Multiple Choice Questions

Transcription

1 Interventional therapies in stroke management: anaesthetic and critical care implications 1. A 72-year-old man undergoes an elective mitral valve repair involving an annuloplasty ring and returns to the intensive care unit. He rapidly becomes hypotensive and transoesophageal echo reveals a new regional wall motion abnormality of the lateral wall. Appropriate statements on this complication may include: (a). The right coronary artery is at risk in this procedure and has likely been damaged. (b). Starting a norepinephrine infusion will improve his coronary perfusion and resolve the regional wall motion abnormality. (c). Papillary muscle rupture is a recognized outcome of this complication. (d). Medical management is appropriate at this point. (e). The circumflex artery may have been damaged or ligated, and this patient needs surgical intervention 2. A 74-year-old gentleman is seen in the preassessment clinic before a transurethral prostate resection. His exercise tolerance is limited by his knee pain and he denies orthopnoea, although he admits to poor sleep, attributable to bladder symptoms. He takes warfarin for atrial fibrillation. A murmur is detected on clinical examination, and an echocardiogram reveals severe mitral stenosis. Regarding this patient: (a). Spinal anaesthesia would be a reasonable choice of anaesthetic. (b). As this patient is relatively asymptomatic, it is safe to proceed with this surgery. (c). When he presents for surgery, he will likely require fluid preloading before induction. (d). This patient is at high risk and requires further investigation, including a stress echocardiogram and assessment of pulmonary artery pressures. (e). Cardioversion will be required before proceeding 3. An active 72-year-old lady is placed on the acute theatre list for hemiarthoplasty after falling and fracturing the neck of her femur while ballroom dancing. A systolic murmur is detected during preoperative assessment. Echocardiography reveals severe mitral regurgitation with a left ventricular ejection fraction of 60% and preserved right ventricular function. Appropriate statements regarding this patient include the following: (a). Surgery needs to be delayed until a stress echocardiogram can be performed. (b). Spinal anaesthesia would be unsafe. (c). Fluid boluses may be needed before induction or to control hypotension. (d). Surgery can go ahead without further delay. (e). Surgery on the hip needs to be combined with mitral valve repair or replacement 4. The obstetric registrar notifies you of a category 2 caesarean section on an 18-year-old primiparous woman with an epidural in situ. She is known to have mitral stenosis from previous rheumatic fever. The delivery plan is for a controlled epidural topup, which proceeds uneventfully. Immediately after delivery she complains of difficulty breathing and becomes acutely dyspnoeic. Regarding this situation: (a). Oxytocin has likely been administered too rapidly and this effect will be transient. (b). This patient requires immediate intubation and ventilation before she deteriorates further. (c). A fluid bolus should be one of the first measures to help stabilize the patient. (d). This patient should be placed head-up and given 100% oxygen with positive endexpiratory pressure (PEEP). (e). This patient is likely to have a high block from the epidural top-up 1 BJA Education Volume 17 Number Published by Oxford University Press on behalf of the British Journal of Anaesthesia 2017

2 Bronchoscopy in critical care 1. Regarding components of bronchoscopes, the following statements are correct: (a). Disposable bronchoscopes contain optical fibres. (b). Fibre-optic bronchoscopes almost always contain xenon as the lamp for white light. (c). The distal tip of bronchoscope is designed for maximum bending. (d). A white light source is ideal for identification of bronchial tumours. (e). The bronchoscope insertion cord is resilient and not easily damaged. 2. There are multiple indications for performing a bronchoscopy in the critical care. Appropriate statements regarding the use of fibre-optic bronchoscopy include: (a). Routine bronchoalveolar lavage (BAL) is useful in the event of aspiration. (b). 2. BAL is superior to blind non-bronchoscopic BAL in diagnosing ventilator-acquired pneumonias. (c). 3. BAL is the gold standard for diagnosis of Pneumocystis jiroveci. (d). 4. Routine bronchoscopy immediately after lobectomy prevents atelectasis. (e). 5. In all patients with haemoptysis or pulmonary haemorrhage, fibre-optic bronchoscopy (FB) can be used as the initial diagnostic and interventional tool. (a). 1. Non-invasive ventilation commenced purely to facilitate FB can prevent respiratory deterioration in spontaneously breathing hypoxaemic patients undergoing FB. (b). 2. If NIV is commenced purely to facilitate FB in a spontaneously breathing hypoxaemic patient, 50% of these patients will require tracheal intubation within 8 h. (c). 3. In patients with chronic obstructive pulmonary disease (COPD) with communityacquired pneumonia, performing NIV to aid early therapeutic FB rather than mechanical ventilation can help avoid intubation in subsequent days. (d). 4. FB in the awake hypoxaemic patient is safe to perform on level 2 or level 3 units. (e). 5. In intensive care, it is common practice to perform FB on the awake patient with NIV. 4. Appropriate statements regarding the physiological implications of fibre-optic bronchoscopy (FB) for critical care include: (a). Insertion of the bronchoscope causes an increase in airway resistance, peak inspiratory pressure, positive end-expiratory pressure and tidal volumes. (b). Assuming turbulent flow, resistance to airflow is inversely proportional to the fourth power of the radius of the tube. (c). Suctioning during FB will decrease the volume delivered by as much as cm 3 (d). Whilst suctioning during FB, PaCO 2 increases by an average of 1.1 kpa. (e). Transient hypoxaemia is less likely than hypercapnia during bronchoscopy 3. Patients with respiratory failure may already be receiving non-invasive ventilation (NIV) or require NIV pre-emptively for fibre-optic bronchoscopy (FB). Appropriate statements regarding the use of FB in the awake patient include: 2 BJA Education Volume 17 Number

3 Paediatric lung isolation 1. A 6-year-old patient requires one-lung ventilation for the resection of a large, left, unilateral lung bulla. Lung isolation for this procedure may be accomplished by using: (a). A 26 French left-sided double-lumen tracheal tube (DLT). (b). A 5.5mm internal diameter (ID) single-lumen tracheal tube with a 5 French bronchial blocker. (c). A 4.5mm ID Fuji Univent tracheal tube. (d). A 3.5mm ID Fuji Univent tracheal tube. (e). Right main-stem endobronchial intubation with a 5.5mm single-lumen tracheal tube. 2. Regarding bronchial blockers, the following statements are true: (a). Vascular catheters such as the Fogarty embolectomy catheter are high-pressure devices and consequently their use may lead to damage to the bronchus. (b). Dedicated airway bronchial blockers, such as the Arndt or Fuji Uniblocker, are high-volume, low-pressure devices. (c). Lung isolation is easily accomplished on a 6- month-old by using a small 2.2 mm bronchoscope and a 5 French bronchial blocker, placing both devices inside the tracheal tube. (d). Both the 5 French Arndt bronchial blocker and the 5 French Fuji Uniblocker have a central channel that allows suctioning and continuous positive airway pressure (CPAP), whereas the Fogarty embolectomy catheter does not. (e). Once the 5 French Arndt bronchial blocker is positioned and the nylon guide wire is removed, repositioning is difficult. 3. Using a fibre-optic scope with an outer diameter of 3.4 mm and a 7 French bronchial blocker with the coaxial technique (both bronchoscope and bronchial blocker within the tracheal tube lumen), the size (ID) of single-lumen tracheal tube that can be used is: (a). 5.0 mm. (b). 5.5 mm. (c). 6.0 mm. (d). 6.5 mm. (e). 7.0 mm. 4. Regarding the 2.2 mm fibre-optic bronchoscope: (a). It is the smallest fibre-optic bronchoscope that is in general use. (b). It will fit through a 3.0 ID single-lumen tracheal tube. (c). It will fit through a 3.0 ID single-lumen tracheal tube and effective ventilation can be achieved. (d). It will fit through a 4.0 ID single-lumen tracheal tube. (e). It will fit through a 4.0 ID single-lumen tracheal tube, and some ventilation is possible. 3 BJA Education Volume 17 Number

4 High-flow nasal oxygen therapy 1. High-flow nasal oxygen therapy (HFNOT) delivery systems: (a). Deliver gases warmed to a maximum of 43 C. (b). Can provide positive end-expiratory pressure (PEEP) of up to 10 cm H 2 O. (c). Allow the delivery of nebulized drugs. (d). Can be used with a bubble humidifier to provide humidification. (e). Require a pipeline gas supply. 2. A 65-year-old male with a body mass index (BMI) of 39 kg/m 2 has his trachea extubated after coronary artery bypass grafting. He is noted to have arterial oxygen saturations on air of 89% and a respiratory rate of 28 bpm. Concerning highflow nasal oxygen therapy (HFNOT) after cardiac surgery: 4. An 85-year-old lady with moderately severe chronic obstructive pulmonary disease (COPD) undergoes emergency laparotomy for a perforated duodenal ulcer. She is extubated on day 2 after surgery. She is commenced on a morphine patient-controlled analgesia pump: (a). Extubating her trachea and commencing her with continuous positive airway pressure (CPAP) would significantly reduce her likelihood of requiring tracheal reintubation. (b). HFNOT would need to be removed in order for her to commence oral nutrition. (c). HFNOT has been shown to be as effective as CPAP in this population. (d). When commencing HFNOT, high flows should be commenced and then titrated down. (e). HFNOT is contraindicated in COPD patients. (a). HFNOT is contraindicated after cardiac surgery. (b). Oxygen saturation/fraction of inspired oxygen (SpO 2 /FiO 2 ) ratio is likely to significantly improve on commencing HFNOT. (c). HFNOT is likely to avert the need for reintubation. (d). HFNOT has greater benefits for respiratory function in the obese population. (e). HFNOT is as effective as bilevel positive airway pressure (BiPAP) in this population. 3. In airway management: (a). HFNOT provides an anatomical oxygen reservoir within the nasopharynx and oropharynx. (b). Pre-oxygenation with HFNOT in severe respiratory failure can result in fewer and less severe arterial oxygen desaturations. (c). HFNOT has been used successfully for oxygenation during awake fibre-optic intubation. (d). HFNOT is poorly tolerated because of high gas flow through the nose. (e). HFNOT in the apnoeic patient does not contribute to carbon dioxide clearance. 4 BJA Education Volume 17 Number

5 Oesophageal cancer and the anaesthetist 1. Regarding the nutrition of patients in relation to oesophageal cancer, the following statements are true: (a). Low dietary intake of fruit and vegetables is a risk for developing adenocarcinoma of the oesophagus. (b). The majority of patients who present for surgery are cachectic because of dysphagia and effects of chemotherapy. (c). Patients with high body mass index (BMI) are not suffering from malnutrition. (d). Nutritional support, with fortified drinks and nasogastric or jejunostomy feeding can be used to optimize nutrition before surgery. (e). Endoscopic deployment of stents to alleviate dysphagia usually requires general anaesthesia. 4. A 70-year-old man is an inpatient on a surgical ward with metastatic oesophageal cancer and marked symptomatic dysphagia. You are asked to review him due to problems with pain relief. The following statements are appropriate: (a). Endoscopic intervention may aid analgesia. (b). Gabapentin is a useful adjunctive agent. (c). Fentanyl preparations may be useful. (d). He may be suffering from chronic pain related to previous surgery. (e). Cautious initial dosing is necessary. 2. The incidence of respiratory complications after oesophagectomy can be reduced by: (a). Use of a conservative intravenous fluid management strategy and avoiding fluid overload. (b). Removal of the nasogastric tube on the first postoperative day. (c). Instituting non-invasive ventilation after extubation. (d). The prophylactic use of steroids such as methylprednisolone. (e). The use of lung-protective ventilation strategies with lower tidal volumes. 3. When considering surgical approach in oesophagectomy: (a). All surgical approaches require thoracotomy. (b). Minimally invasive oesophagectomy means that regional anaesthesia is not required. (c). Two separately sited epidurals may be required to cover thoracotomy and abdominal incisions adequately. (d). The best lymph node clearance for patients undergoing oesophagectomy is achieved via an open approach (e.g. the Ivor Lewis procedure). (e). One-lung ventilation is not required in transhiatal oesophagectomy. 5 BJA Education Volume 17 Number

6 Plasma volume, tissue oedema, and the steady-state Starling principle (e). Hypoalbuminaemia only occurs when there is albumin loss from albuminuria and crystalloid resuscitated haemorrhage. 1. The subglycocalyx space: (a). Is called a protected space. (b). Is bounded within the interendothelial space by the endothelial glycocalyx layer and the interendothelial tight junction strand. (c). In health contains filtrate that is almost protein-free. (d). Contains a higher albumin concentration when Staverman s reflection coefficient falls. (e). Is a prominent feature of splenic capillaries. 2. Regarding albumin: (a). It is largely restricted to the plasma volume. (b). It redistributes to the tissues when the capillary pressure (Pcap) is reduced.. (c). It has a Stokes radius of <2 nm. (d). It carries sphyngosine-1-phosphate from circulating erythrocytes to the endothelial cells. (e). The transcapillary escape rate is normally about 5% per hour but increases to 10 15% per hour after major surgery. 3. Components of the capillary barrier that are involved in the tonic regulation of permeability include: (a). The basal lamina. (b). Adherens junction proteins. (c). Pericytes. (d). Tight junctional strands. (e). The endothelial glycocalyx layer. 4. In systemic inflammation: (a). Vascular endothelial growth factor induces the formation of diaphragm fenestrations across endothelial cells. (b). Enhanced formation of small guanosine triphosphate (GTP)-ases damages capillary permeabilty. (c). Integrins act upon collagen fibres to increase interstitial fluid pressure. (d). Glomerular endothelial glycocalyx injury leads to albuminuria. 6 BJA Education Volume 17 Number