Sugammadex is a medication used to quickly reverse the effects of muscle relaxation caused by drugs like rocuronium bromide or vecuronium bromide. The 2020 guidelines for sedation and anesthesia outside of the operating room recommend having a complete set of emergency drugs, including specific reversal agents like naloxone, sugammadex, and flumazenil, readily accessible. Sugammadex is a modified form of gamma cyclodextrin that is effective in rapidly reversing the neuromuscular blockade caused by these specific drugs.

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.

Jet ventilation through a needle cricothyroidotomy typically involves using a 1 bar (100 Kpa) oxygen source.

Further Reading:

Cricothyroidotomy, also known as cricothyrotomy, is a procedure used to create an airway by making an incision between the thyroid and cricoid cartilages. This can be done surgically with a scalpel or using a needle method. It is typically used as a short-term solution for establishing an airway in emergency situations where traditional intubation is not possible.

The surgical technique involves dividing the cricothyroid membrane transversely, while some recommend making a longitudinal skin incision first to identify the structures below. Complications of this procedure can include bleeding, infection, incorrect placement resulting in a false passage, fistula formation, cartilage fracture, subcutaneous emphysema, scarring leading to stenosis, and injury to the vocal cords or larynx. There is also a risk of damage to the recurrent laryngeal nerve, and failure to perform the procedure successfully can lead to hypoxia and death.

There are certain contraindications to surgical cricothyroidotomy, such as the availability of less invasive airway securing methods, patients under 12 years old (although a needle technique may be used), laryngeal fracture, pre-existing or acute laryngeal pathology, tracheal transection with retraction into the mediastinum, and obscured anatomical landmarks.

The needle (cannula) cricothyroidotomy involves inserting a cannula through the cricothyroid membrane to access the trachea. This method is mainly used in children in scenarios where ENT assistance is not available. However, there are drawbacks to this approach, including the need for high-pressure oxygen delivery, which can risk barotrauma and may not always be readily available. The cannula is also prone to kinking and displacement, and there is limited evacuation of expiratory gases, making it suitable for only a short period of time before CO2 retention becomes problematic.

In children, the cannula cricothyroidotomy and ventilation procedure involves extending the neck and stabilizing the larynx, inserting a 14g or 16g cannula at a 45-degree angle aiming caudally, confirming the position by aspirating air through a saline-filled syringe, and connecting it to an insufflation device or following specific oxygen pressure and flow settings for jet ventilation.

If a longer-term airway is needed, a cricothyroidotomy may be converted to

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.

In patients with pre-existing hypovolaemia, the amount of sodium thiopentone administered should be reduced by half. This is because sodium thiopentone can cause venodilation and myocardial depression, which can result in significant hypovolaemia. Alternatively, an induction agent that does not cause hypotension, such as Etomidate, can be used instead. It is important to note that both propofol and thiopentone are known to cause hypotension.

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.

Benzodiazepines are medications that are utilized to address emergence phenomena, which are characterized by restlessness and distressing hallucinations experienced upon awakening from ketamine sedation or induction. These phenomena are more frequently observed in older children and adults, affecting approximately one out of every three adults. To manage emergence phenomena, benzodiazepines may be administered.

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.

Rocuronium is a type of neuromuscular blocker that does not cause depolarization.

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.

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.

The administration of nitrous oxide increases the amount of inhaled anaesthetic gases in the body through a phenomenon called the ‘second gas effect’. Nitrous oxide is much more soluble than nitrogen, with a solubility that is 20 to 30 times higher. When nitrous oxide is given, it causes a decrease in the volume of air in the alveoli. Additionally, nitrous oxide can enhance the absorption of other inhaled anaesthetic agents through the second gas effect. However, it is important to note that nitrous oxide alone cannot be used as the sole maintenance agent in anaesthesia.

Further Reading:

Entonox® is a mixture of 50% nitrous oxide and 50% oxygen that can be used for self-administration to reduce anxiety. It can also be used alongside other anesthesia agents. However, its mechanism of action for anxiety reduction is not fully understood. The Entonox bottles are typically identified by blue and white color-coded collars, but a new standard will replace these with dark blue shoulders in the future. It is important to note that Entonox alone cannot be used as the sole maintenance agent in anesthesia.

One of the effects of nitrous oxide is the second-gas effect, where it speeds up the absorption of other inhaled anesthesia agents. Nitrous oxide enters the alveoli and diffuses into the blood, displacing nitrogen. This displacement causes the remaining alveolar gases to become more concentrated, increasing the fractional content of inhaled anesthesia gases and accelerating the uptake of volatile agents into the blood.

However, when nitrous oxide administration is stopped, it can cause diffusion hypoxia. Nitrous oxide exits the blood and diffuses back into the alveoli, while nitrogen diffuses in the opposite direction. Nitrous oxide enters the alveoli much faster than nitrogen leaves, resulting in the dilution of oxygen within the alveoli. This can lead to diffusion hypoxia, where the oxygen concentration in the alveoli is diluted, potentially causing oxygen deprivation in patients breathing air.

There are certain contraindications for using nitrous oxide, as it can expand in air-filled spaces. It should be avoided in conditions such as head injuries with intracranial air, pneumothorax, recent intraocular gas injection, and entrapped air following a recent underwater dive.

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.

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.