What is the next step in managing poor tidal volumes during a laparoscopic partial nephrectomy while using the argon beam coagulator (ABC)?

From the Guidelines

The next step in managing poor tidal volumes during a laparoscopic partial nephrectomy while using the argon beam coagulator (ABC) is to immediately release the pneumoperitoneum to allow for lung re-expansion. This is based on the principle of lung-protective ventilation, which emphasizes the importance of maintaining adequate tidal volumes and preventing lung injury during mechanical ventilation 1. The use of argon beam coagulator can lead to argon gas embolism or excessive intra-abdominal pressure, displacing the normal pneumoperitoneum gas and increasing abdominal pressure, thereby decreasing diaphragmatic excursion. Some key points to consider in this scenario include:

• The importance of individualized mechanical ventilation to improve intraoperative respiratory function 1
• The need to avoid high tidal volumes and inspiratory pressures, which can lead to lung injury 1
• The potential benefits of using lower argon flow rates, shorter activation periods, and more frequent venting of the pneumoperitoneum to minimize the risk of argon gas embolism or excessive intra-abdominal pressure
• The importance of monitoring end-tidal CO2 and peak airway pressures throughout the remainder of the case to detect early signs of recurrence. In terms of specific recommendations, the guidelines suggest using a low-tidal-volume protective-ventilation strategy (6-8 ml/kg predicted body weight) and individualizing PEEP to the patient to avoid increases in driving pressure while maintaining a low tidal volume 1. However, in this specific scenario, releasing the pneumoperitoneum is the most critical step to take immediately, as it allows for lung re-expansion and can help to improve tidal volumes. After releasing the pneumoperitoneum, the anesthesiologist can then adjust the ventilation strategy as needed to optimize lung protection and ensure adequate gas exchange.

From the Research

Managing Poor Tidal Volumes during Laparoscopic Partial Nephrectomy

• The use of the argon beam coagulator during laparoscopic partial nephrectomy can lead to poor tidal volumes, which may be caused by the increased pressure inside the abdominal cavity or the absorption of carbon dioxide.
• According to the study 2, the argon beam coagulator can cause thermal injury to renal parenchyma, but it can also reduce operative time and blood loss.
• To manage poor tidal volumes, the anesthesiologist may need to adjust the ventilator settings, such as increasing the respiratory rate or decreasing the tidal volume.
• The study 3 found that low tidal volume ventilation during pneumoperitoneum can cause a mixed respiratory and metabolic acidosis, but it also found that end-tidal CO2 (EtCO2) is a good non-invasive monitor for estimating PaCO2 during low tidal volume ventilation.
• The study 4 found that the application of low tidal volume with positive end-expiratory pressure (PEEP) can improve ventilatory and oxygenation parameters during laparoscopic surgery.
• The study 5 found that low tidal volume ventilation was associated with a significantly reduced incidence of postoperative pulmonary complications (PPCs) compared to conventional tidal volume ventilation during laparoscopic surgeries.

Possible Next Steps

• Decrease CO2 insufflation flow rate to reduce the pressure inside the abdominal cavity and improve tidal volumes 3, 4.
• Lower the argon generator power setting to reduce the thermal injury to renal parenchyma and improve hemostasis 2.
• Release the pneumoperitoneum to reduce the pressure inside the abdominal cavity and improve tidal volumes, but this may not be feasible during the procedure.
• Increase the respiratory rate or adjust the ventilator settings to improve tidal volumes and oxygenation 3, 4, 5.