When treating thyroid storm, it is important to administer certain drugs immediately. These include a beta blocker like propranolol or a calcium channel blocker if a beta blocker cannot be used. Corticosteroids like hydrocortisone or dexamethasone are also given. Additionally, antithyroid drugs like propylthiouracil are administered. However, it is crucial to wait at least one hour after giving the antithyroid drugs before administering iodine solution such as Lugol’s iodine. This is because iodine can worsen thyrotoxicosis by stimulating thyroid hormone synthesis. Propylthiouracil, on the other hand, inhibits the normal interactions of iodine and peroxidase with thyroglobulin, which is why it is given first and allowed time to take effect.

Further Reading:

The thyroid gland is an endocrine organ located in the anterior neck. It consists of two lobes connected by an isthmus. The gland produces hormones called thyroxine (T4) and triiodothyronine (T3), which regulate energy use, protein synthesis, and the body’s sensitivity to other hormones. The production of T4 and T3 is stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland, which is in turn stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus.

Thyroid disorders can occur when there is an imbalance in the production or regulation of thyroid hormones. Hypothyroidism is characterized by a deficiency of thyroid hormones, while hyperthyroidism is characterized by an excess. The most common cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. It is more common in women and is often associated with goiter. Other causes include subacute thyroiditis, atrophic thyroiditis, and iodine deficiency. On the other hand, the most common cause of hyperthyroidism is Graves’ disease, which is also an autoimmune disorder. Other causes include toxic multinodular goiter and subacute thyroiditis.

The symptoms and signs of thyroid disorders can vary depending on whether the thyroid gland is underactive or overactive. In hypothyroidism, common symptoms include weight gain, lethargy, cold intolerance, and dry skin. In hyperthyroidism, common symptoms include weight loss, restlessness, heat intolerance, and increased sweating. Both hypothyroidism and hyperthyroidism can also affect other systems in the body, such as the cardiovascular, gastrointestinal, and neurological systems.

Complications of thyroid disorders can include dyslipidemia, metabolic syndrome, coronary heart disease, heart failure, subfertility and infertility, impaired special senses, and myxedema coma in severe cases of hypothyroidism. In hyperthyroidism, complications can include Graves’ orbitopathy, compression of the esophagus or trachea by goiter, thyrotoxic periodic paralysis, arrhythmias, osteoporosis, mood disorders, and increased obstetric complications.

Myxedema coma is a rare and life-threatening complication of severe hypothyroidism. It can be triggered by factors such as infection or physiological insult and presents with lethargy, bradycardia, hypothermia, hypotension, hypoventilation, altered mental state, seizures and/or coma.

This patient is currently experiencing moderate shock, classified as class III. This level of shock corresponds to a loss of 30-40% of their circulatory volume, which is equivalent to a blood loss of 1500-2000 mL.

Hemorrhage can be categorized into four different classes based on physiological parameters and clinical signs. These classes are classified as class I, class II, class III, and class IV.

In class I hemorrhage, the blood loss is up to 750 mL or up to 15% of the blood volume. The pulse rate is less than 100 beats per minute, and the systolic blood pressure is normal. The pulse pressure may be normal or increased, and the respiratory rate is within the range of 14-20 breaths per minute. The urine output is greater than 30 mL per hour, and the patient’s CNS/mental status is slightly anxious.

In class II hemorrhage, the blood loss ranges from 750-1500 mL or 15-30% of the blood volume. The pulse rate is between 100-120 beats per minute, and the systolic blood pressure remains normal. The pulse pressure is decreased, and the respiratory rate increases to 20-30 breaths per minute. The urine output decreases to 20-30 mL per hour, and the patient may experience mild anxiety.

The patient in this case is in class III hemorrhage, with a blood loss of 1500-2000 mL or 30-40% of the blood volume. The pulse rate is elevated, ranging from 120-140 beats per minute, and the systolic blood pressure is decreased. The pulse pressure is also decreased, and the respiratory rate is elevated to 30-40 breaths per minute. The urine output decreases significantly to 5-15 mL per hour, and the patient may experience anxiety and confusion.

Class IV hemorrhage represents the most severe level of blood loss, with a loss of over 40% of the blood volume. The pulse rate is greater than 140 beats per minute, and the systolic blood pressure is significantly decreased. The pulse pressure is decreased, and the respiratory rate is over 40 breaths per minute. The urine output becomes negligible, and the patient may become confused and lethargic.

Gout and pseudogout are both characterized by the presence of crystal deposits in the joints that are affected. Gout occurs when urate crystals are deposited, while pseudogout occurs when calcium pyrophosphate crystals are deposited. Under a microscope, these crystals can be distinguished by their appearance. Urate crystals are needle-shaped and negatively birefringent, while calcium pyrophosphate crystals are brick-shaped and positively birefringent.

Gout can affect any joint in the body, but it most commonly manifests in the hallux metatarsophalangeal joint, which is the joint at the base of the big toe. This joint is affected in approximately 50% of gout cases. On the other hand, pseudogout primarily affects the larger joints, such as the knee.

The speed at which local anesthetics take effect is primarily determined by their lipid solubility. The onset of action is directly influenced by how well the anesthetic can dissolve in lipids, which is in turn related to its pKa value. A higher lipid solubility leads to a faster onset of action. The pKa value, which represents the acid-dissociation constant, is an indicator of lipid solubility. An anesthetic agent with a pKa value closer to 7.4 is more likely to be highly lipid soluble.

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.

If a patient with a tracheostomy is experiencing difficulty breathing and it is not possible to pass a suction catheter, the next step is to deflate the cuff. Deflating the cuff can help determine if the tracheostomy tube is obstructed or displaced by allowing air to flow around the tube within the airway. The following steps are followed in order: 1) Remove the inner tube and any speaking cap/valve if present. 2) Attempt to pass the suction catheter. 3) If the suction catheter cannot be passed, deflate the cuff. 4) If the patient’s condition does not stabilize or improve, the tracheostomy tube may need to be removed. This process is summarized in the green algorithm.

Further Reading:

Patients with tracheostomies may experience emergencies such as tube displacement, tube obstruction, and bleeding. Tube displacement can occur due to accidental dislodgement, migration, or erosion into tissues. Tube obstruction can be caused by secretions, lodged foreign bodies, or malfunctioning humidification devices. Bleeding from a tracheostomy can be classified as early or late, with causes including direct injury, anticoagulation, mucosal or tracheal injury, and granulation tissue.

When assessing a patient with a tracheostomy, an ABCDE approach should be used, with attention to red flags indicating a tracheostomy or laryngectomy emergency. These red flags include audible air leaks or bubbles of saliva indicating gas escaping past the cuff, grunting, snoring, stridor, difficulty breathing, accessory muscle use, tachypnea, hypoxia, visibly displaced tracheostomy tube, blood or blood-stained secretions around the tube, increased discomfort or pain, increased air required to keep the cuff inflated, tachycardia, hypotension or hypertension, decreased level of consciousness, and anxiety, restlessness, agitation, and confusion.

Algorithms are available for managing tracheostomy emergencies, including obstruction or displaced tube. Oxygen should be delivered to the face and stoma or tracheostomy tube if there is uncertainty about whether the patient has had a laryngectomy. Tracheostomy bleeding can be classified as early or late, with causes including direct injury, anticoagulation, mucosal or tracheal injury, and granulation tissue. Tracheo-innominate fistula (TIF) is a rare but life-threatening complication that occurs when the tracheostomy tube erodes into the innominate artery. Urgent surgical intervention is required for TIF, and management includes general resuscitation measures and specific measures such as bronchoscopy and applying direct digital pressure to the innominate artery.

The primary treatment option for hypertensive encephalopathy, a condition characterized by sudden confusion, severe headache, and coordination problems due to significantly elevated blood pressure, is labetalol.

Further Reading:

A hypertensive emergency is characterized by a significant increase in blood pressure accompanied by acute or progressive damage to organs. While there is no specific blood pressure value that defines a hypertensive emergency, systolic blood pressure is typically above 180 mmHg and/or diastolic blood pressure is above 120 mmHg. The most common presentations of hypertensive emergencies include cerebral infarction, pulmonary edema, encephalopathy, and congestive cardiac failure. Less common presentations include intracranial hemorrhage, aortic dissection, and pre-eclampsia/eclampsia.

The signs and symptoms of hypertensive emergencies can vary widely due to the potential dysfunction of every physiological system. Some common signs and symptoms include headache, nausea and/or vomiting, chest pain, arrhythmia, proteinuria, signs of acute kidney failure, epistaxis, dyspnea, dizziness, anxiety, confusion, paraesthesia or anesthesia, and blurred vision. Clinical assessment focuses on detecting acute or progressive damage to the cardiovascular, renal, and central nervous systems.

Investigations that are essential in evaluating hypertensive emergencies include U&Es (electrolyte levels), urinalysis, ECG, and CXR. Additional investigations may be considered depending on the suspected underlying cause, such as a CT head for encephalopathy or new onset confusion, CT thorax for suspected aortic dissection, and CT abdomen for suspected phaeochromocytoma. Plasma free metanephrines, urine total catecholamines, vanillylmandelic acid (VMA), and metanephrine may be tested if phaeochromocytoma is suspected. Urine screening for cocaine and/or amphetamines may be appropriate in certain cases, as well as an endocrine screen for Cushing’s syndrome.

The management of hypertensive emergencies involves cautious reduction of blood pressure to avoid precipitating renal, cerebral, or coronary ischemia. Staged blood pressure reduction is typically the goal, with an initial reduction in mean arterial pressure (MAP) by no more than 25% in the first hour. Further gradual reduction to a systolic blood pressure of 160 mmHg and diastolic blood pressure of 100 mmHg over the next 2 to 6 hours is recommended. Initial management involves treatment with intravenous antihypertensive agents in an intensive care setting with appropriate monitoring.

Central retinal vein occlusion (CRVO) is a condition that usually leads to painless, one-sided vision loss. When examining the retina, it may appear similar to a ‘pizza thrown against a wall’, with swollen retinal veins, swelling of the optic disc, numerous flame-shaped hemorrhages, and cotton wool spots. Hypertension is present in about 65% of CRVO cases and is more common in individuals aged 65 and above.

On the other hand, branch retinal vein occlusion (BRVO) typically affects only one section of the retina, resulting in visual field deficits in that specific quadrant rather than complete vision loss.

Atropine and pralidoxime are both considered antidotes for treating organophosphate poisoning. Organophosphates work by inhibiting acetylcholinesterase at nerve synapses. In addition to providing supportive care and administering antidotes, it is important to decontaminate patients as part of their treatment plan for organophosphate poisoning.

While both atropine and pralidoxime are recognized as antidotes, pralidoxime is not commonly used. Atropine works by competing with acetylcholine at the muscarinic receptors. On the other hand, pralidoxime helps reactivate acetylcholinesterase-organophosphate complexes that have not lost an alkyl side chain, known as non-aged complexes. However, pralidoxime is not effective against organophosphates that have already formed or rapidly form aged acetylcholinesterase complexes. The evidence regarding the effectiveness of pralidoxime is conflicting.

Further Reading:

Chemical incidents can occur as a result of leaks, spills, explosions, fires, terrorism, or the use of chemicals during wars. Industrial sites that use chemicals are required to conduct risk assessments and have accident plans in place for such incidents. Health services are responsible for decontamination, unless mass casualties are involved, and all acute health trusts must have major incident plans in place.

When responding to a chemical incident, hospitals prioritize containment of the incident and prevention of secondary contamination, triage with basic first aid, decontamination if not done at the scene, recognition and management of toxidromes (symptoms caused by exposure to specific toxins), appropriate supportive or antidotal treatment, transfer to definitive treatment, a safe end to the hospital response, and continuation of business after the event.

To obtain advice when dealing with chemical incidents, the two main bodies are Toxbase and the National Poisons Information Service. Signage on containers carrying chemicals and material safety data sheets (MSDS) accompanying chemicals also provide information on the chemical contents and their hazards.

Contamination in chemical incidents can occur in three phases: primary contamination from the initial incident, secondary contamination spread via contaminated people leaving the initial scene, and tertiary contamination spread to the environment, including becoming airborne and waterborne. The ideal personal protective equipment (PPE) for chemical incidents is an all-in-one chemical-resistant overall with integral head/visor and hands/feet worn with a mask, gloves, and boots.

Decontamination of contaminated individuals involves the removal and disposal of contaminated clothing, followed by either dry or wet decontamination. Dry decontamination is suitable for patients contaminated with non-caustic chemicals and involves blotting and rubbing exposed skin gently with dry absorbent material. Wet decontamination is suitable for patients contaminated with caustic chemicals and involves a warm water shower while cleaning the body with simple detergent.

After decontamination, the focus shifts to assessing the extent of any possible poisoning and managing it. The patient’s history should establish the chemical the patient was exposed to, the volume and concentration of the chemical, the route of exposure, any protective measures in place, and any treatment given. Most chemical poisonings require supportive care using standard resuscitation principles, while some chemicals have specific antidotes. Identifying toxidromes can be useful in guiding treatment, and specific antidotes may be administered accordingly.

The typical range for the partial pressure of carbon dioxide (pCO2) is 4.4-6.4 kilopascals (kPa). In terms of arterial blood gas (ABG) results, the normal range for pO2 (partial pressure of oxygen) is 10-14.4 kPa or 70-100 millimeters of mercury (mmHg). The normal range for pCO2 is 4.4-6.4 kPa or 35-45 mmHg. Additionally, the normal range for bicarbonate levels is 23-28 millimoles per liter (mmol/L).

Further Reading:

Arterial blood gases (ABG) are an important diagnostic tool used to assess a patient’s acid-base status and respiratory function. When obtaining an ABG sample, it is crucial to prioritize safety measures to minimize the risk of infection and harm to the patient. This includes performing hand hygiene before and after the procedure, wearing gloves and protective equipment, disinfecting the puncture site with alcohol, using safety needles when available, and properly disposing of equipment in sharps bins and contaminated waste bins.

To reduce the risk of harm to the patient, it is important to test for collateral circulation using the modified Allen test for radial artery puncture. Additionally, it is essential to inquire about any occlusive vascular conditions or anticoagulation therapy that may affect the procedure. The puncture site should be checked for signs of infection, injury, or previous surgery. After the test, pressure should be applied to the puncture site or the patient should be advised to apply pressure for at least 5 minutes to prevent bleeding.

Interpreting ABG results requires a systematic approach. The core set of results obtained from a blood gas analyser includes the partial pressures of oxygen and carbon dioxide, pH, bicarbonate concentration, and base excess. These values are used to assess the patient’s acid-base status.

The pH value indicates whether the patient is in acidosis, alkalosis, or within the normal range. A pH less than 7.35 indicates acidosis, while a pH greater than 7.45 indicates alkalosis.

The respiratory system is assessed by looking at the partial pressure of carbon dioxide (pCO2). An elevated pCO2 contributes to acidosis, while a low pCO2 contributes to alkalosis.

The metabolic aspect is assessed by looking at the bicarbonate (HCO3-) level and the base excess. A high bicarbonate concentration and base excess indicate alkalosis, while a low bicarbonate concentration and base excess indicate acidosis.

Analyzing the pCO2 and base excess values can help determine the primary disturbance and whether compensation is occurring. For example, a respiratory acidosis (elevated pCO2) may be accompanied by metabolic alkalosis (elevated base excess) as a compensatory response.

The anion gap is another important parameter that can help determine the cause of acidosis. It is calculated by subtracting the sum of chloride and bicarbonate from the sum of sodium and potassium.

A surgical cricothyroidotomy is a procedure performed in emergency situations to secure the airway by making an incision in the cricothyroid membrane. It is also known as an emergency surgical airway (ESA) and is typically done when intubation and oxygenation are not possible.

There are certain conditions in which a surgical cricothyroidotomy should not be performed. These include patients who are under 12 years old, those with laryngeal fractures or pre-existing or acute laryngeal pathology, individuals with tracheal transection and retraction of the trachea into the mediastinum, and cases where the anatomical landmarks are obscured due to trauma.

The procedure is carried out in the following steps:
1. Gathering and preparing the necessary equipment.
2. Positioning the patient on their back with the neck in a neutral position.
3. Sterilizing the patient’s neck using antiseptic swabs.
4. Administering local anesthesia, if time permits.
5. Locating the cricothyroid membrane, which is situated between the thyroid and cricoid cartilage.
6. Stabilizing the trachea with the left hand until it can be intubated.
7. Making a transverse incision through the cricothyroid membrane.
8. Inserting the scalpel handle into the incision and rotating it 90°. Alternatively, a haemostat can be used to open the airway.
9. Placing a properly-sized, cuffed endotracheal tube (usually a size 5 or 6) into the incision, directing it into the trachea.
10. Inflating the cuff and providing ventilation.
11. Monitoring for chest rise and auscultating the chest to ensure adequate ventilation.
12. Securing the airway to prevent displacement.

Potential complications of a surgical cricothyroidotomy include aspiration of blood, creation of a false passage into the tissues, subglottic stenosis or edema, laryngeal stenosis, hemorrhage or hematoma formation, laceration of the esophagus or trachea, mediastinal emphysema, and vocal cord paralysis or hoarseness.