Category: Basic Sciences

Lactate Physiology and Predicting Disease Severity

Lactate Physiology and Predicting Disease Severity

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A middle aged man presented with urosepsis after several days antibiotic therapy in the community. He was in septic shock, with tachypnoea, tachycardia and hypotension. He had raised inflammatory markers and acute kidney injury. His initial lactate level was 14mmol/L with a significant metabolic acidosis (base deficit 21). He was commenced on iv antibiotics, noradrenaline and renal replacement therapy. Lactate levels cleared to less than 2mmol/L over the next 24hrs. He weaned off noradrenaline in 72 hours and CVVHDF over the next 5 days.

How is lactate produced and what is its significance in predicting the severity of critical illness?

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Invasive Streptococcal A Infections and Intravenous Immunoglobulin

Invasive Streptococcal A Infections and Intravenous Immunoglobulin

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A middle aged woman presented with a one day history of swollen, painful red thigh after a prodromal sore throat. She had a exquisitely tender left thigh and knee with cellulitis. She was apyrexial, with normal heart rate and blood pressure, but had a respiratory rate of 24. She had a neutrophilia (28), elevated CRP, hyperlactataemia (4.1) an acute kidney injury (creat 170) and a mild coagulopathy. She was given analgesia, broad spectrum antibiotics (including clindamycin) and underwent a CT thigh which showed muscle swelling in the anterior compartment with fluid tracking up to the hip. Knee aspirate showed large number of gram positive cocci, later confirmed as Streptococcus A. Two hours into her admission the inflammation was involving the groin. She underwent exploration and debridement in theatre, and was noradrenaline dependent postoperatively. She was commenced on intravenous immunoglobulin on the same day. She required further debridement of the leg and lower abdomen on day 3. She gradually weaned off support, and underwent several more operations for closure of wounds and reconstructive surgery.

What is the role of IVIG in Invasive Streptococcal Infections

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Medical Management of Abdominal Compartment Syndrome

Medical Management of Abdominal Compartment Syndrome

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An elderly man was admitted after a Hartman’s procedure with primary closure for a perforated sigmoid diverticulum with four quadrant peritonitis. Postoperatively, he remained ventilated and noradrenaline dependent. His intra-abdominal pressures gradually rose from 15 to 24mmHg. Urine output was poor, and he required peak pressures of 28cmH2O to achieve 6ml/kg tidal volumes. Vasopressor requirements gradually increased and a diagnosis of abdominal compartment syndrome was made. Medical management was attempted with fluid resuscitation, increased sedation, aspiration of nasogastric tube and neuromuscular blockade. However this did not improve the intra-abdominal pressures so the patient returned to theatre laparostomy and VAC dressing. On return from theatre, intra-abdominal pressures stabilised between 12 and 15mmHg. Noradrenaline requirements fell and urine output improved. The abdomen was closed on day 5 and he was discharged from ICU on day 10.

What non-surgical strategies can be used to reduce intra-abdominal pressure?

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Management of Life-Threatening Tricyclic Antidepressant Overdose

Management of Life-Threatening Tricyclic Antidepressant Overdose

Steve Mathieu1 Comment

A 44-year-old lady was brought to ED by ambulance after her partner found her drowsy in her bedroom with multiple empty packets of Amitriptyline scattered around the bed. The ambulance crew found no other medications in the immediate vicinity. Her partner had last seen her two hours previously that evening and described a history of depression, previous overdoses and chronic alcohol excess.  On arrival in ED, her airway was self-maintained but she had signs of vomitus around her mouth and smelled strongly of alcohol. Heart rate was 125, NIBP 92/38 and ECG showed sinus rhythm with prolonged PR and QRS intervals (240ms and 200ms, respectively). ABG showed a metabolic acidosis with lack of respiratory compensation, with hyperlactataemia (4.1). GCS was 9 (E2M5V2) although she appeared agitated with bilaterally dilated pupils. There was no external evidence of injury. The impression was of life-threatening Tricyclic Antidepressant (TCA) overdose within the last 2 hours along with alcohol ingestion.

What are the main features of a Tricyclic Antidepressant overdose? What treatment options are available?

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Hypertonic Saline for Raised Intracranial Pressure

Hypertonic Saline for Raised Intracranial Pressure

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A 40 year old male was brought into ED following a high speed road traffic accident. The patient was ejected from the vehicle. The patient was managed according to ATLS guidelines. He suffered extensive injuries including facial fractures, traumatic subarachnoid haemorrhage and multiple intra-cerebral haemorrhages, a flail chest and thoracic and cervical spine injuries. Once stabilised, the patient was transferred to the neurosurgical intensive care unit where an intra-cranial pressure (ICP) monitor was inserted to measure intracranial pressures. His ICP was persistently raised despite optimising respiratory parameters, deep sedation, muscle relaxation and then mannitol. A decision was made to commence an infusion of hypertonic saline 2.7% according to the local protocol. The ICP improved rapidly and stabilised and removed the need to proceed with surgical decompressive craniotomy.

What is the evidence for the use of hypertonic saline in the treatment of acutely raised intracranial pressure?Read More »

Nutrition in Acute Pancreatitis

Nutrition in Acute Pancreatitis

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A 55-year-old previously healthy lady was admitted with pancreatitis secondary to gallstones. Her admission modified Glasgow Score was 4, and CT scan showed approximately 70% necrosis of the pancreas encompassing the neck, body and tail with sparing of the head. She rapidly developed ARDS, AKI and vasoplegia, and subsequently developed abdominal compartment syndrome requiring decompressive laparotomy. Her later complications included intraabdominal collections requiring percutaneous drainage, upper GI bleeding, and staged closure of her laparostomy. She was initially commenced on enteral NG feeding but developed high NG aspirates despite pro-kinetics. Parenteral nutrition (PN) was commenced in combination with a ‘trophic’ enteral feed. Four weeks into her admission her triglyceride level was found to be elevated, necessitating lipid free PN and cessation of propofol. This led to a drop in her triglyceride level.

How should we manage the provision of nutrition in acute pancreatitis?

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Corticosteroids in Septic Shock

Corticosteroids in Septic Shock

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A week after an elective colectomy, a 70yr old man developed septic shock and multiorgan failure secondary to anastomotic breakdown. He was managed according to surviving sepsis guidelines with source control, early antibiotics, fluids and noradrenaline. The patient remained hypotensive and refractory to noradrenaline therapy, and had vasopressin and low dose hydrocortisone infusion commenced.

What is the evidence for the use of corticosteroids in septic shock?Read More »

Nutrition in the Intensive Care Unit

Nutrition in the Intensive Care Unit

Steve Mathieu1 Comment

A middle aged man is admitted with abdominal pain and vomiting. He has a history of alcohol excess. A CT scan shows evidence of pancreatic necrosis. Supportive care is initiated and an NGT placed for supplementary enteral nutrition. After 3 days, he is referred to ICU as his oxygen requirements have increased and he is requiring non-invasive ventilation. It is noted that he has had very large gastric aspirates. Parenteral nutrition is commenced at this point.

What is the evidence for enteral versus parenteral feed as a source of nutrition in critically ill patients?Read More »

Heparin Induced Thrombocytopenia

Heparin Induced Thrombocytopenia

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A 62 year old lady with a metallic aortic valve was admitted to the cardiac unit for urgent surgical repair of a severely regurgitant mitral valve. He was normally on warfarin for his metal valve. This was stopped and unfractionated heparin commenced on day 4 once his INR level had dropped below the therapeutic range. The patient’s platelet count was 147*10^9/L on admission. By day 4 it had dropped to 85*10^9/L. After heparin was started it dropped further to a nadir of 55*10^9/L on day 8.

Could this be due to heparin induced thrombocytopenia? What investigations are required and how should we treat it?
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Hepatorenal Syndrome

Hepatorenal Syndrome

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A 54 year old man with a history of alcohol excess was admitted under the medical team with an upper gastro-intestinal bleed. He had a background of pulmonary fibrosis that limited his exercise tolerance to 30 yards. Antibiotics, terlipressin and fluid resuscitation, including blood, were given. An oesophago-gastro-duodenoscopy demonstrated severe portal gastropathy but no active bleeding or varices. An abdominal ultrasound demonstrated cirrhosis and some moderate ascites. On day two of the patient’s hospital admission he was admitted to the intensive care unit (ICU) with respiratory failure and non-invasive ventilation was started. Over the next few days his condition deteriorated and he required vasopressor support. By day 6 the patient was oliguric, and his creatinine had risen from 102 to 155 µmoles/l.

What is the cause for his acute kidney injury? Could it be hepatorenal syndrome? Read More »