A practical guide to the management of medical emergencies - part 4 doc

190 SPECIFIC PROBLEMS: CARDIOVASCULAR Acute pulmonary edema TABLE 29.5 Further drug therapy of acute cardiogenic pulmonary edema Systolic blood pressure Action >110 mmHg Give another dose of furosemide 40–80 mg IV Start a nitrate infusion 90–110 mmHg Start a dobutamine infusion at 5 µg/kg/min; this can be given via a peripheral line Increase the dose by 2.5 µg/kg/min every 10 min until systolic BP is >110 mmHg or a maximum dose of 20 µg/kg/min has been reached A nitrate infusion can be added if systolic BP is maintained at >110 mmHg 80–90 mmHg Start a dopamine infusion at 10 µg/kg/min; this must be given via a central line Increase the dose by 5 µg/kg/min every 10 min until systolic BP is >110 mmHg If systolic BP remains <90 mmHg despite dopamine 20 µg/kg/min, use norepinephrine instead A nitrate infusion can be added if systolic BP is maintained at >110 mmHg <80 mmHg Start a norepinephrine infusion at 2.5 µg/kg/min; this must be given via a central line Increase the dose by 2.5 µg/kg/min every 10 min until systolic BP is >110 mmHg A nitrate infusion can be added if systolic BP is maintained at >110 mmHg CHAPTER 29 191 Acute pulmonary edema TABLE 29.6 Ventilatory support for respiratory failure due to cardiogenic pulmonary edema Disadvantages and Mode of ventilation Indications Contraindications complications Non-invasive Oxygenation failure: oxygen Recent facial, upper airway or upper Discomfort from tightly ventilatory support saturation <92% despite gastrointestinal tract surgery fi tting facemask with continuous FiO 2 > 40% Vomiting or bowel obstruction Discourages coughing and positive airways Ventilatory failure: mild to Copious secretions clearing of secretions pressure (CPAP) moderate respiratory Hemodynamic instability acidosis, arterial pH 7.25– Impaired consciousness, confusion 7.35 or agitation Endotracheal Upper airway obstruction Severely impaired functional capacity Adverse hemodynamic intubation and Impending respiratory arrest and/or severe comorbidity effects mechanical Airway at risk because of Cardiac disorder not remediable Pharyngeal, laryngeal and ventilation neurological disease or Patient has expressed wish not to tracheal injury coma (GCS 8 or lower) be ventilated Pneumonia Oxygenation failure: PaO 2 Ventilator-induced lung <7.5–8 kPa despite injury (e.g. pneumothorax) supplemental oxygen/NIV Complications of sedation Ventilatory failure: moderate and neuromuscular to severe respiratory blockade acidosis, arterial pH < 7.25 GCS, Glasgow Coma Scale. 192 SPECIFIC PROBLEMS: CARDIOVASCULAR Acute pulmonary edema TABLE 29.7 Management of acute respiratory distress syndrome (ARDS) Element Comment Transfer to ITU ARDS is usually part of multiorgan failure Oxygenation Increase inspired oxygen, target PaO 2 >8 kPa Ventilation will be needed if PaO 2 is <8 kPa despite FiO 2 60% Ventilation in the prone position improves oxygenation Hemoglobin should be kept around 10 g/dl (to give the optimum balance between oxygen- carrying capacity and blood viscosity) Fluid balance Renal failure is commonly associated with ARDS Consider early hemofi ltration Prevention and Sepsis is a common cause and complication of treatment of sepsis ARDS sepsis Culture blood, tracheobronchial aspirate and urine daily Treat presumed infection with broad-spectrum antibiotic therapy Nutrition Enteral feeding if possible, via nasogastric tube if ventilation needed DVT prophylaxis Give DVT prophylaxis with stockings and LMW heparin Prophylaxis against Give proton pump inhibitor gastric stress ulceration DVT, deep vein thrombosis; ITU, intensive therapy unit; LMW, low molecular weight. CHAPTER 29 193 Acute pulmonary edema Further reading European Society of Cardiology. Guidelines on the diagnosis and treatment of acute heart failure (2005). European Society of Cardiology website (http://www.escardio. org/knowledge/guidelines/Guidelines_list.htm?hit=quick). McMurray JJV, Pfeffer MA. Heart failure. Lancet 2005; 365: 1877–89. Peter JV, et al. Effect of non-invasive positive pressure ventilation (NIPPV) on mortality in patients with acute cardiogenic pulmonary oedema: a meta-analysis. Lancet 2006; 367: 1155–63. Ware LB, Matthay MA. The acute respiratory distress syndrome. N Engl J Med 2000; 342: 1334–49. Ware LB, Matthay MA. Acute pulmonary edema. N Engl J Med 2005; 353: 2788–96. TABLE 29.8 Negative-pressure pulmonary edema • Seen in the early postoperative period • Due to forced inspiration in the presence of upper airway obstruction (e.g. from laryngospasm after extubation) • After relief of laryngospasm, patients develop clinical and radiological features of pulmonary edema • Typically resolves over the course of a few hours with supportive care • Cardiogenic pulmonary edema should be excluded by clinical assessment, ECG and echocardiography Cardiac valve disease and prosthetic heart valves 30 Cardiac valve disease and prosthetic heart valves 194 Further management directed by cause and severity of valve lesion, and clinical setting (Tables 30.4–30.6) Suspected valve disease: • Unexplained hypotension/pulmonary edema (murmur may not be audible) • Exertional syncope with ejection systolic murmur • Fever with evidence of infective endocarditis • Incidental finding of murmur Key observations (Table 1.2) Urgent echocardiography and other investigation if acute illness (Tables 30.1, 30.2, 30.3) ALERT In severe aortic stenosis with a low cardiac output, the transvalve gradient will fall and the aortic stenosis may be erroneously graded as moderate. ALERT If mitral regurgitation reported as ‘mild’ or ‘moderate’ is associated with a hyperdynamic left ventricle in a patient with shock, the likely diagnosis is critical regurgitation. Cardiac valve disease and prosthetic heart valves TABLE 30.2 Echocardiography in valve disease: key information • Valve(s) affected and grade of stenosis or regurgitation • Left ventricular size and function • If there is acute severe aortic regurgitation, evidence of raised left ventricular end-diastolic pressure (early closure of the mitral valve and E deceleration time <150 ms) • Evidence for etiology, e.g. infective endocarditis (p. 203), ruptured chord • Pulmonary artery pressure and right ventricular function • Ascending aortic diameter and evidence of abscess or dissection TABLE 30.1 Urgent investigation in suspected valve disease • ECG • Chest X-ray • Echocardiogram if pulmonary edema, unexplained hypotension, likely endocarditis, thromboembolism • Full blood count and fi lm • Erythrocyte sedimentation rate (ESR) and C-reactive protein • Blood culture (three sets) if infective endocarditis is suspected • Blood glucose • Sodium, potassium and creatinine • Liver function tests • Urine stick test and microscopy Further reading American College of Cardiology and American Heart Association. Guidelines for the management of patients with valvular heart disease (2006). American College of Car- diology website (http://www.acc.org/qualityandscience/clinical/topic/topic.htm). Butchart EC et al. Recommendation for the management of patients after heart valve surgery. Eur Heart J 2005; 26: 2463–71. European Society of Cardiology. Guidelines on the management of valvular heart disease (2007). European Society of Cardiology website (http://www.escardio.org/knowledge/ guidelines/Guidelines_list.htm?hit=quick). Seiler C. Management and follow up of prosthetic heart valves. Heart 2004; 90: 818–24. Cardiac valve disease and prosthetic heart valves TABLE 30.3 Causes of acute pulmonary edema in native and prosthetic valve disease Setting Causes Acute native valve Acute aortic regurgitation: regurgitation • Endocarditis • Aortic dissection • Deceleration injury, e.g. RTA Acute mitral regurgitation: • Myocardial infarction giving papillary muscle rupture or dysfunction • Endocarditis • Ruptured chord in fl oppy mitral valve • Deceleration injury e.g. RTA Prosthetic valve Dehiscence (early, caused by surgical technique or friable tissue; or late, usually caused by endocarditis) Thrombosis causing a stuck mechanical leafl et. Rare in biological valves Primary failure causing either obstruction (as a result of calcifi cation) or regurgitation (as a result of a tear in a biological cusp). Rarely occurs before 5 years in the mitral position or 7 years in the aortic position unless the patient is aged <45 years Endocarditis Chronic native valve disease Acute myocardial infarction or myocardial or prosthetic valve ischemia Arrhythmia Poor compliance with diuretic therapy Drugs causing fl uid retention (e.g. NSAIDs, steroids) Iatrogenic fl uid overload Endocarditis Progression of disease NSAIDs, non-steroidal anti-infl ammatory drugs; RTA, road traffi c accident. CHAPTER 30 197 Cardiac valve disease and prosthetic heart valves TABLE 30.4 Aortic valve disease Valve lesion Setting Management Severe aortic Presenting with Start a loop diuretic stenosis heart failure If hypotensive, start dobutamine (p. 190) The only defi nitive treatment is valve replacement A low left ventricular ejection fraction may be reversible and is not a contraindication to aortic valve replacement Noted incidentally/ Severe aortic stenosis is a needing non- contraindication to all but cardiac surgery life-saving non-cardiac surgery. Otherwise requires cardiac referral and consideration of aortic valve replacement before proceeding with original management plan Avoid epidural anesthetics Avoid vasodilators, e.g. angiotensin-converting enzyme inhibitors which should only be used under specialist guidance Avoid drugs with negative inotropic effect Moderate aortic stenosis may also cause symptoms and be associated with sudden death and should prompt cardiac referral Continued 198 SPECIFIC PROBLEMS: CARDIOVASCULAR Cardiac valve disease and prosthetic heart valves Valve lesion Setting Management Severe aortic Presenting with Consider infective endocarditis regurgitation heart failure Request urgent cardiac opinion if there are signs of a high LV end-diastolic pressure since these patients can deteriorate rapidly Critical aortic regurgitation can lead to vasoconstriction with normalization of the diastolic pressure (usually <70 mmHg and often 30 or 40 mmHg in severe regurgitation) Give a loop diuretic If systolic BP <100 mmHg, start dobutamine If oxygen saturation <92% despite 60% oxygen and patient tiring, discuss mechanical ventilation Discuss urgent specialist investigation and surgery with a cardiologist Noted incidentally/ Refer for a cardiology opinion needing non- especially if there are cardiac surgery indications for surgery: • Exertional breathlessness • LV systolic diameter >5.0 cm • Aortic root dilatation Patients with LV compensation usually tolerate non-cardiac surgery well BSA, body surface area; LV, left ventricular. CHAPTER 30 199 Cardiac valve disease and prosthetic heart valves ALERT Severe aortic stenosis is frequently associated with systemic hypertension rather than hypotension and narrow pulse pressure. TABLE 30.5 Mitral valve disease Valve lesion Setting Management Severe mitral Presenting with Give a loop diuretic stenosis pulmonary edema Left atrial pressure is highly dependent on heart rate. Treat atrial fi brillation with digoxin and if the ventricular rate is >100 bpm, add verapamil or a beta-blocker. If there is sinus tachycardia give a beta-blocker, e.g. metoprolol 25 mg 12-hourly PO Avoid mechanical ventilation unless essential because of the risks of circulatory collapse. Maintain peripheral vascular resistance with norepinephrine Discuss mitral valve replacement or balloon valvotomy with a cardiologist Continued ALERT In severe valve disease, a murmur may not be obvious if the cardiac output is low and/or breath sounds loud. [...]... paradoxus may be palpable in the radial artery, with the pulse disappearing on inspiration Continued Cardiac tamponade Bleeding into pericardial space • Penetrating and blunt chest trauma including external cardiac compression • Bleeding from cardiac chamber or coronary artery caused by perforation/laceration as a complication of cardiac catheterization, percutaneous coronary intervention, pacemaker insertion,... sedimentation rate; NSAID, non-steroidal anti-inflammatory drug CH AP TE R 32 215 T A B L E 32 5 Idiopathic pericarditis NSAID, non-steroidal anti-inflammatory drug Further reading European Society of Cardiology Guidelines on the diagnosis and management of pericardial diseases (20 04) European Society of Cardiology website (http://www.escardio org/knowledge/guidelines/Guidelines_list.htm?hit=quick) Goodman... Examination • Blood pressure in both arms • Presence and symmetry of the major pulses, check for radiofemoral delay • Carotid, abdominal and femoral bruits • Check for signs of heart failure and aortic regurgitation • Abdominal mass (e.g palpable kidneys or abdominal aortic aneurysm) • Fundi: retinal hemorrhages, exudates or papilledema (not due to other causes) define accelerated phase or ‘malignant’... subarachnoid hemorrhage (p 321) and stroke Hypertensive encephalopathy is favored by the gradual onset of symptoms and the absence (or late appearance) of focal neurological signs If there is diagnostic doubt, a CT scan should be obtained to exclude cerebral or subarachnoid hemorrhage before starting IV therapy T A B L E 34 4 Intravenous labetalol for aortic dissection and hypertensive encephalopathy... abdominal striae, proximal myopathy (unable to rise from chair without using arms) Increased urinary free cortisol excretion Pheochromocytoma Paroxysmal headache, sweating or palpitation Hypertensive crisis following anesthesia or administration of contrast Family history of pheochromocytoma Increased urinary catecholamine excretion Continued CH AP TE R 34 223 Clues/investigation Coarctation of aorta Radiofemoral... sets of blood cultures before starting antibiotic therapy The sensitivity of transthoracic echo for vegetations is much lower than for native valves, about 15%, and transesophageal echocardiography is usually necessary to confirm the diagnosis Surgery is more likely to be necessary than for native valves Anemia Investigate as for any anemia, not forgetting the possibility of endocarditis Virtually all... CARDI OVASCULAR Valve lesion Cardiac valve disease and prosthetic heart valves Management Noted incidentally /needing noncardiac surgery Indications for intervention are: • Symptoms • High pulmonary artery pressure Patients with critical mitral stenosis tolerate non-cardiac surgery badly unless the rate is controlled pharmacologically Also consider urgent balloon valvotomy Presenting with heart failure... mechanical valves produce minor hemolysis (disrupted cells on the film, high LDH and bilirubin, low haptoglobin) caused by normal transprosthetic regurgitation Usually the hemoglobin remains normal Hemolytic anemia suggests leakage usually around the valve (paraprosthetic regurgitation), which is often small and only detectable on transesophageal echocardiography Refer for a cardiac opinion CRP, C-reactive... pericardiocentesis or central venous cannulation • Bleeding after cardiac surgery • Cardiac rupture after myocardial infarction • Aortic dissection with retrograde extension into pericardial space • Anticoagulant therapy or thrombolytic therapy given (inappropriately) for pericarditis Cardiac tamponade 218 S P E C IFIC PROBLEMS: CARDI OVASCULAR 2 When does it happen? • Typically in cardiac tamponade,... penicillin allergy Infective endocarditis T A B L E 31 5 Empirical antibiotic therapy in suspected infective endocarditis* T A B L E 31 6 Modified Duke criteria for the diagnosis of infective Infective endocarditis endocarditis (IE) Pathological criteria • Positive histology or microbiology of pathological material obtained at removal of a peripheral embolus (as well as at autopsy or cardiac surgery) Major . a range of 3 4. Continued 202 SPECIFIC PROBLEMS: CARDIOVASCULAR Cardiac valve disease and prosthetic heart valves Complication Management Arrange an early appointment with the anticoagulation. heart valves. Heart 20 04; 90: 818– 24. Cardiac valve disease and prosthetic heart valves TABLE 30.3 Causes of acute pulmonary edema in native and prosthetic valve disease Setting Causes Acute native. (http://www.acc.org/qualityandscience/clinical/topic/topic.htm). Butchart EC et al. Recommendation for the management of patients after heart valve surgery. Eur Heart J 2005; 26: 246 3–71. European Society of Cardiology. Guidelines on the management of valvular