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Biomedical subjects

A G Davison

Publications and source records attributed to A G Davison.

At least 19 recordsLinked to original sources

Oxygen alert cards and controlled oxygen: preventing emergency admissions at risk of hypercapnic acidosis receiving high inspired oxygen concentrations in ambulances and A&E departments.

BACKGROUND: Appropriate resuscitation of hypoxic patients is fundamental in emergency admissions. To achieve this, it is standard practice of ambulance staff to administer high concentrations of oxygen to patients who may be in respiratory distress. A proportion of patients with chronic respiratory disease will become hypercapnic on this. OBJECTIVES AND METHODS: A scheme was agreed between the authors' hospital and the local ambulance service, whereby patients with a history of previous hypercapnic acidosis with a Pao2 >10.0 kPa--indicating that oxygen may have worsened the hypercapnia--are issued with "O2 Alert" cards and a 24% Venturi mask. The patients are instructed to show these to ambulance and A&E staff who will then use the mask to avoid excessive oxygenation. The scheme was launched in 2001 and this paper present the results of an audit of the scheme in 2004. RESULTS: A total of 18 patients were issued with cards, and 14 were readmitted on 69 occasions. Sufficient documentation for auditing purposes was available for 52 of the 69 episodes. Of these audited admissions, 63% were managed in the ambulance, in line with card-holder protocol. This figure rose to 94% in the accident and emergency department. CONCLUSION: These data support the usability of such a scheme to prevent iatrogenic hypercapnia in emergency admissions.

Acidosis, Respiratory↗

Hospital at home for chronic obstructive pulmonary disease: an integrated hospital and community based generic intermediate care service for prevention and early discharge.

Recent randomized controlled studies have reported success for hospital at home for prevention and early discharge of chronic obstructive pulmonary disease (COPD) patients using hospital based respiratory nurse specialists. This observational study reports results using an integrated hospital and community based generic intermediate care service. The length of care, readmission within 60 days and death within 60 days in the early discharge (9.37 days, 21.1%, 7%) and the prevention of admission (five to six days, 34.1%, 3.8%) are similar to previous studies. We suggest that this generic community model of service may allow hospital at home services for COPD to be introduced in more areas.

Aged↗

Increasing social and psychological information conveyed to General Practitioners after bad news consultations by use of separate letters from the Lung Cancer Nurse Specialist.

Multidisciplinary teams (MDT) now review all cases of lung cancer. These teams include a Lung Cancer Nurse Specialist (LCNS). These Nurses help support the patient and should facilitate communication and liaise with other services. The LCNS is present when the diagnosis is given to the patient but also usually spends time afterwards with the patient and their family. We postulated that a separate letter from the LCNS to the General Practitioner (GP) after the consultations would convey extra information to the GP. In 58 new lung cancer patients reviewed in the clinic, the LCNS and Physician independently wrote separate letters after the consultation in which the diagnosis of lung cancer was given. The GPs were asked by questionnaire about the usefulness of the letter from the LCNS. This letter was considered by the GP to provide extra information in: (i) 69% concerning the patients reaction to the diagnosis; (ii) 85% concerning who attended the clinic with the patient; (iii) 85% about what referrals were made to community services; (iv) 86% about who the patient was living with; (v) 81% about who the patients carers were; (vi) 81% information on the patients condition; (vii) 70% concerning the information given to patients about benefits. Ninety-seven percent of the GPs found the LCNS letter useful or very useful and 92% of the GPs thought that the information in the letter would be useful or very useful when they next saw the patient. Separate and independent letters from the LCNS after "bad news" consultation in lung cancer provides added useful information for GPs. Ninety-one percent of the GPs wanted the letters from the LCNS to continue.

Communication↗

Obstructive sleep apnea presenting as pseudopheochromocytoma: a case report.

Sudden arousal from sleep causes a transient surge in sympathetic nervous activity. Repeated arousals, as occur in obstructive sleep apnea (OSA), are well documented to cause a more prolonged sympathetic overactivity and consequent elevations in 24-h urinary catecholamine levels. We describe here a series of five patients, each presenting with a clinical and biochemical picture indistinguishable from that of pheochromocytoma. Thorough investigations have failed to find catecholamine-secreting tumor in any of these subjects, but all have been diagnosed with OSA. Primary treatment of OSA with nasal continuous positive airways pressure has led to normalization of systemic blood pressure and urinary catecholamines. Pseudopheochromocytoma is therefore a rare, but treatable, presentation of obstructive sleep apnea.

Adrenal Gland Neoplasms↗

Telemedicine for multidisciplinary lung cancer meetings.

According to recent UK guidelines on the management of lung cancer, all cases should be reviewed prospectively by a lung cancer multidisciplinary team (MDT) and a thoracic surgeon should be readily available to liaise with the MDT. However, there is a shortage of thoracic surgeons in the UK. Over a one-year period, 28 MDT meetings were held at a district general hospital in Southend, at which 62 patients were presented to a tertiary cardiothoracic centre in London, 80 km away, via ISDN videoconferencing at 384 kbit/s. The annual resection rate increased by 30% following the introduction of the telemedicine MDTmeetings, and the mean time from first being seen in the clinic to surgery was reduced from 69 to 54 days.We estimate that the telemedicine meetings saved over three working weeks of thoracic surgical time during the year.

England↗

Diaphragm strength in acute systemic lupus erythematosus in a patient with paradoxical abdominal motion and reduced lung volumes.

Diaphragmatic weakness is reported as a common feature of the shrinking lung syndrome of systemic lupus erythematosus (SLE). However, in chronic stable SLE it has been shown that, despite poor performance of voluntary tests of diaphragm strength, twitch pressures obtained by stimulating the phrenic nerves are normal. We present a patient with acute SLE and pulmonary involvement who, despite having paradoxical abdominal motion and low maximal inspiratory pressures during voluntary manoeuvres, had normal diaphragm strength when assessed with magnetic stimulation of the phrenic nerves. Following immunosuppressive therapy symptoms and lung function improved, yet diaphragm contractility remained normal and unchanged. We suggest that this case supports the view that reduced diaphragm muscle contractility per se does not explain the small volume lungs and respiratory symptoms in patients with acute SLE.

Adult↗

Age and the treatment of lung cancer.

BACKGROUND: The average age of patients with lung cancer is increasing and there are large numbers of elderly symptomatic patients with this common disease. However, there are few data on how the treatment of this group differs from that of younger patients. METHODS: From 1 January 1990 information was collected for the Southend Lung Cancer Registry on all patients with a diagnosis of lung cancer in a geographically well defined health district of the UK with a population of 325,000. Every effort was made to find new cases from all departments of the hospital, including all clinical diagnoses, histopathological and cytological reports, and necropsies. All death certificates in the district were examined, irrespective of age, for any diagnosis of lung cancer. This therefore included any patient not seen by the hospital services. The differences in initial treatment have been analysed for three age groups: under 65, 65-74 years, and over 75. RESULTS: The 563 cases of lung cancer diagnosed during a 30 month period were included in the study, of whom 240 (43%) were aged over 75 years. The overall mean age was 71 years (range 31-95). The incidence of lung cancer in the general population was 69 per 100,000, but in men over 75 years of age it rose to 751 per 100,000. For all patients the active treatment rate (chemotherapy, surgery, or radiotherapy) was 49%, but for patients not reviewed by a chest physician (n = 86) it was only 21%. There were large differences in initial treatment between age groups. For patients with non-small cell lung cancer (NSCLC) reviewed by a chest physician, surgery was undertaken in 18% of those under 65, 12% of the 65-74 age group, and 2.1% of those over 75. For patients with small cell lung cancer (SCLC) reviewed by a chest physician, 79% of those aged under 65, 64% of the 65-74 age group, and 41% of patients aged over 75 received chemotherapy. In patients with NSCLC reviewed by a chest physician, chemotherapy was given to 21% under 65, 6.4% in the 65-74 age group, and none over 75. If no histological diagnosis was made 37% of patients aged under 75 and only 5.4% of those over 75 received either surgery, radiotherapy, or chemotherapy. Patients not reviewed by a chest physician were less likely to have had a histological diagnosis. Differences in treatment rates with age persisted even after allowing for performance score status at presentation. CONCLUSIONS: Lung cancer is a common disease in the elderly and, in our district, 43% of patients were aged 75 or over at presentation. Age alone appeared to be a major factor in influencing treatment choices, and treatment was more likely if histological confirmation was obtained. Further detailed analysis of the reasons for the differences is needed. Patients referred to chest physicians were more likely to have both histological confirmation and active treatment. This study supports the contention that all patients with a diagnosis of lung cancer, irrespective of age or condition, should be assessed by an accredited chest physician.

Adult↗

Hypokalaemic rhabdomyolysis: an unusual presentation of coeliac disease.

OBJECTIVE: To describe the clinical presentation and management of a patient with hypokalaemic rhabdomyolysis secondary to coeliac disease. DESIGN: Retrospective study. SETTING: Hospital based. PATIENT: A 60-year-old Caucasian man presenting with weakness caused by hypokalaemic rhabdomyolysis secondary to coeliac disease. INTERVENTIONS: Following the diagnosis by jejunal biopsy, the patient was treated with both intravenous and oral potassium supplements, and a gluten-free diet. OUTCOME MEASURES: Resolution of weakness and restitution of normal villous architecture following treatment. RESULTS: The patient's myopathy responded to the potassium supplements, his diarrhoea and histological changes resolved while on the gluten-free diet. CONCLUSION: Patients with coeliac disease may present with hypokalaemia in association with steatorrhoea. If potassium loss is rapid, rhabdomyolysis may occur. Coeliac disease should be considered a cause of malabsorption-induced hypokalaemic rhabdomyolysis.

Adult↗

The use of multiple parameters to characterize cadmium-induced renal dysfunction resulting from occupational exposure.

Renal function has been examined in a group of 77 subjects occupationally exposed to cadmium fume and dust, together with a referent group of 103 age- and socioeconomically matched subjects. Fourteen biochemical parameters were measured on each subject. Three different ways of combining the information from all 14 tests were used to identify those subjects with renal dysfunction. These were first to count the number of parameters in which a subject recorded an abnormal test result. Second, the z value was computed for each parameter for each person by comparison with the mean and standard deviation of a derived normal population; these z scores were then summed. Lastly a multivariate distance measure, Mahalanobis D2, was determined for each subject from the distribution of normal subjects. The three approaches showed a considerable degree of agreement in identifying subjects with renal dysfunction, but they also displayed complementary strengths and weaknesses. The consensus of the three techniques was then taken to define truly dysfunctional subjects and each of the 14 parameters, and some combinations of pairs of parameters were tested as to their sensitivity and specificity. For this group of subjects, it was not possible to improve greatly on the use of retinol binding protein on its own. Were a second parameter to be chosen, it would be desirable to choose one reflecting the glomerular filtration rate, but the absence of a suitable sensitive biological monitoring parameter precludes a firm recommendation.

Blood Proteins↗

Occupational asthma in salbutamol process workers.

Occupational asthma after exposure to salbutamol in the pharmaceutical industry has not been previously reported. The occurrence of occupational asthma is described in two pharmaceutical process workers who were likely to have inhaled doses appreciably in excess of the therapeutic dose range. The findings do not lead to an unequivocal conclusion on the mechanism of the asthma but it was probably a pharmacological consequence of high exposure.

Adult↗

Osteochondroma of the rib: an unusual cause of haemothorax.

The case is described of a 36 year old woman who presented with a large left sided haemothorax. A thoracic computed tomographic (CT) scan suggested there was a bony outgrowth arising from the fourth rib. This was resected surgically and found to be an osteochondroma which was surrounded by blood clot. No definite site of bleeding was identified, but it is thought that the tumour may have traumatised the lung, the pericardiacophrenic artery, or the superior pulmonary vein, resulting in life threatening haemorrhage.

Adult↗

Randomized trial comparing weekly versus 3-week chemotherapy in small-cell lung cancer: a Cancer Research Campaign trial.

PURPOSE: A randomized trial of chemotherapy, given on either a 1-week or a 3-week schedule, was performed in small-cell lung cancer (SCLC) patients. The aim was to determine if weekly scheduling produced survival superior to conventional treatment. PATIENTS AND METHODS: Four hundred thirty-eight patients with SCLC with either limited disease (LD; 276 patients) or good-prognosis extensive disease (ED; 162 patients) were randomized. Weekly chemotherapy was 12 alternating cycles of ifosfamide/doxorubicin and cis-platin/etoposide (PE), while 3-week treatment was six alternating cycles of cyclophosphamide/doxorubicin/vincristine (CAV) and PE. Thoracic irradiation was administered 3 weeks after completion of chemotherapy to LD patients who attained a complete response (CR) or partial response (PR). Patients were well matched for clinical characteristics and prognostic factors. RESULTS: Overall response was the same in both arms: 82.3% (39.4% CR) with weekly and 81.1% (36.9% CR) with 3-week treatment. The median survival (MS) durations were 10.8 and 10.6 months for weekly and 3-week chemotherapy, respectively. The 2-year survival rates were 11.8% and 11.7% in the weekly and 3-week arms, respectively. Received dose-intensity (DI) was 73.9% of projected for weekly treatment and 92.7% for 3-week treatment. Hematologic toxicity was the major dose-limiting toxicity for the weekly treatment. CONCLUSION: This trial excludes at 90% power a benefit of greater than 10% for 2-year survival for weekly treatment. The received DI was reduced to a greater extent with weekly treatment, mainly due to hematologic toxicity.

Adult↗

Regulation by membrane potential of phosphatidylinositol hydrolysis in pancreatic islets.

In pancreatic islets stimulated with carbamylcholine (carbachol), hydrolysis of both phosphatidylinositol (PtdIns) and phosphatidylinositol bisphosphate (Ptd-InsP2) occurs and can be measured as the inositol monophosphates Ins(1)P1, or Ins(4)P1, respectively (Biden, T. J., Prugue, M. L., and Davison, A. G. M. (1992) Biochem. J. 285, 541-549). Our current aim was to establish whether these two events were independently regulated. Rats islets were labeled with either [3H]inositol or [3H]arachidonic acid for measurement of InsP1s by high performance liquid chromatography or diacylglycerol by TLC, respectively. The rise in Ins(1)P1 due to carbachol (1 min) was inhibited by 50% by concomitantly raising extracellular KCl ([K+]e) from 6 to 30 mM, thereby depolarizing the islets. Similar results, obtained in the absence of extracellular Ca2+, exclude the involvement of voltage-gated Ca2+ channels. Conversely, hyperpolarization, by lowering [K+]e to 3 mM, increased by 30% the rise in Ins(1)P1. In fact, over the [K+]e range of 3 to 48 mM, stimulated Ins(1)P1 accumulation was directly proportional to the calculated membrane potential. In contrast, raising [K+]e from 6 to 48 mM exerted no significant effect on carbachol-stimulated Ins(4)P1 levels, and both Ins(1)P1 and Ins(4)P1 were unaffected in the absence of carbachol. The rises in Ins(1)P1 (but not Ins(4)P1) were also inhibited by depolarization with the sodium pump inhibitor, ouabain, or the K+ channel blocker, tolbutamide. Stimulated diacylglycerol accumulation and insulin secretion (20 min) showed a biphasic dependency on [K+]e, being less pronounced at 6 mM than at either 3 or 30 mM KCl. This reflects a selective potentiation of PtdIns and PtdInsP2 hydrolysis, due, respectively, to hyperpolarization and the gating of voltage-dependent Ca2+ channels. The differential regulation of these two hydrolytic events is probably important for independent control of the activation of protein kinase C and Ca2+ mobilization and might play a role in modulating the secretory response in vivo.

Animals↗