Is there a role for botulinum toxin A in the emergency setting for delayed abdominal wall closure in the management of the open abdomen? A systematic review.

INTRODUCTION: Emergency laparotomy for either trauma or non-trauma indications is common and management is varied. Use of the open abdomen technique allowing for planned re-look is an option; however, performing delayed definitive fascial closure (DFC) following this can be a challenge. The use of botulinum toxin-A (BTX) infiltration into the lateral abdominal wall has been well documented within the elective setting; its use within the emergency setting is undecided. This systematic review assesses the efficacy and safety of BTX injection into the lateral abdominal wall muscles in the emergency setting. The primary outcome is DFC rate. METHODS: Systematic review was performed according to the PROSPERO registered protocol (CRD42020205130). Papers were dual screened for eligibility, and included if they met pre-stated criteria where the primary outcome was DFC. Articles reporting fewer than five cases were excluded. Bias was assessed using the Cochrane Risk of Bias and Joanna Brigg's appraisal tools. FINDINGS: Fourteen studies were screened for eligibility, twelve full texts were reviewed and two studies were included. Both studies showed evidence of bias due to confounding factors and lack of reporting. Both studies suggested significantly higher rates of DFC than reported in the literature against standard technique (90.7% vs 66%); however, these data are difficult to interpret due to strict study inclusion criteria or lack of a control population. CONCLUSION: The use of BTX is deemed safe and its effects in the emergency situation may have great potential. Unfortunately, to date, there is insufficient evidence to facilitate opinion.

Bespoke regional blocks for axillary sentinel node biopsy.

INTRODUCTION: Axillary sentinel node biopsy for melanoma is routinely performed under general anaesthesia. Emerging evidence has shown general anaesthetics are associated with increased mortality in the context of the COVID-19 pandemic. In the interest of patient safety, we have designed a series of bespoke axillary regional blocks enabling surgeons to remove nodes up to and including level III without the need for a general anaesthetic. The aim of this study was to assess the feasibility of performing axillary sentinel node biopsy under such blocks. METHODS: Approval was granted by the Joint Study Review Committee on behalf of the Research and Ethics Department. Ten consecutive patients having axillary sentinel node biopsy for melanoma were included in this prospective study. Patients completed a Quality of Recovery-15 (QoR15) questionnaire preoperatively and 24 h postoperatively. DISCUSSION: One patient had a positive sentinel node, the remining were negative. A significant reduction in time spent in hospital post-operatively (p = 0.0008) was observed. QoR15 patient reported outcome measures demonstrated high levels of satisfaction evidenced by lack of statistical difference between pre and post-operative scores (p = 0.0118). 80% of patients were happy to have a regional block and 90% were happy to attend hospital during the pandemic. CONCLUSION: ASNB under regional block is safe, negates risks associated with performing GAs during the COVID-19 pandemic and facilitates quicker theatre turnover and discharge from hospital. Collaboration between anaesthetic and surgical teams has enabled this change in practice. There is a learning curve with both patient selection, education and development of technique.

The effect of needle dimensions and infusion rates on injection pressures in regional anaesthesia needles: a bench-top study.

Animal studies have shown that injection pressures > 75 kPa indicate probable intrafascicular needle tip position. This study describes the flow/pressure characteristics of seven common needle systems. A syringe pump delivered flow rates of 5, 6.67, 10, 13.3, 15 and 20 ml.min(-1) through these needle systems, while keeping the needle tips open to atmosphere. A pressure transducer connected between the syringe and needle provided a real-time graphical display for analysis. Mean plateau pressures increased linearly with flow and with decreasing needle diameter (2.7-92 kPa). Flow rates > 17 ml.min(-1) and needle sizes 22 G and smaller produced mean plateau pressures > 75 kPa. Pressure monitors upstream from the needle may produce false-positive alarms at high flow rates due to needle resistance, and unreliable readings due to non-laminar flow. We recommend injection rates ≤ 15 ml.min(-1) (0.25 ml.s(-1) ) to reduce the effect of factors upstream from the needle tip as a cause of high pressure readings.