A systematic review of the impact of postoperative aerobic exercise training in patients undergoing surgery for intra-abdominal cancers

INTRODUCTION

Enhanced recovery after surgery (ERAS) programmes which advocate early mobility after surgery have improved immediate clinical outcomes for patients undergoing abdominal cancer resections with curative intent. However, the impact of continued physical activity on patient-related outcomes and functional recovery is not well defined. The aim of this review was to assess the impact of postoperative aerobic exercise training, either alone or in conjunction with another exercise modality, on patients who have had surgery for intra-abdominal cancer.

METHODS

A literature search was performed of electronic journal databases. Eligible papers needed to report an outcome of aerobic capacity in patients older than 18 years of age, who underwent cancer surgery with curative intent and participated in an exercise programme (not solely ERAS) that included an aerobic exercise component starting at any point in the postoperative pathway up to 12 weeks.

RESULTS

Eleven studies were deemed eligible for inclusion consisting of two inpatient, one mixed inpatient/outpatient and eight outpatient studies. Meta-analysis of four outpatient studies, each reporting change in 6-min walk test (6MWT), showed a significant improvement in 6MWT with exercise (MD 74.92 m, 95% CI 48.52-101.31 m). The impact on health-related quality of life was variable across studies.

CONCLUSION

Postoperative exercise confers benefits in improving aerobic function post surgery and can be safely delivered in various formats (home-based or group/supervised).

Long-acting PGE2 and Lisinopril Mitigate H-ARS

Thrombocytopenia is a major complication in hematopoietic-acute radiation syndrome (H-ARS) that increases the risk of mortality from uncontrolled hemorrhage. There is a great demand for new therapies to improve survival and mitigate bleeding in H-ARS. Thrombopoiesis requires interactions between megakaryocytes (MKs) and endothelial cells. 16, 16-dimethyl prostaglandin E2 (dmPGE2), a longer-acting analogue of PGE2, promotes hematopoietic recovery after total-body irradiation (TBI), and various angiotensin-converting enzyme (ACE) inhibitors mitigate endothelial injury after radiation exposure. Here, we tested a combination therapy of dmPGE2 and lisinopril to mitigate thrombocytopenia in murine models of H-ARS following TBI. After 7.75 Gy TBI, dmPGE2 and lisinopril each increased survival relative to vehicle controls. Importantly, combined dmPGE2 and lisinopril therapy enhanced survival greater than either individual agent. Studies performed after 4 Gy TBI revealed reduced numbers of marrow MKs and circulating platelets. In addition, sublethal TBI induced abnormalities both in MK maturation and in in vitro and in vivo platelet function. dmPGE2, alone and in combination with lisinopril, improved recovery of marrow MKs and peripheral platelets. Finally, sublethal TBI transiently reduced the number of marrow Lin-CD45-CD31+Sca-1- sinusoidal endothelial cells, while combined dmPGE2 and lisinopril treatment, but not single-agent treatment, accelerated their recovery. Taken together, these data support the concept that combined dmPGE2 and lisinopril therapy improves thrombocytopenia and survival by promoting recovery of the MK lineage, as well as the MK niche, in the setting of H-ARS.

Delay in Source Control in Perforated Peptic Ulcer Leads to 6% Increased Risk of Death Per Hour: A Nationwide Cohort Study

BACKGROUND

Delay to theatre for patients with intra-abdominal sepsis is cited as a particular risk factor for death. Our aim was to evaluate the potential relationship between hourly delay from admission to surgery and post-operative mortality in patients with perforated peptic ulcer (PPU).

METHODS

All patients entered in the National Emergency Laparotomy Audit who had an emergency laparotomy for PPU within 24 h of admission from December 2013 to November 2017 were included. Time to theatre from admission was modelled as a continuous variable in hours. Outcome was 90-day mortality. Logistic regression adjusting for confounding factors was performed.

RESULTS

3809 patients were included, and 90-day mortality rate was 10.61%. Median time to theatre was 7.5 h (IQR 5-11.6 h). The odds of death increased with time to operation once adjustment for confounding variables was performed (per hour after admission adjusted OR 1.04 95% CI 1.02-1.07). In patients who were physiologically shocked (N = 334), there was an increase of 6% in risk-adjusted odds of mortality for every hour Em Lap was delayed after admission (OR 1.06 95% CI 1.01-1.11).

CONCLUSION

Hourly delay to theatre in patients with PPU is independently associated with risk of death by 90 days. Therefore, we suggest that surgical source control should occur as soon as possible after admission regardless of time of day.

Trainee-led emergency laparotomy operating

Background

To achieve completion of training in general surgery, trainees are required to demonstrate competency in common procedures performed at emergency laparotomy. The aim of this study was to describe the patterns of trainee-led emergency laparotomy operating and the association between postoperative outcomes.

Methods

Data on all patients who had an emergency laparotomy between December 2013 and November 2017 were extracted from the National Emergency Laparotomy Audit database. Patients were grouped by grade of operating surgeon: trainee (specialty registrar) or consultant (including post-Certificate of Completion of Training fellows). Trends in trainee operating by deanery, hospital size and time of day of surgery were investigated. Univariable and adjusted regression analyses were performed for the outcomes 90-day mortality and return to theatre, with analysis of patients in operative subgroups segmental colectomy, Hartmann's procedure, adhesiolysis and repair of perforated peptic ulcer disease.

Results

The study cohort included 87 367 patients. The 90-day mortality rate was 15·1 per cent in the consultant group compared with 11·0 per cent in the trainee group. There were no increased odds of death by 90 days or of return to theatre across any of the operative groups when the operation was performed with a trainee listed as the most senior surgeon in theatre. Trainees were more likely to operate independently in high-volume centres (highest- versus lowest-volume centres: odds ratio (OR) 2·11, 95 per cent c.i. 1·91 to 2·33) and at night (00.00 to 07.59 versus 08.00 to 11.59 hours; OR 3·20, 2·95 to 3·48).

Conclusion

There is significant variation in trainee-led operating in emergency laparotomy by geographical area, hospital size and by time of day. However, this does not appear to influence mortality or return to theatre.

Long-term outcomes of biological mesh repair following extra levator abdominoperineal excision of the rectum: an observational study of 100 patients

Background

Current evidence suggests that pelvic floor reconstruction following extralevator abdominoperineal excision of rectum (ELAPER) may reduce the risk of perineal herniation of intra-abdominal contents. Options for reconstruction include mesh and myocutaneous flaps, for which long-term follow-up data is lacking. The aim of this study was to evaluate the long-term outcomes of biological mesh (Surgisis^®, Biodesign™) reconstruction following ELAPER.

Methods

A retrospective review of all patients having ELAPER in a single institution between 2008 and 2018 was perfomed. Clinic letters were scrutinised for wound complications and all available cross sectional imaging was reviewed to identify evidence of perineal herniation (defined as presence of intra-abdominal content below a line between the coccyx and the lower margin of the pubic symphysis on sagittal view).

Results

One hundred patients were identified (median age 66, IQR 59–72 years, 70% male). Median length of follow-up was 4.9 years (IQR 2.3–6.7 years). One, 2- and 5-year mortality rates were 3, 8 and 12%, respectively. Thirty three perineal wounds had not healed by 1 month, but no mesh was infected and no mesh needed to be removed. Only one patient developed a symptomatic perineal hernia requiring repair. On review of imaging a further 7 asymptomatic perineal hernias were detected. At 4 years the cumulative radiologically detected perineal hernia rate was 8%.

Conclusions

This study demonstrates that pelvic floor reconstruction using biological mesh following ELAPER is both safe and effective as a long-term solution, with low major complication rates. Symptomatic perineal herniation is rare following mesh reconstruction, but may develop sub clinically and be detectable on cross-sectional imaging.

Association between surgeon special interest and mortality after emergency laparotomy

Background

Approximately 30 000 emergency laparotomies are performed each year in England and Wales. Patients with pathology of the gastrointestinal tract requiring emergency laparotomy are managed by general surgeons with an elective special interest focused on either the upper or lower gastrointestinal tract. This study investigated the impact of special interest on mortality after emergency laparotomy.

Methods

Adult patients having emergency laparotomy with either colorectal or gastroduodenal pathology were identified from the National Emergency Laparotomy Audit database and grouped according to operative procedure. Outcomes included all-cause 30-day mortality, length of hospital stay and return to theatre. Logistic and Poisson regression were used to analyse the association between consultant special interest and the three outcomes.

Results

A total of 33 819 patients (28 546 colorectal, 5273 upper gastrointestinal (UGI)) were included. Patients who had colorectal procedures performed by a consultant without a special interest in colorectal surgery had an increased adjusted 30-day mortality risk (odds ratio (OR) 1·23, 95 per cent c.i. 1·13 to 1·33). Return to theatre also increased in this group (OR 1·13, 1·05 to 1·20). UGI procedures performed by non-UGI special interest surgeons carried an increased adjusted risk of 30-day mortality (OR 1·24, 1·02 to 1·53). The risk of return to theatre was not increased (OR 0·89, 0·70 to 1·12).

Conclusion

Emergency laparotomy performed by a surgeon whose special interest is not in the area of the pathology carries an increased risk of death at 30 days. This finding potentially has significant implications for emergency service configuration, training and workforce provision, and should stimulate discussion among all stakeholders.

Reliability of frailty assessment in the critically ill: a multicentre prospective observational study

Demand for critical care among older patients is increasing in many countries. Assessment of frailty may inform discussions and decision making, but acute illness and reliance on proxies for history-taking pose particular challenges in patients who are critically ill. Our aim was to investigate the inter-rater reliability of the Clinical Frailty Scale for assessing frailty in patients admitted to critical care. We conducted a prospective, multi-centre study comparing assessments of frailty by staff from medical, nursing and physiotherapy backgrounds. Each assessment was made independently by two assessors after review of clinical notes and interview with an individual who maintained close contact with the patient. Frailty was defined as a Clinical Frailty Scale rating > 4. We made 202 assessments in 101 patients (median (IQR [range]) age 69 (65-75 [60-80]) years, median (IQR [range]) Acute Physiology and Chronic Health Evaluation II score 19 (15-23 [7-33])). Fifty-two (51%) of the included patients were able to participate in the interview; 35 patients (35%) were considered frail. Linear weighted kappa was 0.74 (95%CI 0.67-0.80) indicating a good level of agreement between assessors. However, frailty rating differed by at least one category in 47 (47%) cases. Factors independently associated with higher frailty ratings were: female sex; higher Acute Physiology and Chronic Health Evaluation II score; higher category of pre-hospital dependence; and the assessor having a medical background. We identified a good level of agreement in frailty assessment using the Clinical Frailty Scale, supporting its use in clinical care, but identified factors independently associated with higher ratings which could indicate personal bias.

Impact of the calcium form of β-hydroxy-β-methylbutyrate upon human skeletal muscle protein metabolism

BACKGROUND & AIMS

β-hydroxy-β-methylbutyrate (HMB) is purported as a key nutritional supplement for the preservation of muscle mass in health, disease and as an ergogenic aid in exercise. Of the two available forms of HMB (calcium (Ca-HMB) salt or free acid (FA-HMB)) - differences in plasma bioavailability have been reported. We previously reported that ∼3 g oral FA-HMB increased muscle protein synthesis (MPS) and reduced muscle protein breakdown (MPB). The objective of the present study was to quantify muscle protein metabolism responses to oral Ca-HMB.

METHODS

Eight healthy young males received a primed constant infusion of 1,2 ¹³C₂ leucine and ²H₅ phenylalanine to assess MPS (by tracer incorporation in myofibrils) and MPB (via arterio-venous (A-V) dilution) at baseline and following provision of ∼3 g of Ca-HMB; muscle anabolic (MPS) and catabolic (MPB) signalling was assessed via immunoblotting.

RESULTS

Ca-HMB led a significant and rapid (<60 min) peak in plasma HMB concentrations (483.6 ± 14.2 μM, p < 0.0001). This rise in plasma HMB was accompanied by increases in MPS (PA: 0.046 ± 0.004%/h, CaHMB: 0.072 ± 0.004%/h, p < 0001) and suppressions in MPB (PA: 7.6 ± 1.2 μmol Phe per leg min^-1, Ca-HMB: 5.2 ± 0.8 μmol Phe per leg min^-1, p < 0.01). Increases in the phosphorylation of mTORc1 substrates i.e. p70S6K1 and RPS6 were also observed, with no changes detected in the MPB targets measured.

CONCLUSIONS

These findings support the pro-anabolic properties of HMB via mTORc1, and show that despite proposed differences in bioavailability, Ca-HMB provides a comparable stimulation to MPS and suppression of MPB, to FA-HMB, further supporting its use as a pharmaconutrient in the modulation of muscle mass.

Simulation fails to replicate stress in trainees performing a technical procedure in the clinical environment

INTRODUCTION

Simulation-based training (SBT) has become an increasingly important method by which doctors learn. Stress has an impact upon learning, performance, technical, and non-technical skills. However, there are currently no studies that compare stress in the clinical and simulated environment. We aimed to compare objective (heart rate variability, HRV) and subjective (state trait anxiety inventory, STAI) measures of stress theatre with a simulated environment.

METHODS

HRV recordings were obtained from eight anesthetic trainees performing an uncomplicated rapid sequence induction at pre-determined procedural steps using a wireless Polar RS800CX monitor © in an emergency theatre setting. This was repeated in the simulated environment. Participants completed an STAI before and after the procedure.

RESULTS

Eight trainees completed the study. The theatre environment caused an increase in objective stress vs baseline (p = .004). There was no significant difference between average objective stress levels across all time points (p = .20) between environments. However, there was a significant interaction between the variables of objective stress and environment (p = .045). There was no significant difference in subjective stress (p = .27) between environments.

DISCUSSION

Simulation was unable to accurately replicate the stress of the technical procedure. This is the first study that compares the stress during SBT with the theatre environment and has implications for the assessment of simulated environments for use in examinations, rating of technical and non-technical skills, and stress management training.

EGFR-Stat3 signalling in nerve glial cells modifies neurofibroma initiation

Neurofibromatosis type 1 (NF1) is an inherited disease in which affected patients are predisposed to develop benign Schwann cell (SC) tumours called neurofibromas. In the mouse, loss of Nf1 in the SC lineage causes neurofibroma formation. The tyrosine kinase receptor EGFR is expressed in Schwann cell precursors (SCP), which have been implicated in plexiform neurofibroma initiation. To test if EGFR activity affects neurofibroma initiation, size, and/or number, we studied mice expressing human EGFR in SCs and SCP in the context of mice that form neurofibromas. Neurofibroma number increased in homozygous CNP-hEGFR mice versus heterozygous littermates, and neurofibroma number and size increased when CNP-hEGFR was crossed to Nf1^fl/fl;DhhCre mice. Conversely, diminished EGFR signalling in Nf1^fl/fl;DhhCre;Wa2/+ mice decreased neurofibroma number. In vivo transplantation verified the correlation between EGFR activity and neurofibroma formation. Mechanistically, expression of CNP-hEGFR increased SCP/neurofibroma-initiating cell self-renewal, a surrogate for tumour initiation, and activated P-Stat3. Further, Il-6 reinforced Jak2/Stat3 activation in SCPs and SCs. These gain- and loss-of function assays show that levels of tyrosine kinase expression in SCPs modify neurofibroma initiation.

Anaesthetists stress is induced by patient ASA grade and may impair non-technical skills during intubation

BACKGROUND

The aims of this study were to determine if patient ASA grade was associated with increased stress in anaesthetists with a subsequent effect on non-technical skills.

METHODS

Stress was measured using a validated objective (heart rate variability or heart rate) and subjective tool. We studied eight consultant anaesthetists at baseline (rest) and during 16 episodes of intubation with an ASA 1 or 2 patient vs. an ASA 3 or 4 patient. The primary outcome for the study was objective and subjective stress between both patient groups. Secondary outcomes were non-technical skill ratings and the association between stress measurements.

RESULTS

ASA 3 or 4 patients were associated with increases in objective stress when compared to baseline (mean 4.6 vs. 6.7; P = 0.004). However, ASA 1 or 2 patients were not associated with increases in stress when compared to baseline (mean 4.6 vs. 4.7; P = 1). There was no significant difference in subjective stress between the groups (P = 0.18). Objective stress negatively affected situational awareness (P = 0.03) and decision-making (P = 0.03); however, these did not decline to a clinically significant threshold. Heart rate variability (r = 0.60; P = 0.002) better correlated with subjective stress when compared to heart rate (r = 0.30; P = 0.15). Agreement between raters for Anaesthetic Non-Technical Skills (ANTS) scores was acceptable (ICC = 0.51; P = 0.003).

CONCLUSION

This study suggests that higher patient ASA grade can increase stress in anaesthetists, which may impair non-technical skills.

A 31-day time to surgery compliant exercise training programme improves aerobic health in the elderly

BACKGROUND

Over 41,000 people were diagnosed with colorectal cancer (CRC) in the UK in 2011. The incidence of CRC increases with age. Many elderly patients undergo surgery for CRC, the only curative treatment. Such patients are exposed to risks, which increase with age and reduced physical fitness. Endurance-based exercise training programmes can improve physical fitness, but such programmes do not comply with the UK, National Cancer Action Team 31-day time-to-treatment target. High-intensity interval training (HIT) can improve physical performance within 2-4 weeks, but few studies have shown HIT to be effective in elderly individuals, and those who do employ programmes longer than 31 days. Therefore, we investigated whether HIT could improve cardiorespiratory fitness in elderly volunteers, age-matched to a CRC population, within 31 days.

METHODS

This observational cohort study recruited 21 healthy elderly participants (8 male and 13 female; age 67 years (range 62-73 years)) who undertook cardiopulmonary exercise testing before and after completing 12 sessions of HIT within a 31-day period.

RESULTS

Peak oxygen consumption (VO2 peak) (23.9 ± 4.7 vs. 26.2 ± 5.4 ml/kg/min, p = 0.0014) and oxygen consumption at anaerobic threshold (17.86 ± 4.45 vs. 20.21 ± 4.11 ml/kg/min, p = 0.008) increased after HIT.

CONCLUSIONS

It is possible to improve cardiorespiratory fitness in 31 days in individuals of comparable age to those presenting for CRC surgery.

Systematic review of pre-operative exercise in colorectal cancer patients

The aim of this systematic review was to evaluate the evidence for exercise interventions prior to surgery for colorectal cancer resection. The evidence for use of exercise to improve physical fitness and surgical outcomes is as yet unknown. A systematic search was performed of MEDLINE, EMBASE, CINAHL, AMED and BNI databases for studies involving pre-operative exercise in colorectal cancer patients. Eight studies were included in the review. There is evidence that pre-operative exercise improves functional fitness, and to a lesser extent objectively measurable cardio-respiratory fitness prior to colorectal cancer resection. There is no clear evidence at present that this improvement in fitness translates into reduced peri-operative risk or improved post-operative outcomes. Current studies are limited by risk of bias. This review highlights the common difficulty in transferring promising results in a research setting, into significant improvements in the clinical arena. Future research should focus on which type of exercise is most likely to maximise patient adherence and improvements in cardio-respiratory fitness. Ultimately, adequately powered, randomised controlled trials are needed to investigate whether pre-operative exercise improves post-operative morbidity and mortality.

Day-case closure of ileostomy: feasible, safe and efficient

AIM

Over 5000 loop ileostomy closures were performed in the UK in 2013 with a median inpatient stay of 5 days. Previously we have successfully implemented a 23-h protocol for loop ileostomy closure which was modified for same-day discharge. We present our early experience of day-case loop ileostomy closure.

METHOD

A specific patient pathway for day-case discharge following loop ileostomy closure was implemented with inclusion criteria to conform with British Association of Day Surgery guidelines. Exclusion criteria included postoperative chemoradiotherapy, multiple comorbidities and social care needs. Follow-up consisted of telephone contact (24 and 72 h after discharge) and a routine outpatient appointment. Patients were provided with a 24-h contact point in case of emergency.

RESULTS

Fifteen (12 male) patients were enrolled of median age 67 (39-80) years. The median operating time was 41 (23-80) min. The indication for ileostomy formation was to cover a low anterior resection for adenocarcinoma (13), reversal of Hartmann's procedure (1) and functional bowel disorder (1). The median interval from the primary procedure to day-case loop ileostomy closure was 8 (3-14) months. Every patient was discharged on the day of surgery. There were no complications related to the surgery and there was one readmission due to a urinary tract infection. The median length of follow-up was 4 (2-16) months.

CONCLUSION

Our early experience shows that day-case loop ileostomy closure is feasible, safe and efficient. This protocol will become standard within our institution for suitable patients, saving on average five inpatient bed days per patient.

Ionizing radiation induces myofibroblast differentiation via lactate dehydrogenase

Pulmonary fibrosis is a common and dose-limiting side-effect of ionizing radiation used to treat cancers of the thoracic region. Few effective therapies are available for this disease. Pulmonary fibrosis is characterized by an accumulation of myofibroblasts and excess deposition of extracellular matrix proteins. Although prior studies have reported that ionizing radiation induces fibroblast to myofibroblast differentiation and collagen production, the mechanism remains unclear. Transforming growth factor-β (TGF-β) is a key profibrotic cytokine that drives myofibroblast differentiation and extracellular matrix production. However, its activation and precise role in radiation-induced fibrosis are poorly understood. Recently, we reported that lactate activates latent TGF-β through a pH-dependent mechanism. Here, we wanted to test the hypothesis that ionizing radiation leads to excessive lactate production via expression of the enzyme lactate dehydrogenase-A (LDHA) to promote myofibroblast differentiation. We found that LDHA expression is increased in human and animal lung tissue exposed to ionizing radiation. We demonstrate that ionizing radiation induces LDHA, lactate production, and extracellular acidification in primary human lung fibroblasts in a dose-dependent manner. We also demonstrate that genetic and pharmacologic inhibition of LDHA protects against radiation-induced myofibroblast differentiation. Furthermore, LDHA inhibition protects from radiation-induced activation of TGF-β. We propose a profibrotic feed forward loop, in which radiation induces LDHA expression and lactate production, which can lead to further activation of TGF-β to drive the fibrotic process. These studies support the concept of LDHA as an important therapeutic target in radiation-induced pulmonary fibrosis.

Assessing surgeon stress when operating using heart rate variability and the State Trait Anxiety Inventory: will surgery be the death of us?

AIM

Performance in the operating room is affected by a combination of individual, patient and environmental factors amongst others. Stress has a potential negative impact on performance with the quality of surgical practice and patient safety being affected as a result. In order to appreciate the level of stress encountered during surgical procedures both objective and subjective methods can be used. This study reports the use of a combined objective (physiological) and subjective (psychological) method for evaluating stress experienced by the operating surgeon.

METHOD

Six consultant colorectal surgeons were evaluated performing eighteen anterior resections. Heart rate was recorded using a wireless chest strap at eight pre-determined operative steps. Heart Rate Variability indices were calculated offline using computerized software. Surgeon reported stress was collected using the State Trait Anxiety Inventory, a validated clinical stress scale.

RESULTS

A significant increase in stress was demonstrated in all surgeons whilst operating as indicated by sympathetic tone (control: 4.02 ± 2.28 vs operative: 11.42 ± 4.63; P < 0.0001). Peaks in stress according to operative step were comparable across procedures and surgeons. There was a significant positive correlation with subjective reporting of stress across procedures (r = 0.766; P = 0.0005).

CONCLUSION

This study demonstrates a significant increase in sympathetic tone in consultant surgeons measured using heart rate variability during elective colorectal resections. A significant correlation can be demonstrated between HRV measurements and perceived stress using the State Trait Anxiety Inventory. A combined approach to assessing operative stress is required to evaluate any effect on performance and outcomes.

Simple psoas cross-sectional area measurement is a quick and easy method to assess sarcopenia and predicts major surgical complications

AIM

Radiologically assessed muscle mass has been suggested as a surrogate marker of functional status and frailty and may predict patients at risk of postoperative complications. We hypothesize that sarcopenia negatively impacts on postoperative recovery and is predictive of complications.

METHOD

One hundred patients undergoing elective resection for colorectal carcinoma were included in this study. Lean muscle mass was estimated by measuring the cross-sectional area of the psoas muscle at the level of the third lumbar vertebra identified on a preoperative CT scan, normalizing for patient height. Perioperative morbidity was scored according to the Clavien-Dindo classification. All statistical data analyses were carried out using the Statistical Package for the Social Sciences (SPSS) version 20.0.

RESULTS

Fifteen per cent of patients were identified as sarcopenic. There were no deaths in the study group. Sarcopenia was associated with a significantly increased risk of developing major complications (Grade 3 or greater, OR = 5.41, 95% CI: 1.45-20.15, P = 0.01). Sarcopenia did not predict length of stay, critical care dependency or time to mobilization.

CONCLUSION

Sarcopenia, as a marker of frailty, is an important risk factor in surgical patients but difficult to estimate using bedside testing. CT scans, performed for preoperative staging, provide an opportunity to quantify lean muscle mass without additional cost or exposure to radiation and eliminate the inconvenience of further investigations.

Comparison of magnetic resonance urography to dimercaptosuccinic acid scan for the identification of renal parenchyma defects in children with vesicoureteral reflux

OBJECTIVE

The objective of this study was to compare the accuracy of dimercaptosuccinic acid (DMSA) renal scan to magnetic resonance urography (MRU) in the identification of renal parenchyma defects (RPD).

MATERIALS AND METHODS

Twenty-five children with history of acute pyelonephritis and vesicoureteral reflux underwent DMSA scan and MRU to determine the presence of RPD. DMSA scans and MRUs were each evaluated by two radiologists and agreement achieved by consensus. Discordant DMSA-MRU findings were re-evaluated in a side-by-side comparison and an ultimate consensus reached.

RESULTS

The ultimate consensus diagnosis was 18 kidneys with RPDs in 15 patients, of which five were classified as mild RPDs, six as moderate RPDs, and seven as severe RPDs. Although DMSA scan and MRU were similar in their ability to diagnose RPDs, MRU was considered to represent the true diagnosis in 11 of the 12 discordant cases in consensus review by four pediatric radiologists. MRU showed a much higher inter-observer agreement with a weighted kappa of 0.96 for both kidneys compared to 0.71 for the right kidney and 0.86 for the left kidney by DMSA scan.

CONCLUSIONS

Our results suggest that MRU is superior to DMSA scan in the identification of renal parenchyma defects.

Surgical resection of primary tumour improves aerobic performance in colorectal cancer

BACKGROUND

Colorectal cancer is the third most common cancer in the UK, with patients suffering declines in muscle mass and aerobic function. We hypothesised that tumour removal in non-metastatic colorectal cancer would lead to a restoration of lean muscle mass and increases in objective and subjective measures of aerobic performance.

METHODS

We recruited two groups: patients with colorectal cancer (n = 30, 65.3 (51-77) y, body mass index 27.67 (4.83) kg m(-2)) and matched controls (n = 30, 64.6 (42-77) y, BMI 27.14 (3.51) kg m(-2)). Controls underwent a single study while colorectal cancer patients were studied before and 10 months after tumour resection. Aerobic performance was assessed via cardiopulmonary exercise testing and activity questionnaires. Lean muscle mass was measured via dual-energy X-ray absorptiometry.

RESULTS

Lean muscle mass was not different between groups (control: 47.82 (8.23); pre-resection: 52.41 (10.59); post-resection: 52.38 (10.52), kg). Anaerobic threshold was lower in pre-operative patients compared to controls (14.40 (3.23) vs. 19.67 (5.81) ml kg(-1) min(-1), p < 0.0001), increasing significantly post-resection (17.00 (3.56) ml kg(-1) min(-1)p < 0.0001). Self reported maximal physical activity was lower after resection compared to preoperatively (pre-resection 6.0 (6.5-5 IQR), post-resection 3.75 (4-3 IQR), p < 0.0001).

CONCLUSION

In colorectal cancer, anaerobic threshold is reached more rapidly than in matched controls, returning toward normal with tumour resection. Self-reported measures of activity do not mirror this objective change, cardiopulmonary exercise testing may therefore allow for a more accurate evaluation of pre and postoperative performance capability. The variance between objective and subjective measures of exercise capacity may be important in determining return to normal activities.

Should laparoscopic reversal of Hartmann's procedure be the first line approach in all patients?

BACKGROUND/AIMS

To assess if the laparoscopic reversal of Hartmann's can be attempted in all patients, without detriment to short or long-term outcomes if the patient is subsequently converted to open.

METHODS

Retrospective review of a prospectively collected database of all reversals under 8 surgeons at a single unit over 105 months, two surgeons attempting laparoscopic reversal in all patients, two pre-selecting for the laparoscopic approach and four utilising the open approach. Long-term follow-up data for re-admissions, re-operations and incisional hernia rate obtained from a postal questionnaire.

RESULTS

45 laparoscopic and 50 primary open reversals were identified. There was no difference in the mean age or previous peritonitis rate in either group. Laparoscopic conversion rate was 29% (13 patients). On intention to treat analysis, a significant difference was identified in the overall 30-day post-operative surgical morbidity (8.9% Laparoscopic-attempted vs 26.0% Open, p = 0.030). There was no difference in operating times (mean 164 vs 172 min, p = 0.896) despite the 13 patients converted to an open procedure. Mean length of stay was significantly lower in the laparoscopic-attempted group at 6.8 days (5.2-8.4) vs 14.9 days (6.4-23.7) in the open group (p = 0.001). Anastomotic leak rates were not statistically different. The median follow up was 27 months (range 6-105); 60% of patients completed a postal follow-up questionnaire. There was no difference in short-term or long-term re-admission or reoperation rates.

CONCLUSIONS

Laparoscopic reversal of Hartamann's is associated with shorter hospital stay and lower morbidity even in unselected patients. Long-term outcomes are similar.

Could Telephone Reviews Reduce Read Mission Rates After Laparoscopic Colorectal Surgery?

Significant advances have been made recently in the management of patients undergoing colorectal surgery. demonstration of the advantages of laparoscopic colorectal surgery over the open approach in terms of faster patient recovery, shorter length of hospital stay, less pain and fewer wound problems with identical oncological outcome has led to the widespread adoption of the technique. Simultaneously, based on the original work of Kehlet, enhanced recovery after surgery (ERAS) programmes that capitalise on the reduced physiological insult stimulated by laparoscopic surgery have gained in popularity. Coupled, laparoscopic surgery and ERAS allow many patients undergoing major colorectal resections to be discharged from hospital on the first to third post-operative day.

Pulmonary injury after combined exposures to low-dose low-LET radiation and fungal spores

Exposure to infectious microbes is a likely confounder after a nuclear terrorism event. In combination with radiation, morbidity and mortality from an infection may increase significantly. Pulmonary damage after low-dose low-LET irradiation is characterized by an initial diffuse alveolar inflammation. By contrast, inhaled fungal spores produce localized damage around pulmonary bronchioles. In the present study, we assessed lung injury in C57BL/6 mice after combined exposures to whole-body X radiation and inhaled fungal spores. Either animals were exposed to Aspergillus spores and immediately irradiated with 2 Gy, or the inoculation and irradiation were separated by 8 weeks. Pulmonary injury was assessed at 24 and 48 h and 1, 2, 4, 8, and 24 weeks later using standard H&E-stained sections and compared with sham-treated age-matched controls. Immunohistochemistry for invasive inflammatory cells (macrophages, neutrophils and B and T lymphocytes) was performed. A semi-quantitative assessment of pulmonary injury was made using three distinct parameters: local infiltration of inflammatory cells, diffuse inflammation, and thickening and distortion of alveolar architecture. Radiation-induced changes in lung architecture were most evident during the first 2 weeks postexposure. Fungal changes were seen over the first 4 weeks. Simultaneous combined exposures significantly increased the duration of acute pulmonary damage up to 24 weeks (P < 0.01). In contrast, administration of the fungus 8 weeks after irradiation did not produce enhanced levels of acute pulmonary damage. These data imply that the inhalation of fungal spores at the time of a radiation exposure alters the susceptibility of the lungs to radiation-induced injury.

From small acorns--developing a laparoscopic colorectal surgical service

INTRODUCTION

Randomised controlled trials have shown that laparoscopic colorectal surgery is equal in terms of safety to open surgery. Benefits have been seen for length of stay, blood loss, immune suppression and analgesia requirements. The aim of this study was to assess the safety and feasibility of introducing laparoscopic colorectal surgery to our unit.

PATIENTS AND METHODS

Prospectively collected cases of all patients undergoing laparoscopic colorectal surgery between July 2003 and July 2007 were reviewed.

RESULTS

A total of 143 patients (75 males and 68 females) with a mean age of 65.8 years (range, 21-95 years) underwent surgery. Laparoscopic resection for colorectal malignancy was performed in 93 patients (65%). The conversion rate for all cases was 14.7%. Mean operative time was 203 min (range, 100-400 min), with a mean blood loss of 180 ml. The mean number of lymph nodes in malignant cases was 13.8 with clear resection margin in all but one case. The mean postoperative stay was 5.6 days (median, 4 days; range, 2-35 days). UKCCR standard for lymph node retrieval was achieved in 62.6% of cases. There were four postoperative deaths. The overall 30-day morbidity rate was 21.7%. The service is consultant-led with 9.8% of cases performed by senior trainees and 37% of procedures performed by two consultants.

CONCLUSIONS

Laparoscopic colorectal surgery is technically feasible and safe in our hands. Although operative time is longer, this is counterbalanced by shorter hospital stay. The results from this series support the findings of others and continuing development of this service.

Spatial and temporal variations of meiofaunal communities from the western sector of the Gulf of Batabanó, Cuba: III. Vertical distribution

The vertical distribution of meiofauna within subtidal sediments was studied in four stations pertaining to mangrove or muddy flats habitats. In 2003, replicated samples were taken in dry (February) and wet (July) seasons at the Bacunagua Inlet, southwestern coast of Cuba. The abundance and number of meiofaunal taxa exhibited a vertical gradient possibly due to changes in the concentrations of oxygen and hydrogen sulphide, rather than food availability along this gradient. Nematodes are capable of distributing themselves throughout the whole sediment column due to their ability to tolerate reducing conditions; however depletion of communities along depth was evident. Their presence in deeper sediments (6 - 10 cm) suggests that certain species are adequately adapted to spend their entire life cycle in these harsh environments (where soluble tannins and decomposing organic matter predominate). Copepods showed a strong limitation to vertical distribution (concentrating in the top 2 cm), possibly in response to a sharp vertical decline in oxygenation within these organically enriched sediments.

Nociceptin and urotensin-II concentrations in critically ill patients with sepsis

BACKGROUND

The systemic inflammatory response to infection (sepsis) involves widespread organ dysfunction, including changes in immune modulation, cardiovascular derangements, and neural activation. Two neuropeptide/receptor systems, nociceptin/orphanin FQ (N/OFQ) which acts at the non-classical opioid receptor NOP and urotensin-II (U-II) which acts at the urotensin receptor (UT), have been implicated in neural, immune, and cardiovascular system function. In this study, we make measurements of these peptides in critically ill patients.

METHODS

Plasma samples from 21 critically ill patients with sepsis were collected over four consecutive days. Plasma N/OFQ and U-II concentrations were determined by radioimmunoassay and compared with biochemical and clinical markers of illness severity, including serum creatinine, bilirubin, platelet and white cell counts, admission APACHE II and serial SOFA scores.

RESULTS

Median (inter-quartile range) admission plasma N/OFQ concentrations in sepsis were higher in patients who died within 30 days (n=4) compared with survivors (n=17); 3.0 (2.5-5.0) vs 1.0 (1.0-2.5) pg ml(-1) (P=0.028). Plasma N/OFQ concentrations were increased in a subgroup of five patients who had undergone major gastrointestinal surgery. There were no significant changes in plasma U-II concentrations. There were no correlations between plasma U-II and N/OFQ concentrations and markers of illness severity and organ system dysfunction.

CONCLUSIONS

Plasma N/OFQ concentrations were increased in critically ill patients with sepsis who had undergone major gastrointestinal surgery and in patients who subsequently died. Further work is required to clarify the significance of plasma N/OFQ concentrations in sepsis.

Does cigarette smoking increase plasma urotensin II concentrations?

OBJECTIVE

Human urotensin II (UII) acts on the urotensin (UT) receptor and is the most potent mammalian vasoconstrictor identified to date. The role of UII in human cardiovascular regulation remains unclear, and the results of plasma measurements have been conflicting, perhaps because different measurement techniques have been used. The effects of cigarette smoking on plasma UII concentrations are unknown. The primary aim of our study was to demonstrate whether cigarette smoking had any effect on plasma UII concentrations in otherwise healthy volunteers. Our secondary aim was to compare the results obtained from assaying simultaneously using both radioimmunoassay (RIA) and immunoluminometric assay (ILMA).

METHODS

Blood was taken from 20 healthy male non-smokers and 20 healthy male cigarette smokers. Plasma was separated and stored at -70 degrees C. Samples were batch analysed simultaneously for UII using RIA and ILMA.

RESULTS

Median (range) plasma UII concentrations were lower in non-smokers [1.67 (1.0-2.27) pg ml(-1)] compared to smokers [2.62 (1.87-3.46) pg ml(-1)] (P = 0.03) measured using RIA. Those who had smoked a cigarette in the 10 min before sampling had greater concentrations of UII [3.10 (1.87-4.60) pg ml(-1)] compared to controls (P = 0.01). Plasma UII concentrations determined by ILMA were consistently low with no differences between groups.

CONCLUSION

The data obtained by RIA show that smoking may increase plasma concentrations of UII with a more pronounced increase when a cigarette has been smoked recently. There was a complete lack of correlation between RIA and ILMA for the whole data set, which suggests that some of the variability in plasma UII reported in the literature may result from differences between assays.

Influence of the parathyroid glands on bone metabolism

Bone is a classic target tissue for parathyroid hormone (PTH), whose calciotropic effect is mediated largely via catabolic actions on this tissue. Paradoxically, PTH also exerts anabolic actions, with intermittent injections of PTH or its amino-terminal fragments causing an increase in bone formation and bone mass, actions that form the basis for the use of PTH in the treatment of osteoporosis. Besides vitamin D, PTH is the only other known bone anabolic agent. High-affinity PTH receptors (PTH-1R) have been detected on osteoblasts and osteoclasts (albeit in lower numbers). Bone turnover, which includes activation of osteoclasts and osteoblasts, appears to be best reflected not by absolute concentrations of PTH (which can vary based on the assay and antibody used) but by a balance of circulating full-length PTH-(1-84) and amino-terminally truncated C-PTH fragments. When PTH-(1-84) is predominant, bone turnover is promoted. Among PTH fragments, PTH-(7-84) appears to be the most potent antagonist of PTH-(1-84). The mechanisms involved in these effects are unclear although mediation via unique C-terminal receptors has been suggested. We propose that, within the range of total PTH (100-1000 pg mL(-1)), the ratio of PTH-(1-84)/C-PTH fragment is a valuable tool for diagnosis of bone turnover. Data indicate that at PTH levels < 100-150 pg mL(-1) and > 1000 pg mL(-1), the ratio looses its predictive power. Assay type, patient characteristics (race, underlying renal disease) and treatment attributes (vitamin D, corticosteroids, phosphate binders) have an impact on the PTH ratio, and care should be used in interpreting assay results and making subsequent treatment decisions.

Impairment of sustained attention after major gynaecological surgery *

BACKGROUND AND OBJECTIVES

The sustained attention to response task (SART) test is a sensitive indicator of deficits in sustained attention and is simple to perform. Sustained attention is impaired for a short period after minor surgery under general anaesthesia but the magnitude and duration of this effect after major surgery is unknown. We used the SART test to investigate deficits in sustained attention in patients undergoing major surgery under general anaesthesia.

METHODS

The SART test was completed before surgery and at 24, 48 and 72 h postoperatively by 20 ASA I-II female patients (mean age 48.6 yr) undergoing total abdominal hysterectomy under general anaesthesia. It was also completed by 20 age-matched female controls at similar time intervals to evaluate the effect of repeated test performance.

RESULTS

There was a significant (P < 0.05) interaction between the groups in number of errors made (a measure of sustained attention deficit). The number of errors decreased in control subjects on repeated performance of the SART test but remained unchanged in patients undergoing total abdominal hysterectomy. The differences between groups remained significant after 72 h (P < 0.05). Patients' overall response times slowed significantly at 24-48 h (P < 0.05), but this recovered by 72 h after surgery. In contrast, overall response times in the control group tended to accelerate on repeated performance of the SART.

CONCLUSIONS

The results of this study suggest that 72 h following major surgery patients have deficits in sustained attention compared with controls. Control subjects demonstrated a marked learning effect on repeated test performance compared with patients.

Differential effects of calmodulin and protein kinase C antagonists on bone resorption and acid transport activity

Tamoxifen inhibits bone resorption by disrupting calmodulin-dependent processes. Since tamoxifen inhibits protein kinase C in other cells, we compared the effects of tamoxifen and the PKC inhibitor, bis indolylmaleimide II (bIM), on bone resorption and acid transport activity in isolated membrane vesicles. Bis indolylmaleimide inhibited bone resorption 50% with an IC50 approximately 3 microM, as well as acid transport activity in a concentration -dependent manner with an IC50 of approximately 0.4 IM. The IC50 of bIM for inhibiting acid transport activity was similar to that of calmodulin antagonists. The potassium ionophore, valinomycin, failed to restore bIM or tamoxifen-dependent inhibition of acid transport, suggesting that bIM and tamoxifen both inhibit H(+)-ATPase activity. Half maximal inhibitory concentrations of tamoxifen and bIM were not additive in acid transport assays, suggesting different sites of action. Furthermore, exogenous calmodulin blocked tamoxifen, but not bIM, -dependent inhibition of acid transport. We also compared the effects of tamoxifen and bIM on phosphorylation of proteins in isolated membrane fractions as determined by 32P incorporation and autoradiography. Tamoxifen had no effect on protein phosphorylation in contrast to bIM, which inhibited phosphorylation of eight proteins with different apparent kinetics. The data suggest that, while tamoxifen and bIM both affect H(+)-ATPase activity, the mechanisms of action are different.

Increasing Plasmodium falciparum malaria in southwest London: a 25 year observational study

AIMS

To identify changes in the presenting number and species of imported malaria in children in southwest London.

METHODS

A prospective single observer study over 25 years (1975-99) of all cases of paediatric malaria seen at St George's Hospital.

RESULTS

A confirmed diagnosis was made in 249 children (56% boys; 44% girls; median age 8.0 years). Of these, 53% were UK residents and 44% were children travelling to the UK. A significant increase was noted in the number of cases over the 25 years (1975-79: mean 4.8 cases/year; 1990-99: mean 13.7 cases/year). Over the 25 years Plasmodium falciparum was seen in 77%, P vivax in 14%, P ovale in 6%, and P malariae in 3% of cases. P falciparum had increased in frequency (1975-79: P falciparum 50%, P vivax 50%; 1990-99: P falciparum 82%, P vivax 6%), associated with an increase in the proportion of children acquiring their infection in sub-Saharan Africa. Median time between arrival in the UK to the onset of fever was: P falciparum, 5 days; P ovale, 25 days; P malariae, 37 days; and P vivax, 62 days. Median time interval between the onset of fever to commencement of treatment was 4 days. This had not improved over the 25 year period. Only 41% of UK resident children presenting to hospital had taken prophylaxis and the overall number of symptomatic children taking no prophylaxis was increasing.

CONCLUSION

Imported childhood P falciparum malaria is increasing in southwest London associated with increasing travel from sub-Saharan Africa. Over the 25 year period there has been no improvement in chemoprophylaxis rates or time to diagnosis.

Minimally invasive direct coronary artery bypass surgery under high thoracic epidural

IMPLICATIONS

This report describes the use of high-thoracic epidural anesthesia for a patient undergoing minimally invasive direct coronary artery bypass.

Dielectrophoretic assembly of electrically functional microwires from nanoparticle suspensions

A new class of microwires can be assembled by dielectrophoresis from suspensions of metallic nanoparticles. The wires are formed in the gaps between planar electrodes and can grow faster than 50 micrometers per second to lengths exceeding 5 millimeters. They have good ohmic conductance and automatically form electrical connections to conductive islands or particles. The thickness and the fractal dimension of the wires can be controlled, and composite wires with a metallic core surrounded by a latex shell can be assembled. The simple assembly process and their high surface-to-volume ratio make these structures promising for wet electronic and bioelectronic circuits.