We studied six patients with isolated bilateral paralysis or severe weakness of the diaphragm, present for 2 to 60 months (mean = 25), to document the clinical and respiratory sequelae of the condition. Severe diaphragm dysfunction was confirmed by the demonstration of the very low maximal transdiaphragmatic pressure (Pdi) generated by either a sniff (13 +/- 6 cm H2O, normal 148 +/- 24) or a static inspiration (11 +/- 8, normal 108 +/- 30) and during bilateral phrenic nerve stimulation (0.8 +/- 2.0, normal 22 +/- 4). Resting arterial blood gases were normal (SaO2 = 95 to 97%) and no oxygen desaturation occurred during maximal exercise on a treadmill. Maximum voluntary ventilation was low and related to PImax (r = 0.89). Overnight sleep monitoring showed that time spent in rapid eye movement sleep was normal (mean 55 +/- 36 min, range 26 to 117 min). Mean maximum increment in transcutaneous CO2 was within normal limits (6 +/- 2 mm Hg, range 3 to 9 mm Hg). Three patients had occasional brief episodes of oxygen desaturation (mean maximal decrease 13 +/- 10%, range 2 to 27%); however, only two of these spent a measurable proportion of total sleep time (TST) with an SaO2 of less than 80% (1% and 3% TST, respectively). No patient has developed any symptoms of nocturnal hypoventilation or chronic respiratory failure during periods of observation of up to five yr. We conclude that bilateral paralysis or very severe weakness of the diaphragm does not of itself lead to respiratory failure unless weakness of other respiratory muscles is present.

REM-related oxygen desaturation occurs in advanced Duchenne muscular dystrophy (DMD) and might be an independent predictor of disease progression. We have followed 18 patients for 10 yr after an initial respiratory sleep study or until death or onset of nasal ventilation. We measured baseline spirometry, blood gas tensions, maximal respiratory pressures, and body mass index. In 11 cases, VC was recorded serially. Median survival was 50 (range, 13 to 89) mo from initial study and unrelated to age at time of study, BMI, or mouth pressures but correlated with PaCO2 (r = -0.72, p < 0.005, n = 17), minimal nocturnal SaO2 (r = 0.62, p < 0.007, n = 18) and VC (r = 0. 65, p < 0.005, n = 17). Cox regression analysis showed a VC of less than 1 L at the time of study to be the best single predictor of subsequent survival. The only measure associated with age of death was the age at which the VC fell below 1 L (r = 0.79, p < 0.004). These data suggest measurement of PaCO2 or serial assessment of VC should be studied further as valid methods of assessing prognosis in DMD.

To exanine the role of delay in recovery of peripheral muscle function following exercise in the fatigue experienced by patients with the chronic fatigue syndrome (CFS) and to examine the influence of effort perception in limiting exercise performance in these patients, a study was carried out on a group of twelve patients with chronic fatigue syndrome and 12 sex and age-matched sedentary control subjects. Symptom limited incremental cycle exercise tests including measurements of perceived exertion were performed followed by examination of the contractile properties of the quadriceps muscle group for up to 48 hours. Muscle function was assessed by percutaneous electrical stimulation and maximum voluntary contractions. Muscle function at rest and during recovery was normal in CFS patients as assessed by maximum isometric voluntary contraction, 20:50 Hz tetanic force ratio and maximum relaxation rate. Exercise duration and the relationship between heart rate and work rate during exercise were similar in both groups. CFS patients had higher perceived exertion scores in relation to heart rate during exercise representing a reduced effort sensation threshold of 3-2 units on an unmodified Borg scale in CFS patients. Patients with chronic fatigue syndrome show normal muscle physiology before and after exercise. Raised perceived exertion scores during exercise suggest that central factors are limiting exercise capacity in these patients. (7 Neurol Neurosurg Psychiatry 1993;56:993-998)

Ten patients with respiratory failure and nocturnal hypoventilation were treated for three to nine months by nasal intermittent positive pressure ventilation. Four patients had chronic obstructive lung disease (median FEV, 19% predicted) and six restrictive chest wall disorders (median FVC 25% predicted); eight of the patients also had cardiac failure. The median daytime arterial oxygen tension, measured before and after at least three months' treatment, increased from 6-2 (range 5.4-9.6) to 9 1 (7.1-9.8) kPa in those with restrictive disease (p < 0-05), and from 6-0 (5.7-6 5) to 7 1 (6 3-7 7) kPa in the four with airflow limitation (NS). Median values for arterial carbon dioxide tension over the same time fell from 8-2 (range 6-7-9 8) to 6-5 (6-0-6 9) kPa in the group with restrictive disease (p < 005) and from 8-2 (7.0-9 2) to 7-1 (4.9-7.7) kPa in those with airflow limitation (p < 0 02). Total sleep time while patients were using nasal positive pressure ventilation varied from 155 to 379 (median 341) minutes, and included 4-26% rapid eye movement sleep (median 14%). The percentage of monitored time during the night in which the arterial oxygen saturation was less than 80% fell from a median (range) of 96 (3-100) to 4 (0-9) in the six patients with restrictive disease and from 100 (98-100) to 40 (2-51) in those with airflow limitation. There were no changes in spirometric values but exercise tolerance improved in all patients. The technique may prove an acceptable alternative to long term domiciliary oxygen therapy in selected patients.

-General hospitals have commonly involved a wide range of medical specialists in the care of unselected medical emergency admissions. In 1999, the Royal Liverpool University Hospital, a 915-bed hospital with a busy emergency service, changed its system of care for medical emergencies to allow early placement of admitted patients under the care of the most appropriate specialist team, with interim care provided by specialist acute physicians on an acute medicine unit -a system we have termed 'specialty triage'. Here we describe a retrospective study in which all 133,509 emergency medical admissions from February 1995 to January 2003 were analysed by time-series analysis with correction for the underlying downward trend from 1995 to 2003. This showed that the implementation of specialty triage in May 1999 was associated with a subsequent additional reduction in the mortality of the under-65 age group by 0.64% (95% CI 0.11 to 1.17%; P=0.021) from the 2.4% mortality rate prior to specialty triage, equivalent to approximately 51 fewer deaths per year. No significant effect was seen for those over 65 or all age groups together when corrected for the underlying trend. Length of stay and readmission rates showed a consistent downward trend that was not significantly affected by specialty triage. The data suggest that appropriate specialist management improves outcomes for medical emergencies, particularly amongst younger patients. KEY WORDS: acute medicine, mortality, outcome, specialism IntroductionThere is good evidence that patients with acute medical conditions may fare better in respect of a range of clinical outcomes if they are cared for by a medical team whose specialty interest is relevant to their complaint. This has been shown for myocardial infarction, 1 unstable angina, 2 asthma, 3-8 pneumothorax, 9 pleural effusion, 10-11 acute upper gastrointestinal haemorrhage, 12-14 diabetes 15 and stroke. 16 Indeed, it would be a strong indictment of the emphasis on specialty training over the past 20 years if there were no benefit in being looked after by a specialist. Nevertheless, it is common practice in the United Kingdom for patients who are ill enough to warrant emergency admission to be looked after by a specialty team that has been randomly selected according to the day of the week or week of the year, a system that might be termed 'calendar triage' , even though less ill patients, referred to the same hospital for an outpatient opinion, are likely to be seen by the relevant specialists. This widely accepted anomaly has arisen partly as a result of perceived necessity driven by staffing constraints and partly by the need to provide training in general internal medicine. An alternative model, 'specialty triage' , can be developed for the larger general hospital to allow patients admitted as medical emergencies to be placed under the care of the relevant specialty team with initial care directed by specialists in acute medicine. 17 We introduced this system at the Royal Liverpool University Hospital in ...

The case of a 54 year old man with Fabry's disease and extensive jejunal and colonic diverticulosis causing colonic stricture is presented. Histological examination of the resected colon revealed evidence of ceramide trihexose deposition in the myenteric nerve plexus. Colonic involvement in Fabry's disease has not been reported before.

Two patients are described with CharcotMarie-Tooth disease and chronic peripheral neuropathy. Both had dyspnoea, orthopnoea, and evidence of severe diaphragm weakness. Expiratory muscle function was well preserved and abnormalities of gas exchange during sleep were only minor.Charcot-Marie-Tooth disease comprises a group of inherited disorders characterised by chronic degeneration of peripheral nerves and nerve roots, resulting in distal muscle atrophy. Respiratory muscle weakness is not a generally recognised feature. One previous report described diaphragmatic dysfunction in two siblings with the disease,' although non-insulin dependent diabetes was also present. We describe two patients with severe diaphragmatic dysfunction not explained by any additional pathology. PatientsPatient I was a 58 year old man with severe, generalised, predominantly motor neuropathy, with some loss of sensation in the legs. Elevation of both hemidiaphragms on the chest radiograph and paradoxical diaphragm motion detected by fluoroscopy had first been noted five years previously. At that time vital capacity was 1 litre, having been 2 1 several years previously. His chest radiograph and spirometric results had not changed when he was referred to us five years later. He complained of breathlessness on exertion, although his exercise capacity was severely limited by his neurological condition. He described severe breathlessness on slipping down in bed.Patient 2 was a 48 year old man who had severe weakness of all four limbs, with a progressive deterioration in walking ability over the previous three years. He had distal loss of light touch and pinprick sensation and joint position sense in all four limbs. He had experienced urgency of micturition for the past 18 years and more recently some frequency of defaecation. He had become progressively more short of breath on exertion, with orthopnoea for the previous two years. Both hemidiaphragms were raised on the chest radiograph.Neither patient had symptoms of nocturnal hypoventilation, and daytime blood gas tensions were normal. InvestigationsForced expiratory volume in one second (FEV,)

Oropharyngeal tuberculosis is a rare presentation of the disease even in the presence of extensive pulmonary tuberculosis. A case is described in which a retropharyngeal abscess, causing stridor and threatening respiratory obstruction, was the only manifestation of Mycobacterium tuberculosis infection.We describe a case ofpharyngeal tuberculosis that is unusual both in its presentation-threatened obstruction of the airway-and because there was no sign of pulmonary tuberculosis. Case reportA 58 year old merchant seaman, born in Aden and nominally resident in Britain for 30 years, presented with a three day history of increasing difficulty in swallowing and a one day history of difficulty in breathing. He was febrile (37 4°C), with stridor and an intermittent cough. Bilateral firm, painless cervical lymphadenopathy was present. Direct inspection of the oropharynx showed a large tense mass originating from the posterior pharyngeal wall and almost occluding the airway. Physical examination otherwise showed nothing remarkable; there were no abnormal signs in the chest and no generalised lymphadenopathy or hepatosplenomegaly. The chest radiograph was normal. A lateral radiograph of the neck showed a large soft tissue mass prevertebrally causing almost total occlusion of the airway (figure). There was also extensive cervical osteoarthritis but no evidence of osteomyelitis. Investigations showed normal urea and electrolyte concentrations, a white cell count of 5 8 109/l (57% lymphocytes), a haemoglobin concentration of 12-8 g/dl and an erythrocyte sedimentation rate of 57 mm in one hour.The mass was incised under local anaesthesia with immediate relief of symptoms. A large amount of pus was removed; microscopic examination showed scanty Gram positive cocci but no acid fast bacilli on Ziehl-Neelsen staining. Bacterial culture was negative. Fine needle aspiration of the cervical nodes showed no evidence of bacterial or mycobacterial infection.