Suxamethonium is a medication that can cause an increase in serum potassium levels by causing potassium to leave muscle cells. This can be a problem in patients who already have high levels of potassium, such as those with crush injuries. Therefore, suxamethonium should not be used in these cases.

Further Reading:

Rapid sequence induction (RSI) is a method used to place an endotracheal tube (ETT) in the trachea while minimizing the risk of aspiration. It involves inducing loss of consciousness while applying cricoid pressure, followed by intubation without face mask ventilation. The steps of RSI can be remembered using the 7 P’s: preparation, pre-oxygenation, pre-treatment, paralysis and induction, protection and positioning, placement with proof, and post-intubation management.

Preparation involves preparing the patient, equipment, team, and anticipating any difficulties that may arise during the procedure. Pre-oxygenation is important to ensure the patient has an adequate oxygen reserve and prolongs the time before desaturation. This is typically done by breathing 100% oxygen for 3 minutes. Pre-treatment involves administering drugs to counter expected side effects of the procedure and anesthesia agents used.

Paralysis and induction involve administering a rapid-acting induction agent followed by a neuromuscular blocking agent. Commonly used induction agents include propofol, ketamine, thiopentone, and etomidate. The neuromuscular blocking agents can be depolarizing (such as suxamethonium) or non-depolarizing (such as rocuronium). Depolarizing agents bind to acetylcholine receptors and generate an action potential, while non-depolarizing agents act as competitive antagonists.

Protection and positioning involve applying cricoid pressure to prevent regurgitation of gastric contents and positioning the patient’s neck appropriately. Tube placement is confirmed by visualizing the tube passing between the vocal cords, auscultation of the chest and stomach, end-tidal CO2 measurement, and visualizing misting of the tube. Post-intubation management includes standard care such as monitoring ECG, SpO2, NIBP, capnography, and maintaining sedation and neuromuscular blockade.

Overall, RSI is a technique used to quickly and safely secure the airway in patients who may be at risk of aspiration. It involves a series of steps to ensure proper preparation, oxygenation, drug administration, and tube placement. Monitoring and post-intubation care are also important aspects of RSI.

The highest amount of Prilocaine that can be administered without adrenaline is 6 mg per kilogram of body weight. However, if Prilocaine is used in combination with adrenaline, the maximum dose increases to 8mg per kilogram.

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.

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.

It is crucial to continuously monitor the oxygen saturation, blood pressure, ECG, and temperature of critically ill patients during transfers. If the patient is intubated, monitoring of end-tidal CO2 is also necessary. The minimum standard monitoring requirements for any critically ill patient during transfers include ECG, oxygen saturation, blood pressure, and temperature. Additionally, if the patient is intubated, monitoring of end-tidal CO2 is mandatory. It is important to note that the guidance from ICS/FICM suggests that monitoring protocols for intra-hospital transfers should be similar to those for interhospital transfers.

Further Reading:

Transfer of critically ill patients in the emergency department is a common occurrence and can involve intra-hospital transfers or transfers to another hospital. However, there are several risks associated with these transfers that doctors need to be aware of and manage effectively.

Technical risks include equipment failure or inadequate equipment, unreliable power or oxygen supply, incompatible equipment, restricted positioning, and restricted monitoring equipment. These technical issues can hinder the ability to detect and treat problems with ventilation, blood pressure control, and arrhythmias during the transfer.

Non-technical risks involve limited personal and medical team during the transfer, isolation and lack of resources in the receiving hospital, and problems with communication and liaison between the origin and destination sites.

Organizational risks can be mitigated by having a dedicated consultant lead for transfers who is responsible for producing guidelines, training staff, standardizing protocols, equipment, and documentation, as well as capturing data and conducting audits.

To optimize the patient’s clinical condition before transfer, several key steps should be taken. These include ensuring a low threshold for intubation and anticipating airway and ventilation problems, securing the endotracheal tube (ETT) and verifying its position, calculating oxygen requirements and ensuring an adequate supply, monitoring for circulatory issues and inserting at least two IV accesses, providing ongoing analgesia and sedation, controlling seizures, and addressing any fractures or temperature changes.

It is also important to have the necessary equipment and personnel for the transfer. Standard monitoring equipment should include ECG, oxygen saturation, blood pressure, temperature, and capnographic monitoring for ventilated patients. Additional monitoring may be required depending on the level of care needed by the patient.

In terms of oxygen supply, it is standard practice to calculate the expected oxygen consumption during transfer and multiply it by two to ensure an additional supply in case of delays. The suggested oxygen supply for transfer can be calculated using the minute volume, fraction of inspired oxygen, and estimated transfer time.

Overall, managing the risks associated with patient transfers requires careful planning, communication, and coordination to ensure the safety and well-being of critically ill patients.

The most significant factor in predicting postoperative nausea and vomiting (PONV) is being female. Females are three times more likely than males to experience PONV. Additionally, not smoking increases the risk of PONV by about two times. Having a history of motion sickness, PONV, or both also approximately doubles the risk of PONV. Age is another factor, with older adults being less likely to suffer from PONV. In children, those below 3 years of age have a lower risk of PONV compared to those older than 3.

Further Reading:

postoperative nausea and vomiting (PONV) is a common occurrence following procedures performed under sedation or anesthesia. It can be highly distressing for patients. Several risk factors have been identified for PONV, including female gender, a history of PONV or motion sickness, non-smoking status, patient age, use of volatile anesthetics, longer duration of anesthesia, perioperative opioid use, use of nitrous oxide, and certain types of surgery such as abdominal and gynecological procedures.

To manage PONV, antiemetics are commonly used. These medications work by targeting different receptors in the body. Cyclizine and promethazine are histamine H1-receptor antagonists, which block the action of histamine and help reduce nausea and vomiting. Ondansetron is a serotonin 5-HT3 receptor antagonist, which blocks the action of serotonin and is effective in preventing and treating PONV. Prochlorperazine is a dopamine D2 receptor antagonist, which blocks the action of dopamine and helps alleviate symptoms of nausea and vomiting. Metoclopramide is also a dopamine D2 receptor antagonist and a 5-HT3 receptor antagonist, providing dual action against PONV. It is also a 5-HT4 receptor agonist, which helps improve gastric emptying and reduces the risk of PONV.

Assessment and management of PONV involves a comprehensive approach. Healthcare professionals need to assess the patient’s risk factors for PONV and take appropriate measures to prevent its occurrence. This may include selecting the appropriate anesthesia technique, using antiemetics prophylactically, and providing adequate pain control. In cases where PONV does occur, prompt treatment with antiemetics should be initiated to alleviate symptoms and provide relief to the patient. Close monitoring of the patient’s condition and response to treatment is essential to ensure effective management of PONV.

Suxamethonium, also called succinylcholine, is a type of drug used to block neuromuscular transmission. It acts as an agonist by binding to acetylcholine receptors at the neuromuscular junction. Unlike acetylcholine, suxamethonium is not broken down by acetylcholinesterase, which means it stays bound to the receptors for a longer time, leading to prolonged inhibition of neuromuscular transmission. Eventually, suxamethonium is metabolized by plasma cholinesterase.

Further Reading:

Rapid sequence induction (RSI) is a method used to place an endotracheal tube (ETT) in the trachea while minimizing the risk of aspiration. It involves inducing loss of consciousness while applying cricoid pressure, followed by intubation without face mask ventilation. The steps of RSI can be remembered using the 7 P’s: preparation, pre-oxygenation, pre-treatment, paralysis and induction, protection and positioning, placement with proof, and post-intubation management.

Preparation involves preparing the patient, equipment, team, and anticipating any difficulties that may arise during the procedure. Pre-oxygenation is important to ensure the patient has an adequate oxygen reserve and prolongs the time before desaturation. This is typically done by breathing 100% oxygen for 3 minutes. Pre-treatment involves administering drugs to counter expected side effects of the procedure and anesthesia agents used.

Paralysis and induction involve administering a rapid-acting induction agent followed by a neuromuscular blocking agent. Commonly used induction agents include propofol, ketamine, thiopentone, and etomidate. The neuromuscular blocking agents can be depolarizing (such as suxamethonium) or non-depolarizing (such as rocuronium). Depolarizing agents bind to acetylcholine receptors and generate an action potential, while non-depolarizing agents act as competitive antagonists.

Protection and positioning involve applying cricoid pressure to prevent regurgitation of gastric contents and positioning the patient’s neck appropriately. Tube placement is confirmed by visualizing the tube passing between the vocal cords, auscultation of the chest and stomach, end-tidal CO2 measurement, and visualizing misting of the tube. Post-intubation management includes standard care such as monitoring ECG, SpO2, NIBP, capnography, and maintaining sedation and neuromuscular blockade.

Overall, RSI is a technique used to quickly and safely secure the airway in patients who may be at risk of aspiration. It involves a series of steps to ensure proper preparation, oxygenation, drug administration, and tube placement. Monitoring and post-intubation care are also important aspects of RSI.

When suxamethonium is administered for neuromuscular blockade during rapid sequence induction, one of the clinical observations typically seen is muscle fasciculations. However, when rocuronium is used instead, muscle fasciculations are not present.

Further Reading:

Rapid sequence induction (RSI) is a method used to place an endotracheal tube (ETT) in the trachea while minimizing the risk of aspiration. It involves inducing loss of consciousness while applying cricoid pressure, followed by intubation without face mask ventilation. The steps of RSI can be remembered using the 7 P’s: preparation, pre-oxygenation, pre-treatment, paralysis and induction, protection and positioning, placement with proof, and post-intubation management.

Preparation involves preparing the patient, equipment, team, and anticipating any difficulties that may arise during the procedure. Pre-oxygenation is important to ensure the patient has an adequate oxygen reserve and prolongs the time before desaturation. This is typically done by breathing 100% oxygen for 3 minutes. Pre-treatment involves administering drugs to counter expected side effects of the procedure and anesthesia agents used.

Paralysis and induction involve administering a rapid-acting induction agent followed by a neuromuscular blocking agent. Commonly used induction agents include propofol, ketamine, thiopentone, and etomidate. The neuromuscular blocking agents can be depolarizing (such as suxamethonium) or non-depolarizing (such as rocuronium). Depolarizing agents bind to acetylcholine receptors and generate an action potential, while non-depolarizing agents act as competitive antagonists.

Protection and positioning involve applying cricoid pressure to prevent regurgitation of gastric contents and positioning the patient’s neck appropriately. Tube placement is confirmed by visualizing the tube passing between the vocal cords, auscultation of the chest and stomach, end-tidal CO2 measurement, and visualizing misting of the tube. Post-intubation management includes standard care such as monitoring ECG, SpO2, NIBP, capnography, and maintaining sedation and neuromuscular blockade.

Overall, RSI is a technique used to quickly and safely secure the airway in patients who may be at risk of aspiration. It involves a series of steps to ensure proper preparation, oxygenation, drug administration, and tube placement. Monitoring and post-intubation care are also important aspects of RSI.

Ketamine administration can lead to various side effects, including nystagmus and diplopia. Other potential side effects include tachycardia, hypertension, laryngospasm, unpleasant hallucinations or emergence phenomena, nausea and vomiting, hypersalivation, increased intracranial and intraocular pressure, and abnormal tonic-clonic movements.

Further Reading:

There are four commonly used induction agents in the UK: propofol, ketamine, thiopentone, and etomidate.

Propofol is a 1% solution that produces significant venodilation and myocardial depression. It can also reduce cerebral perfusion pressure. The typical dose for propofol is 1.5-2.5 mg/kg. However, it can cause side effects such as hypotension, respiratory depression, and pain at the site of injection.

Ketamine is another induction agent that produces a dissociative state. It does not display a dose-response continuum, meaning that the effects do not necessarily increase with higher doses. Ketamine can cause bronchodilation, which is useful in patients with asthma. The initial dose for ketamine is 0.5-2 mg/kg, with a typical IV dose of 1.5 mg/kg. Side effects of ketamine include tachycardia, hypertension, laryngospasm, unpleasant hallucinations, nausea and vomiting, hypersalivation, increased intracranial and intraocular pressure, nystagmus and diplopia, abnormal movements, and skin reactions.

Thiopentone is an ultra-short acting barbiturate that acts on the GABA receptor complex. It decreases cerebral metabolic oxygen and reduces cerebral blood flow and intracranial pressure. The adult dose for thiopentone is 3-5 mg/kg, while the child dose is 5-8 mg/kg. However, these doses should be halved in patients with hypovolemia. Side effects of thiopentone include venodilation, myocardial depression, and hypotension. It is contraindicated in patients with acute porphyrias and myotonic dystrophy.

Etomidate is the most haemodynamically stable induction agent and is useful in patients with hypovolemia, anaphylaxis, and asthma. It has similar cerebral effects to thiopentone. The dose for etomidate is 0.15-0.3 mg/kg. Side effects of etomidate include injection site pain, movement disorders, adrenal insufficiency, and apnoea. It is contraindicated in patients with sepsis due to adrenal suppression.

The finger has a total of four digital nerves. Two of these nerves, known as the palmar digital nerves, run along the palm side of each finger. The other two nerves, called the dorsal digital nerves, are located on the back side of the finger. However, the dorsal nerve supply changes slightly at the level of the proximal IP joint. Beyond this point, the dorsal nerve supply comes from the dorsal branch of the palmar digital nerve.

Further Reading:

Digital nerve blocks are commonly used to numb the finger for various procedures such as foreign body removal, dislocation reduction, and suturing. Sensation to the finger is primarily provided by the proper digital nerves, which arise from the common digital nerve. Each common digital nerve divides into two proper digital nerves, which run along the palmar aspect of the finger. These proper digital nerves give off a dorsal branch that supplies the dorsal aspect of the finger.

The most common technique for digital nerve blocks is the digital (ring) block. The hand is cleaned and the injection sites are cleansed with an alcohol swab. A syringe containing 1% lidocaine is prepared, and the needle is inserted at the base of the finger from a dorsal approach. Lidocaine is infiltrated under the skin, and the needle is then advanced towards the palmar aspect of the finger to inject more lidocaine. This process is repeated on the opposite side of the finger.

It is important not to use lidocaine with adrenaline for this procedure, as it may cause constriction and ischemia of the digital artery. Lidocaine 1% is the preferred local anesthetic, and the maximum dose is 3 ml/kg up to 200 mg. Contraindications for digital nerve blocks include compromised circulation to the finger, infection at the planned injection site, contraindication to local anesthetic (e.g. allergy), and suspected compartment syndrome (which is rare in the finger).

Complications of digital nerve blocks can include vascular injury to the digital artery or vein, injury to the digital nerve, infection, pain, allergic reaction, intravascular injection (which can be avoided by aspirating prior to injection), and systemic local anesthetic toxicity (which is uncommon with typical doses of lidocaine).

The BURP maneuver is a technique used to assist with intubation. It involves applying pressure in a specific direction on the larynx. The acronym BURP stands for backwards (B), upwards (U), rightwards (R), and pressure (P). To perform the maneuver correctly, the thyroid cartilage is moved backwards, 2 cm upwards, and 0.5cm – 2 cm to the right in relation to the anatomical position.

Further Reading:

A difficult airway refers to a situation where factors have been identified that make airway management more challenging. These factors can include body habitus, head and neck anatomy, mouth characteristics, jaw abnormalities, and neck mobility. The LEMON criteria can be used to predict difficult intubation by assessing these factors. The criteria include looking externally at these factors, evaluating the 3-3-2 rule which assesses the space in the mouth and neck, assessing the Mallampati score which measures the distance between the tongue base and roof of the mouth, and considering any upper airway obstructions or reduced neck mobility.

Direct laryngoscopy is a method used to visualize the larynx and assess the size of the tracheal opening. The Cormack-Lehane grading system can be used to classify the tracheal opening, with higher grades indicating more difficult access. In cases of a failed airway, where intubation attempts are unsuccessful and oxygenation cannot be maintained, the immediate priority is to oxygenate the patient and prevent hypoxic brain injury. This can be done through various measures such as using a bag-valve-mask ventilation, high flow oxygen, suctioning, and optimizing head positioning.

If oxygenation cannot be maintained, it is important to call for help from senior medical professionals and obtain a difficult airway trolley if not already available. If basic airway management techniques do not improve oxygenation, further intubation attempts may be considered using different equipment or techniques. If oxygen saturations remain below 90%, a surgical airway such as a cricothyroidotomy may be necessary.

Post-intubation hypoxia can occur for various reasons, and the mnemonic DOPES can be used to identify and address potential problems. DOPES stands for displacement of the endotracheal tube, obstruction, pneumothorax, equipment failure, and stacked breaths. If intubation attempts fail, a maximum of three attempts should be made before moving to an alternative plan, such as using a laryngeal mask airway or considering a cricothyroidotomy.