Management of Life-Threatening Tricyclic Antidepressant Overdose

Management of Life-Threatening Tricyclic Antidepressant Overdose

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

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 »

Neuroprognostication Post Cardiac Arrest (Post TTM Era)

Neuroprognostication Post Cardiac Arrest (Post TTM Era)

A  young adult female with known diagnosis of poorly controlled type 1 diabetes mellitus was admitted with out-of-hospital cardiac arrest. She had only recently been discharged from hospital after an admission with diabetic ketoacidosis. On arrival she had a GCS 3 with minimal respiratory effort. She was in profound DKA. Her temperature was 34.7°C on admission to ICU and she had targeted temperature management aiming for 36°C which was achieved within 2 hours. Her pH had normalised to 7.35 within 8 hours. 48 hours later one pupil became fixed and dilated. CT brain was consistent with global hypoxic ischaemic injury. EEG and SSEP on day 3 revealed severe lack of normal cortical activity. After discussion with family, treatment was withdrawn on day 4.

How do we undertake neuroprognostication after cardiac arrest in the post-TTM era?

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Dexamethasone in Bacterial Meningitis

Dexamethasone in Bacterial Meningitis

A previously healthy 25 year old female was admitted with low GCS and a fever. She had a 24 history of viral symptoms including sore throat and a headache. On admission she had a GCS of 3, temperature of 38.9°C and raised inflammatory markers. She was intubated but did not require vasopressor support. A CT brain showed diffuse cerebral swelling, effacement of the sulci, sylvian fissures, basal cisterns and 3rd/4th ventricles, and early cerebellar tonsillar herniation. Lumbar puncture was not performed due to CT appearances. She was commenced on intravenous (IV) ceftriaxone 2g twice daily, IV acyclovir 800mg three times daily, and IV dexamethasone 10mg four times daily. Unfortunately, her pupils remained fixed and dilated on sedation hold 36 hours later, and she was making no respiratory efforts. She subsequently became a DBD organ donor.

What is the evidence for dexamethasone in bacterial meningitis?

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Decompressive Laparotomy in Abdominal Compartment Syndrome

Decompressive Laparotomy in Abdominal Compartment Syndrome

A 55 yr old man developed severe necrotizing pancreatitis with multiorgan failure. One week into his illness he had developed multiple intra-abdominal collections and had high intra-abdominal pressures. Initial conservative management failed, percutaneous drainage of his collections failed to reduce the abdominal pressures, and he underwent decompressive laparotomy.

What is the evidence behind the current guidelines for the measurement of intra-abdominal hypertension and the use of decompressive laparotomy in the management of Abdominal Compartment Syndrome?Read More »

Transfusion in Sepsis

Transfusion in Sepsis

A 85 year old man presented with acute bowel obstruction. He had a history of hypertension and diverticulitis disease, but was active for his age. He was not known to have coronary or any other vascular pathology. At laparotomy, a large diverticulitis abscess was identified. When this was manipulated, he developed an SVT with a ventricular rate of 210 bpm which progressed to VT. He received 1 mg adrenaline and 2 minutes CPR in total, with no electrical shocks. At this point perfusion and pressure returned. Surgery was expedited and simplified. He remained intubated and ventilated on ITU post-operatively. ECG demonstrated global t-wave inversion. He required noradrenaline and adrenaline to maintain blood pressure. During the initial 48 hours, his haemoglobin (Hb) fell from 11.9 g/dl to 8.1 g/dl, raising the suggestion of packed red cell (PRC) transfusion.

What is the most appropriate threshold to transfuse packed red cells in critically ill patients?Read More »

Sodium Bicarbonate in Amitriptyline Overdose

Sodium Bicarbonate in Amitriptyline Overdose

A 40 year old man with pre-existing mental health problems presented after an overdose of 6g of amitriptyline. He was deeply unconscious and required invasive ventilation. He was commenced on bicarbonate therapy and hyperventilated to pH 7.5. Around 12 hours after admission he developed tonic-clonic seizures, a broad complex tachycardia and subsequently suffered a cardiac arrest that was refractory to defibrillation, adrenaline and amiodarone. He was given additional 8.4% bicarbonate and further defibrillation attempts and was successfully resuscitated after 90 minutes.

What is the rationale for the use of sodium bicarbonate in the management of amitriptyline overdose?Read More »

Botulism

Botulism

A young female IV drug abuser presented with dysarthria, diplopia and weakness with loss of her gag reflex. She had recently had an abscess wound on her arm debrided. She was intubated for airway protection, and underwent early tracheostomy. She was treated with intravenous antibiotics and botulism antitoxin after electromyography and nerve conduction studies were consistent with a diagnosis of botulism. She was weaned from the ventilator within 2 weeks and the Health Protection Agency later confirmed the presence of botulism neurotoxin A from wound swabs.

What are the clinical features of Botulism and how is it managed?Read More »

Critical Care Echocardiography

Critical Care Echocardiography

A 34 year old IV drug abuser was admitted with respiratory failure, bilateral patchy changes on chest X-ray, raised inflammatory markers and septic shock. She was intubated and commenced on antibiotics and noradrenaline. An in-house Focussed Intensive Care Echo was performed to guide fluid resuscitation. This was suggestive of hypovolaemia, but a large mobile mass was also observed in the left ventricular chamber. A departmental echo the next day confirmed the presence of a large vegetation on the anterior mitral valve leaflet with severe mitral regurgitation. She underwent a further period of stabilisation and underwent a mitral valve replacement.

What is the evidence for the development of in-house echocardiography skills within the critical care setting?Read More »

Glycaemic Control on the ICU

Glycaemic Control on the ICU

A 76 year old man with no comorbidities was admitted to the intensive care unit following an oesophagectomy. During routine blood sugar monitoring, his blood glucose was found to be just over 10 for two consecutive readings so he was commenced on a variable rate insulin infusion. Six hours later, despite hourly monitoring, he had a blood sugar of 3.6. The insulin infusion was stopped and his blood sugar rose back to normal levels. He suffered no apparent ill effects from his hypoglycaemic episode.

What is the rationale behind current glycaemic control on the intensive care unit?Read More »