Hospital outcomes and long-term survival after referral to a specialized weaning unit.

BACKGROUND.: Prolonged invasive mechanical ventilation (IMV) is a frequent challenge, and an increasing number of patients are transferred from intensive care units to long-term acute care hospitals or specialized weaning units. There are few published data for discharge home rates, use of noninvasive ventilation (NIV), or long-term survival. METHODS.: A case-note and database review was conducted of patients admitted to a UK national specialized weaning unit for weaning from IMV between 1992 and 2012. Patients were grouped into diagnostic categories according to the predominant cause of weaning failure. Weaning outcomes and long-term survival were assessed according to diagnostic group and mode of ventilation on discharge. RESULTS.: Four hundred and fifty-eight patients were transferred for weaning from IMV. Four hundred and seventeen (91%) survived to hospital discharge, of whom at least 343 (82%) were ultimately discharged to their own home. Three hundred and thirty (72%) weaned from IMV, of whom 142 weaned from all ventilation and 188 weaned to nocturnal NIV. Weaning success was highest for patients with chronic obstructive pulmonary disease and chest wall disorders. Median survival from unit discharge was 25 months (interquartile range 5-74), with the longest survival seen for patients discharged with nocturnal NIV [37 (12-81) months]. CONCLUSIONS.: These results confirm successful weaning outcomes for patients transferred to a specialized weaning and long-term ventilation service. In contrast to other service models, most patients achieved discharge to their own home.

Recessive mutations in the cancer gene Ataxia Telangiectasia Mutated (ATM), at a locus previously associated with metformin response, cause dysglycaemia and insulin resistance.

AIM: To investigate glucose and insulin metabolism in participants with ataxia telangiectasia in the absence of a diagnosis of diabetes. METHODS: A standard oral glucose tolerance test was performed in participants with ataxia telangiectasia (n = 10) and in a control cohort (n = 10). Serial glucose and insulin measurements were taken to permit cohort comparisons of glucose-insulin homeostasis and indices of insulin secretion and sensitivity. RESULTS: During the oral glucose tolerance test, the 2-h glucose (6.75 vs 4.93 mmol/l; P = 0.029), insulin concentrations (285.6 vs 148.5 pmol/l; P = 0.043), incremental area under the curve for glucose (314 vs 161 mmol/l/min; P = 0.036) and incremental area under the curve for insulin (37,720 vs 18,080 pmol/l/min; P = 0.03) were higher in participants with ataxia telangiectasia than in the controls. There were no significant differences between groups in fasting glucose, insulin concentrations or insulinogenic index measurement (0.94 vs 0.95; P = 0.95). The Matsuda index, reflecting whole-body insulin sensitivity, was lower in participants with ataxia telangiectasia (5.96 vs 11.03; P = 0.019) than in control subjects. CONCLUSIONS: Mutations in Ataxia Telangiectasia Mutated (ATM) that cause ataxia telangiectasia are associated with elevated glycaemia and low insulin sensitivity in participants without diabetes. This indicates a role of ATM in glucose and insulin metabolic pathways.

Cerebrospinal fluid hypocretin levels are normal in idiopathic REM sleep behaviour disorder.

BACKGROUND: Rapid eye movement (REM) sleep behaviour disorder (RBD) is a common sleep disorder that can be associated with a number of neurodegenerative conditions as well as with narcolepsy. Current diagnostic criteria require overnight polysomnography, and there are no other biomarkers available. The control of REM sleep is complex with a putative on/off switch within the brainstem activated, amongst other things, by hypocretinergic pathways from the lateral hypothalamus. METHODS: Cerebrospinal fluid hypocretin levels were measured in five patients with idiopathic RBD. RESULTS: Hypocretin levels were between 254 and 450 pg/ml and therefore within the normal range of >100 pg/ml. CONCLUSION: Hypocretin levels in patients with idiopathic RBD are normal.

Why does gender influence survival in obstructive sleep apnoea?

The study aim was to compare the mortality risk of men and women diagnosed with obstructive sleep apnoea (OSA) and started on treatment with continuous positive airway pressure (CPAP). From August to December 2003 we reviewed the hospital records of patients who had started on CPAP for OSA between July 1995 and June 1998. Mortality rates were compared between men and women. Associations with mortality risk were determined using univariate and multivariate Cox's proportional hazards regression. The sample comprised 292 men and 47 women. Eight percent of the men and 23% of the women died (p=0.003). Univariate analysis showed increased mortality risk was associated with female sex, greater age when CPAP was started, a pre-treatment minimum nocturnal oxygen saturation (SpO(2)) <75%, a higher Charlson comorbidity index score and discontinuation of CPAP treatment. Female sex remained associated with increased mortality independent of age, minimum SpO(2) and CPAP use, but was not independent of the Charlson score. Women diagnosed with OSA and treated with CPAP demonstrated a 3.44 greater mortality risk than men, mostly due to greater comorbidity.

Vocal fold palsy due to plombage for tuberculosis.

A 67-year-old patient, who had previously undergone Lucite ball plombage for pulmonary tuberculosis, presented with a hoarse voice, intermittent stridor and breathlessness. Direct laryngoscopy confirmed a left vocal fold palsy. A left supraclavicular mass became apparent and a computerized tomograph (CT) scan showed that a Lucite ball had migrated into her supraclavicular fossa. Subsequently she developed left arm pain and weakness. The balls were removed surgically, following which her arm symptoms improved but her voice remained unchanged. Migration of implanted material should be considered when new symptoms appear in patients who have undergone plombage treatment.

Clinical experience and physiologic results with an implantable intratracheal oxygen catheter.

Ten patients with chronic lung disease received an implanted ITOC. Seven patients continue to use their catheters after a mean period of 14.75 months. Four catheters were removed, 2 at 1 month, 1 after 10 months and 1 after 13 months. One patient requested a second catheter. Three patients experienced mucus plug formation; this was transient in two patients, but led to removal of the catheter in the third. To determine the degree of oxygen-saving afforded by the ITOC, SaO2 was measured at rest and during exercise for eight of the ten subjects using a double-blind technique. The calculated oxygen savings were around 40 percent both at rest and during exercise. The ITOCs were well received by the majority of our patients and were shown to produce a useful saving of oxygen which is of benefit to patients using portable systems and those who require high oxygen flow rates.

Kyphosis secondary to tuberculosis osteomyelitis as a cause of ventilatory failure. Clinical features, mechanisms, and management.

STUDY OBJECTIVES: To investigate the relationship of thoracic kyphosis following tuberculosis to the development of ventilatory failure and to assess the efficacy on nocturnal noninvasive ventilatory support. DESIGN: Retrospective consecutive case series with crossover from a phase without noninvasive ventilatory support to a phase with this treatment. SETTING: The Respiratory Support and Sleep Centre, Papworth, Hospital, Cambridge, England. PATIENTS: Seven patients with thoracic kyphosis following tuberculous osteomyelitis which had been contracted by the age of 4 years were studied. Their mean age was 53 (SD 7.1) years and the mean angle of kyphosis was 113.60. All patients were in ventilatory failure. INTERVENTIONS: The patients were treated with nocturnal noninvasive ventilation with either an individually constructed cuirass shell and a negative pressure pump or nasal intermittent positive pressure ventilation using a volume preset ventilator. MEASUREMENT AND RESULTS: Each patient underwent an initial clinical assessment along with radiologic studies of the spine, pulmonary function tests, daytime arterial blood gas tensions, and overnight recordings of arterial saturation, and transcutaneous carbon dioxide tension. They were reassessed in detail at a mean of 5 years after starting ventilatory support. Symptoms, vital capacity, daytime carbon dioxide tension, and overnight oximetry had all improved following treatment. Temporary withdrawal of ventilatory support led to severe sleep fragmentation in four patients and the appearance of central apneas and hypopneas in the other three. Six of the 7 patients were alive at a mean of 5.7 years after starting nocturnal ventilation. CONCLUSION: These results show that ventilatory failure may develop, after an interval of many years, in patients with a severe thoracic kyphosis due to tuberculosis in childhood. Noninvasive nocturnal ventilatory support can control the symptoms of ventilatory failure, improve the physiologic abnormalities, and is associated with prolonged survival.

Obstructing tracheal lipoma: management of a rare tumor.

Benign neoplasms of the trachea are rare. We describe a 46-year-old patient with a lipoma arising from the membranous trachea and causing severe respiratory obstruction. Investigation and management of this problem are discussed, and the literature is reviewed.

Narcolepsy and psychopathology: is there an association?

BACKGROUND: It is widely believed that patients with narcolepsy show high rates of associated psychiatric disturbance, especially schizophrenia and depression. However, surveys have produced conflicting findings and have not addressed the potential confounding effects of stimulant drug treatment. METHOD: Forty-five patients with narcolepsy attending a sleep disorder clinic and 50 matched normal controls underwent structured psychiatric interview. Using a 'lifetime' approach, psychiatric symptoms and diagnoses were established for both groups. RESULTS: Four of the narcolepsy patients but none of the controls had experienced psychotic symptoms. All four patients were taking amphetamines, and the symptoms resolved when the dose was lowered or treatment was changed to modafinil. The lifetime frequency of various depressive syndromes did not differ significantly between the groups. CONCLUSIONS: Contrary to previous claims this study found little to suggest that narcolepsy is associated with schizophrenia. Nor, despite its serious social and occupational consequences, does narcolepsy appear to be associated with an increased frequency of diagnosable depressive disorders.

Extrinsic allergic alveolitis: problems in diagnosis and a potential use for computed tomography.

Bird fancier's lung, the most common form of extrinsic allergic alveolitis in Britain, can be a difficult diagnostic problem. The symptoms are non-specific, often insidious in onset and frequently misdiagnosed as influenza or a viral or bacterial pneumonia. Frequently there is a delay in eliciting the history of exposure to the antigen. The chest radiograph is often less impressive than the clinical presentation and may be normal despite severe symptoms, impaired respiratory function and florid pathological changes. We present three cases demonstrating these diagnostic problem. In two cases, high resolution computed tomography demonstrated the typical 'ground glass' opacification seen in active alveolitis. This allowed targeting of transbronchial biopsies which revealed an inflammatory infiltrate of the interstitium with granuloma formation and inflammatory cells in some alveoli. The problems in diagnosis and the potential role of high resolution computed tomography are discussed.

Bambuterol: effective in nocturnal asthma.

Bambuterol was compared with placebo in 28 patients with nocturnal asthma in a randomized, double-blind cross-over study. All patients were symptomatic despite taking inhaled beta 2-agonists, inhaled corticosteroids (in 26 patients the median daily dose was 1500 micrograms) and oral corticosteroids (in eight patients the median daily dose was 10 mg). Patients demonstrated > or = 20% overnight fall in peak expiratory flow (PEF) for at least half of the 14-day run-in period. They then entered two treatment periods lasting 14 days when bambuterol 20 mg nocte and placebo were given in random order. Compared to placebo, bambuterol produced a 16% improvement in mean PEF on waking (271 l min-1 vs. 239 l min-1 P = 0.0002) and a 10% improvement in evening PEF measured 24 h after drug intake (318 l min-1 vs. 296 l min-1 P = 0.01). Bambuterol significantly reduced frequency of nocturnal awakening from 1.1 to 0.7 per night (P = 0.01) and nocturnal beta 2-agonist use from 2.7 to 2.1 puffs (P = 0.0004). Other nocturnal symptoms: cough, wheeze and dyspnoea were also significantly reduced during bambuterol treatment and patients quality of sleep was improved. The results indicate bambuterol (20 mg nocte) provides effective nocturnal bronchodilation with sustained effect for 24 h and may have a useful therapeutic role in the control of symptomatic nocturnal asthma.

Appearances on computed tomography following thoracoplasty for pulmonary tuberculosis.

Thoracic computed tomography was performed in 32 patients who had undergone thoracoplasty as part of their treatment for pulmonary tuberculosis. Pleural thickening and the prevalence of bronchiectasis were more marked in the operated hemithorax. Bullae were more prevalent in the operated hemithorax but the difference was not statistically significant. In all but one patient, scoliosis was present. Illustrative examples are presented to demonstrate the range of appearances following this operation.

Surgical relief of snoring due to palatal flutter: a preliminary report.

We describe our experience in the surgical treatment of 32 patients with severe snoring. In the first 16 patients we used the standard surgical procedure of uvulopalatopharyngoplasty (UPP) but found this unsatisfactory because of its radical nature, complications and uncertain outcome. We therefore investigated the mechanics of snoring in the laboratory as a help in devising a more effective operation. These studies have shown that there are several methods by which snoring can be generated but that palatal flutter is probably the most important. The dominant parameters in the generation of flutter of the palate are its length and stiffness. Any removal of tissue to shorten the palate as in UPP inevitably risks impairing its function, so we chose the stiffening alternative. Using the laser, a central longitudinal strip of mucosa was removed from the surface of the soft palate which healed by fibrosis, producing the required stiffening. The early results of this new procedure show that snoring has been eliminated or greatly reduced in 14 of 16 patients and that apart from local pain there have been no complications.

Permanent perceptive deafness due to Streptococcus suis type II infection.

We report a case of meningitis and perceptive deafness caused by Streptococcus suis type II (Group R beta-haemolytic streptococcus). The illness is known to be an occupational hazard of pigmeat handlers and our patient worked in a pet food factory processing pig meat. His hearing loss was very severe and showed no improvement despite adequate antibiotic treatment. The organism that was isolated is the first to show penicillin resistance. The implications of this for antibiotic treatment are discussed.

Respiration during sleep in neuromuscular and thoracic cage disorders.

Many of the neuromuscular and thoracic cage disorders are associated with disorders of breathing during sleep. The abnormal mechanics of the chest wall impairs respiratory muscle function and this is compounded if there is underlying muscle weakness. Respiratory abnormalities appear during REM sleep before NREM or wakefulness. Central sleep apnoeas are characteristic, but obstructive apnoeas are also occur because of loss of tone in the upper airway dilator muscles. Arousals from sleep return the blood gases towards normal, but cause fragmentation of sleep, leading to daytime sleepiness. Ventilatory failure occurs particularly if the vital capacity is less than 1.0-1.5 litres or if the maximal inspiratory mouth pressure is less than 20-25cmH2O. Non invasive ventilation effectively prevents both central and obstructive apnoeas and improves the sleep architecture and daytime blood gases.

Pregnancy in neuromuscular and skeletal disorders.

Pregnancy often poses a risk to patients with neuromuscular and skeletal disorders when these affect the respiratory muscles or the rib cage. The outlook is determined both by the severity of the underlying condition and the physiological changes during pregnancy. Patients with a vital capacity of less than 1 to 1.5 litres, hypercapnia, severe scoliosis, diaphragm weakness or pulmonary hypertension before pregnancy are particularly at risk. Pregnancy may adversely affect the conducting airways, respiratory pump and gas exchange in the lungs. Close monitoring of high risk patients during pregnancy is required and either a termination of pregnancy or mechanical respiratory support may be indicated if ventilatory or cardiac failure develops.

Rehabilitation in neuromuscular disorders and thoracic wall deformities.

The causes of neuromuscular disorders and thoracic wall deformities are often incurable, but there are a wide range of supportive treatments that have been introduced with the aim of improving the patient's quality of ife. There are very few studies evaluating these and as a result it is still uncertain what role they have. This review analyses the outcomes of and possible indications for these therapies. The importance of recognizing the needs of each individual patient is emphasized and the use of pulmonary rehabilitation programmes with a standard combination of treatments should be reconsidered.

Home mechanical ventilation in children: techniques, outcomes and ethics.

Various neuromuscular and pulmonary disorders can cause ventilatory failure in children. Tracheostomy ventilation in the home is especially valuable in younger children who require ventilatory support for most of the day and who have bulbar dysfunction but newer noninvasive techniques especially nasal mask ventilation are often preferable. It is important to select the type of ventilator and to choose the interface with the patient carefully in order to maximise the child's quality of life.