Procedure
CO2 Absorption and Excretion During Laparoscopy
- CO2 Absorption from Peritoneal Space: CO2 is rapidly absorbed from the peritoneal space during laparoscopy -> this may result in respiratory acidosis, if not properly managed
- Direct effects of hypercapnia + acidosis: decreased mycocardial contractility, snesitization of myocardium to arrhythmogenic effects of pressors, systemic vasodilation
- Centrally-mediated (autonomic) effects of hypercapnia: sympathetic stimulation with tachycardia and vasoconstriction
- Factors Increasing CO2 Absorption During Laparoscopy
- High intra-abdominal pressure
- Prolonged laparoscopic surgery: allows more time to absorb CO2
- Factors Decreasing CO2 Excretion During Laparoscopy
- Anesthesiology mismanagement with inadequate minute ventilation maintained on the ventilator
- Lung disease: this will increase the required minute ventilation to maintain normal pCO2 during the case
- High intra-abdominal pressure: cephalad displacement of the diaphragm decreases lung volumes and produces restriction -> impairs mechanical ventilation
- Trendelenburg position: cephalad displacement of the diaphragm decreases lung volumes and produces restriction -> impairs mechanical ventilation
Effects of Increased Intra-Abdominal Pressure During Laparoscopy
- Mechanical Impairment of Venous Return: decreased preload
- Enhanced CO2 Absorption: as noted above
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Impairment of CO2 Excretion via Minute Ventilation: as noted above
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Monitoring of intra-abdominal pressure during laparoscopy is crucial, since it may contribute to both increased CO2 absorption and decreased CO2 excretion (via ventilation)
- Maintenance of low-moderate intra-abdominal pressures (<12 mm Hg) during laparoscopy can decrease the incidence of adverse effects that result from abdominal CO2 insufflation
Adverse Effects/Complications
Pulmonary Adverse Effects/Complications
- Air Embolism (see Air Embolism, [[Air Embolism]])
- Capnothorax (see Capnothorax, [[Capnothorax]])
- Intra-Operative Hypercapnia (see Hypercapnia, [[Hypercapnia]])
Other Adverse Effects/Complications
- Carbon Dioxide Pneumoperitoneum (see Pneumoperitoneum, [[Pneumoperitoneum]])
- Decreased Splanchnic Perfusion: proportional to the elevation in intra-abdominal pressure
References
- Circulatory and Respiratory Complications of Carbon Dioxide Insufflation. Dig Surg 2004;21:95–105