Surgical trainee experiences from 2013 to 2023 within the United Kingdom as reported by the General Medical Council National Training Survey

INTRODUCTION

The General Medical Council (GMC) issues annual surveys to all doctors within the United Kingdom (UK) in a formal postgraduate training scheme. This facilitates the monitoring of experiences for quality assurance purposes. Low job satisfaction has been associated with heightened levels of burnout and staff turnover, alongside deteriorating clinical care and productivity levels.

METHODS

We gathered and extracted data from the publicly available online GMC reporting tool. Data ranged from 2013 to 2023 and spanned 12 postgraduate surgical training programmes across all 18 indicators available. In total, 198 individual metrics were recorded, in addition to burnout. We conducted trend analysis and yearly average mean scores for individual metrics, burnout and geographical differences for 141 individual training programmes within the 16 training regions.

RESULTS

Of the 198 metrics analysed, 83 (42 ​%) were found to have statistically significant negative trends (P ​< ​0.05), in comparison to 24 (12 ​%) with positive trends. 5 specialities had over 50 ​% of metrics showing a significant negative trend. Overall satisfaction was negative in all 12 programmes, with eight reaching significance (P ​< ​0.05). Of 141 individual training programmes, 29 ​% showed a significantly negative trend in overall satisfaction, with 1 ​% demonstrating a significant positive trend (P ​< ​0.05).

CONCLUSION

Our study is the first to explore long-term trends in trainee reported surgical training experiences within the UK. Our data have revealed widespread worsening trainee reported experiences and dissatisfaction across multiple specialities and geographical regions, especially in key areas of overall satisfaction, self-development, and clinical supervision.

Incidence and trends in workplace violence within emergency departments in the United Kingdom 2017-2022: an observational time series analysis

Background

Workplace violence (WPV) is a notable issue facing healthcare services and workers globally. WPV impacts upon the well-being of staff and can put healthcare provision at risk with detrimental effects on patient care. This study aims to investigate and quantify, at national and regional levels, the incidence and trends of WPV within emergency departments (EDs).

Methods

We requested data relating to WPV from all 152 trusts with an ED in the United Kingdom from January 2017-March 2022. We applied interrupted time series and trend analysis to check for significant differences in WPV across the COVID-19 pandemic.

Results

We conducted time series analysis on 58 million attendances and detected statistically significant increases in WPV in March 2020-5.06/100,000 attendances (95% CI 1.59/100,000-8.53/100,000 p < 0.01) and May 2020-20.63/100,000 attendances (95% CI 9.39-31.87 p < 0.01). Rises in incidents of 0.37/100,000 attendances per month (95% CI 0.21-0.53 p < 0.0001) were found January 2017-March 2020. We analyzed 96 million attendances for yearly trends, which revealed statistically significant increasing trends of WPV in London and North-West England (p < 0.05), and physical WPV in the North West England (p < 0.05).

Conclusion

There have been dramatic increases in incidents of WPV in United Kingdom EDs over the last 5 years with concerning rises during the COVID-19 period. Our findings highlight the potential to further demoralize a workforce already under significant strain, resulting in increased absences for physical or mental health and an exodus of staff. Therefore, trusts should ensure there are robust systems in place to protect and safeguard staff.

Physical activity intensity profiles associated with cardiometabolic risk in middle-aged to older men and women

Accelerometers provide detailed data about physical activity (PA) across the full intensity spectrum. However, when examining associations with health, results are often aggregated to only a few summary measures [e.g. time spent "sedentary" or "moderate-to-vigorous" intensity PA]. Using multivariate pattern analysis, which can handle collinear exposure variables, we examined associations between the full PA intensity spectrum and cardiometabolic risk (CMR) in a population-based sample of middle-aged to older adults. Participants (n = 3660; mean ± SD age = 69 ± 8y and BMI = 26.7 ± 4.2 kg/m²; 55% female) from the EPIC-Norfolk study (UK) with valid accelerometry (ActiGraph-GT1M) data were included. We used multivariate pattern analysis with partial least squares regression to examine cross-sectional multivariate associations (r) across the full PA intensity spectrum [minutes/day at 0-5000 counts-per-minute (cpm); 5 s epoch] with a continuous CMR score (reflecting waist, blood pressure, lipid, and glucose metabolism). Models were sex-stratified and adjusted for potential confounders. There was a positive (detrimental) association between PA and CMR at 0-12 cpm (maximally-adjusted r = 0.08 (95%CI 0.06-0.10). PA was negatively (favourably) associated with CMR at all intensities above 13 cpm ranging between r = -0.09 (0.07-0.12) at 800-999 cpm and r = -0.14 (0.11-0.16) at 75-99 and 4000-4999 cpm. The strongest favourable associations were from 50 to 800 cpm (r = 0.10-0.12) in men, but from ≥2500 cpm (r = 0.18-0.20) in women; with higher proportions of model explained variance for women (R² = 7.4% vs. 2.3%). Most of the PA intensity spectrum was beneficially associated with CMR in middle-aged to older adults, even at intensities lower than what has traditionally been considered "sedentary" or "light-intensity" activity. This supports encouragement of PA at almost any intensity in this age-group.

Joint associations between objectively measured physical activity volume and intensity with body fatness: the Fenland study

BACKGROUND/OBJECTIVES

Physical activity energy expenditure (PAEE) represents the total volume of all physical activity. This can be accumulated as different underlying intensity profiles. Although volume and intensity have been studied in isolation, less is known about their joint association with health. We examined this association with body fatness in a population-based sample of middle-aged British adults.

METHODS

In total, 6148 women and 5320 men from the Fenland study with objectively measured physical activity from individually calibrated combined heart rate and movement sensing and DXA-derived body fat percentage (BF%) were included in the analyses. We used linear and compositional isocaloric substitution analysis to examine associations of PAEE and its intensity composition with body fatness. Sex-stratified models were adjusted for socio-economic and dietary covariates.

RESULTS

PAEE was inversely associated with body fatness in women (beta = -0.16 (95% CI: -0.17; -0.15) BF% per kJ day-1 kg-1) and men (beta = -0.09 (95% CI: -0.10; -0.08) BF% per kJ day-1 kg-1). Intensity composition was significantly associated with body fatness, beyond that of PAEE; the reallocation of energy to vigorous physical activity (>6 METs) from other intensities was associated with less body fatness, whereas light activity (1.5-3 METs) was positively associated. However, light activity was the main driver of overall PAEE volume, and the relative importance of intensity was marginal compared to that of volume; the difference between PAEE in tertile 1 and 2 in women was associated with 3 percentage-point lower BF%. Higher vigorous physical activity in the same group to the maximum observed value was associated with 1 percentage-point lower BF%.

CONCLUSIONS

In this large, population-based cohort study with objective measures, PAEE was inversely associated with body fatness. Beyond the PAEE association, greater levels of intense activity were also associated with lower body fatness. This contribution was marginal relative to PAEE. These findings support current guidelines for physical activity which emphasise that any movement is beneficial, rather than specific activity intensity or duration targets.

146 Ligamentization and Remnant Integration: Implications for Scapholunate Reconstruction

Introduction

Scapholunate interosseous ligament (SLIL) injuries are common but remain a therapeutic challenge. Current treatment modalities prioritize restoration of normal anatomy with reconstruction where appropriate. To date, no reconstructive technique has been described that discusses the potential benefit of the preservation of the scapholunate ligament remnant. Little is known about the ‘ligamentization’ of grafts within the wrist. However, a growing body of knee literature suggests that remnant sparing may confer some benefit. In the absence of wrist specific studies, this literature must guide areas for potential augmentation of current surgical practices.

Method

We conducted a systematic review of the literature using Pubmed, Embase and Medline. Keywords were ‘Ligament’ AND ‘Reconstruction’ AND ‘Remnant’. We identified 366 original studies for title and abstract review. A total of 5 studies were included in the final analysis.

Results

In 5 animal studies, remnant stump integration resulted in enhanced ligamentization of grafted tissue as measured by vascularity, biomechanics, and proprioception.

Conclusions

Our review demonstrates a trend towards enhanced early ligamentization in grafts that incorporate the remnant stump. Remnant preservation is not currently performed in SLIL reconstruction and may provide an avenue for enhanced therapies. As such, it is a promising area for further, wrist specific, research.

Wearable-device-measured physical activity and future health risk

Use of wearable devices that monitor physical activity is projected to increase more than fivefold per half-decade1. We investigated how device-based physical activity energy expenditure (PAEE) and different intensity profiles were associated with all-cause mortality. We used a network harmonization approach to map dominant-wrist acceleration to PAEE in 96,476 UK Biobank participants (mean age 62 years, 56% female). We also calculated the fraction of PAEE accumulated from moderate-to-vigorous-intensity physical activity (MVPA). Over the median 3.1-year follow-up period (302,526 person-years), 732 deaths were recorded. Higher PAEE was associated with a lower hazard of all-cause mortality for a constant fraction of MVPA (for example, 21% (95% confidence interval 4-35%) lower hazard for 20 versus 15 kJ kg-1 d-1 PAEE with 10% from MVPA). Similarly, a higher MVPA fraction was associated with a lower hazard when PAEE remained constant (for example, 30% (8-47%) lower hazard when 20% versus 10% of a fixed 15 kJ kg-1 d-1 PAEE volume was from MVPA). Our results show that higher volumes of PAEE are associated with reduced mortality rates, and achieving the same volume through higher-intensity activity is associated with greater reductions than through lower-intensity activity. The linkage of device-measured activity to energy expenditure creates a framework for using wearables for personalized prevention.

Descriptive epidemiology of energy expenditure in the UK: findings from the National Diet and Nutrition Survey 2008-15

Background

Little is known about population levels of energy expenditure, as national surveillance systems typically employ only crude measures. The National Diet and Nutrition Survey (NDNS) in the UK measured energy expenditure in a 10% subsample by gold-standard doubly labelled water (DLW).

Methods

DLW-subsample participants from the NDNS (383 males, 387 females) aged 4–91 years were recruited between 2008 and 2015 (rolling programme). Height and weight were measured and body-fat percentage estimated by deuterium dilution.

Results

Absolute total energy expenditure (TEE) increased steadily throughout childhood, ranging from 6.2 and 7.2 MJ/day in 4- to 7-year-olds to 9.7 and 11.7 MJ/day for 14- to 16-year-old girls and boys, respectively. TEE peaked in 17- to 27-year-old women (10.7 MJ/day) and 28- to 43-year-old men (14.4 MJ/day), before decreasing gradually in old age. Physical-activity energy expenditure (PAEE) declined steadily with age from childhood (87 kJ/day/kg in 4- to 7-year-olds) through to old age (38 kJ/day/kg in 71- to 91-year-olds). No differences were observed by time, region and macronutrient composition. Body-fat percentage was strongly inversely associated with PAEE throughout life, irrespective of expressing PAEE relative to body mass or fat-free mass. Compared with females with <30% body fat, females with >40% recorded 29 kJ/day/kg body mass and 18 kJ/day/kg fat-free mass less PAEE in analyses adjusted for age, geographical region and time of assessment. Similarly, compared with males with <25% body fat, males with >35% recorded 26 kJ/day/kg body mass and 10 kJ/day/kg fat-free mass less PAEE.

Conclusions

This first nationally representative study reports levels of human-energy expenditure as measured by gold-standard methodology; values may serve as a reference for other population studies. Age, sex and body composition are the main determinants of energy expenditure.

Key Messages

This is the first nationally representative study of human energy expenditure, covering the UK in the period 2008-2015.

Total energy expenditure (MJ/day) increases steadily with age throughout childhood and adolescence, peaks in the 3^rd decade of life in women and 4^th decade of life in men, before decreasing gradually in old age.

Physical activity energy expenditure (kJ/day/kg or kJ/day/kg fat-free mass) declines steadily with age from childhood to old age, more steeply so in males.

Body-fat percentage is strongly inversely associated with physical activity energy expenditure.

We found little evidence that energy expenditure varied by geographical region, over time, or by dietary macronutrient composition.

Descriptive epidemiology of physical activity energy expenditure in UK adults (The Fenland study)

BACKGROUND

Physical activity (PA) plays a role in the prevention of a range of diseases including obesity and cardiometabolic disorders. Large population-based descriptive studies of PA, incorporating precise measurement, are needed to understand the relative burden of insufficient PA levels and to inform the tailoring of interventions. Combined heart and movement sensing enables the study of physical activity energy expenditure (PAEE) and intensity distribution. We aimed to describe the sociodemographic correlates of PAEE and moderate-to-vigorous physical activity (MVPA) in UK adults.

METHODS

The Fenland study is a population-based cohort study of 12,435 adults aged 29-64 years-old in Cambridgeshire, UK. Following individual calibration (treadmill), participants wore a combined heart rate and movement sensor continuously for 6 days in free-living, from which we derived PAEE (kJ•day- 1•kg- 1) and time in MVPA (> 3 & > 4 METs) in bouts greater than 1 min and 10 min. Socio-demographic information was self-reported. Stratum-specific summary statistics and multivariable analyses were performed.

RESULTS

Women accumulated a mean (sd) 50(20) kJ•day- 1•kg- 1 of PAEE, and 83(67) and 33(39) minutes•day- 1 of 1-min bouted and 10-min bouted MVPA respectively. By contrast, men recorded 59(23) kJ•day- 1•kg- 1, 124(84) and 60(58) minutes•day- 1. Age and BMI were also important correlates of PA. Association with age was inverse in both sexes, more strongly so for PAEE than MVPA. Obese individuals accumulated less PA than their normal-weight counterparts, whether considering PAEE or allometrically-scaled PAEE (- 10 kJ•day- 1•kg- 1 or - 15 kJ•day- 1•kg-2/3 in men). Higher income and manual work were associated with higher PA; manual workers recorded 13-16 kJ•kg- 1•day- 1 more PAEE than sedentary counterparts. Overall, 86% of women and 96% of men accumulated a daily average of MVPA (> 3 METs) corresponding to 150 min per week. These values were 49 and 74% if only considering bouts > 10 min (15 and 31% for > 4 METs).

CONCLUSIONS

PA varied by age, sex and BMI, and was higher in manual workers and those with higher incomes. Light physical activity was the main driver of PAEE; a component of PA that is currently not quantified as a target in UK guidelines.

The Use of Surgical Bone Staples to Stabilise Corrective Osteotomies of the Radius in Four Dogs

Orthopaedic staples were used to stabilise corrective closing wedge osteotomies of the distal radius in four dogs with forelimb angular deformity. External coaptation was used for four to six weeks. All of the dogs had excellent limb function and cosmetic appearance of the limb. Evidence of implant failure was not observed. Surgical staples were a reliable implant for the stabilisation of radial wedge osteotomies, and particularly useful in cases where the osteotomy is distally located resulting in a short distal radial fragment.

Four dogs with premature closure of the distal ulnar growth plate or lateral aspect of the distal radial physis were treated by corrective radial cuneiform osteotomies which were stabilised with orthopaedic surgical staples and short term external coaptation. All of the dogs had an excellent functional and cosmetic result.

Knowledge and perceived implementation of food safety risk analysis framework in Latin America and the Caribbean region

Risk analysis is increasingly promoted as a tool to support science-based decisions regarding food safety. An online survey comprising 45 questions was used to gather information on the implementation of food safety risk analysis within the Latin American and Caribbean regions. Professionals working in food safety in academia, government, and private sectors in Latin American and Caribbean countries were contacted by email and surveyed to assess their individual knowledge of risk analysis and perceptions of its implementation in the region. From a total of 279 participants, 97% reported a familiarity with risk analysis concepts; however, fewer than 25% were able to correctly identify its key principles. The reported implementation of risk analysis among the different professional sectors was relatively low (46%). Participants from industries in countries with a long history of trade with the United States and the European Union, such as Mexico, Brazil, and Chile, reported perceptions of a higher degree of risk analysis implementation (56, 50, and 20%, respectively) than those from the rest of the countries, suggesting that commerce may be a driver for achieving higher food safety standards. Disagreement among respondents on the extent of the use of risk analysis in national food safety regulations was common, illustrating a systematic lack of understanding of the current regulatory status of the country. The results of this survey can be used to target further risk analysis training on selected sectors and countries.

Aortic stent grafts

Abdominal aortic aneurysms (AAAs) occur when weakened areas of the abdominal aortic wall result in a ballooning of the blood vessel. Attributed risk factors include smoking, atherosclerosis and hypertension. Traditionally, AAAs were treated with open surgery, involving a large abdominal incision and the placement of a synthetic graft. The introduction of endovascular aneurysm repair (EVAR) however, proved to have many advantages over open repair, chief among which is a lower perioperative morbidity and mortality rate. EVAR is likely to continue to evolve and the complications associated with this procedure will likely continue to decrease. In the meantime, the benefit of the continued, detailed analyses of explanted devices is twofold: (1) for future development of new devices; and (2) cognisance of complications that arise with any new device. This review is a guide to the many FDA approved stents which are commercially available, and those likely to become available following clinical trials.

Therapeutic hypercapnia reduces pulmonary and systemic injury following in vivo lung reperfusion

Permissive hypercapnia, involving tolerance to elevated Pa(CO(2)), is associated with reduced acute lung injury (ALI), thought to result from reduced mechanical stretch, and improved outcome in ARDS. However, deliberately elevating inspired CO(2) concentration alone (therapeutic hypercapnia, TH) protects against ALI in ex vivo models. We investigated whether TH would protect against ALI in an in vivo model of lung ischemia-reperfusion (IR). Anesthetized open chest rabbits were ventilated (standard eucapnic settings), and were randomized to TH (FI(CO(2)) 0.12) versus control (FI(CO(2)) 0.00). Pa(CO(2)) and arterial pH values achieved in the TH versus CON groups were 101 +/- 3 versus 44.4 +/- 4 mm Hg and 7.10 +/- 0.03 versus 7.37 +/- 0.03, respectively. Following left lung ischemia and reperfusion, TH versus control was associated with preservation of lung mechanics, attenuation of protein leakage, reduction in pulmonary edema, and improved oxygenation. Indices of systemic protection included improved acid-base and lactate profile, in the absence of systemic hypoxemia. In the TH group, mean BALF TNF-alpha levels were 3.5% of CON levels (p < 0.01), and mean 8-isoprostane levels were 30% of CON levels (p = 0.02). Western blot analysis demonstrated reduced lung tissue nitrotyrosine in TH, indicating attenuation of tissue nitration. Finally, preliminary data suggest that TH may attenuate apoptosis following lung IR. We conclude that in the current model TH is protective versus IR lung injury and mechanisms of protection include preservation of lung mechanics, attenuation of pulmonary inflammation, and reduction of free radical mediated injury. If these findings are confirmed in additional models, TH may become a candidate for clinical testing in critical care.

Involvement of cytosolic phospholipase A2 and secretory phospholipase A2 in arachidonic acid release from human neutrophils

The purpose of this study was to define the role of secretory phospholipase A2 (sPLA2), calcium-independent PLA2, and cytosolic PLA2 (cPLA2) in arachidonic acid (AA) release from fMLP-stimulated human neutrophils. While fMLP induced the release of extracellular sPLA2 activity and AA, 70% of sPLA2 activity remained associated with the cell. Treatment with the cell-impermeable sPLA2 inhibitors DTT or LY311-727, or the anti-sPLA2 Ab 3F10 all inactivated extracellular sPLA2 activity, but had minimal effect on neutrophil AA mass release. In contrast, coincubation of streptolysin-O toxin-permeabilized neutrophils with DTT, LY311-727, or 3F10 all decreased [3H8]AA release from [3H8]AA-labeled, fMLP-stimulated cells. Exposure to fMLP resulted in a decrease in the electrophoretic mobility of cPLA2, a finding consistent with cPLA2 phosphorylation, and stimulated the translocation of cPLA2 from cytosolic to microsomal and nuclear compartments. The role of cPLA2 was further evaluated with the cPLA2 inhibitor methyl arachidonyl fluorophosphonate, which attenuated cPLA2 activity in vitro and decreased fMLP-stimulated AA mass release by intact neutrophils, but had no effect on neutrophil sPLA2 activity. Inhibition of calcium-independent PLA2 with haloenol lactone suicide substrate had no effect on neutrophil cPLA2 activity or AA mass release. These results indicate a role for cPLA2 and an intracellular or cell-associated sPLA2 in the release of AA from fMLP-stimulated human neutrophils.

Impact of red cell salvage on transfusion requirements during elective abdominal aortic aneurysm repair

Elective abdominal aortic aneurysm (AAA) surgery may result in substantial blood loss. Concerns regarding the safety, availability, and acceptability of homologous blood have led to initiatives toward reducing transfusion requirements at the time of aneurysm repair. This study was designed to determine if the routine use of intraoperative red cell salvage and autotransfusion resulted in a reduction in homologous transfusion at our institution. A retrospective review of elective AAA repairs in the years 1987, 1992, and 1997 was carried out. Demographic data, operative details, blood loss, hemoglobin levels, red cell salvage and return volumes, and transfusion requirements were recorded and compared across the study years. From this study we conclude that routine use of red cell salvage and autotransfusion is an effective means for reducing transfusion requirements in elective AAA repair.

A CD18 antibody prevents lung injury but not hypotension after intestinal ischemia-reperfusion

Antibodies to the neutrophil CD18 integrin have been shown to ameliorate the local effects of intestinal ischemia and reperfusion (I/R). In addition to local mucosal injury, intestinal I/R results in systemic hypotension and injury to the lungs with lung leukosequestration. This study tests the effect of a CD18 monoclonal antibody on the hypotension and lung injury after intestinal I/R. In anesthetized rabbits, the superior mesenteric artery was clamped for 60 min followed by 3 h of reperfusion. Animals were treated with saline, an anti-CD18 monoclonal antibody (R15.7 MAb), or nonspecific immunoglobulin G. Another non-ischemic group were sham controls. Neutrophil sequestration was assessed by measure of lung myeloperoxidase (MPO) and permeability by lung-to-blood concentration ratio of 125I-labeled bovine serum albumin and wet-to-dry weight ratio. Immediately after reperfusion, mean arterial pressure fell to 49 +/- 2.1 mmHg and remained at this level. The hypotension was unaffected by treatment with R15.7 MAb. Thirty minutes after reperfusion, the circulating white blood cell count fell to 2.91 +/- 0.53 x 10(3)/mm3 vs. sham 6.40 +/- 0.66 x 10(3)/mm3 (P < 0.05). Treatment with R15.7 MAb prevented this fall in white blood cell count (5.75 +/- 1.59 x 10(3)/mm3). At 3 h of reperfusion in saline-treated animals there was increased MPO, 74.8 +/- 4.9 U/g vs. 42.0 +/- 4.8 U/g in sham animals (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

A Mac-1 antibody reduces liver and lung injury but not neutrophil sequestration after intestinal ischemia-reperfusion

BACKGROUND

Intestinal ischemia and reperfusion (I/R) result in leukosequestration and injury to the liver and lungs. The adherence-dependent oxidative burst of neutrophils requires cell adhesion through the Mac-1 integrin. Neutrophil-mediated tissue injury may depend on this specific cell adhesion event. This study tests the effect of a Mac-1 (CD 11b) monoclonal antibody (MAb) (R17) on liver and lung injury after intestinal I/R.

METHODS

After collaterals were ligated in anesthetized rats, the superior mesenteric artery was clamped for 60 minutes followed by 3 hours of reperfusion. Animals were treated with saline solution, R17, or nonspecific immunoglobulin M. Another nonischemic group of rats were sham controls. Lung and intestinal polymorphonuclear leukocyte sequestration was assessed by measurement of myeloperoxidase and lung permeability by bronchoalveolar lavage blood concentration ratio of 125I-labeled bovine serum albumin.

RESULTS

At 3 hours of reperfusion lung and intestinal myeloperoxidase and lung permeability were increased. Treatment with R17 MAb did not reduce intestinal or lung myeloperoxidase but prevented increased lung permeability. Similarly, after treatment with saline solution, liver polymorphonuclear leukocyte sequestration increased after 3 hours of reperfusion, and serum alanine aminotransferase level rose eightfold. R17 MAb did not significantly reduce liver neutrophil sequestration; however, it reduced alanine aminotransferase level more than 50% when compared to saline solution controls. At 3 hours of reperfusion there was a leukocytosis (white blood cell count, 14.9 +/- 1.0 x 10(3)/mm3 vs 6.0 +/- 0.8 in sham [p less than 0.05]). The white blood cell count was unaffected by R17 MAb.

CONCLUSIONS

These data indicate that a MAb to the neutrophil Mac-1 integrin reduces lung and liver injury after intestinal I/R but does not reduce lung or intestinal leukosequestration.

Ascending cholangitis: surgery versus endoscopic or percutaneous drainage

A retrospective review of 61 patients with calculous cholangitis was carried out. There were 31 men and 30 women and their mean age was 75.8 years. All patients had abdominal pain, 87% had chills and fever, 65% had clinical jaundice, 23% were in shock, and 54% had positive blood cultures. Because intravenous hydration and antibiotics did not help, 33 patients underwent surgery, 25 patients underwent endoscopic papillotomy (EP), and three patients underwent percutaneous transhepatic drainage of the common bile duct (PTD). Morbidity in the surgery group included two wound infections, one respiratory failure, and one renal failure. Morbidity in the EP-PTD group was one case of arterial bleeding requiring surgery and one of pancreatitis treated conservatively. Two patients (6%) died in the surgery group, one of sepsis and the other of cardiorespiratory arrest. In the EP-PTD group nine patients (32%) died of sepsis and multisystem organ failure. These patients were considered too ill to undergo surgery and thus repeat EP-PTD was carried out. Cholangitis persisted, and retained common bile duct stones with sepsis was the cause of death. Thus when initial EP or PTD is unsuccessful, surgical exploration of the common bile duct should be carried out to control sepsis.

The rate and distribution of muscle blood flow after prolonged ischemia

The magnitude and distribution of muscle blood flow in the lower extremity after relief of an acute arterial occlusion may influence the extent of the resulting necrosis. The object of this study was to document the distribution of blood flow in the resting state and after prolonged periods of complete ischemia, and to assess the relationship between the degree of reactive hyperemia and subsequent necrosis. The isolated bilateral canine gracilis muscle preparation that we have previously characterized was used for microsphere studies. Total blood flow was measured by means of timed venous collections, and the distribution of flow was determined by means of a multiple microsphere injection technique. Measurements of microsphere distribution and blood flow were made before ischemia and during the initial 48 minutes of reperfusion after both 4 and 5 hours of normothermic ischemia, which resulted in 46.7% +/- 6% and 71.2% +/- 7% necrosis, respectively. The muscle was harvested and sectioned transversely into six slices approximately 1.5 cm thick, and the extent of necrosis was quantified by means of nitroblue tetrazolium staining 48 hours after reperfusion. Blood flow distribution during the early reperfusion phase was determined in each muscle slice and in both the alive and dead portions of each slice by use of the microsphere injection technique. Preischemic blood flow was distributed homogeneously throughout the muscle and was 4.5 +/- 0.8 ml/100 gm/min (mean +/- SEM, n = 8). On reperfusion total flow was 6 to 10 times higher than it was before ischemia and was distributed predominantly to the middle slices (p less than 0.05, n = 12).(ABSTRACT TRUNCATED AT 250 WORDS)

Free radical mediated damage in skeletal muscle

Skeletal muscle subjected to prolonged ischemia will develop significant injury, however it can withstand periods of ischemia that would be irreversible in other tissues such as brain and heart. Reperfusion injury has been measured and suggested to occur secondary to oxygen free radicals. The increases in vascular permeability and resistance following ischemia/reperfusion can be blunted using free radical scavengers. Also skeletal muscle necrosis can be reduced if these scavengers are provided in high concentration during reperfusion. Recently increases in hydroxy-conjugated dienes, a marker of lipid peroxidation, have been found in reperfused skeletal muscle, providing chemical evidence for free radical injury during reperfusion. These studies have provided some insight into ischemia/reperfusion injury in skeletal muscle, but more investigations are required to detail the mechanisms involved in this injury.

Measurement of hydroxy-conjugated dienes after ischemia-reperfusion in canine skeletal muscle

Recent studies have suggested that oxygen-derived free radicals are involved in the reperfusion injury of ischemic skeletal muscle. Although postischemic necrosis and increased vascular permeability have been attenuated with the addition of free radical scavengers, no unequivocal chemical evidence for free radical injury in skeletal muscle is available. The purpose of this study was to identify products of free radical-mediated membrane injury by isolation of lipid oxidation products (hydroxy-conjugated dienes) from postischemic skeletal muscle. The bilateral canine gracilis muscle model was used, and in each pair one muscle was exposed to 3 and the other to 5 h of normothermic ischemia. Muscle biopsies were taken before and at end ischemia, as well as during the first 3 h of reperfusion. Phospholipids were extracted from the muscle biopsies and the fatty acids hydrolyzed from the 2 position. After methylation, the oxidized fatty acid esters were separated by high-performance liquid chromatography. Hydroxy diene peaks absorbing at 235 nm were collected and subjected to gas chromatography-mass spectrometry (GC-MS) for positive structural identification. No significant increase in the level of conjugated dienes occurred during ischemia. Significant increases, however, were detected during the period of reperfusion, although the time when peak levels were achieved varied between animals. The cumulative sum of dienes produced during reperfusion in both 3- and 5-h muscles was significantly increased over pre- and end-ischemic values. The hydroxy-conjugated diene isomers of 18:2 and 20:4 were positively identified in reperfusion biopsies by GC-MS. These studies provide chemical evidence of free radical-mediated lipid oxidation during reperfusion of ischemic skeletal muscle.

Quantitation of postischemic skeletal muscle necrosis: histochemical and radioisotope techniques

Skeletal muscle necrosis will result from prolonged periods of ischemia. The purpose of this study was to develop a method to estimate the extent of necrosis using nitroblue tetrazolium staining and technetium scanning. The bilateral canine gracilis muscle preparation with total vascular isolation was exposed to 4 hr of complete normothermic ischemia followed by reperfusion. After 45 hr of reperfusion 99mTc pyrophosphate (PYP) was injected and 3 hr later the muscles were harvested, cut into six slices, and stained with nitroblue tetrazolium. Biopsies were taken from tetrazolium-positive and -negative areas for electron microscopy to confirm the ability of the stain to distinguish viable from necrotic muscle. Computerized planimetry of the staining pattern was used to estimate the extent of necrosis as a percentage of the total muscle. Electron microscopy confirmed the validity of nitroblue tetrazolium to discriminate between viable and necrotic skeletal muscle in this experimental model. After 4 hr of ischemia the percentage necrosis was 30.2 +/- 6.1% (mean +/- SEM, n = 12), there was no difference in the extent of necrosis in left vs right paired muscles, using tetrazolium staining or technetium PYP uptake. There was a statistically significant correlation between the percentage necrosis and the density of 99mTc PYP uptake per muscle (r = 0.83, P less than 0.001) and per slice (r = 0.94, P less than 0.001). This study demonstrates the ability of tetrazolium staining to accurately differentiate between viable and necrotic skeletal muscle and provides a reproducible method for estimating the extent of necrosis in the gracilis muscle model.

The extent and distribution of skeletal muscle necrosis after graded periods of complete ischemia

The management of an acutely ischemic extremity requires knowledge of the response of skeletal muscle (the largest component of the lower limb) to prolonged periods of complete normothermic ischemia. We have used the canine gracilis muscle model to evaluate the extent and distribution of ischemic necrosis after 3 and 5 hours of ischemia and 48 hours of reperfusion. Each muscle was cut into six slices, and the extent and distribution of postischemic necrosis identified by means of nitroblue tetrazolium staining and 99mTc pyrophosphate uptake. After 3, 4, and 5 hours of ischemia the extent of necrosis was 2.0% +/- 0.9%, 30.3% +/- 6.0%, and 90.1% +/- 3.5% (mean +/- SEM), respectively. A statistically significant correlation exists between the extent of necrosis and the uptake of 99mTc pyrophosphate uptake per gram of tissue (y = 1574.9x - 8.4, r = 0.84, p less than 0.001). Most necrosis was centrally located and found in the thickest portion of the muscle. We conclude that there is a graded response in the extent of skeletal muscle necrosis related to the length of ischemic stress rather than an "all-or-none" phenomenon. This central distribution of necrosis makes the usual external evaluation of ischemic damage clinically unreliable. In addition, since there was no enveloping fascia in this model, a compartment release alone may not prevent the development of skeletal muscle necrosis. This knowledge of the response of skeletal muscle to ischemia may lead to an improved clinical approach to an extremity suffering a prolonged ischemic insult.