Respiratory medicine
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Respiratory medicine · Feb 1998
Bronchoalveolar lavage causes decrease in PaO2, increase in (A-a) gradient value and bronchoconstriction in asthmatics.
The aims of this study were to (1) record the changes of (arterial oxygen partial pressure) PaO2, (arterial carbon dioxide partial pressure) PaCO2, (percentage saturation of haemoglobin with oxygen in arterial blood) SaO2 and alveolar-arterial (A-a) oxygen gradiant resulting from bronchoalveolar lavage (BAL) in asthmatic and normal subjects; (2) measure changes in forced expiratory volume in 1 s (FEV1), vital capacity forced (FVC) associated with BAL; and (3) assess possible predictive factors for the degree of hypoxaemia and impairment of spirometry resulting from BAL. Bronchoscopy and BAL (150 ml) were performed in 24 asthmatics and 15 healthy subjects. Serial arterial blood samples (radial artery) were obtained in all subjects: T1 and before T2 after local anaesthesia; T3 at end of bronchoscopy; T4 after BAL and 5 min, 15 min, 1 h, 2 h, 8 h and 24 h (T5-T10) after the procedure, FEV1 and FVC were measured immediately before and 5 min afer bronchoscopy. ⋯ The fall in FEV1 after BAL was significantly greater in asthmatics (32.4 +/- 10.0%) than in healthy subjects (17.7 +/- 4.6; P < 0.001). Severity of asthma, basline FEV1 or initial PaO2 did not predict the degree of hypoxaemia or the fall of FEV1. It is concluded that BAL causes more severe hypoxaemia and a greater decrease in FEV1 in asthmatics compared to healthy subjects, strongly supporting the recommendation of special caution and careful monitoring when BAL is undertaken in asthmatics.
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Respiratory medicine · Feb 1998
Failure of CPAP therapy in obstructive sleep apnoea syndrome: predictive factors and treatment with bilevel-positive airway pressure.
Continuous positive airway pressure (CPAP) is the most widely used therapy for obstructive sleep apnoea (OSA). Despite its general efficacy, oxygen desaturation due to hypoventilation persists in some patients. The present study analysed the factors which are associated with this primary failure and, moreover, examined the effect of a bilevel positive airway pressure (BiPAP) trial. ⋯ In conclusion, patients with OSA resistant to initial CPAP are morbidly obese with impaired awake blood gas values. The percentage of time spent at < 90% of nocturnal SaO2 is independently associated with initial failure of CPAP. BiPAP in the control mode is adequate for nocturnal ventilation, and improves awake blood gas values.
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Respiratory medicine · Nov 1997
Comparative StudyPulmonary function after coronary artery bypass surgery.
Coronary artery bypass graft surgery (CABG) adversely affects pulmonary function tests (PFTs). Although several previous studies have addressed these changes, none has measured the forced vital capacity (FVC) on a daily basis. The purpose of the present study was to assess serial changes in the FVC following CABG and to identify factors that may influence these changes. ⋯ The nadir of FVC occurs immediately after surgery and improves gradually thereafter. However, on the tenth postoperative day, the FVC still remains more than 30% below pre-operative values. Since there is only a slight tendency for patients undergoing IMA grafting to have larger decreases in their pulmonary function, patients with ventilatory impairment should not be excluded from IMA grafting.
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Respiratory medicine · Oct 1997
ReviewPropofol for sedation in the intensive care unit: essentials for the clinician.
Propofol is a short-acting intravenous anesthetic commonly utilised in the intensive care unit (ICU) for sedation of mechanically ventilated patients. The rapid onset and termination of action make it an attractive drug for use in the ICU. ⋯ However, there are potential adverse reactions associated with the drug. This review discusses the pharmacology, administration and adverse effects associated with propofol with which clinicians who administer propofol should be familiar.
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Respiratory medicine · Sep 1997
Case ReportsMultiple tracheal strictures following mechanical ventilation.
Patients presenting with features of airway narrowing (cough, wheeze, exertional breathlessness and obstructive spirometry) may be suffering from either localized or generalized airway obstruction. Doctors sometimes overlook the possibility of localized obstruction (whether due to tumour, foreign body aspiration or stenosis), and patients may experience symptoms for a long time before the correct diagnosis is made.