Heat stroke is a condition characterized by a systemic inflammatory response, where the core body temperature rises above 40.6°C. It is accompanied by alterations in mental state and varying degrees of organ dysfunction.

There are two types of heat stroke. The first is classic non-exertional heat stroke, which occurs when individuals are exposed to high environmental temperatures. This form of heat stroke is commonly seen in elderly patients during heat waves.

The second type is exertional heat stroke, which occurs during intense physical activity in hot weather conditions. This form of heat stroke is often observed in endurance athletes who participate in strenuous exercise in high temperatures.

Amiodarone is a medication that is recommended to be administered after the third shock in a shockable cardiac arrest (Vf/pVT) while chest compressions are being performed. The prescribed dose is 300 mg, given as an intravenous bolus that is diluted in 5% dextrose to a volume of 20 mL. It is important to note that amiodarone is not suitable for treating PEA or asystole.

In cases where VF/pVT persists after five defibrillation attempts, an additional dose of 150 mg of amiodarone should be given. However, if amiodarone is not available, lidocaine can be used as an alternative. The recommended dose of lidocaine is 1 mg/kg. It is crucial to avoid administering lidocaine if amiodarone has already been given.

Amiodarone is classified as a membrane-stabilizing antiarrhythmic drug. It works by prolonging the duration of the action potential and the refractory period in both the atrial and ventricular myocardium. This medication also slows down atrioventricular conduction and has a similar effect on accessory pathways.

Additionally, amiodarone has a mild negative inotropic action, meaning it weakens the force of heart contractions. It also causes peripheral vasodilation through non-competitive alpha-blocking effects.

It is important to note that while there is no evidence of long-term benefits from using amiodarone, it may improve short-term survival rates, which justifies its continued use.

The recommended first-line diagnostic test for TMJ dislocation is an OPG. The Royal College of Emergency Medicine suggests that an OPG is the most effective initial imaging technique for diagnosing TMJ dislocation. However, mandibular series X-ray views and CT scans can also be used as alternative imaging methods.

Further Reading:

TMJ dislocation occurs when the mandibular condyle is displaced from its normal position in the mandibular fossa of the temporal bone. The most common type of dislocation is bilateral anterior dislocation. This occurs when the mandible is dislocated forward and the masseter and pterygoid muscles spasm, locking the condyle in place.

The temporomandibular joint is unique because it has an articular disc that separates the joint into upper and lower compartments. Dislocation can be caused by trauma, such as a direct blow to the open mouth, or by traumatic events like excessive mouth opening during yawning, laughing, shouting, or eating. It can also occur during dental work.

Signs and symptoms of TMJ dislocation include difficulty fully opening or closing the mouth, pain or tenderness in the TMJ region, jaw pain, ear pain, difficulty chewing, and facial pain. Connective tissue disorders like Marfan’s and Ehlers-Danlos syndrome can increase the likelihood of dislocation.

If TMJ dislocation is suspected, X-rays may be done to confirm the diagnosis. The best initial imaging technique is an orthopantomogram (OPG) or a standard mandibular series.

Management of anterior dislocations involves reducing the dislocated mandible, which is usually done in the emergency department. Dislocations to the posterior, medial, or lateral side are usually associated with a mandibular fracture and should be referred to a maxillofacial surgeon.

Reduction of an anterior dislocation involves applying distraction forces to the mandible. This can be done by gripping the mandible externally or intra-orally. In some cases, procedural sedation or local anesthesia may be used, and in rare cases, reduction may be done under general anesthesia.

After reduction, a post-reduction X-ray is done to confirm adequate reduction and rule out any fractures caused by the procedure. Discharge advice includes following a soft diet for at least 48 hours, avoiding wide mouth opening for at least 2 weeks, and supporting the mouth with the hand during yawning or laughing. A Barton bandage may be used to support the mandible if the patient is unable to comply with the discharge advice. Referral to a maxillofacial surgeon as an outpatient is also recommended.

During cardiac arrest, Lidocaine is administered through a slow IV injection at an initial dose of 1 mg/kg when deemed suitable.

Further Reading:

In the management of respiratory and cardiac arrest, several drugs are commonly used to help restore normal function and improve outcomes. Adrenaline is a non-selective agonist of adrenergic receptors and is administered intravenously at a dose of 1 mg every 3-5 minutes. It works by causing vasoconstriction, increasing systemic vascular resistance (SVR), and improving cardiac output by increasing the force of heart contraction. Adrenaline also has bronchodilatory effects.

Amiodarone is another drug used in cardiac arrest situations. It blocks voltage-gated potassium channels, which prolongs repolarization and reduces myocardial excitability. The initial dose of amiodarone is 300 mg intravenously after 3 shocks, followed by a dose of 150 mg after 5 shocks.

Lidocaine is an alternative to amiodarone in cardiac arrest situations. It works by blocking sodium channels and decreasing heart rate. The recommended dose is 1 mg/kg by slow intravenous injection, with a repeat half of the initial dose after 5 minutes. The maximum total dose of lidocaine is 3 mg/kg.

Magnesium sulfate is used to reverse myocardial hyperexcitability associated with hypomagnesemia. It is administered intravenously at a dose of 2 g over 10-15 minutes. An additional dose may be given if necessary, but the maximum total dose should not exceed 3 g.

Atropine is an antagonist of muscarinic acetylcholine receptors and is used to counteract the slowing of heart rate caused by the parasympathetic nervous system. It is administered intravenously at a dose of 500 mcg every 3-5 minutes, with a maximum dose of 3 mg.

Naloxone is a competitive antagonist for opioid receptors and is used in cases of respiratory arrest caused by opioid overdose. It has a short duration of action, so careful monitoring is necessary. The initial dose of naloxone is 400 micrograms, followed by 800 mcg after 1 minute. The dose can be gradually escalated up to 2 mg per dose if there is no response to the preceding dose.

It is important for healthcare professionals to have knowledge of the pharmacology and dosing schedules of these drugs in order to effectively manage respiratory and cardiac arrest situations.

The scalp is primarily supplied with blood from branches of the external carotid artery. The posterior half of the scalp is specifically supplied by three branches of the external carotid artery. These branches are the superficial temporal artery, which supplies blood to the frontal and temporal regions of the scalp, the posterior auricular artery, which supplies blood to the area above and behind the external ear, and the occipital artery, which supplies blood to the back of the scalp.

Further Reading:

The scalp is the area of the head that is bordered by the face in the front and the neck on the sides and back. It consists of several layers, including the skin, connective tissue, aponeurosis, loose connective tissue, and periosteum of the skull. These layers provide protection and support to the underlying structures of the head.

The blood supply to the scalp primarily comes from branches of the external carotid artery and the ophthalmic artery, which is a branch of the internal carotid artery. These arteries provide oxygen and nutrients to the scalp tissues.

The scalp also has a complex venous drainage system, which is divided into superficial and deep networks. The superficial veins correspond to the arterial branches and are responsible for draining blood from the scalp. The deep venous network is drained by the pterygoid venous plexus.

In terms of innervation, the scalp receives sensory input from branches of the trigeminal nerve and the cervical nerves. These nerves transmit sensory information from the scalp to the brain, allowing us to perceive touch, pain, and temperature in this area.

TCA toxicity can be identified through specific changes seen on an electrocardiogram (ECG). Sinus tachycardia, which is a faster than normal heart rate, and widening of the QRS complex are key features of TCA toxicity. These ECG changes occur due to the blocking of sodium channels and muscarinic receptors (M1) by the medication. In the case of an amitriptyline overdose, additional ECG changes may include prolongation of the QT interval, an R/S ratio greater than 0.7 in lead aVR, and the presence of ventricular arrhythmias such as torsades de pointes. The severity of the QRS prolongation on the ECG is associated with the likelihood of adverse events. A QRS duration greater than 100 ms is predictive of seizures, while a QRS duration greater than 160 ms is predictive of ventricular arrhythmias like ventricular tachycardia or torsades de pointes.

Further Reading:

Tricyclic antidepressant (TCA) overdose is a common occurrence in emergency departments, with drugs like amitriptyline and dosulepin being particularly dangerous. TCAs work by inhibiting the reuptake of norepinephrine and serotonin in the central nervous system. In cases of toxicity, TCAs block various receptors, including alpha-adrenergic, histaminic, muscarinic, and serotonin receptors. This can lead to symptoms such as hypotension, altered mental state, signs of anticholinergic toxicity, and serotonin receptor effects.

TCAs primarily cause cardiac toxicity by blocking sodium and potassium channels. This can result in a slowing of the action potential, prolongation of the QRS complex, and bradycardia. However, the blockade of muscarinic receptors also leads to tachycardia in TCA overdose. QT prolongation and Torsades de Pointes can occur due to potassium channel blockade. TCAs can also have a toxic effect on the myocardium, causing decreased cardiac contractility and hypotension.

Early symptoms of TCA overdose are related to their anticholinergic properties and may include dry mouth, pyrexia, dilated pupils, agitation, sinus tachycardia, blurred vision, flushed skin, tremor, and confusion. Severe poisoning can lead to arrhythmias, seizures, metabolic acidosis, and coma. ECG changes commonly seen in TCA overdose include sinus tachycardia, widening of the QRS complex, prolongation of the QT interval, and an R/S ratio >0.7 in lead aVR.

Management of TCA overdose involves ensuring a patent airway, administering activated charcoal if ingestion occurred within 1 hour and the airway is intact, and considering gastric lavage for life-threatening cases within 1 hour of ingestion. Serial ECGs and blood gas analysis are important for monitoring. Intravenous fluids and correction of hypoxia are the first-line therapies. IV sodium bicarbonate is used to treat haemodynamic instability caused by TCA overdose, and benzodiazepines are the treatment of choice for seizure control. Other treatments that may be considered include glucagon, magnesium sulfate, and intravenous lipid emulsion.

There are certain things to avoid in TCA overdose, such as anti-arrhythmics like quinidine and flecainide, as they can prolonged depolarization. Amiodarone should

The Severity of Alcohol Dependence Questionnaire (SADQ) is a brief, self-administered questionnaire consisting of 20 items. It was developed by the World Health Organisation with the aim of assessing the severity of alcohol dependence. Another assessment tool recommended by NICE is the Leeds Dependence Questionnaire (LDQ), which is a self-completion questionnaire comprising of 10 items. The LDQ is designed to measure dependence on various substances. Both the SADQ and LDQ are considered useful in evaluating the severity of alcohol misuse.

NICE suggests the use of specific assessment tools to effectively evaluate the nature and severity of alcohol misuse. The AUDIT is recommended for identification purposes and as a routine outcome measure. For assessing the severity of dependence, the SADQ or LDQ are recommended. To evaluate the severity of withdrawal symptoms, the Clinical Institute Withdrawal Assessment of Alcohol Scale, revised (CIWA-Ar) is recommended. Lastly, the APQ is recommended for assessing the nature and extent of problems arising from alcohol misuse.

to the NICE guidance on the diagnosis, assessment, and management of harmful drinking and alcohol dependence.

Plasmodium falciparum malaria is transmitted by female mosquitoes of the Anopheles genus. The Aedes genus, on the other hand, is responsible for spreading diseases like dengue fever and yellow fever. The parasite enters hepatocytes and undergoes asexual reproduction, resulting in the release of merozoites into the bloodstream. These merozoites then invade the red blood cells of the host. The incubation period for Plasmodium falciparum malaria ranges from 7 to 14 days.

The main symptom of malaria is known as the malarial paroxysm, which consists of a cyclical pattern of cold chills, followed by a stage of intense heat, and finally a period of profuse sweating as the fever subsides. However, some individuals may experience a continuous fever instead.

Currently, the recommended treatment for P. falciparum malaria is artemisinin-based combination therapy (ACT). This involves combining fast-acting artemisinin-based compounds with drugs from a different class. Companion drugs used in ACT include lumefantrine, mefloquine, amodiaquine, sulfadoxine/pyrimethamine, piperaquine, and chlorproguanil/dapsone. Artemisinin derivatives such as dihydroartemisinin, artesunate, and artemether are also used.

If artemisinin combination therapy is not available, oral quinine or atovaquone with proguanil hydrochloride can be used as an alternative. However, quinine is not well-tolerated for prolonged treatment and should be combined with another drug, typically oral doxycycline (or clindamycin for pregnant women and young children).

Severe or complicated cases of falciparum malaria require specialized care in a high dependency unit or intensive care setting. Intravenous artesunate is recommended for all patients with severe or complicated falciparum malaria, as well as those at high risk of developing severe disease (e.g., if more than 2% of red blood cells are parasitized) or if the patient is unable to take oral treatment. After a minimum of 24 hours of intravenous artesunate treatment and improvement in the patient’s condition, a full course of artemisinin combination therapy should be administered orally.

ACE inhibitors work by inhibiting the conversion of angiotensin I to angiotensin II. As a result, the effects of angiotensin II are reduced, leading to the dilation of vascular smooth muscle and the efferent arteriole of the glomerulus. This, in turn, has several effects on renal measurements. Firstly, it causes an increase in renal plasma flow. Secondly, it leads to a decrease in filtration fraction. Lastly, it results in a decrease in glomerular filtration rate.

One of the diagnostic criteria for ARDS is the presence of hypoxemia. Other criteria include the onset of symptoms within 7 days of a clinical insult or new/worsening respiratory symptoms, bilateral opacities on chest X-ray that cannot be fully explained by other conditions, and respiratory failure that cannot be fully attributed to cardiac failure or fluid overload.

Further Reading:

ARDS is a severe form of lung injury that occurs in patients with a predisposing risk factor. It is characterized by the onset of respiratory symptoms within 7 days of a known clinical insult, bilateral opacities on chest X-ray, and respiratory failure that cannot be fully explained by cardiac failure or fluid overload. Hypoxemia is also present, as indicated by a specific threshold of the PaO2/FiO2 ratio measured with a minimum requirement of positive end-expiratory pressure (PEEP) ≥5 cm H2O. The severity of ARDS is classified based on the PaO2/FiO2 ratio, with mild, moderate, and severe categories.

Lung protective ventilation is a set of measures aimed at reducing lung damage that may occur as a result of mechanical ventilation. Mechanical ventilation can cause lung damage through various mechanisms, including high air pressure exerted on lung tissues (barotrauma), over distending the lung (volutrauma), repeated opening and closing of lung units (atelectrauma), and the release of inflammatory mediators that can induce lung injury (biotrauma). These mechanisms collectively contribute to ventilator-induced lung injury (VILI).

The key components of lung protective ventilation include using low tidal volumes (5-8 ml/kg), maintaining inspiratory pressures (plateau pressure) below 30 cm of water, and allowing for permissible hypercapnia. However, there are some contraindications to lung protective ventilation, such as an unacceptable level of hypercapnia, acidosis, and hypoxemia. These factors need to be carefully considered when implementing lung protective ventilation strategies in patients with ARDS.