From the Guidelines
Intravenous (IV) muscle relaxants are medications used to facilitate interventional procedures, such as abdominal laparotomy or laparoscopy surgery, by inducing muscle relaxation.
Key Points
- The use of muscle relaxants is recommended to facilitate interventional procedures in abdominal laparotomy or laparoscopy surgery, with strong agreement 1.
- Muscle relaxants are used to induce deep block, which may allow operating at lower pressure while maintaining intra-abdominal space for surgery 1.
- Neuromuscular monitoring should be a standard of care when using muscle relaxants, as cumulative dosing of intermediate muscle relaxants increases the risk of postoperative pulmonary complications 1.
- The use of muscle relaxants is probably recommended to facilitate interventional procedures in ENT laser surgery, with strong agreement 1.
Important Considerations
- The required intensity of neuromuscular blockade (moderate vs. deep) in abdominal laparotomy or laparoscopy surgery is not established, due to insufficient data in the literature 1.
- Reducing intra-abdominal pressure below 10-12 mmHg may result in a reduction in the physiological effects of pneumoperitoneum, leading to improved renal blood flow and lower peak airway ventilator pressures 1.
From the Research
Definition and Purpose of Intravenous (IV) Muscle Relaxants
- IV muscle relaxants are drugs that are administered intravenously to provide paralysis and relaxation of skeletal muscles during surgical procedures 2, 3.
- They are used to secure paralysis and maintain paralysis, allowing for optimal relaxation of skeletal muscles during surgery 2.
- IV muscle relaxants do not affect consciousness and have no pain relieving effect, but they provide optimal relaxation of skeletal muscles, which may otherwise require high doses of anaesthetic drugs 3.
Types and Characteristics of IV Muscle Relaxants
- There are two main types of muscle relaxants: suxamethonium (curacit) and curare compounds, which work by interfering with the normal signalling system between nerve and muscle 3.
- Nondepolarizing neuromuscular blocking agents, such as atracurium and mivacurium, have an intermediate or short duration of action, making them suitable for administration by infusion 2.
- The choice of IV muscle relaxant is important, as it should cause negligible side-effects and have a rapid onset of action 2, 3.
Administration and Monitoring of IV Muscle Relaxants
- IV muscle relaxants are typically administered by continuous infusion, which requires careful monitoring to maintain an adequate level of block 2, 4.
- The routine use of neuromuscular monitoring is recommended when a continuous infusion of a relaxant is used 2.
- New programmable syringe infusion pumps provide a degree of simplicity and accuracy in operation, making IV infusion of muscle relaxants a simple and practical reality for most procedures 5.