgar score <7).

STUDY DESIGN

A cumulative sum (CUSUM) chart-based system was used to monitor the rate of low Apgar scores over 2 years. Root cause analysis (RCA) was used to investigate for causes of periods of increased low Apgar score rates.

RESULTS

A period of deteriorated outcome (increased rates of low Apgar) occurred in August 2006. RCA identified deficiencies in cardiotocograph education, which were addressed by targeted training and mentoring. Prompt resolution followed, with the rates returning to baseline and staying within acceptable limits through to the end of evaluation in December 2007.

CONCLUSION

Prospective and continuous monitoring of clinical outcomes using the CUSUM chart method is feasible and may be beneficial. Early detection of an adverse trend allows for timely corrective action, and may lead to overall improvements in performance.

Revision rates after primary hip and knee replacement in England between 2003 and 2006

BACKGROUND

Hip and knee replacement are some of the most frequently performed surgical procedures in the world. Resurfacing of the hip and unicondylar knee replacement are increasingly being used. There is relatively little evidence on their performance. To study performance of joint replacement in England, we investigated revision rates in the first 3 y after hip or knee replacement according to prosthesis type.

METHODS AND FINDINGS

We linked records of the National Joint Registry for England and Wales and the Hospital Episode Statistics for patients with a primary hip or knee replacement in the National Health Service in England between April 2003 and September 2006. Hospital Episode Statistics records of succeeding admissions were used to identify revisions for any reason. 76,576 patients with a primary hip replacement and 80,697 with a primary knee replacement were included (51% of all primary hip and knee replacements done in the English National Health Service). In hip patients, 3-y revision rates were 0.9% (95% confidence interval [CI] 0.8%-1.1%) with cemented, 2.0% (1.7%-2.3%) with cementless, 1.5% (1.1%-2.0% CI) with "hybrid" prostheses, and 2.6% (2.1%-3.1%) with hip resurfacing (p < 0.0001). Revision rates after hip resurfacing were increased especially in women. In knee patients, 3-y revision rates were 1.4% (1.2%-1.5% CI) with cemented, 1.5% (1.1%-2.1% CI) with cementless, and 2.8% (1.8%-4.5% CI) with unicondylar prostheses (p < 0.0001). Revision rates after knee replacement strongly decreased with age.

INTERPRETATION

Overall, about one in 75 patients needed a revision of their prosthesis within 3 y. On the basis of our data, consideration should be given to using hip resurfacing only in male patients and unicondylar knee replacement only in elderly patients.

Mortality in men admitted to hospital with acute urinary retention: database analysis

OBJECTIVES

To investigate mortality in men admitted to hospital with acute urinary retention and to report on the effects of comorbidity on mortality.

DESIGN

Analysis of the hospital episode statistics database linked to the mortality database of the Office for National Statistics.

SETTING

NHS hospital trusts in England, 1998-2005.

PARTICIPANTS

All men aged over 45 who were admitted to NHS hospitals in England with a first episode of acute urinary retention.

MAIN OUTCOME MEASURES

Mortality in the first year after acute urinary retention and standardised mortality ratio against the general population.

RESULTS

During the study period, 176 046 men aged over 45 were admitted to hospital with a first episode of acute urinary retention. In 100 067 men with spontaneous acute urinary retention, the one year mortality was 4.1% in men aged 45-54 and 32.8% in those aged 85 and over. In 75 979 men with precipitated acute urinary retention, mortality was 9.5% and 45.4%, respectively. In men with spontaneous acute urinary retention aged 75-84, the most prevalent age group, the one year mortality was 12.5% in men without comorbidity and 28.8% in men with comorbidity. The corresponding figures for men with precipitated acute urinary retention were 18.1% and 40.5%. Compared with the general population, the highest relative increase in mortality was in men aged 45-54 (standardised mortality ratio 10.0 for spontaneous and 23.6 for precipitated acute urinary retention) and the lowest for men 85 and over (1.7 and 2.4, respectively).

CONCLUSIONS

Mortality in men admitted to hospital with acute urinary retention is high and increases strongly with age and comorbidity. Patients might benefit from multi-disciplinary care to identify and treat comorbid conditions.

The CUSUM chart method as a tool for continuous monitoring of clinical outcomes using routinely collected data

BACKGROUND

The lack of robust systems for monitoring quality in healthcare has been highlighted. Statistical process control (SPC) methods, utilizing the increasingly available routinely collected electronic patient records, could be used in creating surveillance systems that could lead to rapid detection of periods of deteriorating standards. We aimed to develop and test a CUmulative SUM (CUSUM) based surveillance system that could be used in continuous monitoring of clinical outcomes, using routinely collected data. The low Apgar score (5 minute Apgar score < 7) was used as an example outcome.

METHOD

A surveillance system based on the Observed minus Expected (O-E) as well as the 2-sided Log-Likelihood CUSUM charts was developed. The Log-Likelihood chart was designed to detect a 50% rise (deterioration) and halving (improvement) in the odds of low Apgar scores. Baseline rates were calculated from data for 2001 to 2004, and were used to monitor deliveries for 2005. Deliveries for nulliparous and multiparous women were monitored separately. All analyses were retrospective.

RESULTS

The CUSUM system detected periods of increased rates of low Apgar scores for each of the nulliparous and multiparous cohorts. The overall rate for 2005 was eventually found to be 0.67%, which was higher than the baseline reference rate of 0.44% from 2001 to 2004.

CONCLUSION

CUSUM methods can be used in continuous monitoring of clinical outcomes using routinely collected data. Used prospectively, they could lead to the prompt detection of periods of suboptimal standards.

Continuous monitoring tools for pediatric surgical outcomes: an example using biliary atresia

PURPOSE

Continuous monitoring tools can be used to monitor surgical outcomes over time. We illustrate the use of CUmulative SUM (CUSUM) charts in monitoring outcomes of Kasai portoenterostomy for treatment of biliary atresia at a supraregional unit.

METHODS

Data on 57 consecutive infants who underwent a Kasai portoenterostomy performed by a single surgeon between June 1994 and June 2006 were collected. A procedure was defined as successful if clearance of jaundice (plasma bilirubin level <20 micromol/l) was achieved within 6 months of surgery. We applied cumulative observed-minus-expected, sequential probability ratio test (SPRT), and zero-resetting SPRT CUSUM charts and compared the results with those of standard aggregate data analyses. An expected failure rate of 43.0%, based on the national average failure rate, was used.

RESULTS

The failure rate observed after 57 operations was 29.8%. The zero-resetting SPRT chart indicated a lower-than-expected failure rate earlier than did the aggregate data analyses and any of the other continuous monitoring techniques.

CONCLUSIONS

The CUSUM chart method provides ongoing feedback that can be used for continuous monitoring of the outcome of a procedure to ensure that standards of care are maintained. Its use as a routine monitoring tool in pediatric surgery deserves wider recognition.

Pregnancy after organ transplantation: a report from the UK Transplant pregnancy registry

BACKGROUND

Maternal and fetal complications in pregnancies after renal transplantation have been highlighted in several reports, but information on their main predisposing factors is limited. The U.K. Transplant Pregnancy Registry was established in 1997 to obtain detailed information on pregnancies in female organ transplant recipients across the U.K.

METHODS

For each female kidney, liver, or cardiothoracic organ transplant recipient who had had a recent pregnancy, data on maternal and fetal factors and pregnancy outcomes were collected using forms completed by their transplant follow-up and obstetric units. For kidney transplant recipients, the factors that influence pregnancy outcome were studied using logistic regression, and the effect of pregnancy on graft function was analyzed.

RESULTS

There were live births in 83%, 69%, and 79% of pregnancies in cardiothoracic organ, liver, and kidney recipients, respectively. In 50% of live births from renal patients, delivery was preterm (<37 weeks), with 83% of the preterm infants delivered via caesarean. Preterm delivery was associated with maternal drug-treated hypertension and impaired renal function. A matched case-control study showed no evidence of increased renal allograft loss after pregnancy. A univariate survival analysis, however, suggested an association between drug-treated hypertension during pregnancy and poorer postpregnancy graft survival. In patients with prepregnancy serum creatinine (SCr) >150 micromol/L, a trend toward increased postpregnancy SCr was identified.

CONCLUSIONS

Pregnancy is likely to end in a live birth in a majority of organ transplant recipients. In patients with greater prepregnancy SCr and/or drug-treated hypertension during pregnancy, however, subsequent renal function may be adversely affected.

Urinary iodine excretion in pregnant women as an index of the impact of a national iodization programme

OBJECTIVE

To evaluate the extent to which increase in iodine requirement was achieved in pregnant women who attended the antenatal clinic at Harare Central Hospital.

DESIGN

Cross sectional.

SETTING

Samples were collected from pregnant women attending antenatal clinic at Harare Central Hospital, and from lactating mothers and their infants.

SUBJECTS

100 pregnant women attending the antenatal clinic at Harare Central hospital, 80 infants, 80 lactating women and 18 non-pregnant women.

MAIN OUTCOME MEASURES

Comparison of urinary iodine excretion levels among pregnant women, lactating mothers and their infants.

RESULT

The results indicated lower urinary iodine excretion levels for the pregnant women and lactating mothers compared to the urinary iodine excretion of the infants and the breast milk iodine content. The urinary iodine excretion level of the non-pregnant control women was median (first and third quartiles): 18.5 microg/dl (30.0, 30.2 microg/dl). The urinary iodine excretion level of the lactating mothers was median (first and third quartiles): 12.0 mg/dl (7.6, 19.5 mg/dl) compared to the level of the infants, median (first and third quartiles): 26.5 mg/dl (18.8, 11.5 mg/dl). A significant difference was noted between the median urinary iodine excretion levels of the mothers, and the median levels of the infants, p = 0.001. The mean milk iodine content was 21.2 +/- 6.8 mg/dl. There was no correlation between breast milk iodine levels and the urinary iodine excretion levels of the infants, (p = 0.96, r = 0.006). Positive correlation was found between maternal urinary iodine excretion levels and the urinary iodine excretion levels of the infants, p = 0.016 r = 0.285. Serum FT4, and TSH levels were found to be higher for infants at six weeks after birth, (FT4 =20.91 +/- 5.65 pmol/L) and median TSH = 2.28 mIU/ml (1.36, 0.86) mIU/rnl, compared to levels at 12 weeks postpartum: (FT4 = 17.53-*6.4 pmol/L) and median TSH = 2.02 mIU/ml, (0.84, 1.55) mIU/ml. The differences were not significant.

CONCLUSION

The results indicated a significant reduction in the urinary iodine content of pregnant women, and lactating mothers which did not appear to have any relationship to the urinary iodine excretion levels of infants and iodine content of breast milk. Iodine intake needed to be raised to reflect the recent proposed recommendations.