CHAPTER 39 257 Acute asthma TABLE 39.2 Immediate management of life-threatening asthma attack Element Comment Obtain help Call for help from a chest physician or senior colleague in medicine, and an anesthetist in case urgent endotracheal intubation/ ventilation is needed Oxygen Give oxygen 60–100% Nebulized bronchodilator Give salbutamol 5 mg plus ipratropium 500 µg by oxygen-driven nebulizer, repeated every 15–30 min Corticosteroid Give prednisolone 50 mg PO and hydrocortisone 100 mg IV If not improving after 15–30 min, consider adding: IV bronchodilator Aminophylline 250 mg IV over 20 min (not if the patient is already taking an oral theophylline) or Salbutamol 250 µg IV over 10 min followed by an infusion Monitor ECG if IV bronchodilator given Magnesium Magnesium sulfate 1.2–2 g IV over 20 min Further reading British Thoracic Society and Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. Thorax 2003; 58 (suppl I): i1–i94. Holgate ST, Polosa R. The mechanisms, diagnosis, and management of severe asthma in adults. Lancet 2006; 368: 80–93. 258 SPECIFIC PROBLEMS: RESPIRATORY Acute asthma TABLE 39.3 Further management of acute severe asthma Element Comment Oxygen Give humidifi ed oxygen 40–60% to maintain SaO 2 >92% Bronchodilator Give salbutamol 5 mg plus ipratropium 500 µg by oxygen-driven nebulizer, every 30 min to 6-hourly as required Switch from nebulized to inhaled bronchodilator therapy when peak fl ow (PF) is >75% of predicted/best Corticosteroid Continue prednisolone 40–50 mg PO daily or hydrocortisone 100 mg 6-hourly IV Oral prednisolone should be given until the acute attack has completely resolved (no sleep disturbance, normal effort tolerance, and PF >80% of predicted/best) As a rule of thumb, oral prednisolone should be continued for double the length of time it takes for PF to return to this level, to a maximum of 21 days Start inhaled steroid at least 24 h before discharge and check inhaler technique Antibiotic therapy Only a minority of asthma attacks are provoked by bacterial infection and antibiotics are not routinely required Give antibiotic therapy as for pneumonia (p. 272) if there is focal shadowing on the chest X-ray or fever or purulent sputum Supportive care Ensure a fl uid intake of 2–3 L/day Check electrolytes the day after admission Continued CHAPTER 39 259 Acute asthma Element Comment Salbutamol and steroid may result in signifi cant hypokalemia. Give potassium supplement if the plasma level is <3.5 mmol/L Monitoring Continuous monitoring of arterial oxygen saturation while needing supplemental oxygen Recheck arterial blood gases if SaO 2 <92% or there is clinical deterioration Check PF before and after inhaled bronchodilator (and at least four times daily during admission) Discharge when PF is stable at >75% predicted/ best, with <25% diurnal variation in the 24 h before discharge, on the same medication that will be taken at home TABLE 39.4 Investigation and monitoring in acute asthma Arterial blood gases • Check arterial blood gases if there are clinical signs of a severe or life-threatening attack (Table 39.1) or if arterial oxygen saturation by oximetry is <92% • Recheck arterial blood gases within 2 h of starting treatment if: – Initial PaO 2 is <8 kPa unless oxygen saturation by oximetry is >92% – Initial PaCO 2 is normal or raised – There is clinical deterioration • Check arterial blood gases again if the patient’s condition has not improved after 4–6 h Continued 260 SPECIFIC PROBLEMS: RESPIRATORY Acute asthma Chest X-ray • Arrange a chest X-ray for: – Life-threatening attack – Poor response to treatment – If ventilation is needed – Suspected pneumomediastinum or pneumothorax – Suspected pneumonia Blood tests • Check electrolytes, creatinine, glucose and full blood count if admission is needed • Check serum theophylline level if aminophylline infusion is needed for >24 h (target level 55–110 µmol/L) Peak fl ow • Check and record peak fl ow 15–30 min after starting treatment and thereafter according to the response • Check and record peak fl ow nebulized and inhaled bronchodilator (at least four times daily) during hospital stay and until controlled after discharge From British guidelines on the management of asthma. Thorax 2003; 58: Suppl I. TABLE 39.5 Checklist before discharge after acute asthma • Stable on discharge medication for 24 h • Inhaler technique checked and recorded • Peak fl ow >75% of predicted/best and diurnal variation <25% • Oral and inhaled steroid prescribed • Inhaler technique checked • Own peak fl ow meter and written asthma action plan • General practitioner follow-up arranged within two working days • Follow-up appointment in asthma clinic within 4 weeks Acute exacerbation of chronic obstructive pulmonary disease 40 Acute exacerbation of chronic obstructive pulmonary disease 261 Continued (1) Acute exacerbation of known chronic obstructive pulmonary disease (COPD) • Increased breathlessness/wheeze • Increased sputum volume/purulence Key observations (Table 1.2) Oxygen 28%, ECG monitor, IV access Nebulized salbutamol 5 mg + ipratropium 500 µg by air-driven nebulizer If conscious level reduced: see (2) Management (Table 40.3) • Controlled oxygen • Ventilatory support if needed (see (2), Table 40.4) • Bronchodilator • Corticosteroid • Antibiotic • Supportive care Clinical improvement within 24–48 h? Yes Discharge planning (Table 40.5) No Consider other diagnoses (p. 93) Seek advice from chest physician Urgent investigation (Table 40.1) Focused assessment (Table 40.2) 262 SPECIFIC PROBLEMS: RESPIRATORY Acute exacerbation of chronic obstructive pulmonary disease TABLE 40.1 Urgent investigation in acute exacerbation of chronic obstructive pulmonary disease (COPD) • Chest X-ray (check for focal shadowing indicative of pneumonia, or pneumothorax) • Arterial blood gases and pH • ECG • Echocardiography if there are clinical signs of congestive heart failure, raised plasma brain natriuretic peptide or if the diagnosis is uncertain • Plasma brain natriuretic peptide (if normal, effectively excludes associated left ventricular dysfunction) • Sputum culture if purulent sputum or focal shadowing on chest X-ray • Blood culture if febrile or focal shadowing on chest X-ray • Blood glucose • Sodium, potassium and creatinine • Plasma theophylline level (if taking theophylline) • Full blood count • C-reactive protein (2) Respiratory failure complicating acute exacerbation of COPD (PaO 2 <8 kPa despite oxygen, or pHa <7.35) Assess conscious level and arterial pH Reduced conscious level Feeble respiratory efforts pHa <7.25 Call intensive therapy unit (ITU) team Endotracheal intubation and mechanical ventilation if appropriate (Table 40.4) Normal conscious level pHa 7.25–7.35 Transfer to high-dependency unit (HDU) for non-invasive ventilation (Table 40.4) Normal conscious level pHa >7.35 Manage on ward with controlled oxygen (Table 40.3) Reassess clinical status and arterial blood gases after 1–2 h CHAPTER 40 263 Acute exacerbation of chronic obstructive pulmonary disease TABLE 40.2 Focused assessment in suspected acute exacerbation of chronic obstructive pulmonary disease (COPD) History • Breathlessness: usual and recent change • Wheeze: usual and recent change • Sputum: usual volume/purulence and recent change • Effort tolerance: usual (e.g. ability to cope with activities of daily living unaided; distance walked on the fl at; number of stairs climbed without stopping) and recent change • Previous acute exacerbations requiring hospital admission/ventilation • Previous lung function tests and arterial blood gases (from the notes): an FEV 1 50–80% of predicted signifi es mild COPD; 30–50%, moderate COPD; less than 30%, severe COPD • Requirement for home nebulized bronchodilator and/or oxygen therapy • Concurrent illness, especially cardiac Examination • Conscious level • Respiratory rate • Arterial oxygen saturation • Use of accessory muscles of respiration • Paradoxical abdominal breathing • Lung signs • Peak fl ow • Heart rate, blood pressure, jugular venous pressure • Peripheral edema FEV 1 , forced expiratory volume in 1 s. Further reading Calverley PMA, Walker P. Chronic obstructive pulmonary disease. Lancet 2003; 362: 1051–61. Keenan SP. Which patients with acute exacerbations of chronic obstructive pulmonary disease benefi t from noninvasive positive-pressure ventilation? A systematic review of the literature. Ann Intern Med 2003; 138: 861–70. National clinical guideline on management of chronic obstructive pulmonary disease in adults in primary and secondary care. Thorax 2004; 59 (suppl I): i1–i232. 264 SPECIFIC PROBLEMS: RESPIRATORY Acute exacerbation of chronic obstructive pulmonary disease TABLE 40.3 Management of acute exacerbation of chronic obstructive pulmonary disease (COPD) Element Comment Oxygen Give oxygen if SaO 2 on air is <92%/PaO 2 <8 kPa (SaO 2 <88%, PaO 2 <7.5 kPa if known chronic respiratory failure) Start with an inspired oxygen of 28% (or 2 L/min by nasal prongs) Check arterial gases and pH 1 h after starting oxygen Increase inspired oxygen to 35% if PaO 2 is <7.5 kPa (<6.5 kPa if known chronic respiratory failure) If this oxygen level cannot be attained, or arterial pH falls below 7.35, consider ventilatory support (fl ow diagram 2, Table 40.4): ask advice from a chest physician Supplemental oxygen should be continued until arterial oxygen saturation is >90% breathing air Ventilatory See fl ow diagram 2 and Table 40.4 support Bronchodilator Give salbutamol 2.5–5.0 mg by nebulizer up to 4-hourly and/or Ipratropium 500 µg by nebulizer up to 4-hourly Switch from nebulized to inhaled bronchodilator therapy when the patient no longer needs supplemental oxygen If the patient is severely ill and does not respond to nebulized salbutamol and ipratropium: • Give aminophylline 250 mg IV over 20 min (not if the patient is already taking a theophylline) • Follow this with an infusion of aminophylline 750–1500 mg over 24 h, according to body size Corticosteroid Give prednisolone 30 mg daily for 7–14 days Consider osteoporosis prophylaxis in patients needing frequent courses of corticosteroid Continued CHAPTER 40 265 Acute exacerbation of chronic obstructive pulmonary disease Element Comment Antibiotic Indicated if there is evidence of infection, as shown therapy by fever, or increased sputum volume and purulence Initial therapy is with amoxycillin 500 mg 8-hourly PO If the patient is allergic to penicillin or has received a penicillin in the previous month, use trimethoprim 200 mg 12-hourly PO or doxycycline 200 mg daily PO Modify therapy in light of sputum and blood culture results. Give a 7-day course If there is no response to amoxycillin, consider using co-amoxiclav or ciprofl oxacin. In ill patients, use cefuroxime or cefotaxime IV Supportive Ensure a fl uid intake of 2–3 L/day care Check electrolytes the day after admission. Salbutamol and steroids may result in signifi cant hypokalemia. Give potassium supplement if the plasma level is <3.5 mmol/L Physiotherapy is of little value unless sputum is copious (>25 ml/day) or there is mucus plugging with lobar atelectasis DVT prophylaxis with stockings/LMW heparin Assess/treat comorbidities, e.g. atrial fi brillation, congestive heart failure Monitoring Continuous monitoring of arterial oxygen saturation while needing supplemental oxygen Monitoring of arterial blood gases as required in patients receiving ventilatory support DVT, deep vein thrombosis; LMW, low molecular weight. Acute exacerbation of chronic obstructive pulmonary disease TABLE 40.4 Ventilatory support in acute exacerbation of chronic obstructive pulmonary disease (COPD) Method Indications Contraindications Comments NIV with bilevel PaO 2 <7.5–8 kPa Decreased conscious level Around 20% of patients positive airways despite supplemental Respiratory rate <12/min cannot tolerate NIV pressure (BiPAP) oxygen Arterial pH <7.25 If arterial pH is <7.3, admit to ITU Arterial pH <7.35 Copious secretions Consider mechanical ventilation if no Orofacial abnormalities which improvement in arterial pH and other prevent fi tting of the mask variables within 1–2 h of starting NIV Endotracheal Impending respiratory arrest Known severe COPD with Potential complications of intubation and Deteriorating conscious level severely impaired functional barotraumas and infection, and mechanical PaO 2 <7.5–8 kPa despite capacity and/or severe inability to wean some patients ventilation supplemental oxygen/NIV comorbidity from the ventilator Arterial pH <7.25 Patient has expressed wish Inability to protect airway or not to be ventilated to clear copious secretions Doxapram PaO 2 <7.5–8 kPa despite Respiratory rate >20/min Has not been proven to improve supplemental oxygen survival or reduce the need for Arterial pH <7.35 mechanical ventilation NIV not available and mechanical ventilation not appropriate ITU, intensive therapy unit; NIV, non-invasive positive pressure ventilation. [...]... known) and give high-flow oxygen • Call an anesthetist: endotracheal intubation may be needed to allow suctioning of the airway and adequate ventilation • Put in a large-bore IV cannula and take blood for urgent cross-match and other investigation (Table 45. 3) • Restore circulating volume and correct coagulopathy (see Table 57 .4) • Contact a thoracic surgeon for advice on further management Bleeding may... T A B L E 43 3 Needle aspiration of pneumothorax 1 Identify the 3rd to 4th intercostal space in the midaxillary line 2 Infiltrate with lidocaine down to and around the pleura over the pneumothorax 3 Connect a 21 G (green) needle to a three-way tap and a 60 ml syringe 4 With the patient semirecumbent, insert the needle into the pleural space Withdraw air and expel it via the three-way tap 5 Obtain a. .. respiratory acidosis, arterial pH 7. 25 7. 35 Upper airway obstruction Impending respiratory arrest Airway at risk because of neurological disease or coma (GCS score 8 or lower) Oxygenation failure: PaO2 . present, aspirate a sample and send for Gram stain and culture Cavitation Particularly associated with tuberculosis and Staphylococcus aureus infection, but may also occur in Gram-negative and anaerobic . medication that will be taken at home TABLE 39.4 Investigation and monitoring in acute asthma Arterial blood gases • Check arterial blood gases if there are clinical signs of a severe or life-threatening. CHAPTER 39 257 Acute asthma TABLE 39.2 Immediate management of life-threatening asthma attack Element Comment Obtain help Call for help from a chest physician or senior colleague in medicine,