The earliest and most common clinical indication of malignant hyperthermia is typically an increase in end tidal CO2 levels.

Further Reading:

Malignant hyperthermia is a rare and life-threatening syndrome that can be triggered by certain medications in individuals who are genetically susceptible. The most common triggers are suxamethonium and inhalational anaesthetic agents. The syndrome is caused by the release of stored calcium ions from skeletal muscle cells, leading to uncontrolled muscle contraction and excessive heat production. This results in symptoms such as high fever, sweating, flushed skin, rapid heartbeat, and muscle rigidity. It can also lead to complications such as acute kidney injury, rhabdomyolysis, and metabolic acidosis. Treatment involves discontinuing the trigger medication, administering dantrolene to inhibit calcium release and promote muscle relaxation, and managing any associated complications such as hyperkalemia and acidosis. Referral to a malignant hyperthermia center for further investigation is also recommended.

The most frequent reason for sudden inability to urinate in males is an enlarged prostate.

Further Reading:

Urinary retention is the inability to completely or partially empty the bladder. It is commonly seen in elderly males with prostate enlargement and acute retention. Symptoms of acute urinary retention include the inability to void, inability to empty the bladder, overflow incontinence, and suprapubic discomfort. Chronic urinary retention, on the other hand, is typically painless but can lead to complications such as hydronephrosis and renal impairment.

There are various causes of urinary retention, including anatomical factors such as urethral stricture, bladder neck contracture, and prostate enlargement. Functional causes can include neurogenic bladder, neurological diseases like multiple sclerosis and Parkinson’s, and spinal cord injury. Certain drugs can also contribute to urinary retention, such as anticholinergics, opioids, and tricyclic antidepressants. In female patients, specific causes like organ prolapse, pelvic mass, and gravid uterus should be considered.

The pathophysiology of acute urinary retention can involve factors like increased resistance to flow, detrusor muscle dysfunction, bladder overdistension, and drugs that affect bladder tone. The primary management intervention for acute urinary retention is the insertion of a urinary catheter. If a catheter cannot be passed through the urethra, a suprapubic catheter can be inserted. Post-catheterization residual volume should be measured, and renal function should be assessed through U&Es and urine culture. Further evaluation and follow-up with a urologist are typically arranged, and additional tests like ultrasound may be performed if necessary. It is important to note that PSA testing is often deferred for at least two weeks after catheter insertion and female patients with retention should also be referred to urology for investigation.

When a patient is semi-conscious, it is less likely for the nasopharyngeal airway adjuncts (NPA’s) to trigger the gag reflex compared to oropharyngeal airways. Therefore, NPA’s are typically the preferred option in these cases.

Further Reading:

Techniques to keep the airway open:

1. Suction: Used to remove obstructing material such as blood, vomit, secretions, and food debris from the oral cavity.

2. Chin lift manoeuvres: Involves lifting the head off the floor and lifting the chin to extend the head in relation to the neck. Improves alignment of the pharyngeal, laryngeal, and oral axes.

3. Jaw thrust: Used in trauma patients with cervical spine injury concerns. Fingers are placed under the mandible and gently pushed upward.

Airway adjuncts:

1. Oropharyngeal airway (OPA): Prevents the tongue from occluding the airway. Sized according to the patient by measuring from the incisor teeth to the angle of the mandible. Inserted with the tip facing backwards and rotated 180 degrees once it touches the back of the palate or oropharynx.

2. Nasopharyngeal airway (NPA): Useful when it is difficult to open the mouth or in semi-conscious patients. Sized by length (distance between nostril and tragus of the ear) and diameter (roughly that of the patient’s little finger). Contraindicated in basal skull and midface fractures.

Laryngeal mask airway (LMA):

– Supraglottic airway device used as a first line or rescue airway.
– Easy to insert, sized according to patient’s bodyweight.
– Advantages: Easy insertion, effective ventilation, some protection from aspiration.
– Disadvantages: Risk of hypoventilation, greater gastric inflation than endotracheal tube (ETT), risk of aspiration and laryngospasm.

Note: Proper training and assessment of the patient’s condition are essential for airway management.

Legionella pneumophila is a type of Gram-negative bacterium that can be found in natural water supplies and soil. It is responsible for causing Legionnaires’ disease, a serious illness. Outbreaks of this disease have been associated with poorly maintained air conditioning systems, whirlpool spas, and hot tubs. In the past, there have been instances of Legionnaires’ disease outbreaks on cruise ships due to inadequate maintenance of air conditioning and shower units.

The pneumonic form of Legionnaires’ disease presents with certain clinical features. Initially, there may be a mild flu-like prodrome lasting for 1-3 days. A persistent cough, which is usually non-productive and occurs in approximately 90% of cases, is also common. Other symptoms include pleuritic chest pain, haemoptysis, headache, nausea, vomiting, diarrhoea, and anorexia. Additionally, some individuals may experience a condition called syndrome of inappropriate antidiuretic hormone secretion (SIADH), which can lead to hyponatraemia.

It is important to note that infections caused by Legionella pneumophila are resistant to amoxicillin. However, they can be effectively treated with macrolide antibiotics like erythromycin or quinolones such as ciprofloxacin. Tetracyclines, including doxycycline, can also be used for treatment.

Lipid emulsion is known to cause pancreatitis as a common side effect. According to the AAGBI guidelines, patients who are given lipid emulsion should be closely monitored with regular clinical evaluations. This includes conducting amylase or lipase tests daily for two days after receiving the emulsion.

Further Reading:

Local anaesthetics, such as lidocaine, bupivacaine, and prilocaine, are commonly used in the emergency department for topical or local infiltration to establish a field block. Lidocaine is often the first choice for field block prior to central line insertion. These anaesthetics work by blocking sodium channels, preventing the propagation of action potentials.

However, local anaesthetics can enter the systemic circulation and cause toxic side effects if administered in high doses. Clinicians must be aware of the signs and symptoms of local anaesthetic systemic toxicity (LAST) and know how to respond. Early signs of LAST include numbness around the mouth or tongue, metallic taste, dizziness, visual and auditory disturbances, disorientation, and drowsiness. If not addressed, LAST can progress to more severe symptoms such as seizures, coma, respiratory depression, and cardiovascular dysfunction.

The management of LAST is largely supportive. Immediate steps include stopping the administration of local anaesthetic, calling for help, providing 100% oxygen and securing the airway, establishing IV access, and controlling seizures with benzodiazepines or other medications. Cardiovascular status should be continuously assessed, and conventional therapies may be used to treat hypotension or arrhythmias. Intravenous lipid emulsion (intralipid) may also be considered as a treatment option.

If the patient goes into cardiac arrest, CPR should be initiated following ALS arrest algorithms, but lidocaine should not be used as an anti-arrhythmic therapy. Prolonged resuscitation may be necessary, and intravenous lipid emulsion should be administered. After the acute episode, the patient should be transferred to a clinical area with appropriate equipment and staff for further monitoring and care.

It is important to report cases of local anaesthetic toxicity to the appropriate authorities, such as the National Patient Safety Agency in the UK or the Irish Medicines Board in the Republic of Ireland. Additionally, regular clinical review should be conducted to exclude pancreatitis, as intravenous lipid emulsion can interfere with amylase or lipase assays.

The most frequent cause of non-allergic drug induced angioedema is ACE inhibitors. Symptoms usually appear several days to weeks after beginning the medication. It is important to note that penicillin and NSAIDs are the primary drug culprits for angioedema, but they trigger it through an IgE mediated allergic mechanism, resulting in both angioedema and urticaria. The onset of symptoms in these cases typically occurs within minutes to hours after exposure.

Further Reading:

Angioedema and urticaria are related conditions that involve swelling in different layers of tissue. Angioedema refers to swelling in the deeper layers of tissue, such as the lips and eyelids, while urticaria, also known as hives, refers to swelling in the epidermal skin layers, resulting in raised red areas of skin with itching. These conditions often coexist and may have a common underlying cause.

Angioedema can be classified into allergic and non-allergic types. Allergic angioedema is the most common type and is usually triggered by an allergic reaction, such as to certain medications like penicillins and NSAIDs. Non-allergic angioedema has multiple subtypes and can be caused by factors such as certain medications, including ACE inhibitors, or underlying conditions like hereditary angioedema (HAE) or acquired angioedema.

HAE is an autosomal dominant disease characterized by a deficiency of C1 esterase inhibitor. It typically presents in childhood and can be inherited or acquired as a result of certain disorders like lymphoma or systemic lupus erythematosus. Acquired angioedema may have similar clinical features to HAE but is caused by acquired deficiencies of C1 esterase inhibitor due to autoimmune or lymphoproliferative disorders.

The management of urticaria and allergic angioedema focuses on ensuring the airway remains open and addressing any identifiable triggers. In mild cases without airway compromise, patients may be advised that symptoms will resolve without treatment. Non-sedating antihistamines can be used for up to 6 weeks to relieve symptoms. Severe cases of urticaria may require systemic corticosteroids in addition to antihistamines. In moderate to severe attacks of allergic angioedema, intramuscular epinephrine may be considered.

The management of HAE involves treating the underlying deficiency of C1 esterase inhibitor. This can be done through the administration of C1 esterase inhibitor, bradykinin receptor antagonists, or fresh frozen plasma transfusion, which contains C1 inhibitor.

In summary, angioedema and urticaria are related conditions involving swelling in different layers of tissue. They can coexist and may have a common underlying cause. Management involves addressing triggers, using antihistamines, and in severe cases, systemic corticosteroids or other specific treatments for HAE.

Addison’s disease is characterized by several classical biochemical features. One of these features is an increase in ACTH levels, which is a hormone that stimulates the production of cortisol. Additionally, individuals with Addison’s disease often have elevated serum renin levels, which is an enzyme involved in regulating blood pressure. Another common biochemical feature is hyponatremia, which refers to low levels of sodium in the blood. Hyperkalemia, or high levels of potassium, is also frequently observed in individuals with Addison’s disease. Furthermore, hypercalcemia, an excess of calcium in the blood, may be present. Hypoglycemia, or low blood sugar levels, is another characteristic feature. Lastly, metabolic acidosis, a condition where the body produces too much acid or cannot eliminate it properly, is often seen in individuals with Addison’s disease.

Traumatic aortic rupture, also known as traumatic aortic disruption or transection, occurs when the aorta is torn or ruptured due to physical trauma. This condition often leads to sudden death because of severe bleeding. Motor vehicle accidents and falls from great heights are the most common causes of this injury.

The patients with the highest chances of survival are those who have an incomplete tear near the ligamentum arteriosum of the proximal descending aorta, close to where the left subclavian artery branches off. The presence of an intact adventitial layer or contained mediastinal hematoma helps maintain continuity and prevents immediate bleeding and death. If promptly identified and treated, survivors of these injuries can recover. In cases where traumatic aortic rupture leads to sudden death, approximately 50% of patients have damage at the aortic isthmus, while around 15% have damage in either the ascending aorta or the aortic arch.

Initial chest X-rays may show signs consistent with a traumatic aortic injury. However, false-positive and false-negative results can occur, and sometimes there may be no abnormalities visible on the X-ray. Some of the possible X-ray findings include a widened mediastinum, hazy left lung field, obliteration of the aortic knob, fractures of the 1st and 2nd ribs, deviation of the trachea to the right, presence of a pleural cap, elevation and rightward shift of the right mainstem bronchus, depression of the left mainstem bronchus, obliteration of the space between the pulmonary artery and aorta, and deviation of the esophagus or NG tube to the right.

A helical contrast-enhanced CT scan of the chest is the preferred initial investigation for suspected blunt aortic injury. It has proven to be highly accurate, with close to 100% sensitivity and specificity. CT scanning should be performed liberally, as chest X-ray findings can be unreliable. However, hemodynamically unstable patients should not be placed in a CT scanner. If the CT results are inconclusive, aortography or trans-oesophageal echo can be performed for further evaluation.

Immediate surgical intervention is necessary for these injuries. Endovascular repair is the most common method used and has excellent short-term outcomes. Open repair may also be performed depending on the circumstances. It is important to control heart rate and blood pressure during stabilization to reduce the risk of rupture. Pain should be managed with appropriate analgesic

Haemothorax often leads to reduced or absent air entry, a dull percussion sound, and decreased fremitus on the affected side. Commonly observed symptoms in patients with haemothorax include decreased or absent air entry, a dull percussion note when the affected side is tapped, reduced fremitus on the affected side, and in cases of massive haemothorax, tracheal deviation away from the affected side. Other signs that may be present include a rapid heart rate (tachycardia), rapid breathing (tachypnoea), low blood pressure (hypotension), and signs of shock.

Further Reading:

Haemothorax is the accumulation of blood in the pleural cavity of the chest, usually resulting from chest trauma. It can be difficult to differentiate from other causes of pleural effusion on a chest X-ray. Massive haemothorax refers to a large volume of blood in the pleural space, which can impair physiological function by causing blood loss, reducing lung volume for gas exchange, and compressing thoracic structures such as the heart and IVC.

The management of haemothorax involves replacing lost blood volume and decompressing the chest. This is done through supplemental oxygen, IV access and cross-matching blood, IV fluid therapy, and the insertion of a chest tube. The chest tube is connected to an underwater seal and helps drain the fluid, pus, air, or blood from the pleural space. In cases where there is prompt drainage of a large amount of blood, ongoing significant blood loss, or the need for blood transfusion, thoracotomy and ligation of bleeding thoracic vessels may be necessary. It is important to have two IV accesses prior to inserting the chest drain to prevent a drop in blood pressure.

In summary, haemothorax is the accumulation of blood in the pleural cavity due to chest trauma. Managing haemothorax involves replacing lost blood volume and decompressing the chest through various interventions, including the insertion of a chest tube. Prompt intervention may be required in cases of significant blood loss or ongoing need for blood transfusion.

The current recommendations from NICE for managing warfarin in the presence of bleeding or an abnormal INR are as follows:

In cases of major active bleeding, regardless of the INR level, the first step is to stop administering warfarin. Next, 5 mg of vitamin K (phytomenadione) should be given intravenously. Additionally, dried prothrombin complex concentrate, which contains factors II, VII, IX, and X, should be administered. If dried prothrombin complex is not available, fresh frozen plasma can be given at a dose of 15 ml/kg.

If the INR is greater than 8.0 and there is minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is greater than 8.0 with no bleeding, warfarin should be stopped. Oral administration of 1-5 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with no bleeding, one or two doses of warfarin should be withheld, and the subsequent maintenance dose should be reduced.

For more information, please refer to the NICE Clinical Knowledge Summary on the management of warfarin therapy and the BNF guidance on the use of phytomenadione.