Urgent 2-week referrals for CNS/brain tumours: a retrospective audit.

OBJECTIVE: To assess the effectiveness of the 2-week referral system for CNS/brain tumours and to contrast this with the number of patients with neurological cancers identified independently of this system. METHOD: Retrospective casenote review of patients referred to emergency neurology clinics pre-implementation of the 2-week referral system. Retrospective review of GP referral letters via this system and comparison to Department of Health referral guidelines. Review of corresponding casenotes to determine the actual neurological diagnosis. Identification of patients with CNS/brain tumours diagnosed independently of this system from a local CNS cancer register. RESULTS: Over a 3-month period pre-implementation of the referral system, of 12 patients referred as emergencies, none had CNS/brain cancer. Forty-three patients were referred via this system over a 9-month period to neurology departments of a teaching hospital and a district general hospital. Thirty per cent of the referrals did not follow the Department of Health guidelines. Only 9% actually had CNS tumours (two astrocytomas, two cerebral metastases). The remainder were diagnosed with chronic daily headache (10), epilepsy (5), migraine (3), demyelination (2), essential tremor (2), other (17). During this period at least 69 neurological cancers were identified independently of the 2-week system. CONCLUSION: These guidelines may increase diagnostic precision if adhered to rigidly. Inappropriate referrals have extended already lengthy outpatient waiting times in other specialities. We suggest early re-consideration of these guidelines and further study for earlier identification of CNS cancer.

An audit of the use of laser Doppler imaging (LDI) in the assessment of burns of intermediate depth.

This is the first report of an evaluation of the use of a laser Doppler imager (LDI) scanner in the assessment of burn depth in patients. It is based on a 6-month, prospective audit of 76 burns of intermediate depth. Clinical and LDI assessments of burn wound depth were recorded at 48-72 h post-injury. Histological confirmation of depth was obtained from those burns requiring surgery. A healing time of less than 21 days was taken as confirmation of the injury being an superficial dermal burn. The accuracy of LDI in the assessment of burn depth was 97%, compared with 60-80% for established clinical methods. This audit confirms that LDI is a very accurate measurement tool for the assessment of burn wound depth. We recommend that all burns of intermediate depth should be analysed in this way in order to ensure appropriate management of the burn, to avoid unnecessary surgery and to reduce hospital stay and costs.

Primary cerebral non-Hodgkin's lymphoma: problems with diagnosis and development of a protocol for management.

The prognosis for primary cerebral non-Hodgkin's lymphoma has improved markedly in the under-70 age group with the introduction of combined chemotherapy and radiotherapy. A review of our patients has revealed difficulty in obtaining definitive histology initially in 21% (9/43). We investigated the role of corticosteroids in these patients and found an idiosyncratic response in that there was no significance either of the cumulative dose (p > 0.424) or the length of treatment (p > 0.453) with the observed regression of lymphoma with corticosteroids. In order to avoid indiscriminate corticosteroid administration we have formulated a management protocol the entry point for which is a patient with enhanced computered tomography appearances of primary cerebral lymphoma.

Prothrombin complex concentrate for oral anticoagulant reversal in neurosurgical emergencies.

The incidence of spontaneous intracranial haemorrhage has increased markedly in line with the increased use of oral anticoagulant agents. Recent guidelines for reversal of this acquired coagulation defect in an emergency have been established, but they are not adhered to in all centres. Our unit is referred between 20 and 60 patients per year (1994-1999) who are anticoagulated and require urgent neurosurgical intervention. In order to investigate this, we performed a prospective study using prothrombin complex concentrate (PCC). PCC was given to the first six patients with intracranial haemorrhage admitted to the neurosurgical unit requiring urgent correction of anticoagulation (Group 1) and compared with patients receiving standard treatment with fresh frozen plasma and vitamin K (Group 2). Mean International Normalised Ratios of Group 1 were 4.86 pretreatment and 1.32 posttreatment, and of Group 2 were 5.32 and 2.30, respectively. Results for complete reversal and reversal time were significant for PCC with p < 0.001. We recommend PCC for rapid and effective reversal of warfarin in life-threatening neurosurgical emergencies.

Use of a pro forma for head injuries in the accident and emergency department--the way forward.

The aim of this study was to assess the quality of documentation of head-injured patients seen in three accident and emergency (A&E) departments using a specially designed head injury pro forma. A 4-week prospective study of a single head injury pro forma was followed by a second similar study with an improved version (two head injury pro formas, one for young children and babies, the other for older children and adults). The main outcome measures were the degree of completion of the pro forma and questionnaire responses from receptionists, nurses and doctors. A total of 1260 patients had their details completed on the pro forma in both studies. Compared with standard hand written A&E notes, the degree of completion of clinical details specific to the head injury were high, eg. over 95% for symptoms. The pro forma was generally well received by A&E staff, particularly after recommended improvements were made, and the majority of staff felt it should be introduced permanently into the A&E department. Concern about its use in cases of very minor head injury and multiple injuries were raised. As well as improved documentation, the pro forma facilitates the process of audit and may have an important role to play in information technology and computers in the future.

Radical excision of sacrococcygeal tumours.

Large sacrococcygeal tumours are rare and remain a difficult management problem. Chordomas are one of the most common tumours in this region and may account for 30-40 per cent of postrectal tumours. Four patients aged between 22 and 66 years, three with chordomas and one with a schwannoma, are described. Each was managed by a combined general and neurosurgical approach. Major radical excision of the tumour involving high amputation of the sacrum and lower sacral nerve root division was performed. These large lesions can be radically excised with limited postoperative morbidity and excellent preservation of neurological function, including sphincter control, provided that one S2 nerve root is left intact.

The effects of electric current on bacteria colonising intravenous catheters.

The effect of a direct electric current (10 microA) on the growth of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis was investigated. When the ends of negatively-charged intravascular catheters were placed in nutrient agar seeded with bacteria, circular zones of inhibition of bacterial growth were observed around the catheters. The zones ranged from 6 to 16 mm in diameter according to the organism under test. Zones of inhibition were not produced around positively-charged catheters. Bacteria colonising the surfaces of catheters were similarly affected by the application of a 10 microA electric current. A negative electric current applied to colonised catheters for 4 to 24 h significantly reduced the number of adherent viable organisms as compared to controls. The results demonstrated that a constant electric current of low amperage might be used to reduce bacterial colonisation of intravascular catheters. This may offer a novel means of protecting catheters and other prosthetic devices from associated sepsis in vivo.

Novel monochromatic optical density meter.

A novel monochromatic optical density meter is described for use with radiographic films. The principles of the instrument are outlined together with a brief description of the construction of a prototype model. The calibration of the meter shows high accuracy (r = 0.9999) in the optical density range 0-1.5 OD when compared to standard neutral density filters.

Effects of pH and temperature on the scanning Soret oximeter.

A new optical measurement technique based on spectral scanning (the scanning Soret oximeter) has previously been described. The technique has now been tested under extremes of physiological pH and temperature, the effects of which are shown to be negligible.

A novel electrical method for the prevention of microbial colonization of intravascular cannulae.

An electrical device designed to prevent microbial attachment to plastic intravascular cannulae is described. The device produced an electrical current (10 microA) in both carbon-impregnated and 'Hydrocath' cannulae. In-vitro models were utilized to demonstrate that the current can block several mechanisms by which microorganisms gain initial access to intravascular devices, including extra- and intra-luminal routes. The electrical system prevented organisms from traversing along both the external and internal surfaces of the cannulae. Effective prevention of cannula colonization was demonstrated subsequent to challenge with Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, Proteus mirabilis, Pseudomonas aeruginosa and Candida albicans. The findings suggest that the electrical device may offer in-vivo cannula protection from microbial attachment and colonization, thereby reducing the potential for infection.

Measurement technique for the determination of blood oxygen saturation.

A new optical measurement technique based on spectral scanning is described for the determination of oxygen saturation of whole blood. The principles of this technique are outlined, together with a calibration procedure used to test its feasibility in vitro. The preliminary results show that the accuracy of the new technique is of the order +/- 2% over the full range of oxygen saturation. This degree of accuracy is comparable with commercial CO-oximeters.

A laser Doppler scanner for imaging blood flow in skin.

This paper describes a novel medical instrument that produces an image of blood flow in the capillaries under the skin surface. A laser beam is used to detect blood cell motion from the Doppler broadening of the laser light scattered from the skin. The image is generated by scanning the laser beam in a raster. The design of a practical clinical instrument is outlined and some preliminary results are presented.

Can photography be used to measure isodose distributions of space irradiance for laser photodynamic therapy?

The space irradiance isodose distribution of light delivered in tissue by an interstitial optical fibre may be determined by photographing the light diffusing out of the tissue. Provided that a plane of symmetry is photographed, it is shown that there is no significant distortion of the isodose distribution measured in this way. Two series of photographs were taken to test the method. In one set, a partially reflecting film was used to simulate the presence of the missing tissue. Isodose distributions obtained were in agreement with the predictions of diffusion theory. The isodoses were "scaled' by measuring the space irradiance at one point with a bulb-tipped optical fibre. Optical parameters are deduced from the measurements. The method, which is simple and fast in use, should be of wide applicability.

Carbon dioxide laser irradiation of bacterial targets in vitro.

Agar targets seeded with Escherichia coli and Staphylococcus aureus in roll tubes simulating the vaginal vault were irradiated with a CO2 laser at various power densities and durations. Viable bacteria were detected in the plume emissions in all instances. Staphylococcus aureus was found to be more resistant to the thermal effects of lasing than E. coli. This suggests that CO2 irradiation of cervical lesions could disseminate viable particles which may be a hazard for patients and operators.

Wise Anaerobic Work Station: an evaluation.

The Wise Anaerobic Work Station permitted the growth of type cultures of a range of fastidious obligate anaerobes. In the isolation of anaerobic bacteria from clinical specimens the performance equalled that of a standard anaerobic jar incubated for 48 hours, and gave results superior to those obtained when incubation of jar cultures was interrupted at 24 hours. The Wise Anaerobic Work Station was easy to use and provided comfortable working conditions; running largely on industrial nitrogen, it was more economic than anaerobic cabinets or jars using conventional gas mixtures.

Is the enuretic female bladder without instability normal?

Twenty-one females with a history of nocturnal enuresis were found to have stable bladders on cystometric testing. A stable detrusor is defined as one that is capable of contraction but does not develop abnormal contractions on filling inspite of provocative testing by rapid filling, standing, coughing and erect filling. A detailed assessment of 10 measurements revealed abnormalities in 19 of the 21 cases. This result strengthens the theory that for nocturnal enuresis to occur, two abnormalities are necessary: (a) failure of a full bladder to arouse from sleep, and (b) an abnormality of bladder/urethral function. Identifiable causes of nocturnal enuresis included a small functional bladder capacity, outlet obstruction, increased detrusor contractility and low urethral closure pressure.