Anaesthetics

TO THE EDITOR: We congratulate Heldens and colleagues1 for their work investigating the prevalence and mortality of sepsis within a tertiary hospital intensive care unit (ICU). As the authors rightly point out in their article and podcast, this requires careful screening, consistent diagnostic criteria, and considerable time and effort. The Australian and New Zealand Intensive Care Society (ANZICS) registry provides a highly specific, widely applicable, cost‐effective, timely and practical epidemiological measure of the prevalence and outcomes of sepsis and septic shock as a primary cause of ICU admissions throughout Australia and New Zealand.2 Findings from the registry appear consistent with those of Heldens and colleagues.1 However, their article confirms that there are more patients with sepsis within our ICUs than those who enter with this as an admission diagnosis. Between January 2016 and June 2018, 11.6% (43 529/374 442) of the ICU admissions reported to the ANZICS Adult Patient Database were due to sepsis as defined by the international Sepsis‐3 taskforce.3 In tertiary hospital ICUs, this was slightly higher at 12.1% (19 204/159 067), which is between 14.0% (121/864) by clinical criteria and 11.3% (98/864) by database criteria found within the first 24 hours of ICU admission by Heldens et al. With the recent addition of information about vasopressors and lactate levels, ANZICS can also now confidently identify patients with septic shock. Of 59 069 ICU admissions with available information, 3.3% (1978) had septic shock, again similar to the findings of Heldens et al. ICU admissions in the ANZICS registry due to sepsis or septic shock were associated with mortality of 15.1% and 26.7%, respectively. Heldens et al reported a similar mortality of 24% (8/33) with septic shock identified in the first 24 hours of admission (Appendix, table 4). The study by Heldens et al and the findings from the ANZICS registry are complementary. Together they highlight how the measurement of sepsis depends on the exact definition applied, and the population under consideration, which may vary between clinical practice, prospective observational and interventional studies, and widespread epidemiological comparisons.

David Pilcher · Sue Huckson · Peter Hicks

To the Editor: We commend Cohen and colleagues1 on their recently published study, which is the largest randomised controlled trial (RCT) of acupuncture in the emergency department (ED). We recently completed a systematic review and meta-analysis on the role of acupuncture for analgesia in the emergency setting.2 Our meta-analysis incorporated 19 RCTs and included non-English language publications. The trial by Cohen and colleagues1 was not published at the time of our review; however, it strengthens our main conclusion that acupuncture was non-inferior to standard analgesia in the emergency setting. We also found similar evidence of improved patient satisfaction. It was interesting that the authors reported an adverse effects rate of 51% for acupuncture, whereas our study found an overall rate of 5%, with significant adverse effects being 1%. Our figures are consistent with other reviews3 and almost certainly highlight the difficulties in developing agreed definitions on adverse effects in acupuncture. Our review found that acupuncture in two out of four RCTs decreased pain medication requirements, whereas Cohen and colleagues’ study had the potential to inform this outcome, but did not report such data. The study by Cohen and colleagues1 illustrates many of the challenges in acupuncture trials, including having no sham comparator group. Some acutely painful conditions might resolve simply because of time or careful patient attention. Sham acupuncture is difficult to deliver as a control4 and needs to be plausible, realistic and, if possible, blinded. Our meta-analysis showed acupuncture to be superior, with clinically significant reductions in acute pain scores compared with sham. This latest significant RCT gives further impetus to carefully designed research on acupuncture in the emergency setting, which will require acupuncture techniques applicable to the time-constrained ED environment (eg, ear acupuncture), provision of a suitable sham acupuncture technique, and minimisation of assessment bias. We suggest that the specific outcomes to be assessed should include the impact of acupuncture as an adjunct to standard analgesia, side effects recorded using standard definitions, and reductions in medication use. Most importantly, the analgesic effect of acupuncture is unlikely to be equal for all pain presentations in the emergency setting and, therefore, the conditions for which its role is most beneficial need to be delineated.

Andrew L Jan · Ian Rogers · Eric J Visser

To the Editor: The conclusions made by Cohen and colleagues1 can be challenged on the basis of study design and results. A significant flaw in the design is that of all patients not excluded due to additional medical problems, 38% of potential study participants declined to be included, possibly because they were not prepared to be assigned to the acupuncture-only arm. This flaw introduces a critical bias when analysing the 62% who did participate, as it is reasonable to assume that they are statistically more inclined to experience a placebo benefit from acupuncture and more likely to be positive at 48 hours about repeating this therapy. Even with this bias, however, the results of the study do not support a broad interpretation of non-inferiority, given that 39% of acupuncture-only patients required rescue therapy at or after one hour, compared with 22.5% of pharmacotherapy-only patients. In the context of an emergency department (ED) and patients with mean verbal numerical rating scale score of 8.5 at presentation, this difference in pain reduction and satisfaction with the initial therapy during the first hour of treatment should render the acupuncture-only option unacceptable. The authors have selectively and speculatively interpreted their data to support their enthusiasm for acupuncture. Results for patients with migraine are given minimum discussion or reference in the conclusions. The inferior performance of acupuncture-only patients’ willingness to repeat the therapy at one hour is dismissed as being influenced by patients’ concerns about length of stay and transport arrangements, whereas they indicate that the same parameter at 48 hours is more meaningful. I suggest that the results at one hour more accurately reflect a patient’s experience of their pain and desire for abatement, whereas the improved satisfaction at 48 hours is the result of shifted perspective following self-resolution — in a selected patient population with an existing positive bias for acupuncture. The authors’ suggestion that acupuncture use in EDs would reduce opioid addiction is an opportunistic grab at exploiting popular sentiment among people who do not understand the causes and parameters of this serious problem. This article does not support diversion of resources towards acupuncture use in EDs or a change in evidence-based treatment protocols in emergency medicine.

Anitra J Wenden

In reply

Marc M Cohen · Michael Ben-Meir · Nick Andrianopoulos

To the Editor: Intensive care is a finite and costly resource with nine beds per 100 000 population in Australia and at a cost of $4000 per bed-day. From 1999, the demand for intensive care unit (ICU) beds has increased at an average rate of 2.5% annually.1,2 Faced with increased demand and capacity restraints, fiscal sustainability is dependent on efficient use of limited ICU resources. ICU bed availability varies significantly across countries and creates a threshold for clinicians to admit patients.3 The availability of beds may be influenced by the number of patients well enough for ward discharge but who are exit blocked. ICU access block is a significant safety concern for critically ill patients, and ICU exit block (the inability to discharge a patient who is medically fit for discharge) may contribute significantly to ICU access block.4,5 Using a single-day point prevalence study, we obtained an estimate for ICU exit block in 39 Australian and ten New Zealand adult ICUs in 2014. Across all sites, 13% (median value of exit block across the sample hospitals, 8.1%; interquartile range, 0–23%) of patients in the ICU on the study day were awaiting a ward bed. Patients in Australian ICUs were twice as likely to be exit blocked compared with patients in New Zealand ICUs (14.9% v 7.6%). Hospital and ICU size and location (rural v metropolitan) did not influence levels of exit block, but ICUs with > 80% occupancy had higher levels of exit block (Box). Our results were similar to those of the 2007–14 Australian Council on Healthcare Standards clinical indicator report, which found that about 25% of ICU discharges were delayed for more than 6 hours.5 Using an ICU bed for a patient who no longer needs it represents an inefficient use of resources and risks creating delays in admitting other acutely unwell patients. In the emergency department setting, we have seen the 4-hour rule improve hospital access and outcomes by prioritising transfer of emergency department patients to ward beds. Monitoring ICU access and exit block provides a comparable metric for understanding the effects of prohibiting ICU patient flow and for determining how to safely and efficiently allocate limited resources for critically ill patients. Box – Intensive care unit (ICU) bed occupancy and exit block Bed occupancy No. of ICUs* Median percentage of patients experiencing exit block (IQR) 0–50% 6 0 (0–28.6%) 51–80% 20 0 (0–10.8%) 81–100% 21 13.0% (5.5–25%) IQR = interquartile range. * Two sites did not provide bed occupancy rates so were not included in our analysis.

Matthew H Anstey · Kelly Thompson · Ian Seppelt

To the Editor: In Adelaide, which comprises 78% of the population of South Australia, municipal wastewater has been subject to bimonthly analysis since 2009 to measure trends in substance use. Beginning in October 2015, there was a precipitous decrease in the detection of oxycodone residues in wastewater samples (Box). This decrease was counter to the long term trend of increasing amounts of this opioid in previous samples. Prescribing data show a continuing increase in the use of prescription opioid analgesics (POAs), including oxycodone, nationally and in SA, during the period between 1992 and 2011.1 There is a strong relationship between the amount of POAs used in a community and the amount of harm from opioid dependence and overdose.1 The cause of this regional trend change in oxycodone use has not been established. On 1 July 2015, there were some significant changes in the regulation of work injuries in SA which led to a decrease in the number of complex long term claimants, and there was also a similar change in South Australian motor vehicle injury regulation in July 2013. Complex injury claims are strongly correlated with POA use;2 however, the role of these factors is highly speculative and there may be many other factors that contributed to the results. The methods used for the bimonthly wastewater analysis in Adelaide have been published before,3 and another group used this process to report changes in population methamphetamine use in Queensland.4 From October 2015, there was a change in the established temporal trend for oxycodone residues detected in Adelaide wastewater (Box). However, over the same period, there is no such trend change for national Pharmaceutical Benefits Scheme (PBS) and Repatriation PBS data for the number of oxycodone prescriptions dispensed (not total doses),5 or for Adelaide wastewater residues of methadone, which is predominantly dispensed for treatment of severe opioid use disorders via a specific program. A limitation of our investigations was that no regional oxycodone prescription or wastewater data from other jurisdictions were available for comparison. Nonetheless, our findings suggest that wastewater analysis could potentially be used to rapidly monitor changes in substance use on a regional basis. Box – Oxycodone and methadone residue in Adelaide wastewater compared with national data for the total number of oxycodone prescriptions supplied, December 2011 – February 20175 PBS = Pharmaceutical Benefits Scheme. RPBS = Repatriation Pharmaceutical Benefits Scheme.

Philip Crowley · Jason M White · Benjamin J Tscharke · Cobus Gerber

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Christopher P Alderman · Natalie R Soulsby · Sue M Ward

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Alexandra A Bennett · Simon M Holliday · Milton Cohen

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David C Currow · Jane Phillips · Katherine Clark