Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

Meteoroid Fragmentation in the Martian Atmosphere and the Formation of Crater Clusters

The current rate of small impacts on Mars is informed by more than one thousand impact sites formed in the last 20 years, detected in images of the martian surface. More than half of these impacts produced a cluster of small craters formed by fragmentation of the meteoroid in the martian atmosphere. The spatial distributions, number and sizes of craters in these clusters provide valuable constraints on the properties of the impacting meteoroid population as well as the meteoroid fragmentation process. In this paper, we use a recently compiled database of crater cluster observations to calibrate a model of meteoroid fragmentation in Mars' atmosphere and constrain key model parameters, including the lift coefficient and fragment separation velocity, as well as meteoroid property distributions. The model distribution of dynamic meteoroid strength that produces the best match to observations has a minimum strength of 10-90 kPa, a maximum strength of 3-6 MPa and a median strength of 0.2-0.5 MPa. An important feature of the model is that individual fragmentation events are able to produce fragments with a wide range of dynamic strengths as much as 10 times stronger or weaker than the parent fragment. The calibrated model suggests that the rate of small impacts on Mars is 1.5-4 times higher than recent observation-based estimates. It also shows how impactor properties relevant to seismic wave generation, such as the total impact momentum, can be inferred from cluster characteristics.

Dexmedetomidine sedation for a dental extraction in a patient with known difficult airway

Fibrodysplasia ossificans progressiva is an autosomal dominant condition that causes cervical spine fusion and ankylosis of the temporomandibular joint, resulting in anaesthetic challenges. Awake tracheal intubation with flexible bronchoscopy is recommended for general anaesthetics required by patients with this disease. This case report describes the novel approach of using dexmedetomidine sedation in combination with local anaesthesia to allow dental extraction of the fifth and seventh upper left teeth in a patient with fibrodyplasia ossificans progressive, who had a known difficult airway and profound thrombocytopenia. This procedure was not previously tolerated by the patient under local anaesthesia alone. The use of dexmedetomidine was successful in facilitating completion of the procedure with a high degree of patient satisfaction. We discuss the advantages of dexmedetomidine over other sedative agents due to its minimal effects on respiratory drive and airway muscle tone. We highlight the use of dexmedetomidine for complex cases such as this, where tracheal intubation is potentially challenging, but the procedure itself could be managed under sedation and local anaesthesia.

Invasive Tendon Sheath Fibrosarcoma Causing Radial Osteolysis in a Golden Retriever

This case report details a previously undescribed malignancy of the tendon sheath in a golden retriever. This dog originally presented with lameness of the left forelimb, at which point radiographs revealed a monostotic, lytic lesion of the distal radius with overlying soft-tissue swelling. A fine-needle aspirate was performed, and cytology was compatible with a sarcoma, with the primary differential being an osteosarcoma. After amputation, the leg was submitted for histopathology, which revealed inconsistencies with a typical osteosarcoma lesion, including lack of osteoid deposition. Second opinion histopathology showed a fibrosarcoma that appeared to have originated in the tendon sheath of an extensor tendon and then secondarily invaded the radius. At the time of publication, ∼17 mo after amputation, the dog continues to do well without any evidence of recurrent or metastatic disease.

Surgical management of complex ileocolonic Crohn's disease: a survey of IBD colorectal surgeons to assess variability in operative strategy

INTRODUCTION

To explore the reported variability in the surgical management of ileocolonic Crohn' s disease and identify areas of standard practice, we present this study which aims to assess how different colorectal surgeons with a subspecialty interest in inflammatory bowel disease (IBD) surgery may act in different clinical scenarios of ileocolonic Crohn's disease.

METHODS

Anonymous videos demonstrating the small bowel walkthrough and anonymised patients' clinical data, imaging and pathological findings were distributed to the surgeons using an electronic tool. Surgeons answered on operative strategy, bowel resections, management of small bowel mesentery, type of anastomosis and use of stomas.

RESULTS

Eight small bowel walkthrough videos were registered and 12 assessors completed the survey with a questionnaire completion rate of 87.5%. There was 87.7% agreement in the need to perform an ileocolonic resection. However, the agreement for the need to perform associated surgical procedures such as strictureplasties or further bowel resections was only 57.4%. When an anastomosis was fashioned, the side to side configuration was the most commonly used. The preferred management of the mesentery was dissection close to the bowel.

CONCLUSIONS

The decision on the main procedure to be performed had a high agreement amongst the different assessors, but the treatment of multifocal disease was highly controversial, with low agreement on the need for associated procedures to treat internal fistulae and the use of strictureplasties. At the same time, there was significant heterogeneity in the decision on when to anastomose and when to fashion an ileostomy.

AB0298 PREGNANCY IN RHEUMATIC DISEASE: A REGION WIDE SURVEY OF CURRENT PRACTICE AMONGST CLINICIANS IN THE WESSEX MULTI-DISCIPLINARY CONNECTIVE TISSUE DISEASE NETWORK

Background:

Rheumatic diseases frequently affect females of child-bearing age, with implications for foetal and maternal outcomes.

Two-thirds (66%) of the women who died in the 2016-18 MBRRACE report were known to have pre-existing medical problems1. The NHS long-term plan supports creation of Maternal Medicine Networks to facilitate access to specialist care and advice in pregnancy.

Guidelines exist for use of disease modifying anti-rheumatic drugs (DMARDs) during pregnancy but other aspects of pregnancy related care in rheumatic disease remain less well defined. The Wessex wide connective tissue disease (CTD) network provides a multi-disciplinary forum to discuss cases, to obtain approval for high cost drugs, to compare practice in multiple hospitals but does not specifically discuss pregnancy related uncertainties.

Objectives:

To survey variations in clinical practice relating to rheumatic disease in pregnancy

Methods:

Following careful project planning with the tertiary referral centre obstetric lead consultant for maternal medicine, several areas of care were identified which were prone to local and individual variation. An anonymous online survey relating to these specific areas of pregnancy related care was circulated amongst members of the CTD network, including rheumatology consultants, rheumatology practitioners and specialist trainees.

Results:

16 responses were obtained across 7 hospital sites; 56% were from rheumatology consultants. 12/16 (75%) reported routinely offering contraceptive advice when prescribing DMARDs. Only 4/16 (25%) were aware of a specific pre-natal obstetric clinic available in their hospital. There was major variation in planned frequency of clinical review. 10/16 would increase frequency of review during pregnancy if a patient’s disease became active or unstable; 6/16 would aim to review patients approximately 3 monthly; 3/16 would not routinely increase frequency of review during pregnancy. Planned post-natal care was equally varied. 3/16 would routinely prescribe aspirin to all lupus women during pregnancy despite this being recommended for all women with SLE for prevention of pre-eclampsia2. Prescription of low molecular weight heparin was variable, and several responses were at odds with the current RCOG guidance on the subject3. 8/16 (50%) would prescribe corticosteroids judiciously in case of an acute disease flare.

Conclusion:

This survey has revealed significant variation in practice relating to rheumatic disease in pregnancy. Integrated care with colleagues from the regional referral centre for maternal medicine is required, in keeping with the recently published NICE guidance on the subject4. Adopting a hub and spoke model, with local centres working closely alongside a tertiary centre, will help optimise peri-partum care and outcome for patients with long-term rheumatic conditions.

References:

[1]Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK (MBRRACE-UK) Saving Lives, Improving Mothers’ Care Maternal Report (December 2020). Available at https://www.npeu.ox.ac.uk/assets/downloads/mbrrace-uk/reports/maternal-report-2020/MBRRACE-UK_Maternal_Report_Dec_2020_v10.pdf [Accessed 28 January 2021]

[2]National Institute for Health and Care Excellence (2019) Hypertension in pregnancy: diagnosis and management (NICE guideline 133) Available at https://www.nice.org.uk/guidance/ng133 [Accessed 28 January 2021]

[3]Royal College of Obstetricians and Gynaecologists (2015) Reducing the risk of venous thromboembolism during pregnancy and the puerperium (Green-top Guideline Number 37a) Available at https://www.rcog.org.uk/globalassets/documents/guidelines/gtg-37a.pdf [Accessed 5 January 2021]

[4]National Institute for Health and Care Excellence (2019) Intrapartum care for women with existing medical conditions or obstetric complications and their babies (NICE guideline 121) Available at https://www.nice.org.uk/guidance/ng121 [Accessed 5 January 2021]

Disclosure of Interests:

None declared

Bronchoalveolar lavage fluid IMMY Sona Aspergillus lateral-flow assay for the diagnosis of invasive pulmonary aspergillosis: a prospective, real life evaluation

Prompt and reliable diagnosis of invasive pulmonary aspergillosis (IPA) is essential for early initiation of antifungal therapy. We evaluated bronchoalveolar lavage (BAL) fluid IMMY Sona Aspergillus lateral-flow assay (IMMY LFA) in 92 individuals with suspected pulmonary infection. Sensitivity and specificity (vs. host factor but no IPA) of BAL IMMY LFA for diagnosis of IPA in individuals with any European Organisation for Research and Treatment of Cancer-defied "host factor" were 67% and 85%, respectively. Performance appeared better in individuals with renal transplantation (100%, 100%), compared to those with hematological malignancy and/or allogenic stem cell transplantation (70%, 78%). We found BAL IMMY LFA to be a convenient and useful addition to our diagnostic armory for IPA.

LAY ABSTRACT

We evaluated a new test for diagnosing invasive pulmonary aspergillosis from bronchoscopy samples. We tested 92 people and found that it was 67% sensitive and 85% specific (compared to diagnosis according to a set of internationally recognised criteria). We found this test convenient and useful.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

The use of Endo-SPONGE® in rectal anastomotic leaks: a systematic review

BACKGROUND

The aim of this study was to assess the efficacy of an endoluminal vacuum device (Endo-SPONGE^®) in the treatment of rectal anastomotic leaks.

METHODS

All studies looking at endoluminal vacuum therapy with Endo-SPONGE^® in the treatment of rectal anastomotic leaks were included. A comprehensive search was conducted as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Primary outcome was defined as the rate of total anastomotic salvage, with secondary outcomes including rate of ileostomy closure, additional transrectal closures and functional outcomes RESULTS: Sixteen studies met the inclusion criteria. There was a significant publication bias (z = 3.53, p = 0.0004). Two hundred sixty-six patients were identified. The median treatment failure rate was 11.8% (range 0-44%), with random effects model of 0.17 (95% CI 0.11-0.22). There was improvement with early therapy start (OR 3.48) and negative correlation with neoadjuvant radiotherapy (OR 0.56). Fifty-one percent of all diverting stomas were closed at the end of treatment period and 12.8% of patients required an additional trans-rectal closure of the abscess cavity.

CONCLUSIONS

Endo-SPONGE^® seems to be a useful method of rectal anastomotic leak treatment in selected group of patients; however, the quality of available data is poor and it is impossible to draw a final conclusion. There is unexpected high rate of permanent ileostomy. There is a need for further assessment of this therapy with well-designed randomised or cohort studies.

Video-laparoscopic assessment of the small bowel in Crohn's disease: a comparative study to evaluate surgeons' inter-observer variability

BACKGROUND

Assessment of the entire small bowel is advocated during Crohn's disease (CD) surgery, as intraoperative detection of new lesions may lead to change in the planned procedure. The aim of this study was to evaluate the inter-observer variability in the assessment of extent and severity of CD at the small bowel laparoscopic "walkthrough".

METHODS

A survey on laparoscopic assessment of the small bowel in patients with CD, including items adapted from the MREnterography or ultrasound in Crohn's disease (METRIC) study and from the classification of severity of mesenteric disease was developed by an invited committee of colorectal surgeons. Anonymous laparoscopic videos demonstrating the small bowel "walkthrough" in ileocolonic resection for primary and recurrent CD were distributed to the committee members together with the anonymous survey. The primary outcome was the rate of inter-observer variability on assessment of strictures, dilatations, complications and severity of mesenteric inflammation.

RESULTS

12 assessors completed the survey on 8 small bowel walkthrough videos. The evaluation of the small bowel thickening and of the mesenteric fat wrapping were the most reliable assessments with an overall agreement of 87.1% (k = 0.31; 95% CI - 0.22, 0.84) and 82.7% (k = 0.35; 95% CI - 0.04, 0.73), respectively. The presence of strictures and pre-stenotic dilatation demonstrated agreement of 75.2% (k = 0.06: 95% CI - 0.33, 0.45) and 71.2% (k = 0.33; 95% CI 0.15, 0.51), respectively. Evaluation of fistulae had an overall agreement of 75.3%, while there was a significant variation in the evaluation of mild, moderate and severe mesenteric disease with overall agreement ranging from 33.3 to 100%.

CONCLUSION

Laparoscopic assessment of the small bowel thickening and of the presence of mesenteric fat wrapping is reliable for the intraoperative evaluation of CD with high inter-rater agreement. There is significant heterogeneity in the assessment of the severity of the mesenteric disease involvement.

Paleo-Rock-Hosted Life on Earth and the Search on Mars: A Review and Strategy for Exploration

Here we review published studies on the abundance and diversity of terrestrial rock-hosted life, the environments it inhabits, the evolution of its metabolisms, and its fossil biomarkers to provide guidance in the search for life on Mars. Key findings are (1) much terrestrial deep subsurface metabolic activity relies on abiotic energy-yielding fluxes and in situ abiotic and biotic recycling of metabolic waste products rather than on buried organic products of photosynthesis; (2) subsurface microbial cell concentrations are highest at interfaces with pronounced chemical redox gradients or permeability variations and do not correlate with bulk host rock organic carbon; (3) metabolic pathways for chemolithoautotrophic microorganisms evolved earlier in Earth's history than those of surface-dwelling phototrophic microorganisms; (4) the emergence of the former occurred at a time when Mars was habitable, whereas the emergence of the latter occurred at a time when the martian surface was not continually habitable; (5) the terrestrial rock record has biomarkers of subsurface life at least back hundreds of millions of years and likely to 3.45 Ga with several examples of excellent preservation in rock types that are quite different from those preserving the photosphere-supported biosphere. These findings suggest that rock-hosted life would have been more likely to emerge and be preserved in a martian context. Consequently, we outline a Mars exploration strategy that targets subsurface life and scales spatially, focusing initially on identifying rocks with evidence for groundwater flow and low-temperature mineralization, then identifying redox and permeability interfaces preserved within rock outcrops, and finally focusing on finding minerals associated with redox reactions and associated traces of carbon and diagnostic chemical and isotopic biosignatures. Using this strategy on Earth yields ancient rock-hosted life, preserved in the fossil record and confirmable via a suite of morphologic, organic, mineralogical, and isotopic fingerprints at micrometer scale. We expect an emphasis on rock-hosted life and this scale-dependent strategy to be crucial in the search for life on Mars.

Macro-to-nanoscale investigation of wall-plate joints in the acorn barnacle Semibalanus balanoides: correlative imaging, biological form and function, and bioinspiration

Correlative imaging combines information from multiple modalities (physical-chemical-mechanical properties) at various length scales (centimetre to nanometre) to understand the complex biological materials across dimensions (2D-3D). Here, we have used numerous coupled systems: X-ray microscopy (XRM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), optical light microscopy (LM) and focused ion beam (FIB-SEM) microscopy to ascertain the microstructural and crystallographic properties of the wall-plate joints in the barnacle Semibalanus balanoides. The exoskeleton is composed of six interlocking wall plates, and the interlocks between neighbouring plates (alae) allow barnacles to expand and grow while remaining sealed and structurally strong. Our results indicate that the ala contain functionally graded orientations and microstructures in their crystallography, which has implications for naturally functioning microstructures, potential natural strengthening and preferred oriented biomineralization. Elongated grains at the outer edge of the ala are oriented perpendicularly to the contact surface, and the c-axis rotates with the radius of the ala. Additionally, we identify for the first time three-dimensional nanoscale ala pore networks revealing that the pores are only visible at the tip of the ala and that pore thickening occurs on the inside (soft bodied) edge of the plates. The pore networks appear to have the same orientation as the oriented crystallography, and we deduce that the pore networks are probably organic channels and pockets, which are involved with the biomineralization process. Understanding these multiscale features contributes towards an understanding of the structural architecture in barnacles, but also their consideration for bioinspiration of human-made materials. The work demonstrates that correlative methods spanning different length scales, dimensions and modes enable the extension of the structure-property relationships in materials to form and function of organisms.

Quality of life in patients with upper GI malignancies managed by a strategy of chemoradiotherapy alone versus surgery

BACKGROUND AND OBJECTIVES

Neoadjuvant chemoradiotherapy (nCRT) induces a pathological complete response (pCR) in 25-85% of oesophago-gastric cancer. As surgery entails morbidity and mortality risks and quality of life (QL) impairment, its avoidance in patients without residual disease is desirable. This study aimed to compare quality of life of patients with a cCR who chose surveillance with those who chose surgery.

METHODS

Four groups of patients were studied. Group 1(n = 31) were controls; Group 2 (n = 26) had chemoradiotherapy only; Group 3 (n = 31) had oesophagectomy after nCRT; Group 4 (n = 26) had gastrectomy alone. A 33-point novel questionnaire was administered at two 3 month time points. Participants were also interviewed with a validated questionnaire.

RESULTS

Mean(±sd) quality of life scores in cCR patients offered surveillance (28.9 ± 4.5) were superior to patients undergoing oesophagectomy (32.3 ± 58. p=0.042) or gastrectomy (33.19 ± 5.9, p=0.004). This result was replicated in the validated questionnaire (p=0.017). There was a trend towards increased reflux-related respiratory symptoms in the oesophagectomy group (7.3 ± 2.2 vs 6.5 ± 1.9; p=0.396) and towards early dumping (8.2 ± 1.4 vs 7.1 ± 1.; p=0.239) and vagotomy-related symptoms (1.82 ± 0.9 vs 1.4 ± 0.6; p=0.438) in the gastrectomy group.

CONCLUSIONS

Avoidance of surgery in cCR patients is rewarded with a superior quality of life to those undergoing surgery.

Chemotherapeutic Response and Survival for Patients With an Anal Squamous Cell Carcinoma and Low Hemoglobin Levels

Purpose

Anemia is associated with poor treatment results for a variety of cancers. The effect of low hemoglobin levels on long-term outcomes after the treatment of patients with an anal squamous cell carcinoma (SCC) remains unclear. For that reason, this study aimed to investigate the effect of anemia on treatment outcomes following chemoradiation for an anal SCC.

Methods

This was a retrospective study of all patients who underwent curative treatment for an anal SCC between 2009 and 2015 at 2 trusts in the United Kingdom. Data were collated from prospectively collected cancer databases and were cross-checked with operating-room records and records in the hospitals’ patient management systems.

Results

We identified 103 patients with a median age of 63 years (range, 36–84 years). The median overall survival was 39 months (range, 9–90 months), and the disease-free survival was 36 months (range, 2–90 months). During the follow-up period, 16.5% patients died and 13.6% patients developed recurrence. Twenty-two people were anemic prior to treatment, with a female preponderance (20 of 22). No differences in disease-free survival (P = 0.74) and overall survival (P = 0.12) were noted between patients with anemia and those with normal hemoglobin levels. On regression the analysis, the combination of anemia, the presence of a defunctioning colostomy, lymph-node involvement and higher tumor stage correlated with poor overall survival.

Conclusion

In this study, anemia did not influence disease-free survival or overall survival. We suggest that the interaction between anemia and survival is more complex than previously demonstrated and potentially reliant on other coexisting factors.

IntAct: intra-operative fluorescence angiography to prevent anastomotic leak in rectal cancer surgery: a randomized controlled trial

AIM

Anastomotic leak (AL) is a major complication of rectal cancer surgery. Despite advances in surgical practice, the rates of AL have remained static, at around 10-15%. The aetiology of AL is multifactorial, but one of the most crucial risk factors, which is mostly under the control of the surgeon, is blood supply to the anastomosis. The MRC/NIHR IntAct study will determine whether assessment of anastomotic perfusion using a fluorescent dye (indocyanine green) and near-infrared laparoscopy can minimize the rate of AL leak compared with conventional white-light laparoscopy. Two mechanistic sub-studies will explore the role of the rectal microbiome in AL and the predictive value of CT angiography/perfusion studies.

METHOD

IntAct is a prospective, unblinded, parallel-group, multicentre, European, randomized controlled trial comparing surgery with intra-operative fluorescence angiography (IFA) against standard care (surgery with no IFA). The primary end-point is rate of clinical AL at 90 days following surgery. Secondary end-points include all AL (clinical and radiological), change in planned anastomosis, complications and re-interventions, use of stoma, cost-effectiveness of the intervention and quality of life. Patients should have a diagnosis of adenocarcinoma of the rectum suitable for potentially curative surgery by anterior resection. Over 3 years, 880 patients from 25 European centres will be recruited and followed up for 90 days.

DISCUSSION

IntAct will rigorously evaluate the use of IFA in rectal cancer surgery and explore the role of the microbiome in AL and the predictive value of preoperative CT angiography/perfusion scanning.

The effects of multiple anaesthetic episodes on equine recovery quality

BACKGROUND

Although rare, 70% of equine fatalities during recovery from general anaesthesia (GA) are due to catastrophic fractures from poor recovery quality.

OBJECTIVE

To determine the effect of repeated GA recovery on GA recovery quality.

STUDY DESIGN

Experimental blinded trial.

METHODS

Eight adult horses underwent six GA events on sevoflurane for distal limb MRI examination over a 14-week period. Prior to GA recovery, xylazine was administered. Randomly ordered video-recorded GA recoveries were scored by three blinded board certified veterinary anaesthesiologists, unaware of patient identity or GA event number, for nine parameters using a 100 mm visual analogue scale (VAS) where 0 = worst and 100 = best. The number of attempts to stand, duration of lateral and sternal recumbency, total recovery duration and physiologic parameters during each GA event were recorded. Repeated measures ANOVA were used to detect differences. Agreement between observer VAS scores was determined via inter-rater reliability using an intraclass correlation.

RESULTS

With GA recovery experience, VAS scores for balance and coordination, knuckling, and overall quality of recovery were improved and the duration of lateral recumbency was increased. There were no differences in total recovery duration, number of attempts to stand, physiologic parameters other than heart rate during GA, or VAS scores for activity in lateral recumbency, move to sternal, move to stand, or strength.

MAIN LIMITATIONS

Each GA event was relatively short and there was no surgical stimulation. The same results may not occur if there was surgical stimulation and pain during each GA event.

CONCLUSION

Recovery from GA improves with multiple anaesthetic episodes in horses. Clinicians can advise clients that horses are likely to have better GA recovery on repeated GA recovery due to improved balance and coordination and reduced knuckling. Additionally, there is no change in anaesthetic morbidity with six repeated GA events over a 14-week period.