Introduction:
The increasing popularity of minimally invasive surgery (MIS) brings well-documented patient benefits, yet it also presents challenges for anesthesiologists. These challenges include navigating restricted access to the surgical site, managing gas insufflation into body cavities, and monitoring patients in poorly lit environments. Additionally, as surgical techniques advance, anesthesiologists encounter patients from high-risk groups who were previously considered unsuitable for laparoscopic procedures. The goal of anesthetic management is to safely guide patients through the procedure, minimize laparoscopy-related risks, and address any existing medical conditions, facilitating a swift recovery and early return to normal activities.
The popularity of minimally invasive surgery (MIS) is on the rise due to its advantages, including reduced postoperative pain, quicker recovery, and improved cosmetic outcomes. However, it is important to note that MIS can also pose risks, such as complications related to limited access to the surgical site and gas insufflation.
On the other hand, there could be serious consequences from limited access to the surgical site and gas insufflation into internal cavities. When it comes to monitoring a patient in a dimly illuminated setting, carbon dioxide absorption, creating a pneumoperitoneum (air or gas presence in the abdominal cavity), precise placement, and access restrictions for the anesthetist, MIS presents special obstacles from the perspective of anesthesia. Furthermore, patients from high-risk categories (obese, old, with severe cardiac and respiratory disease) who were previously thought to be inappropriate for the laparoscopic technique are now brought to the anesthetist due to the advancement of surgical techniques and expanding experience. By limiting the unique hazards associated with laparoscopy (a procedure that involves making tiny incisions in the belly or pelvis and using a camera), anesthetic management seeks to ensure the patient's safety during the surgery.
What Are the Principles of Minimally Invasive Surgery?
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The surgical approach varies depending on the procedure, with many requiring a thoracotomy (cut placed between ribs to reach the chest cavity (lungs), potentially involving positions other than strictly supine, and sometimes utilizing single-lung ventilation (SLV). Tailoring the analgesic technique is crucial to minimize postoperative pain in these cases, as direct visualization of the heart and great vessels may not be possible without a sternotomy (incision of the sternum). Thus, transesophageal echocardiography (TEE) is essential for surgical and hemodynamic guidance during most minimally invasive cardiac surgery (MICS) procedures.
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Arterial and venous cannulation commonly occurs through the femoral vessels, with cannula positioning confirmed using TEE. Aortic cross-clamping and myocardial protection, if needed, can be achieved either with direct vision using a special transthoracic clamping device or through endovascular methods, such as using an endo balloon inserted via the femoral or subclavian artery. Retrograde cardioplegia (administering a cardioplegic fluid through a catheter placed in the coronary sinus to safeguard the heart during heart surgery), if required, may involve inserting a coronary sinus catheter, although the limited surgical field can pose technical challenges, and this method is not frequently employed.
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Hemodynamic management and weaning from cardiopulmonary bypass (CPB) follow the same principles as conventional cardiac surgery. Postoperatively, patients are typically extubated within a few hours, and their ICU stay ranges from 24 to 48 hours. A multimodal approach to analgesia, incorporating both pharmacologic and non-pharmacologic methods, is preferred for postoperative pain management.
What Is the Preoperative Management of Minimally Invasive Surgery?
For minimally invasive surgery (MIS), anesthesia is essential to maintaining the best possible operative circumstances, patient comfort, and safety. Specialized anesthetic approaches that are adapted to the specific requirements of minimally invasive procedures are necessary for operations like robotic, endoscopic, or laparoscopic surgeries.
Before diving into the details of anesthesia for MIS, it is critical to comprehend the objectives and difficulties associated with these operations. Compared to open procedures, minimally invasive surgeries seek to minimize trauma, lessen postoperative pain, hasten recovery, and enhance cosmetic results. They do, however, pose certain difficulties for anesthesia practitioners, such as preserving hemodynamic stability, guaranteeing patient immobility, and controlling the consequences of pneumoperitoneum, or gas insufflation, which is utilized to create an internal working area in the body.
How Anesthesia Is Administered Before Minimally Invasive Surgery?
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A mix of general anesthesia and regional anesthesia procedures is usually used for MIS anesthesia. General anesthesia guarantees amnesia (memory loss), analgesia, muscular relaxation, and unconsciousness throughout the process. To minimize the need for systemic opioids and their related side effects, regional anesthetic, such as epidural or spinal anesthesia, can be used to treat pain during and after surgery.
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The induction and maintenance of anesthesia for minimally invasive surgery (MIS) requires careful consideration of the patient's position and the best possible access for the surgical team. The placement of patients undergoing MIS in lateral decubitus (head resting on pillow position), reverse Trendelenburg (patients lie on their backs with their heads elevated above their pelvis and their legs lowered over their hips, positioned at a 30-degree angle), or steep Trendelenburg position (the patient is positioned head-down at an angle of between 30 and 40 degrees) can have an impact on intravenous medication delivery, ventilation, and hemodynamics. To avoid issues related to patient placement, anesthesia physicians must closely monitor hemodynamic indicators, secure the airway, and modify breathing as needed.
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Furthermore, the inhalation of carbon dioxide (CO2) into the abdominal cavity causes pneumoperitoneum, which poses special difficulties for the management of anesthesia. Hypercapnia (elevated partial pressure of carbon dioxide) and acidosis brought on by CO2 absorption may jeopardize tissue perfusion and hemodynamics. To lessen these effects, anesthesia doctors must keep an eye on end-tidal CO2 levels, maintain sufficient ventilation, and maximize fluid management.
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It is critical to maintain a sufficient depth of anesthesia during MIS while avoiding the use of volatile anesthetics and opioids. To reduce opioid consumption and speed up recovery, enhanced recovery after surgery (ERAS) protocols support the use of multimodal analgesia approaches, such as regional anesthesia, non-opioid analgesics, and local anesthetics. Methods like balanced anesthesia, which uses opioids sparingly, or total intravenous anesthesia (TIVA) might assist in achieving the best possible analgesia without extending recovery time or postponing release.
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Goal-directed hydration management and intraoperative monitoring are two more crucial components of anesthesia for MIS. During surgery, hemodynamic monitoring, including cardiac output, central venous pressure, and arterial blood pressure, helps direct fluid delivery and maximize tissue perfusion. With goal-directed fluid management, problems, including organ failure and postponed recovery, are avoided. Intraoperative hypovolemia (low extracellular fluid in the body) and fluid overload are also avoided.
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Additionally, intraoperative neurophysiological monitoring can be used in some MIS procedures, particularly in spinal or neurosurgical interventions, to evaluate nerve function and guard against damage. For the sake of patient safety and enhancing surgical results, anesthesia providers work closely with the surgical team.
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An essential part of anesthesia for MIS is postoperative pain control, which places a focus on early mobilization, less narcotic use, and quick recovery. Transversus abdominis plane (TAP) blocks and continuous epidural infusions are two examples of regional anesthesia procedures that can effectively relieve pain while reducing the need for systemic opioids and promoting early ambulation.
Conclusion:
In conclusion, a customized strategy for anesthesia in minimally invasive surgery is needed to meet the particular difficulties and objectives of these treatments. Anesthetic professionals are responsible for monitoring hemodynamics, facilitating early recovery, optimizing patient positioning, managing the effects of pneumoperitoneum, ensuring appropriate depth of anesthetic, and using multimodal analgesic approaches. Anesthesia doctors are essential to improving patient outcomes and satisfaction during minimally invasive surgery by utilizing evidence-based methods and working closely with the surgical team.
