A survey of the use of 2D ultrasound guidance for insertion of central venous catheters by UK consultant paediatric anaesthetists

BACKGROUND AND OBJECTIVE

National Institute for Clinical Excellence guidance states that 2D imaging ultrasound guidance should be used when inserting internal jugular venous lines in adults and children in the elective situation and should be considered in most clinical circumstances requiring central venous catheter insertion. This survey explored the availability, training and use of ultrasound devices by consultant paediatric anaesthetists in the UK.

METHODS

A questionnaire was distributed to UK members of the Association of Paediatric Anaesthetists of Great Britain and Ireland.

RESULTS

There was a response rate of 63% and of those responding, 212 (81%) inserted paediatric central venous catheters. Ultrasound devices were available in the workplace of 216 (82%) and the average number of devices available per department was two. For elective paediatric theatre cases, 26% of paediatric anaesthetists with access to an ultrasound device always used it when inserting an internal jugular central venous line. The majority (74%) of respondents had received training in the use of 2D ultrasound.

CONCLUSIONS

National Institute for Clinical Excellence guidance on the use of ultrasound locating devices for placing central venous catheters is not universally adhered to. Among the reasons for this are problems with availability of equipment, lack of training in the use of ultrasound and non-acceptance of the guidelines.

Routine staging radiology is not needed for all breast cancer patients

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Background: Early stage breast carcinoma is unlikely to have undergone metastatic spread at the time of presentation. The utility of routine staging liver ultrasound (LUS) and bone scan (BS) in early stage disease is unclear. We postulate that early stage breast cancer patients do not need routine radiological staging. Methods: We studied 200 patients with a diagnosis of invasive breast carcinoma. 100 with symptomatic breast cancer (SBC) and 100 with screen detected (SD). Patients’ histology, tumour markers (CEA, CA 15.3), hormone receptor status, CXR, LUS and BS results were reviewed. Results: All patients underwent curative surgery for early stage invasive breast cancer. 3 patients had liver metastases diagnosed by LUS. Two of these patients were from the SBC and one from SD (grade ≥2, mean tumour size 2.2 cm). 4 patients had bony metastases diagnosed by BS. Three of these were from the SBC and one from SD (grade ≥2, mean tumour size 3.2 cm.). No patients with low-grade T1 tumours had signs of metastasis on BS or US. Conclusions: The incidence of metastatic disease is very low in newly diagnosed early stage breast carcinoma. Our results suggest that patients with low-grade T1 tumours do not need staging BS or US.

No significant financial relationships to disclose.

Size and shape of the posterior neck muscles measured by ultrasound imaging: normal values in males and females of different ages

Measurements of muscle strength or size are valuable indicators of muscle status in health and disease. When force cannot be measured directly, due to a particular muscle being one of a functional group or because of pain, size measurements may be the only option. For such data to be useful, normal values for age and gender are necessary. Procedures for scanning and measuring semispinalis capitis and the deep posterior neck muscles (semispinalis cervicis, multifidus and rotatores) using ultrasound imaging are described and normal data provided on size, shape and symmetry of these muscles from a sample of 99 healthy subjects (46 males aged 20-72 years and 53 females aged 18-70 years). Significant gender differences were found (P<0.001) but muscle size did not alter significantly with age. Between-side symmetry can be used to assess abnormality of the deep neck muscle group but not semispinalis capitis. A regression equation is provided for predicting the cross-sectional area (CSA) of the deep neck muscles from spinous process length in males. Clinically, linear measurements can be used to predict the neck muscle CSAs (r=0.66-0.84, P<0.001). The method described for assessing the neck muscles is a potentially valuable tool in clinical practice.

Ultrasound imaging of lumbar multifidus muscle: normal reference ranges for measurements and practical guidance on the technique

This cross-sectional, prospective study aimed to produce normal reference data for measurements of the lumbar multifidus muscle. A total of 120 subjects, 68 females (aged 20-64 years) and 52 males (20-69 years) were studied. Bilateral transverse ultrasound images were made of multifidus at the fourth and fifth lumbar vertebrae (L4 & L5). Cross-sectional area (CSA, cm(2)) and linear dimensions (AP, anteroposterior; Lat, lateral) were measured and the latter expressed as a ratio (AP/Lat) to reflect shape. Relationships between CSA and anthropometric measures were examined. Multifidus CSA was larger in males (P<0.001) and age had no effect. The CSA was larger at L5 than L4 (P<0.001) and highly correlated between the two levels (males r=0.82, females 0.80). Differences in muscle shape were observed for gender, age and vertebral level. Between-side symmetry was high for size but not shape (CSA <10% difference). Linear measurements multiplied (APxLat) correlated highly with CSA (all groups r0.94, P<0.0001). The AP dimension was also acceptably predictive of CSA at L4 (r0.79). There were no clinically useful correlations between CSA and anthropometric measures. These findings provide normal references ranges for objective assessment of lumbar multifidus. This paper also addresses specific practical issues when scanning multifidus.

Spontaneous rupture of the liver following a normal pregnancy and delivery

Liver haematoma and rupture is a rare but potentially devastating complication of pregnancy. The majority of cases are associated with severe preeclampsia. We report a case of spontaneous hepatic rupture in a 39-year old woman following a normal pregnancy and delivery. Shoulder tip pain and serum haemoglobin of 6.8 prompted immediate imaging with computed tomography. A large subcapsular haematoma involving the right lobe of the liver was identified and managed conservatively. This diagnosis should be considered in the patient who presents with pain in the upper part of the abdomen and signs of haemorrhagic shock, even in the case of an uncomplicated pregnancy.

Injury prevention during physical activity in the Australian Defence Force

INTRODUCTION

Injuries sustained by Australian Defence Force (ADF) personnel during non-combat military training and sports activity are associated with increasing costs due to work days lost, medical treatment, compensation, and early retirement. In 2001, the ADF commissioned a systematic review of the evidence-base for reducing injuries associated with physical activity, while at the same time improving physical activity participation rates to sustain a trained, fit and deployable workforce.

METHOD

Literature from on-line library databases, relevant unclassified military reports, and material from previously published sport-specific injury countermeasure reviews were systematically and critically analysed to address the study aims.

RESULTS

Modification of intensity, frequency and duration of basic military training activities and improved equipment is likely to reduce injury occurrence. Sports injury countermeasures used for the civilian population have merit for the ADF physical activity program. Injury countermeasures should be designed to minimise any possible deterrent effect on the motivation to participate in regular physical activity. Increasing the participation of ADF personnel in physical activity in the presence of evidence-based injury prevention strategies has the potential to increase health, fitness and deployability with minimal impact on injury frequency.

CONCLUSION

Recommendations arising from the review include injury intervention trials in basic military training and sports. These and other interventions should be supported by refinement to ADF injury surveillance systems. Research should focus on interventions with the greatest gain for fitness, deployability, and cost effectiveness.

The beta fibrinogen gene G-455-A polymorphism is a risk factor for Legg-Perthes disease

Legg-Perthes disease is a pediatric hip disorder characterized by avascular necrosis of the femoral head. The etiology of Legg-Perthes disease may involve repeated interruptions of the blood supply to the proximal femur. Thus, the role of thrombosis in Legg-Perthes disease is of interest. The focus of this analysis is an evaluation of the relationship between Legg-Perthes disease and the beta fibrinogen gene G-455-A polymorphism in 55 cases of Legg-Perthes disease and 56 age, race, and gender-matched healthy controls. Parents of subjects completed a questionnaire about their child's lifestyle and medical history. Blood was obtained for plasma and DNA analysis. Study subjects were predominantly white (93%), male (77%) and under age 16 (70%). Cases were more likely to be exposed to passive smoke than were controls (odds ratio 5.6, 95% confidence interval 2.0-12.0). Assuming a dominant genetic model, individuals who possessed either the G/A or A/A genotype were over three times more likely to have Legg-Perthes disease compared to those without the polymorphism (odds ratio 3.4, 95% confidence interval 1.5-7.8). Separate analyzes by smoke exposure revealed that the excess risk of the G-455-A polymorphism occurred in those exposed (odds ratio 7.0) as opposed to those unexposed to passive smoke (odds ratio 1.9). Although this difference in the odds ratios is not statistically significant (P=0.2), it suggests a possible interactive effect of cigarette smoke and the b fibrinogen gene G-455-A polymorphism in the risk of developing Legg-Perthes disease.

Lumbar multifidus muscle size does not differ whether ultrasound imaging is performed in prone or side lying

This methodological study examined the influence of body position when measuring multifidus muscle size using real-time ultrasound imaging. Previous studies examined multifidus with the subject prone but people with certain conditions cannot be studied in this position, so side lying was investigated as an alternative posture. In 20 normal females (aged 19-45 years), the cross-sectional area (CSA) of lumbar multifidus was measured at the level of the fifth lumbar vertebra (L5) on both the right and left sides, with the subject in prone and in side lying. Multifidus CSA was highly correlated between the two positions on both the right (r=0.90) and left (r=0.91) sides. Paired t-tests found no significant differences between the measurements made in the two scanning postures (right P=0.77; left P=0.16). Bland and Altman plots showed good agreement between the two positions, with no systematic difference. These findings demonstrate that measurements of lumbar multifidus at L5 can be made in either prone or side lying and a valid comparison of the results obtained in both positions can be made.

Cryptorchidism: a general surgical perspective

BACKGROUND

The treatment of cryptorchidism has changed, with surgery now advocated before the age of two years. Delayed treatment affects fertility, malignant potential and psychological stress.

AIMS

To assess the pattern of referral of cryptorchid patients to a surgical clinic, management and follow-up.

METHODS

A four-year review of 114 cryptorchid patients examined age at presentation, waiting time, timing of surgery and length of follow-up.

RESULTS

The mean age at presentation to the surgical clinic was 6.7 years (neonatal to 71). The mean age at orchidopexy was 5.6 years. Seventy per cent had a surgical procedure within eight weeks of presentation to a surgeon. Seven per cent were kept under surveillance until a maximum age of three years before orchidopexy was considered. Only 29% proceeded to surgery before the age of two. Seventeen were referred to a paediatric urology unit for further management.

CONCLUSIONS

Orchidopexy seems prudent between one and two years of age. Only one-quarter of patients underwent early orchidopexy. It is vital that it is detected early, by paediatricians at birth or the general practitioners (GPs) at the six-week check up. Prompt referral to a surgeon with a paediatric interest is essential in order to permit surveillance or surgery.

Probabilistic methods in BCI research

This paper suggests a probabilistic treatment of the signal processing part of a brain-computer interface (BCI). We suggest two improvements for BCIs that cannot be obtained easily with other data driven approaches. Simply by using one large joint distribution as a model of the entire signal processing part of the BCI, we can obtain predictions that implicitly weight information according to its certainty. Offline experiments reveal that this results in statistically significant higher bit rates. Probabilistic methods are also very useful to obtain adaptive learning algorithms that can cope with nonstationary problems. An experimental evaluation shows that an adaptive BCI outperforms the equivalent static implementations, even when using only a moderate number of trials. This suggests that adaptive translation algorithms might help in cases where brain dynamics change due to learning effects or fatigue.

Quantification of river-capture-induced base-level changes and landscape development, Sorbas Basin, SE Spain

The Aguas/Feos river system of the Sorbas Basin, SE Spain was captured by an aggressive subsequent stream c. 100 ka. The consequence of the capture event was twofold: (1) basin-scale drainage reorganization via beheading of the southward flowing Aguas/Feos system and re-routing the drainage eastwards into the Vera Basin; and (2) the creation of a new, lower base level and associated upstream propagation of a wave of incision.

The sequence of pre- and post-capture events are well established from previous studies of the Quaternary terrace record. Using these studies, this paper makes the first attempt to quantify the impact of river capture in terms of spatial and temporal variations in rates of incision, sediment flux and surface lowering. This was carried out through construction of 43 valley cross-sections from the ‘captured’ (Upper Aguas), ‘beheaded’ (Feos) and ‘capturing’ streams (Lower Aguas) within the central-southern parts of the Sorbas Basin. Dated pre- and post-capture terrace and corresponding strath levels were plotted on to the valley cross-sections enabling incision amounts, rates and valley cross-sectional areas to be calculated. Sediment fluxes were calculated using a mean valley section method. Surface lowering calculations were made through reconstruction of the top basin-fill surface and subtraction from the modern contour values.

The lowering of base level has resulted in a dramatic increase in incision upstream of the capture site by a factor of 4 to 20. This in turn has been associated with significant pre- and post-capture changes in valley shape. The increased incision resulted in dramatic post-capture increases in valley erosion upstream and downstream of the capture site by a factor of 2 to 9 which can be related to changes in associated stream power as a function of increased gradient and discharge. In excess of 60% of the landscape change can be accounted for by valley-constrained erosion as opposed to overall surface lowering.

Managing faecal retention and incontinence in neurodisability

The large number of patients with faecal retention and/or incontinence in continuing care wards and rehabilitation units presents a considerable challenge. In order to maintain dignity and minimize the unpleasant odour so commonly associated with these wards and units, effective bowel management should be planned for individual patients. For an effective bowel management regime a team approach should be adopted, involving, where possible, the patient and carer as well as all the health professionals administering the care. Two case studies illustrate the use of assessment and management of bowel problems in patients with severe complex neurodisability. Bowel dysfunction in this patient population, in general, is poorly covered in the literature. The present article, by relating theory to practice, offers information and guidance for nurses working with patients who have bowel-related problems.

Sigmoid volvulus after laparoscopic cholecystectomy. An unusual complication

Laparoscopic cholecystectomy has become the standard surgical technique for treating symptomatic gallbladder disease. Intestinal obstruction after laparoscopic cholecystectomy is unusual. We present the case of a 37-year-old man who underwent routine laparoscopic cholecystectomy for cholelithiasis using an American four-port technique. He was well 24 h postoperatively and was discharged. He presented 36 h later with clinical features of bowel obstruction. A sigmoid loop was seen on a plain abdominal radiograph. Laparotomy revealed distension of the large and small bowel to the level of the rectosigmoid junction and a sigmoid volvulus. This was reduced by releasing adhesions to lengthen the sigmoid mesentery. A primary sigmoid resection and anastomosis was not attempted due to luminal discrepancy and lack of bowel preparation. The patient underwent interval sigmoid colectomy 2 weeks later. A sigmoid volvulus following laparoscopic cholecystectomy has not been previously reported. It may be related to the induction of the pneumoperitoneum, combined with the lateral tilt of the table and a long redundant sigmoid colon. This case expands the range of potential complications associated with laparoscopic cholecystectomy and illustrates the need for continued vigilance after apparently routine procedures.

Verification of lung dose in an anthropomorphic phantom calculated by the collapsed cone convolution method

Verification of calculated lung dose in an anthropomorphic phantom is performed using two dosimetry media. Dosimetry is complicated by factors such as variations in density at slice interfaces and appropriate position on CT scanning slice to accommodate these factors. Dose in lung for a 6 MV and 10 MV anterior-posterior field was calculated with a collapsed cone convolution method using an ADAC Pinnacle, 3D planning system. Up to 5% variations between doses calculated at the centre and near the edge of the 2 cm phantom slice positioned at the beam central axis were seen, due to the composition of each phantom slice. Validation of dose was performed with LiF thermoluminescent dosimeters (TLDs) and X-Omat V radiographic film. Both dosimetry media produced dose results which agreed closely with calculated results nearest their physical positioning in the phantom. The collapsed cone convolution method accurately calculates dose within inhomogeneous lung regions at 6 MV and 10 MV x-ray energy.

Auditory evoked potentials to spectro-temporal modulation of complex tones in normal subjects and patients with severe brain injury

In order to assess higher auditory processing capabilities, long-latency auditory evoked potentials (AEPs) were recorded to synthesized musical instrument tones in 22 post-comatose patients with severe brain injury causing variably attenuated behavioural responsiveness. On the basis of normative studies, three different types of spectro-temporal modulation were employed. When a continuous 'clarinet' tone changes pitch once every few seconds, N1/P2 potentials are evoked at latencies of approximately 90 and 180 ms, respectively. Their distribution in the fronto-central region is consistent with generators in the supratemporal cortex of both hemispheres. When the pitch is modulated at a much faster rate ( approximately 16 changes/s), responses to each change are virtually abolished but potentials with similar distribution are still elicited by changing the timbre (e.g. 'clarinet' to 'oboe') every few seconds. These responses appear to represent the cortical processes concerned with spectral pattern analysis and the grouping of frequency components to form sound 'objects'. Following a period of 16/s oscillation between two pitches, a more anteriorly distributed negativity is evoked on resumption of a steady pitch. Various lines of evidence suggest that this is probably equivalent to the 'mismatch negativity' (MMN), reflecting a pre-perceptual, memory-based process for detection of change in spectro-temporal sound patterns. This method requires no off-line subtraction of AEPs evoked by the onset of a tone, and the MMN is produced rapidly and robustly with considerably larger amplitude (usually >5 microV) than that to discontinuous pure tones. In the brain-injured patients, the presence of AEPs to two or more complex tone stimuli (in the combined assessment of two authors who were 'blind' to the clinical and behavioural data) was significantly associated with the demonstrable possession of discriminative hearing (the ability to respond differentially to verbal commands, in the assessment of a further author who was blind to the AEP findings). Behavioural and electrophysiological findings were in accordance in 18/22 patients, but no AEPs could be recorded in two patients who had clear behavioural evidence of discriminative hearing. The absence of long-latency AEPs should not, therefore, be considered indicative of complete functional deafness. Conversely, AEPs were substantially preserved in two patients without behavioural evidence of discriminative hearing. Although not necessarily indicative of conscious 'awareness', such AEP preservation might help to identify sentient patients who are prevented by severe motor disability from communicating their perception.

A prospective study of the length of stay of 150 children following tonsillectomy and/or adenoidectomy

This is a prospective study of the length of stay in 150 children who underwent adenoidectomy, tonsillectomy and adenotonsillectomy with and without grommets. Seventeen children were unsuitable for same-day discharge because of coexisting medical conditions and 39 because of social factors, which meant that 94 children were potentially suitable for same-day discharge. All patients received a standardized surgical and anaesthetic technique. Twenty-eight of the 94 children were kept in for postoperative complications thus 66 (70%) were treated as day cases. Haemorrhage occurred in one (1%); nausea and vomiting prevented discharge of 11 cases; and a further seven were kept overnight since the children were reluctant to eat and drink. Pain control was a problem with nine children (two had nausea and vomiting as well). Two patients had other complications. These results are compared to those found in the literature. Children who have adenoidectomy without tonsillectomy are more suitable for day surgery (P < 0.001). Because of the high risk of minor complications, the authors recommend that children who have tonsillectomy as part of the procedure should be treated from inpatient beds even when discharged on the same day.

Improvement of intraoperative somatosensory evoked potentials by ketamine

Many anaesthetics effect the latency and amplitude of somatosensory evoked potentials (SSEP). We present a patient who underwent two anterior/posterior spine fusions (A/PSF) at age 11 and 12 years old after resection of a spinal astrocytoma. She did have residual neurologic deficits of her lower extremities. SSEPs were unobtainable during the first surgery using an opioid-based anaesthetic. A ketamine-based anaesthetic was used for the second surgery and SSEPs were easily monitored. No other factors seem to have changed between the two surgeries. The anaesthetic management during each procedure is reviewed and the contributions of other factors to SSEP monitoring discussed.

Reliability of assessment tools in rehabilitation: an illustration of appropriate statistical analyses

OBJECTIVE

To provide a practical guide to appropriate statistical analysis of a reliability study using real-time ultrasound for measuring muscle size as an example.

DESIGN

Inter-rater and intra-rater (between-scans and between-days) reliability.

SUBJECTS

Ten normal subjects (five male) aged 22-58 years.

METHOD

The cross-sectional area (CSA) of the anterior tibial muscle group was measured using real-time ultrasonography.

MAIN OUTCOME MEASURES

Intraclass correlation coefficients (ICCs) and the 95% confidence interval (CI) for the ICCs, and Bland and Altman method for assessing agreement, which includes calculation of the mean difference between measures (d), the 95% CI for d, the standard deviation of the differences (SDdiff), the 95% limits of agreement and a reliability coefficient.

RESULTS

Inter-rater reliability was high, ICC (3,1) was 0.92 with a 95% CI of 0.72 --> 0.98. There was reasonable agreement between measures on the Bland and Altman test, as d was -0.63 cm2, the 95% CI for d was -1.4 --> 0.14 cm2, the SDdiff was 1.08 cm2, the 95% limits of agreement -2.73 --> 1.53 cm2 and the reliability coefficient was 2.4. Between-scans repeatability was high, ICCs (1,1) were 0.94 and 0.93 with 95% CIs of 0.8 --> 0.99 and 0.75 --> 0.98, for days 1 and 2 respectively. Measures showed good agreement on the Bland and Altman test: d for day 1 was 0.15 cm2 and for day 2 it was -0.32 cm2, the 95% CIs for d were -0.51 --> 0.81 cm2 for day 1 and -0.98 --> 0.34 cm2 for day 2; SDdiff was 0.93 cm2 for both days, the 95% imits of agreement were -1.71 --> 2.01 cm2 for day 1 and -2.18 --> 1.54 cm2 for day 2; the reliability coefficient was 1.80 for day 1 and 1.88 for day 2. The between-days ICC (1,2) was 0.92 and the 95% CI 0.69 --> 0.98. The d was -0.98 cm2, the SDdiff was 1.25 cm2 with 95% limits of agreement of -3.48 --> 1.52 cm2 and the reliability coefficient 2.8. The 95% CI for d (-1.88 --> -0.08 cm2) and the distribution graph showed a bias towards a larger measurement on day 2.

CONCLUSIONS

The ICC and Bland and Altman tests are appropriate for analysis of reliability studies of similar design to that described, but neither test alone provides sufficient information and it is recommended that both are used.

Primary breast lymphoma

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Larval locomotion of the lancelet

The ontogeny of locomotion in the Florida lancelet (Branchiostoma floridae) is described for the early developmental stages through to metamorphosis. Recently hatched larvae swam at speeds up to 1 mm s-1 using their epidermal cilia; this speed decreased to approximately 0.2 mm s-1 by 60 h after fertilization. Changes in cilia-powered fluid flow could be related to changes in the distribution and density of the epidermal cilia during development. Cilia-powered hovering was the dominant behaviour until metamorphosis. The amount of energy expended by ciliating larvae ranged from 10(-9) to 10(-11) W depending upon the age of the larvae and the model used for estimating the power output. The majority of the energy expended was in the ciliary sublayer next to the body. The first muscular movements were seen in larvae 16 h old. These simple flexions increased in complexity during the first 72 h until a complete undulatory (approximately sinusoidal) wave was propagated down the body in the adult manner. The frequency of undulatory beating increased to approximately 10 Hz during the first 48 h, and the larval head showed a large degree of yaw. Lancelet larvae were also capable of high-speed undulations 5&shy;10 times faster than regular swimming motions. In contrast to ciliating larvae, the energy expended during undulation was at least an order of magnitude greater (10(-8) to 10(-6) W) and radiated beyond the ciliary sublayer.

Premature failure of battery-powered syringe pumps

Failure of battery-powered equipment during the interhospital transfer of patients is potentially life threatening. The time to failure of 60 fully-charged identical syringe pumps (20 from each batch purchased in 1992, 1994 and 1995) was measured. Older pumps were associated with less predictable charge capacity, with 40% of the 1992 pumps failing within 60 min. The premature failure of these pumps is most likely due to poor battery care. It is unsafe to assume that a fully-charged, battery-powered pump will continue to function throughout a long transfer. The routine carriage of spare pumps or a backup power supply is recommended.

Evoked potential monitoring of the upper extremities during thoracic and lumbar spinal deformity surgery: a prospective study

We prospectively investigated the usefulness of somatosensory evoked potential (SEP) monitoring to detect clinically significant peripheral nerve or brachial plexus compression in the upper extremities during spinal deformity surgery. All patients had bilateral median and ulnar nerve SEPs evaluated as a baseline, both intermittently throughout the surgical procedure and at termination of surgery. This information was correlated with pre- and postoperative upper extremity neurologic examinations. Twenty-five upper extremities in 21 patients had intraoperative SEP changes consisting of at least a 60% decline in amplitude or a 10% increase in latency. On many occasions, repositioning of the upper extremities improved the SEP responses to acceptable baselines. Overall, SEP monitoring of the upper extremities was 78% sensitive for detecting upper extremity sensory deficits, 100% sensitive for detecting combined sensory and motor deficits, and 98.5% specific for predicting normal postoperative upper extremity function. We recommend the simultaneous electrophysiologic monitoring of the upper and lower extremities during spinal surgery to allow identification of brachial plexus and/or peripheral nerve stretch/compression that may be amenable to intraoperative correction.

Audit of complete axillary dissection in early breast cancer

The role of complete axillary dissection (CAD) in the management of breast cancer is controversial and largely unresolved. Acceptance of the results of trials incorporating CAD assumes that the axillary dissection is truly complete. To address this point, and also to define quality control criteria for this operation within our unit, we audited 100 consecutive axillary dissections as follows: the primary surgeon performed what he/she felt to be a thorough CAD and submitted separately the contents of level I, II and III for pathological evaluation; a second surgeon then independently assessed the dissection and arbitrarily labelled any further excised tissue as level IV. Level IV nodes were retrieved in 38% of cases. Tumour involvement of level IV nodes was noted in 5% (2/38) of dissections where lymph nodes were retrieved, but in neither instance was pathological staging altered. There was a significant decrease in the incidence of level IV node retrieval from 47% (28/60) in the first 6 months of audit to 20% (8/40) subsequently. This novel approach to our continuing audit identified quality control criteria for this procedure in our unit and suggested that audit of this kind benefits training.

High-performance liquid chromatographic monitoring of metabolic products resulting from the treatment of mouse hepatoma cells with N6-cycloalkylated nucleosides

High-performance liquid chromatography was used to analyze cell lysates and growth medium of mouse hepatoma cells, separately treated with N6-cyclopropyl-, N6-cyclobutyl-, and N6-cyclopentyladenosines, in an effort to gain insight into the mechanism by which these modified nucleosides exert their cytotoxic effect(s). The corresponding 5'-monophosphate of the respective modified nucleoside was detected in the separate cell lysate samples. Both the modified nucleoside and its corresponding 5'-monophosphate were detected in the separate growth medium samples and their relative concentrations therein were determined. These results indicate that the cytotoxicity of these N6-cycloalkylated nucleosides may be attributed to their 5'-monophosphates within the cells.

ABC of colorectal diseases. Colorectal trauma

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Reflex actions of knee joint afferents during contraction of the human quadriceps

(1) The spinal reflex actions of afferents stimulated by knee joint distension have been investigated in man. (2) Cannulation of the knee and infusion of saline raised intra-articular pressure, especially during quadriceps contraction. High pressures did not induce any sensation of pain. Pressure was taken as an index of joint proprioceptor activation. (3) Increased pressure progressively depressed the quadriceps H-reflex, both at rest and during quadriceps contraction. There was no indication of a threshold pressure for this inhibitory action. (4) It is concluded that joint distension inhibits quadriceps motoneurons through spinal pathways that still operate during voluntary contraction. These pathways could thus contribute to pathological weakness after joint injury. (5) Joint distension produced spatial facilitation of non-reciprocal inhibition of quadriceps H-reflexes from afferents in the tibial nerve.

Selenium metabolism and supplementation in patients with muscular dystrophy

We studied selenium metabolism in patients with Duchenne muscular dystrophy and in contrast to previous reports found no significant abnormalities in these patients. Supplementation of muscular dystrophy patients and control subjects with sodium selenite (1 mg selenium/day) induced a variable rise in the activity of the selenium-dependent enzyme glutathione peroxidase in plasma and red cells, but no significant change in muscle glutathione peroxidase activities. There was no effect of selenium supplementation on disease activity in the patients with muscular dystrophy. Thiobarbituric acid-reacting substances (an index of free radical-mediated lipid peroxidation) were elevated in the muscle of patients with Duchenne muscular dystrophy in contrast to patients with other forms of muscular dystrophy and control subjects. This elevation was unaffected by selenium supplementation.

Cardiac complications of total parenteral nutrition: the role of two-dimensional echocardiography in diagnosis

We report three cardiological complications of total parenteral nutrition in four patients, all of the complications were detected by two-dimensional echocardiography. We discuss these complications and make suggestions as to the role of echocardiography in patients on total parenteral nutrition.

Effects of joint pathology on muscle

The muscle wasting associated with joint damage may be highly selective; knee disorders produce quadriceps wasting but little change in the size of the hamstrings. This causes isolated quadriceps weakness, so predisposing to a position of knee flexion. Nociceptors and other receptors in and around the joint can have flexor excitatory and extensor inhibitory actions. At the knee, these receptors are likely to excite hamstrings and inhibit quadriceps. Although other actions could occur, quadriceps inhibition may be favored by a position of knee extension. Quadriceps inhibition will weaken voluntary contraction, reduce tone, and contribute to wasting of the muscle, further predisposing to a position of knee flexion. The potency of quadriceps inhibition may be considerable, even in the absence of perceived pain. A small, apparently trivial effusion (or even a clinically undetectable effusion) may cause important inhibition. In order to improve the orthopedist's ability to prevent flexion contracture of the injured or operated joint, he must look not only for ways of reducing joint pain, but also for ways of preventing activity in other joint afferents. For example, he must consider the possible effects of joint position, intraarticular pressure, suture-line tension, and afferent blockade.

The size and strength of the quadriceps muscles of old and young men

The mean isometric strength of the stronger quadriceps muscles of 12 healthy men in their seventies was 39% less than that of 12 healthy men in their twenties (P less than 0.001). The cross-sectional area of the quadriceps was measured at mid-thigh, by ultrasound scanning; the older men's stronger quadriceps were 25% smaller (P less than 0.001). The ratio of the stronger quadriceps' strength to its cross-sectional area was very similar in the old men to values obtained previously for both old and young women, but averaged 19% less than in the young men (P less than 0.02). Quadriceps size and strength were correlated in the old men (r = 0.77, P = 0.03) but not in the young men (r = 0.15). The principal axis of the relationship between quadriceps size and strength in the old men was very similar to those previously reported for both old and young women. The quadriceps strength of some young men is greater than would be expected from the size of the muscle.

Reflex inhibition of the quadriceps after meniscectomy: lack of association with pain

We have examined the severity and duration of reflex inhibition of quadriceps activation after arthrotomy and meniscectomy, its relationship with pain, and the effect of local anaesthesia on this relationship. Fourteen men, on completion of medial meniscectomy by arthrotomy, received either 10 ml (B10 group) or 15 ml (B15 group) of 0.5% bupivacaine hydrochloride ('Marcaine Plain') into the knee, or no injection (control group). Reflex inhibition of quadriceps was measured as the percentage reduction, from the ipsilateral preoperative value, in the integrated surface electromyogram recorded during maximal voluntary isometric contractions with the knee in extension. Pain during each contraction was recorded on a linear analogue scale. Unoperated limbs showed no evidence of quadriceps inhibition. In the operated limbs, at 1-2 h post-operatively, controls had both severe inhibition (median = 62%) and severe pain on attempting a maximal quadriceps contraction. The B10 group had similar inhibition but less pain (P less than or equal to 0.005, Wilcoxon 2-sample, 1-tailed test). In the B15 group both inhibition (P less than or equal to 0.05) and pain (P less than or equal to 0.01) were less than in the controls. These effects of bupivacaine had been lost by 4-5 h post-operatively. At 3-4 days, inhibition was still severe (median = 75%) in all three groups of patients but pain was only mild or absent. At 10-15 days, median inhibition was still 35%, but there was little or no pain. We conclude that postmeniscectomy inhibition is not simply due to perceived pain but is due, at least in part, to stimuli from the knee.

Hypophosphataemic osteomalacia and myopathy: studies with nuclear magnetic resonance spectroscopy

A patient with familial adult-onset hypophosphataemia, whose myopathy was closely related to the plasma phosphate concentration, was investigated by phosphorus nuclear magnetic resonance spectroscopy (31P n.m.r.) in vivo of the right flexor digitorum superficialis muscle. During hypophosphataemia induced by stopping oral phosphate a significant reduction in measured muscle strength occurred, but the ratios of the intramyocellular levels of phosphocreatine (PCr), adenosine triphosphate (ATP) and inorganic phosphate (Pi) remained unchanged at rest. During exercise these levels changed, as did the intramyocellular pH, but they did not differ from the pattern previously recorded in normal subjects. In four adults with inherited infantile-onset hypophosphataemia (vitamin D-resistant rickets, VDRR) without myopathy, the n.m.r. measurements were normal at rest and during exercise. In one patient with inherited hyperphosphataemia (tumoral calcinosis) the resting PCr: Pi ratio was significantly reduced.

Size and strength of the quadriceps muscles of old and young women

Muscle weakness and wasting may be evaluated objectively by dynamometry and compound ultrasound imaging. We have measured the voluntary isometric strength of the quadriceps muscles of healthy women in their 70s (n = 25) and in their 20s (n = 25) and have compared it with the mid-thigh cross-sectional area of the same muscles. The two groups of women showed similar variability when strength was measured on consecutive days (coefficients of variation: 8%). The older women were 35% weaker than the young women (P less than 0.001) and their quadriceps cross-sectional area was 33% less (P less than 0.001). Quadriceps strength and cross-sectional area were correlated (r = 0.66, P less than 0.001, elderly; r = 0.53, P less than 0.01, young) and the principal axis of the relationship was closely similar for the two groups of women. There is therefore no difference in the intrinsic strength of the quadriceps muscles of healthy women in their third and eighth decades. This report also provides normative data for the objective evaluation of quadriceps weakness and/or wasting in female patients. The techniques involved are straightforward, the dynamometer is easily made, and compound ultrasound imaging is widely available.

The contribution of reflex inhibition to arthrogenous muscle weakness

‘Arthrogenous muscle weakness’ is weakness of muscles acting about an injured or inflamed joint. The weakness may be due to loss of muscle or to inability to activate the muscle (Fig. 1). Weakness of the thigh muscles, and of the quadriceps in particular, is a common and important consequence of knee trauma, surgery or arthritis. Muscle weakness contributes significantly to disability and probably also renders the joint vulnerable to further damage (Fig. 1). This review starts with a brief discussion of the contribution of atrophy to weakness. It concentrates, however, on inhibition of quadriceps activation and suggests some therapeutic implications. It does not deal with the reduced oxidative capacity and increased fatiguability of disused muscle since, although important, these have not been part of our programme of work.

The effect of high-resistance training on the strength and cross-sectional area of the human quadriceps

Seventeen volunteers performed unilateral strength-training of the quadriceps with high-resistance, low-repetition, dynamic exercise, thrice weekly for an average of 5 weeks. Both before and after the training period, bilateral measurements were made of isometric quadriceps strength, quadriceps cross-sectional area (by ultrasound scanning), and thigh circumference. There were no significant changes in the untrained thighs. The trained quadriceps increased their isometric strength by more than they changed their cross-sectional area (mean increments = 15% and 6% respectively). Quadriceps hypertrophy was underestimated by measurements of thigh circumference and could not be predicted from them. We conclude that studies of localized muscle growth require direct measurements of the size of the muscle(s) concerned. Nevertheless, these may still underestimate the improvements in strength produced by high-resistance training.