The risk of infection is highest with femoral central lines.

A central venous catheter (CVC) is a type of catheter that is inserted into a large vein in the body, typically in the neck, chest, or groin. It has several important uses, including CVP monitoring, pulmonary artery pressure monitoring, repeated blood sampling, IV access for large volumes of fluids or drugs, TPN administration, dialysis, pacing, and other procedures such as placement of IVC filters or venous stents.

When inserting a central line, it is ideal to use ultrasound guidance to ensure accurate placement. However, there are certain contraindications to central line insertion, including infection or injury to the planned access site, coagulopathy, thrombosis or stenosis of the intended vein, a combative patient, or raised intracranial pressure for jugular venous lines.

The most common approaches for central line insertion are the internal jugular, subclavian, femoral, and PICC (peripherally inserted central catheter) veins. The internal jugular vein is often chosen due to its proximity to the carotid artery, but variations in anatomy can occur. Ultrasound can be used to identify the vessels and guide catheter placement, with the IJV typically lying superficial and lateral to the carotid artery. Compression and Valsalva maneuvers can help distinguish between arterial and venous structures, and doppler color flow can highlight the direction of flow.

In terms of choosing a side for central line insertion, the right side is usually preferred to avoid the risk of injury to the thoracic duct and potential chylothorax. However, the left side can also be used depending on the clinical situation.

Femoral central lines are another option for central venous access, with the catheter being inserted into the femoral vein in the groin. Local anesthesia is typically used to establish a field block, with lidocaine being the most commonly used agent. Lidocaine works by blocking sodium channels and preventing the propagation of action potentials.

In summary, central venous catheters have various important uses and should ideally be inserted using ultrasound guidance. There are contraindications to their insertion, and different approaches can be used depending on the clinical situation. Local anesthesia is commonly used for central line insertion, with lidocaine being the preferred agent.

To minimize the risk of infection and promote proper healing, the best approach for preparing the skin would be to clean it for 30 seconds with 2% chlorhexidine gluconate in 70% alcohol. This solution has been shown to effectively kill bacteria and reduce the risk of infection. Other options such as povidone-iodine, 90% isopropyl alcohol, and 30% isopropyl alcohol may also have some antimicrobial properties, but they are not as effective as chlorhexidine gluconate.

Further Reading:

Peripheral venous cannulation is a procedure that should be performed following established guidelines to minimize the risk of infection, injury, extravasation, and early failure of the cannula. It is important to maintain good hand hygiene, use personal protective equipment, ensure sharps safety, and employ an aseptic non-touch technique during the procedure.

According to the National Institute for Health and Care Excellence (NICE), the skin should be disinfected with a solution of 2% chlorhexidine gluconate and 70% alcohol before inserting the catheter. It is crucial to allow the disinfectant to completely dry before inserting the cannula.

The flow rates of IV cannulas can vary depending on factors such as the gauge, color, type of fluid used, presence of a bio-connector, length of the cannula, and whether the fluid is drained under gravity or pumped under pressure. However, the following are typical flow rates for different gauge sizes: 14 gauge (orange) has a flow rate of 270 ml/minute, 16 gauge (grey) has a flow rate of 180 ml/minute, 18 gauge (green) has a flow rate of 90 ml/minute, 20 gauge (pink) has a flow rate of 60 ml/minute, and 22 gauge (blue) has a flow rate of 36 ml/minute. These flow rates are based on infusing 1000 ml of normal saline under ideal circumstances, but they may vary in practice.

The internal jugular vein is a significant vein located close to the surface of the body. It is often chosen for the insertion of central venous catheters due to its accessibility. To locate the vein, a needle is inserted into the middle of a triangular area formed by the lower heads of the sternocleidomastoid muscle and the clavicle. It is important to palpate the carotid artery to ensure that the needle is inserted to the side of the artery.

A tension pneumothorax occurs when there is an air leak from the lung or chest wall that acts like a one-way valve. This causes air to build up in the pleural space without any way to escape. As a result, pressure in the pleural space increases and pushes the mediastinum into the opposite hemithorax. If left untreated, this can lead to cardiovascular instability, shock, and cardiac arrest.

The clinical features of tension pneumothorax include respiratory distress and cardiovascular instability. Tracheal deviation away from the side of the injury, unilateral absence of breath sounds on the affected side, and a hyper-resonant percussion note are also characteristic. Other signs include distended neck veins and cyanosis, which is a late sign. It’s important to note that both tension pneumothorax and massive haemothorax can cause decreased breath sounds on auscultation. However, percussion can help differentiate between the two conditions. Hyper-resonance suggests tension pneumothorax, while dullness suggests a massive haemothorax.

Tension pneumothorax is a clinical diagnosis and should not be delayed for radiological confirmation. Requesting a chest X-ray in this situation can delay treatment and put the patient at risk. Immediate decompression through needle thoracocentesis is the recommended treatment. Traditionally, a large-bore needle or cannula is inserted into the 2nd intercostal space in the midclavicular line of the affected hemithorax. However, studies on cadavers have shown better success in reaching the thoracic cavity when the 4th or 5th intercostal space in the midaxillary line is used in adult patients. ATLS now recommends this location for needle decompression in adults. The site for needle thoracocentesis in children remains the same, using the 2nd intercostal space in the midclavicular line. It’s important to remember that needle thoracocentesis is a temporary measure, and the insertion of a chest drain is the definitive treatment.

The subclavian approach for central lines carries the highest risk of pneumothorax. However, it does have advantages such as being accessible during airway control and having easily identifiable landmarks for insertion, even in obese patients. It is important to note that the carotid is not used for CVC’s.

Further Reading:

A central venous catheter (CVC) is a type of catheter that is inserted into a large vein in the body, typically in the neck, chest, or groin. It has several important uses, including CVP monitoring, pulmonary artery pressure monitoring, repeated blood sampling, IV access for large volumes of fluids or drugs, TPN administration, dialysis, pacing, and other procedures such as placement of IVC filters or venous stents.

When inserting a central line, it is ideal to use ultrasound guidance to ensure accurate placement. However, there are certain contraindications to central line insertion, including infection or injury to the planned access site, coagulopathy, thrombosis or stenosis of the intended vein, a combative patient, or raised intracranial pressure for jugular venous lines.

The most common approaches for central line insertion are the internal jugular, subclavian, femoral, and PICC (peripherally inserted central catheter) veins. The internal jugular vein is often chosen due to its proximity to the carotid artery, but variations in anatomy can occur. Ultrasound can be used to identify the vessels and guide catheter placement, with the IJV typically lying superficial and lateral to the carotid artery. Compression and Valsalva maneuvers can help distinguish between arterial and venous structures, and doppler color flow can highlight the direction of flow.

In terms of choosing a side for central line insertion, the right side is usually preferred to avoid the risk of injury to the thoracic duct and potential chylothorax. However, the left side can also be used depending on the clinical situation.

Femoral central lines are another option for central venous access, with the catheter being inserted into the femoral vein in the groin. Local anesthesia is typically used to establish a field block, with lidocaine being the most commonly used agent. Lidocaine works by blocking sodium channels and preventing the propagation of action potentials.

In summary, central venous catheters have various important uses and should ideally be inserted using ultrasound guidance. There are contraindications to their insertion, and different approaches can be used depending on the clinical situation. Local anesthesia is commonly used for central line insertion, with lidocaine being the preferred agent.

The internal jugular vein is a significant vein located close to the surface of the body. It is often chosen for the insertion of central venous catheters due to its accessibility. To locate the vein, a needle is inserted into the middle of a triangular area formed by the lower heads of the sternocleidomastoid muscle and the clavicle. It is important to palpate the carotid artery to ensure that the needle is inserted to the side of the artery.

Anaphylaxis is a severe and life-threatening hypersensitivity reaction that can have sudden onset and progression. It is characterized by skin or mucosal changes and can lead to life-threatening airway, breathing, or circulatory problems. Anaphylaxis can be allergic or non-allergic in nature.

In allergic anaphylaxis, there is an immediate hypersensitivity reaction where an antigen stimulates the production of IgE antibodies. These antibodies bind to mast cells and basophils. Upon re-exposure to the antigen, the IgE-covered cells release histamine and other inflammatory mediators, causing smooth muscle contraction and vasodilation.

Non-allergic anaphylaxis occurs when mast cells degrade due to a non-immune mediator. The clinical outcome is the same as in allergic anaphylaxis.

The management of anaphylaxis is the same regardless of the cause. Adrenaline is the most important drug and should be administered as soon as possible. The recommended doses for adrenaline vary based on age. Other treatments include high flow oxygen and an IV fluid challenge. Corticosteroids and chlorpheniramine are no longer recommended, while non-sedating antihistamines may be considered as third-line treatment after initial stabilization of airway, breathing, and circulation.

Common causes of anaphylaxis include food (such as nuts, which is the most common cause in children), drugs, and venom (such as wasp stings). Sometimes it can be challenging to determine if a patient had a true episode of anaphylaxis. In such cases, serum tryptase levels may be measured, as they remain elevated for up to 12 hours following an acute episode of anaphylaxis.

The Resuscitation Council (UK) provides guidelines for the management of anaphylaxis, including a visual algorithm that outlines the recommended steps for treatment.
https://www.resus.org.uk/sites/default/files/2021-05/Emergency%20Treatment%20of%20Anaphylaxis%20May%202021_0.pdf

The ratio of chest compressions to rescue breaths during CPR is now 30:2. Prior to 2005, the ratio used was 15:2.

Further Reading:

In the event of an adult experiencing cardiorespiratory arrest, it is crucial for doctors to be familiar with the Advanced Life Support (ALS) algorithm. They should also be knowledgeable about the proper technique for chest compressions, the appropriate rhythms for defibrillation, the reversible causes of arrest, and the drugs used in advanced life support.

During chest compressions, the rate should be between 100-120 compressions per minute, with a depth of compression of 5-6 cm. The ratio of chest compressions to rescue breaths should be 30:2. It is important to change the person giving compressions regularly to prevent fatigue.

There are two shockable ECG rhythms that doctors should be aware of: ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT). These rhythms require defibrillation.

There are four reversible causes of cardiorespiratory arrest, known as the 4 H’s and 4 T’s. The 4 H’s include hypoxia, hypovolemia, hypo or hyperkalemia or metabolic abnormalities, and hypothermia. The 4 T’s include thrombosis (coronary or pulmonary), tension pneumothorax, tamponade, and toxins. Identifying and treating these reversible causes is crucial for successful resuscitation.

When it comes to resus drugs, they are considered of secondary importance during CPR due to the lack of high-quality evidence for their efficacy. However, adrenaline (epinephrine) and amiodarone are the two drugs included in the ALS algorithm. Doctors should be familiar with the dosing, route, and timing of administration for both drugs.

Adrenaline should be administered intravenously at a concentration of 1 in 10,000 (100 micrograms/mL). It should be repeated every 3-5 minutes. Amiodarone is initially given at a dose of 300 mg, either from a pre-filled syringe or diluted in 20 mL of Glucose 5%. If required, an additional dose of 150 mg can be given by intravenous injection. This is followed by an intravenous infusion of 900 mg over 24 hours. The first dose of amiodarone is given after 3 shocks.

During pericardiocentesis, a needle is inserted approximately 1-2 cm below and to the left of the xiphisternum. The procedure involves the following steps:
1. Prepare the skin and administer local anesthesia, if time permits.
2. Ensure ECG monitoring is in place.
3. Puncture the skin using a long 16-18g catheter, 1-2 cm below and to the left of the xiphisternum.
4. Advance the catheter towards the tip of the left scapula at a 45-degree angle to the skin.
5. Aspirate fluid from the pericardium while monitoring the ECG for any signs of injury.
6. Once blood from the pericardium is aspirated, leave the catheter in place with a 3-way tap until a formal thoracotomy can be performed.
It is important to note that knowledge of pericardiocentesis is included in the CEM syllabus, although the RCEM may recommend direct thoracotomy as the preferred approach.

Further Reading:

Cardiac tamponade, also known as pericardial tamponade, occurs when fluid accumulates in the pericardial sac and compresses the heart, leading to compromised blood flow. Classic clinical signs of cardiac tamponade include distended neck veins, hypotension, muffled heart sounds, and pulseless electrical activity (PEA). Diagnosis is typically done through a FAST scan or an echocardiogram.

Management of cardiac tamponade involves assessing for other injuries, administering IV fluids to reduce preload, performing pericardiocentesis (inserting a needle into the pericardial cavity to drain fluid), and potentially performing a thoracotomy. It is important to note that untreated expanding cardiac tamponade can progress to PEA cardiac arrest.

Pericardiocentesis can be done using the subxiphoid approach or by inserting a needle between the 5th and 6th intercostal spaces at the left sternal border. Echo guidance is the gold standard for pericardiocentesis, but it may not be available in a resuscitation situation. Complications of pericardiocentesis include ST elevation or ventricular ectopics, myocardial perforation, bleeding, pneumothorax, arrhythmia, acute pulmonary edema, and acute ventricular dilatation.

It is important to note that pericardiocentesis is typically used as a temporary measure until a thoracotomy can be performed. Recent articles published on the RCEM learning platform suggest that pericardiocentesis has a low success rate and may delay thoracotomy, so it is advised against unless there are no other options available.

In patients with hypothermia, the pulse check during CPR should be extended to 1 minute. Additionally, several adjustments need to be made to the CPR protocol. Firstly, mechanical ventilation should be used due to the stiffness of the chest wall. Secondly, the dosing or omission of cardiac arrest drugs should be adjusted based on the patient’s temperature. The defibrillation pattern should also be modified, with 3 shocks attempted before re-attempting defibrillation only when the body temperature is above 30ºC. Certain electrolyte disturbances, such as mild hypokalemia, should not be treated as potassium levels typically rise with Rewarming. It is important to plan for prolonged resuscitation in these cases. Lastly, uncorrected ABG results should be used, without adjusting for temperature.

Further Reading:

Hypothermic cardiac arrest is a rare situation that requires a tailored approach. Resuscitation is typically prolonged, but the prognosis for young, previously healthy individuals can be good. Hypothermic cardiac arrest may be associated with drowning. Hypothermia is defined as a core temperature below 35ºC and can be graded as mild, moderate, severe, or profound based on the core temperature. When the core temperature drops, basal metabolic rate falls and cell signaling between neurons decreases, leading to reduced tissue perfusion. Signs and symptoms of hypothermia progress as the core temperature drops, initially presenting as compensatory increases in heart rate and shivering, but eventually ceasing as the temperature drops into moderate hypothermia territory.

ECG changes associated with hypothermia include bradyarrhythmias, Osborn waves, prolonged PR, QRS, and QT intervals, shivering artifact, ventricular ectopics, and cardiac arrest. When managing hypothermic cardiac arrest, ALS should be initiated as per the standard ALS algorithm, but with modifications. It is important to check for signs of life, re-warm the patient, consider mechanical ventilation due to chest wall stiffness, adjust dosing or withhold drugs due to slowed drug metabolism, and correct electrolyte disturbances. The resuscitation of hypothermic patients is often prolonged and may continue for a number of hours.

Pulse checks during CPR may be difficult due to low blood pressure, and the pulse check is prolonged to 1 minute for this reason. Drug metabolism is slowed in hypothermic patients, leading to a build-up of potentially toxic plasma concentrations of administered drugs. Current guidance advises withholding drugs if the core temperature is below 30ºC and doubling the drug interval at core temperatures between 30 and 35ºC. Electrolyte disturbances are common in hypothermic patients, and it is important to interpret results keeping the setting in mind. Hypoglycemia should be treated, hypokalemia will often correct as the patient re-warms, ABG analyzers may not reflect the reality of the hypothermic patient, and severe hyperkalemia is a poor prognostic indicator.

Different warming measures can be used to increase the core body temperature, including external passive measures such as removal of wet clothes and insulation with blankets, external active measures such as forced heated air or hot-water immersion, and internal active measures such as inhalation of warm air, warmed intravenous fluids, gastric, bladder, peritoneal and/or pleural lavage and high volume renal haemofilter.