Equipoise: an important ethical consideration when contemplating participation in a randomised controlled trial of hyperbaric oxygen treatment in necrotising soft tissue infections

A proposal for a large, multi-centre, randomised controlled trial investigating the role of hyperbaric oxygen treatment (HBOT) in necrotising soft tissue infections (NSTI) has led to much discussion locally and internationally about whether participation is ethical for a centre where stakeholders already consider HBOT standard practice. This article systematically addresses the concept of clinical equipoise specific to the role of HBOT in NSTI, and presents a series of considerations to be taken into account by key stakeholders at potential participating sites.

Reported outcome measures in necrotising soft tissue infections: a systematic review

Introduction

There are inconsistencies in outcome reporting for patients with necrotising soft tissue infections (NSTI). The aim of this study was to evaluate reported outcome measures in NSTI literature that could inform a core outcome set (COS) such as could be used in a study of hyperbaric oxygen in this indication.

Methods

A systematic review of all NSTI literature identified from Cochrane, Ovid MEDLINE and Scopus databases as well as grey literature sources OpenGrey and the New York Academy of Medicine databases which met inclusion criteria and were published between 2010 and 2020 was performed. Studies were included if they reported on > 5 cases and presented clinical endpoints, patient related outcomes, or resource utilisation in NSTI patients. Studies did not have to include intervention. Two independent researchers then extracted reported outcome measures. Similar outcomes were grouped and classified into domains to produce a structured inventory. An attempt was made to identify trends in outcome measures over time and by study design.

Results

Three hundred and seventy-five studies were identified and included a total of 311 outcome measures. Forty eight percent (150/311) of outcome measures were reported by two or more studies. The four most frequently reported outcome measures were mortality without time specified, length of hospital stay, amputation performed, and number of debridements, reported in 298 (79.5%), 260 (69.3%), 156 (41.6%) and 151 (40.3%) studies respectively. Mortality outcomes were reported in 23 different ways. Randomised controlled trials (RCTs) were more likely to report 28-day mortality or 90-day mortality. The second most frequent amputation related outcome was level of amputation, reported in 7.5% (28/375) of studies. The most commonly reported patient-centred outcome was the SF-36 which was reported in 1.6% (6/375) of all studies and in 2/10 RCTs.

Conclusions

There was wide variance in outcome measures in NSTI studies, further highlighting the need for a COS.

Performance of the BBraun perfusor space syringe driver under hyperbaric conditions

BACKGROUND

The BBraun Perfusor Space™ syringe driver is already in use by ambulance services and retrieval teams but has not previously been assessed for hyperbaric chamber use.

METHODS

Pump flow accuracy was tested at rates between 1 and 40 ml· h⁻¹ using three different brands of 50 ml syringe. Function of the occlusion alarms was assessed using the same syringes. The hyperbaric profile involved pressurisation to 284 kPa at 30 kPa· min⁻¹, 30 min at 284 kPa and decompression at 30 kPa· min⁻¹. Output was recorded from differences in weight of collection containers. A single device was tested.

RESULTS

Performance was highly dependent on the syringe type used, with two of the three 50 ml syringes used demonstrating 'stiction' at both low and high occlusion pressure alarm settings, most marked during pressurisation. On decompression from 284 kPa all syringes alarmed at significantly lower pressures. Because of the stiction problems only the flow measurements for the BBrown Omni¬ x 50 ml syringes are reported. At a pressure of 284 kPa, the difference between programmed and delivered rates was within the manufacturer's specification of 10%: at 40 ml· h⁻¹ (median variation 1.25%, IQR 0.5-1.7%), 10 ml· h⁻¹ (8.6%, IQR 8-9.2%), 5 ml· h⁻¹ (-8.8%, IQR - 1.6-8.8%) and 1 ml· h⁻¹ (-4%, IQR 4-12%). Pressurisation was associated with significantly lower flow rates whilst decompression was associated with significantly increased rates. Limited testing at 405 kPa was also within the manufacturer's specifications.

CONCLUSION

A BBraun Infusor Space syringe driver performed within acceptable performance criteria but is highly dependent on syringe type and flow rates. The potential for the device to under deliver on pressurisation and over deliver on depressurisation, however, suggests vigilance and appropriate rate adjustments may be necessary during these phases.

Hyperbaric oxygen in the treatment of calciphylaxis: A case series and literature review

AIMS

Calcific uraemic arteriolopathy (CUA) or calciphylaxis is most commonly seen in end-stage renal disease and is associated with significant morbidity and mortality. The aim of this study was to determine whether hyperbaric oxygen therapy (HBOT) is effective in healing calciphylaxis lesions and to determine if there are any patient factors that can predict wound healing and patient survival.

METHODS

We identified by retrospective review all cases of CUA referred to our institution for treatment with HBOT. We documented the clinical and biochemical parameters of this patient population, the size and distribution of the lesions as well as wound outcomes and patient survival following treatment.

RESULTS

A total 46 patients were identified with CUA associated with renal failure. Of the 46 patients, only 34 received a full course of HBOT. The balance was deemed unsuitable for treatment or was unable to tolerate treatment and was palliated. Of the 34 patients that received a full course of HBOT, 58% showed improvement in their wound scores, with more than half of these patients having complete healing of their wounds. The balance did not benefit from the therapy and had a very poor prognosis. Those that benefited from HBOT survived on average for more than 3 years. The only factor significantly associated with improved wound healing and survival was diabetes.

CONCLUSION

This retrospective analysis suggests a role for HBOT in the treatment of CUA with more than half of the treated patients benefiting and surviving for an average of more than 3 years.

Back to the future: community involvement in the Healthy Start Program

This article discusses how community involvement is incorporated into Healthy Start, a major initiative to reduce infant mortality in selected communities with disproportionately high levels of infant mortality. Based on site visits to each of the fifteen original Healthy Start project areas, we discovered that two main community involvement strategies were used: a service consortium model and a community empowerment model. In the service consortium model, the community is involved primarily through a consortium of local providers, other professionals, and some governmental representatives who help to plan services. The community empowerment model involves the community by engaging neighborhood-based groups, contracting with community-based organizations, employing community residents as lay workers in the Healthy Start program, and creating other economic development initiatives. Important lessons drawn from this study are that the purpose and commitment to community involvement is not always clear; that it is difficult to involve community residents; that efforts to involve the community are extremely labor intensive; that given monetary incentives, it is easier to involve community providers than residents; that community involvement may conflict with efficient program operations; that increased community involvement may create program goals that differ from the program's original goals; and that community involvement may slow program development.

Household participation in the Food Stamp and WIC programs increases the nutrient intakes of preschool children

We examined the effects of household participation in the Food Stamp and WIC Nutrition Programs on the nutrient intakes of preschoolers using data from the 1989-1991 Continuing Survey of Food Intake by Individuals. Nonbreastfeeding children, 1-4 y of age, with 3 d of dietary data and whose households had incomes < 130% of the poverty level were included in the study sample (n = 499). Nutrient adequacy ratios for each of 15 nutrients were the dependent variables in multiple regression models that controlled for the following: age, sex and ethnicity of the individual; income, size and location of the household; schooling of the household head; home ownership; school lunch and breakfast participation; and season in which the interview was conducted. WIC benefits positively influenced (P < 0. 05) the intakes of 10 nutrients. For iron and zinc, the average increase due to WIC represented 16.6 and 10.6%, respectively, of the preschooler recommended dietary allowance (RDA) for these nutrients. The same analyses of the Food Stamp Program revealed increases in five nutrients. For iron and zinc, the average increase due to Food Stamps represented 12.3 and 9.2%, respectively, of the preschooler RDA. The effects of the WIC Program on the intakes of iron and zinc were greater than that of cash income, and neither program affected the intakes of fat, saturated fat or cholesterol.

Medicaid costs and birth outcomes: the effects of prenatal WIC participation and the use of prenatal care

This study examines the effects of prenatal WIC participation and the use of prenatal care on Medicaid costs and birth outcomes in five states--Florida, Minnesota, North Carolina, South Carolina, and Texas. The study period is 1987 for Florida, Minnesota, North Carolina, and South Carolina and January-June 1988 for Texas. Prenatal WIC participation was associated with substantial savings in Medicaid costs during the first 60 days after birth, with estimates ranging from $277 in Minnesota to $598 in North Carolina. For every dollar spent on the prenatal WIC program, the associated savings in Medicaid costs during the first 60 days ranged from $1.77 to $3.13 across the five states. Receiving inadequate levels of prenatal care was associated with increases in Medicaid costs ranging from $210 in Florida to $1,184 in Minnesota. Prenatal WIC participation was associated with higher newborn birthweight, while receiving inadequate prenatal care was associated with lower birthweight.

An analysis of variations in U.S. fertility and female labor force participation trends

This study is based on time series data from 1947-1977 on fertility and female labor force participation, and examines (a) the effects of male relative income and female earnings on the level and timing of fertility and female labor force participation, and (b) the relative importance of variations in relative income and female wage rates in explaining the fluctuations in both fertility and female labor supply. The results suggest that relative income exerts a significant positive effect on fertility and a negative effect on female work effort. However, female wage rates appear to be the dominant factor in explaining variations in fertility and female labor force participation over the past two decades, with increases in female earnings leading to both depressed fertility and increased labor force participation of women.