A brief PowerPoint presentation on the pathology and management of patients with Cyanide poisoning.
Uploaded 10/3/2021 by Lewis Jones
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Winter has finally arrived and a new season brings new environmental factors that may play a part in a patients presentation. As we move into the coldest months of the year the identification and management of hypothermia is something which we may all need to revise. Hypothermia can be categorised into: Mild - 32-35'C Moderate- 28 - 32'C Severe - less than 28'C In these cold months be sure to consider hypothermia in elderly patients and the young when presenting acutely unwell. The identification of hypothermia is seemingly easy with use of a thermometer however the usual oral or tympanic thermometers become less accurate in truly cold patients and a central thermometer (rectal/ oesophageal / bladder) should be used. Signs and symptoms of moderate to severe hypothermia include: Shivering Reduced GCS and sluggish to fixed dilated pupils Bradycardia and hypotension Slow AF Hyperglycaemia AKI can develop if left untreated The ECG can be a clincher in the diagnosis before a temperature is gained and there are characteristic ECG findings that you should be aware of. A specific finding is the "J" or Osborn wave, a positive deflection at the J-point, seen below: The height of the J wave is roughly proportional to the degree of hypothermia. Other ECG findings include: Prolonged PR, QRS and QT intervals Shivering artefact Ventricular ectopics Cardiac arrest due to VT, VF or asystole Below is an example of severe hypothermia demonstrating these features (temp 26 degrees) found on life in the fast lane. This ECG is very similar to a patient recently presenting unresponsive to the ED with a temp of 27'C. Management
Search for and treat secondary cause for hypothermia or leading to unprotected exposure to the cold (i.e sepsis, myxoedema, CVE, overdose, DKA etc). Rewarming strategies: Mild-moderate hypothermia Passive re-warming
Peripheral active re-warming
Severe hypothermia Central active warming
Be very careful transferring a hypothermic patient (particularly patients with temperatures <32'C) as moving the patient alone can trigger VF. Resuscitation Changes to ALS in a hypothermic arrest:
Further reading: https://litfl.com/hypothermia/ https://www.rcemlearning.co.uk/reference/hypothermia/ Martin Dore Dec 20 A patient presents to your department with worsening epigastric/chest pain after eating a chocolate bar. He felt a piece of the bar got stuck low down in his chest and he had been retching afterwards. His pain has been getting worse through the day and on arrival he is tachycardic, tachypneic and slightly hypoxic. He is able to swallow fluids, but despite large doses of IV morphine he remains uncomfortable. An arterial blood gas done by one of your colleagues shows mild type 2 respiratory failure and you are asked for advice. You go and review the patient and the investigations. Despite large doses of analgesia, the patient remains very uncomfortable and is reluctant to take deep breaths. On the CXR you note a subtle double line at the right side of the mediastinum and possible similar in the pericardium. See arrows on the CXR: You suspect a pneumomediastinum and order a CT chest/abdomen +/- contrast. This confirms widespread mediastinal air suggestive of lower oesophageal perforation confirming your clinical suspicion of Boerhaave Syndrome. His hypoxia and type 2 respiratory failure can be explained by underventilating due to the severe pain. CT image from the same patient, reported as: ‘Extensive pneumomediastinum, subcutaneous emphysema and bilateral pleural effusions with lower lobe consolidation. The appearance is suggestive of Boerhaave Syndrome.’ What is Boerhaave syndrome? Spontaneous rupture of the oesophagus, caused by forceful vomiting/retching. First described in 1724 by the Dutch physician Herman Boerhaave who diagnosed the condition in Jan van Wassenaer, a Grand Admiral of the Dutch Fleet who died 24hrs after vomiting, having feasted on a sumptuous meal with copious amounts of wine.* Pathophysiology: Spontaneous oesophageal rupture is caused by a sudden rise in internal oesophageal pressure produced during vomiting. The most common site of the perforation is in the lower third of the oesophagus. Symptoms: The classic triad of vomiting, chest pain and subcutaneous emphysema is only present in 14% of presentations. Other symptoms are upper abdominal pain, dyspnoea, tachypnea, odynophagia. The symptoms are often mistaken for other pathologies, e.g. myocardial infarction, chest infection. Diagnosis: is suspected on CXR by the presence of pneumomediastinum, and sometimes a pleural effusion and/or pneumothorax. A CT scan, ideally with contrast, will confirm the diagnosis. The diagnosis is often missed, and late presentations carry a high mortality. Prior to the advent of surgery the condition was universally lethal. Treatment is surgical intervention for most. Occasionally late presentations might be managed conservatively.
* Completely useless afternote: For the food lovers amongst you: his meal consisted of veal soup, cabbage boiled with mutton, calf sweetbreads, spinach, duck, two larks, apple compote, bread and beer. This was followed by Moselle wine, a dessert of pears, grapes and sweetbreads. No wonder he felt sick afterwards! Fred Declerck Nov 2020 A 41 year old patient presents following and Out Of Hospital Cardiac Arrest. His identity is unknown but the ambulance service do bring his I-Phone with him. Click the Emergency button on the bottom of the locked home screen then click *Medical ID on the bottom of the next screen. Have you updated your own phone? Click Emergency SOS in the settings Menu, then click Edit Emergency Contacts in Health in the next menu and fill in your ICE details. Steve Fordham, November 2020
The are a number of studies in the literature looking at the value of the ECG after an Out of Hospital Cardiac Arrest with ROSC.
Circ Cardiovasc Interv. 2015;8:e002784. DOI: 10.1161/CIRCINTERVENTIONS.115.002784. This 2015 paper looked at 210 Patients who had ROSC after an out of hospital cardiac arrest. The post arrest ECG was classified into 3 main groups. 1) ST elevation or presumably new left bundle branch block (2) Other ECG signs indicating myocardial ischaemia (3) No ECG signs indicating myocardial ischaemia. Coronary Angiography findings were then correlated with the ECG findings. Notable findings were: 1) Mean age 62 +/- 12 years 2) 6 Month survival with good neurological outcome 54% 3) STEMI or presumed new LBBB identified patients with reduced TIMI flow with sensitivity 70%, specificity 62%. 4) An acute coronary occlusion was found in 11% of patients in group (3), those with a post resuscitation ecg showing no signs of Myocardial Ischaemia. 5) 32% of patients with initial non shockable rhythms had significantly reduced TIMI flow at angiography. What does this tell us? After initial resuscitation of the patient with an Out of Hospital Cardiac Arrest consider carefully the need for Emergency PCI even if the ecg shows no ischaemia. Want to read more? https://rebelem.com/the-difoccult-trial-time-to-change-from-stemi-nstemi-to-omi-nomi/ This October 2020 paper and post highlighted by Nick Pocock proposes a new way of thinking in Post Cardiac Arrest Care. Steve Fordham November 2020 |
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