The Role of Antibiotics in Acute Pancreatitis

A 65-year-old woman was admitted with a two-day history of feeling non-specifically unwell, severe upper abdominal pain, anorexia and vomiting. On examination she was tachycardic, hypotensive with epigastric tenderness and guarding. Admission amylase was 1024 mmol/L. A diagnosis of acute pancreatitis was made and she was admitted for conservative management with IV fluids and analgaesia. Her initial Ranson score was 3 placing her at moderate risk of of death. Abdominal ultrasound scanning showed a swollen pancreas with a small amount of free fluid but no gallstones or obstruction to the biliary system. Over the next twelve hours she deteriorated on the ward, developing type 1 respiratory failure for which she was referred to intensive care.

On admission to ITU she was semi-electively intubated and ventilated. A low-dose infusion of noradrenaline required to achieve adequate mean arterial pressure. A CT scan showed inflammatory changes and free fluid around the pancreas with possible early pseudocyst formation but no necrotic areas. Two hours after admission she became pyrexial at 39.5°C with a modest increase in her noradrenaline requirements. Peripheral blood cultures were taken and empirical imipenem started following discussion with microbiology. Subsequent repeated microbiological cultures of blood, ascitic fluid, urine and sputum were negative. A nasojejunal tube was passed to allow enteral feeding.

Over the next 48 hours her sedation was weaned and her respiratory function improved. Vasculitis screens, viral serology, lipids, etc. were all negative or normal. Despite her clinical improvement she remained pyrexial with an elevated CRP and white cell count. Further microbiological sampling was unhelpful, serum procalcitonin middling and repeat CT scan showed maturation of her pseduocyst. Fine needle aspiration was performed and subsequently proved culture negative. Her imipenem was stopped after 7 days after gradual resolution of her noradrenaline requirements. Surgical tracheostomy was performed on day 11 to facilitate ventilatory weaning and she was discharged to the ward on day 21.

What is the role for antibiotics in acute pancreatitis?Read More »

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Enteral vs Parenteral Feeding on ICU

A 70-year-old man had been an inpatient on the intensive care unit for nearly 40 days after a complicated recovery following mitral valve replacement. He was being gradually weaned from the ventilator via tracheostomy but required no other invasive organ support. His intensive care unit stay had been complicated by recurrent respiratory sepsis treated with antibiotics and aggressive physiotherapy. Up until this point he had been fed by a nasogastric tube but began to exhibit signs suggestive of impaired absorption including large nasogastric aspirates and a requirement for higher levels of parenteral electrolyte administration.

Prokinetic treatment with metoclopramide 10mg TDS for 24 hours failed to improve the high aspirate levels which remained in excess of 300ml every four hours. Erythromycin 250mg BD was added with little improvement. Following discussion with gastroenterology colleagues an agreement to place a post-pyloric nasojejunal feeding tube was made; unfortunately this procedure was delayed by a further 48 hours as no endoscopist was free to attend. Parenteral feeding was initiated at this point in order to maintain calorific intake.

Compare enteral and parental nutrition.Read More »

Management of Refractory Intracranial Hypertension

A young man with no significant past medical history was admitted to the Emergency Department following an assault. His Glasgow Coma Score on arrival was 8 with a motor score of 4 and there was evidence of an external head injury. Pupils were symmetrically reactive. He was intubated to facilitate further management. Both primary and secondary surveys were unremarkable apart from multiple contusions to the face and scalp. Multi-slice CT showed no intrabdominal or intrathoracic injury but significant intracranial pathology with subarachnoid and intraventricular blood and multiple, principally frontal contusions. No associated neuraxial fracture was seen.

Urgent neurosurgical opinion was sought which confirmed no immediate target for surgical intervention. The patient was transferred to the intensive care unit where appropriate monitoring was established including the insertion of a fibreoptic subdural intracranial pressure bolt. Initial intracranial pressure was measured at 18 mmHg. Sedation with propofol and alfentanil infusions was titrated to a RASS score of -3, ventilation adjusted to a PaO2 > 13 kPa and PaCO2 4.5-5.0 kPa as per the Brain Trauma Foundation guidelines and an infusion of noradrenaline started to achieve a cerebral perfusion pressure of 60 mmHg. The patient was nursed 30° head-up and although active cooling was not undertaken, temperature maintained at less 35-37.5°C.

There was initial stability but approximately 24 hours after admission sustained rises in intracranial pressure (ICP) in excess of 25 mmHg were seen, necessitating boluses of sedation, the addition of atracurium by infusion, administration of hypertonic saline, cooling to 35°C and brief periods of hyperventilation to a PaCO2 4.0-4.5 kPa albeit without significant control. Urgent repeat CT brain was undertaken which showed evolution of the contusions with signifiant oedema and loss of both the lateral ventricles and basal cisterns.

On further consultation, neurosurgical colleagues again felt that no immediate surgical option was viable; in particular that attempts to insert and external ventricular drain were unlikely to be successful and that contusionectomy would produce significant disability. The patient was randomised into the RESCUEicp trial and thiopentone infusion started at a rate to produce isoelectrical activity on three lead electroencephalogram.

What are the management options for refractory intracranial hypertension?
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Transplantation After Brainstem Death

A 38-year-old previously fit man suffered a grade five subarachnoid haemorrhage. Attempts at coiling failed and he suffered a catastrophic rebleed on-table whereupon his pupils became fixed and dilated. After a suitable sedation washout period he underwent testing which confirmed brainstem death at which point he was referred to the specialist nurse for organ donation. Following counselling of the family and appropriate assessment, donation of his kidneys, liver and heart was agreed.

Upon confirmation of brainstem death, mechanical ventilation was continued to ensure PaO2 greater than 10 kPa and limit peak inflation pressure to less than 30 cmH20. Vasoactive support was switched from noradrenaline to vasopressin 0.02 iu/kg/min. Methylprednisolone and intravenous triiodothyronine were administered whilst awaiting harvest. Blood antibody testing for HIV1+2, Hepatitis B and C, HTLV-1 and CMV IgG were all negative. A transthoracic echocardiogram confirmed good biventricular function; following discussion with the transplant retrieval team a pulmonary artery catheter was floated. Clinical measurements of cardiac output and mixed venous oxygen saturation were satisfactory. Adequate hydration was maintained with crystalloid by infusion and glucose control optimised in the range 8-10 mmol/L with insulin. The dedicated retrieval team performed the organ retrieval eighteen hours after confirmation of brainstem death.

How can we optimise organ function for organ donation?Read More »

Management of Inhalational Injury

A 30-year-old man with no significant past medical history was admitted to ED from a house fire started by a piece of faulty electrical equipment. There were superficial skin burns only but some evidence of a possible inhalation injury with singed nasal hairs and a hoarse voice. Coughing resulted in expectoration of carbonaceous sputum with some haemoptysis. Arterial blood gas analysis revealed a PaO2 of 10.4 kPa on 40% oxygen a carboxyhaemoglobin level of 18%.

Semi-elective endotracheal intubation was performed using an uncut orotracheal tube. Ventilatory parameters were adjusted to give a tidal volume of 6-8 ml/kg and plateau pressure of less than 30 cmH20. Recruitment manouveres were performed to give an optimum compliance in the region of 40-50 ml/cmH20 with a positive end-expiratory pressure of 8 H20. The inspired fraction of oxygen was kept high (i.e. greater than 60%) until there was a fall of the carboxyhaemoglobin level to less than 5% at which point downwards titration was performed as guided by a target SpO2 of 94%.

Fibreoptic bronchoscopy was performed approximately six hours after admission to intensive care which demonstrated carbonaceous colonisation of the lower respiratory tract and areas of erythematous and denuded epithelium. Within 12 hours of intubation significant oedema of the face and upper airway had developed. A restrictive fluid regimen was instituted and there was gradual resolution of this swelling over the next 3 days. At this time, gas exchange was satisfactory and the patient was successfully extubated before being discharged to the high-dependency unit.

How is inhalational injury managed on the ICU?Read More »

High Dose Insulin Infusion for Calcium Channel Blocker Overdose

A 24-year-old was admitted following an intentional overdose of 10mg amlodipine tablets following an argument with his family. Approximately 10 tablets were ingested. On self-presentation two hours after the event, he was clinically stable with no haemodynamic compromise. There was no airway or respiratory compromise and a 12 lead electrocardiogram demonstrated sinus rhythm at 98 beats per minute. Both an arterial blood gas and electrolyte analysis were normal. Ionised calcium was 1.14 mol/L.

Over the following two hours he developed hypotension down to a nadir of 58/32 mmHg without change in heart rate or rhythm or the development of metabolic abnormalities. This was initially treated with intravenous fluids without significant response. A bolus of calcium chloride was administered without success; at this time he was referred to the intensive care team for assessment. Careful clinical examination revealed no other abnormality except hypotension. Neurological function remained intact and there appeared to be a vasodilated state with warm peripheries and relative tachycardia at 110 beats per minute in sinus rhythm.

The patient was transferred to the intensive care unit where an infusion of noradrenaline was commenced, rapidly escalating to a rate of 0.92 mcg/kg/min with little improvement in mean arterial pressure beyond 30-40 mmHg and relative oliguria. After consultation with the National Poisons Service, a high dose infusion of actrapid was commenced at rate of 0.5 units/kg/hour, with subsequent improvement of his haemodynamic parameters and a reduction in his noradrenaline requirement. Over the following 4 hours, both this infusion and the noradrenaline infusion were subsequently weaned off. The patient was discharged to the ward after eight hours and after assessment by the psychiatric team, from hospital the following day.

What are the clinical features of calcium channel blocker overdose and what is the role of high dose insulin infusion?Read More »

Management of Variceal Haemorrhage

A 60-year-old alcoholic was admitted with large-volume, frank haematemesis. On presentation he was hypotensive, tachycardic and obtunded with multiple stigmata of chronic liver disease including a moderate volume of ascites and palpable splenomegaly. Initial phlebotomy revealed a haemoglobin of 6.4 g/dL, INR of 4.5 and bilirubin of 54 μmol/L. Arterial blood gas analysis demonstrated a significant metabolic acidosis and lactate of 11 mmol/L. Large bore intravenous access was established and administration of crystalloid initiated, targeting a systolic blood pressure of 90 mmHg. Urgent cross-match of 10 units of packed red blood cells, clotting products and platelets was requested and the patient was transferred to theatre where upper gastrointestinal tract endoscopy was performed under general anaesthesia. This demonstrated three columns of varices involving the gastro-oesophageal junction. Attempts at banding and injection of sclerosant met with variable success. A Senstaken-Blakemore tube was inserted due to incomplete haemostasis and further attempts at endoscopic therapy abandoned.

The patient was transferred to intensive care. Intravenous cefotaxime and terlipressin were commenced. Further transfusion of clotting products continued as guided by thromboelastography with some slowing of transfusion but red cell requirements persisted at a rate of 1-2 units of blood per hour. At 12 hours, repeat endoscopy was performed – further attempts at sclerotherapy were unsuccessful and transjugular intrahepatic porto-systemic shunting was performed by the interventional radiology team. Upon return to intensive care, a significant reduction in bleeding was noted and both haemodynamic indices and coagulopathy improved over the following 12 hours. A repeat endoscopy demonstrated no evidence of active ongoing bleeding. At this point sedation was stopped; some encephalopathy was evident although this improved in the following 24 hours. Extubation occurred on day 3 after admission and he was discharged to the high-dependency unit at day 5 without significant ongoing acute issues.

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Invasive Ventilation of Life-Threatening Asthma

Invasive Ventilation in Life-Threatening Asthma

An 18-year-old known asthmatic presented with a two-day history of increasing shortness of breath on a background of a recent coryzal illness. She had a background of reasonably poor control and had been admitted to the intensive care unit for mechanical ventilation twice as a child. Her current medication included regular inhaled serotide 250, montelukast 10mg and theophylline MR 450mg BD. At presentation she was in extremis; pulse rate was 65 per minute, blood pressure 75/54 mmHg and respiratory rate 14 per minute. Arterial blood gas analysis demonstrated a PaCO2 of 11 kPa and PaO2 of 7.6 kPa with associated respiratory acidosis. Nebulised salbutamol and intravenous magnesium sulphate therapy was administered. along with 200mg of intravenous hydrocortisone. On arrival of the intensive care team, the patient’s respiratory rate deteriorated to a rate of 4 per minute. Assisted ventilation with a self-inflating bag and 100% oxygen was performed; rapid-sequence intubation was performed using ketamine and rocuronium.

Following intubation, immediate difficulties were experienced with mechanical ventilation. High airway pressures in excess of 40 cmH2O with tidal volumes of less than 200 ml were observed. Immediate chest radiography confirmed correct positioning of the endotracheal tube and excluded a pneumothorax. Adequate sedation and neuromuscular blockade were confirmed. Auscultation confirmed severe, widespread wheeze with limited air entry. Further nebulised salbutamol was administered and an aminophylline infusion initiated. The patient was transferred to the intensive care unit where magnesium, ketamine and vecuronium by infusion were added. Various modes of mechanical ventilation were tried including volume and pressure triggered with varying success; this included lengthening the I:E ratio, frequent disconnections to allow deflation and adjustment of PEEP to maximum compliance. Continuous salbutamol was administered via an ultrasonic nebuliser. Airway pressures remained high and there was little improvement in her acidosis. 2 hours after admission the patient suffered a PEA cardiac arrest from which she could not be resuscitated.

What are the difficulties in ventilating severe asthmatics, and what strategies can we use to overcome them?

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