Carbon Dioxide Embolism During Laparoscopic Right Hepatectomy: A Case Report

Dongjiao Wu

doi:10.36502/2023/ASJBCCR.6315

Asploro Journal of Biomedical and Clinical Case Reports
ISSN: 2582-0370
Article Type: Case Report
DOI: 10.36502/2023/ASJBCCR.6315
Asp Biomed Clin Case Rep. 2023 Aug 05;6(3):195-200

Abstract

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Carbon Dioxide Embolism During Laparoscopic Right Hepatectomy: A Case Report

Dongjiao Wu^1*
¹Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China

Corresponding Author: Dongjiao Wu
Address: Department of Anesthesiology, West China Hospital, Sichuan University No. 37 Guoxuexiang Chengdu, Sichuan, 610041, China.
Received date: 14 July 2023; Accepted date: 29 July 2023; Published date: 05 August 2023

Citation: Wu D. Carbon Dioxide Embolism During Laparoscopic Right Hepatectomy: A Case Report. Asp Biomed Clin Case Rep. 2023 Aug 05;6(3):195-200.

Copyright © 2023 Wu D. This is an open-access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

Keywords: Carbon Dioxide, Embolism, Laparoscopy, Hepatectomy, Case Report

Abstract

Complications of laparoscopic surgery include carbon dioxide (CO₂) embolism, primarily caused by the entry of CO₂ gas into blood vessels or solid organs. If significant clinical symptoms occur, timely intervention is crucial as it can be life-threatening. We report a case of CO₂ embolism during laparoscopic right hepatectomy. The patient was a 37-year-old male with no history of liver or kidney dysfunction. During the procedure, there were two episodes of oxygen desaturation (SpO₂), and the second episode was accompanied by a significant drop in blood pressure and an increase in heart rate. However, there was no sudden decrease in the end-tidal CO₂ partial pressure (ETCO₂). Simultaneously, a grinding murmur was auscultated in the precordial area, and foamy blood was aspirated from the right internal jugular vein catheter. This article describes a case of CO₂ embolism during laparoscopic surgery and provides a summary of its causes, clinical manifestations, diagnosis, and treatment. It is hoped that this article will contribute to the timely recognition and management of such cases, thereby preventing any potential adverse outcomes for patients.

Introduction

Laparoscopic liver resection has become a popular approach for minimizing intraoperative bleeding, reducing incision size, and promoting rapid patient recovery. It involves establishing pneumoperitoneum using CO₂ gas [1]. Laparoscopic liver resection requires low central venous pressure, high intra-abdominal pressure, and specific patient positioning [2]. Additionally, due to the rich and complex vascular structure of the liver, CO₂ embolism can occur. Severe CO₂ embolism can lead to risks such as hypotension, hypoxia, neurological events, arrhythmias, and even cardiac arrest, with a mortality rate as high as 28% [3]. Therefore, timely detection, accurate diagnosis, and appropriate management are crucial.

Here, we report a case of carbon dioxide embolism during laparoscopic right hepatectomy. The primary manifestations included a decrease in SpO₂ accompanied by a drop in blood pressure and an increase in heart rate, while ETCO₂ did not exhibit a sudden decrease. We promptly made the diagnosis and initiated appropriate management.

Case Report

The patient is a 37-year-old male with a height of 163cm and weight of 52kg who was admitted due to intermittent abdominal pain for 1 month. The patient has generally been in good health and had previously undergone left hemihepatectomy in 2018 for a liver hydatid cyst. Preoperative electrocardiogram, routine blood tests, biochemical tests, and coagulation function showed no significant abnormalities. The hydatid cyst IgG antibody test was positive. An abdominal CT scan revealed multiple heterogeneous low-density lesions in the liver, with the largest lesion located in the right lobe measuring approximately 8.10*7.77cm (Fig-1) in maximum cross-section, showing scattered dot-like and streak-like high-density shadows.

Fig-1

Carbon Dioxide Embolism During Laparoscopic Right Hepatectomy: A Case Report — *The Abdominal CT Scan Showed a Large Lesion in the Right Lobe Measuring approximately 8.10*7.77cm*

The patient was undergoing laparoscopic right hemihepatectomy. Upon admission, the patient was conscious. An intravenous infusion of lactated Ringer’s solution (500 ml) was initiated through an open venous access. The electrocardiogram monitoring showed a heart rate of 78 beats per minute, blood pressure of 141/78mmHg, respiratory rate of 15 breaths per minute, and SpO₂ of 96%. Anesthesia induction was performed by sequential intravenous administration of 2mg midazolam, 17.5μg sufentanil, 12mg Cisatracurium, and 60 mg propofol. After satisfactory muscle relaxation, a size 7.5 regular endotracheal tube was placed orally under direct laryngoscopy, with the tube tip positioned 22 cm from the incisors. Bilateral lung auscultation revealed symmetrical breath sounds. Volume-controlled ventilation was initiated, with an airway pressure of 15cmH₂O and an ETCO₂ of 36mmHg. Radial artery cannulation was performed for invasive blood pressure monitoring, and deep venous cannulation was performed on the right internal jugular vein.

The patient was placed in the reverse Trendelenburg position with the legs apart. Surgery commenced with establishing pneumoperitoneum, with an intraabdominal pressure set at 15mmHg and a flow rate of 8 L/min. Approximately 5 minutes after the start of surgery, the SpO₂ gradually decreased from 100% to 95%. No significant abnormalities were observed in blood pressure, heart rate, airway pressure, or ETCO₂. After excluding anesthesia machine and gas supply malfunctions, endotracheal tube kinking, and other factors, the ventilation was switched to pure oxygen ventilation. After increasing positive end-expiratory pressure, the SpO₂ returned to 100%. Arterial blood gas analysis showed a pH of 7.397, a partial pressure of oxygen (PaO₂) of 225.5mmHg, a partial pressure of carbon dioxide (PaCO₂) of 38.6mmHg, and a base excess (BE) of 1.81. Following consultation with the surgical team, the pneumoperitoneum pressure was reduced to 13mmHg.

Around 50 minutes after the start of surgery, the SpO₂ began to decrease slowly again. The monitoring equipment and anesthesia machine were found to be functioning properly, and the depth of the endotracheal tube remained unchanged. At this time, the blood pressure was 85/51mmHg, heart rate was 117 beats per minute, SpO₂ was 82%, ETCO₂ was 47mmHg, and airway pressure increased to 25cmH₂O. Auscultation revealed significantly diminished breath sounds in both lungs, and a grinding murmur was heard in the precordial area. There was palpable crepitus in the anterior chest. The surgical team reported that they were dissecting the hepatic vein, and there was a breach in the hepatic vein. Arterial blood gas analysis showed a pH of 7.115, a PaO₂ of 81.7mmHg, a PaCO₂ of 68.5mmHg, and a BE of -1.9. A high suspicion of CO₂ embolism was raised, and foamy blood was aspirated from the right internal jugular vein central line (Fig-2).

Fig-2: Foamy Blood were drawn out the Right Internal Jugular Vein Central Line

The surgery was immediately paused, and pneumoperitoneum was discontinued. The patient’s position was changed to a head-down left lateral position, and pure oxygen ventilation was initiated. Positive end-expiratory pressure (PEEP) of 5cmH₂O was applied, the fluid infusion rate was increased, and hydroxylamine was administered intravenously to increase blood pressure. The blood pressure increased to 102/61mmHg, SpO₂ returned to 100%, ETCO₂ increased to 47mmHg, and breath sounds were significantly amplified upon lung auscultation. Hemodynamic monitoring using pulse index continuous cardiac output (PICCO) was initiated. After the patient’s circulation stabilized, the surgery was resumed through an open approach. The procedure was completed successfully with an estimated blood loss of approximately 600ml (Fig-3).

Fig-3: Large Lesion Removed from the Right Lobe

Postoperative arterial blood gas analysis showed a pH of 7.321, a PaO₂ of 192.4mmHg, a PaCO₂ of 41.6mmHg, and a BE of -1 (Table-1). The oral secretions were thoroughly cleared, and the endotracheal tube was removed after the patient regained normal spontaneous breathing and consciousness. The patient was then transferred to the post-anesthesia care unit (PACU). On the third day after the surgery, the patient’s vital signs were stable, and the patient was in good spirits. Lung auscultation revealed clear breath sounds without any adventitious sounds.

Table-1: The Arterial Blood Gas Analysis During Operation

Discussion

Laparoscopy is widely used in surgical procedures due to its advantages of minimal invasiveness and rapid recovery. To facilitate the operation, ensure clear visualization, and avoid damage to abdominal organs, pneumoperitoneum is created by insufflating gas into the abdominal cavity. Carbon dioxide, which is colorless, odorless, non-flammable, and highly soluble in blood, is commonly used for establishing artificial pneumoperitoneum [4]. However, CO₂ embolism is a rare complication specific to laparoscopy. The severity of gas embolism depends on the type and volume of gas as well as the rate of gas entry into the vasculature [5,6]. In most cases, CO₂ embolism does not present with clinical symptoms due to the high solubility of CO₂. However, symptomatic CO₂ embolism is uncommon, and if not promptly diagnosed and managed correctly, it can lead to serious consequences [7].

Under conditions of high intraabdominal pressure, CO₂ can enter ruptured blood vessels and subsequently obstruct the right atrium, resulting in decreased cardiac output and systemic hypotension. Some gas emboli may also enter the pulmonary circulation, causing pulmonary hypertension and pulmonary edema [8,9]. During general anesthesia, CO₂ embolism is characterized by hypotension, tachycardia, hypoxemia, hypercapnia, increased airway pressure, and elevated central venous pressure, which can lead to arrhythmias or even cardiac arrest [10]. ETCO₂ abruptly decreases in most cases. The hepatic veins, including the left and right hepatic veins and their tributaries, are prone to air embolism due to their large lumens, thin walls, numerous branches, susceptibility to tearing, and lack of valvular blood reflux. Laparoscopic liver resection, which requires low central venous pressure and high pneumoperitoneum pressure, increases the risk of gas embolism.

Prompt and accurate identification of the aforementioned clinical symptoms is crucial. Studies have indicated that the lethal dose of air entering the bloodstream in adult’s ranges from 3 to 5 ml/kg [7]. ETCO₂ is a convenient, non-invasive, and sensitive indicator of gas embolism, capable of detecting as little as 0.5 milliliters per kilogram of gas entering the circulation [11]. A sudden decrease in ETCO₂ may serve as an important early sign of carbon dioxide embolism, with studies showing it to have a sensitivity of up to 87% [12]. ETCO₂ measures the partial pressure or concentration of carbon dioxide in the mixed alveolar gas exhaled at the end of expiration, which is commonly used to assess a patient’s ventilation, circulatory function, and pulmonary blood flow. When gas enters the venous system and accumulates in the pulmonary artery, it causes a decrease in the ventilation-perfusion ratio, increases physiological dead space, and dilutes the concentration of exhaled carbon dioxide at the end of expiration. Hence, a sudden decrease in PETCO₂ is observed [13]. However, in some cases of carbon dioxide embolism, a short rise in ETCO₂ may result from the absorption of a large amount of carbon dioxide in the bloodstream, leading to higher PaCO₂ levels [14,15]. Therefore, further analysis should be combined with arterial blood gas measurements.

TEE is the most sensitive method for monitoring CO₂ embolism, capable of detecting air volumes as small as 0.02 ml/kg [16]. TEE can detect the occurrence of gas embolism earlier than clinical changes and provides real-time monitoring of gas embolism. In a study of laparoscopic cholecystectomy, CO₂ embolism was detected via TEE in 69% of patients [17]. Secretain et al. developed a software algorithm using transesophageal echocardiography to identify and measure potential emboli during cardiac surgery [18]. When symptomatic CO₂ embolism occurs, prompt management is crucial. First, pneumoperitoneum should be immediately discontinued, and the patient’s position should be changed to a head-down left lateral position to prevent air emboli from entering the pulmonary arteries and the head. Concurrently, pure oxygen ventilation should be initiated to eliminate CO₂ and improve hypoxemia. Increasing positive end-expiratory pressure ventilation, rapidly infusing fluids to raise central venous pressure, using vasopressor medications to maintain hemodynamic stability, and actively performing chest compressions in cases of cardiac arrest can effectively break down large gas emboli into smaller ones. Some patients may have gas extracted from central venous catheters, and a grinding murmur may be auscultated in the precordial area [15].

In this case, a young male patient with a history of liver hydatid cyst excision was scheduled to undergo laparoscopic right hemihepatectomy. Although there was no sudden decrease in ETCO₂, the surgical team observed a breach in the hepatic vein based on clinical presentation and blood gas analysis. Additionally, foamy blood was aspirated from the central venous catheter. Therefore, CO₂ embolism was suspected, and prompt management led to a good prognosis for the patient. However, due to the urgent situation, TEE examination was not performed.

In conclusion, although symptomatic CO₂ embolism during laparoscopy is rare, its potential harm should not be overlooked. Studies have indicated that risk factors for CO₂ embolism include high pneumoperitoneum pressure, previous abdominal or pelvic surgery, and intraoperative venous injury. It is important not to rely solely on a decrease in ETCO₂ for diagnosis but to consider other clinical manifestations. TEE can be performed in critically ill or high-risk patients. Furthermore, in a randomized trial involving 498 patients undergoing laparoscopic surgery, the incidence of CO₂ embolism was significantly higher in the high pneumoperitoneum pressure group (15 mmHg CO₂) compared to the low-insufflation group (12 mmHg CO₂) [19,20]. Therefore, appropriate pneumoperitoneum pressure is an important measure for preventing CO₂ embolism. Early identification, diagnosis, intervention, and effective prevention are essential when CO₂ embolism occurs.

Conclusion

Laparoscopic surgery is becoming increasingly widespread, and the complication of CO₂ embolism cannot be ignored. When significant clinical symptoms occur, prompt identification and appropriate management are crucial. Surgeons and anesthesiologists should actively communicate throughout the surgical procedure, setting appropriate pneumoperitoneum pressure. Anesthesiologists should closely monitor the patient’s hemodynamic changes to detect any early signs of CO₂ embolism.

In situations where feasible, routine transesophageal echocardiography (TEE) monitoring can be performed in critically ill patients or those with large intra-abdominal masses. TEE provides real-time monitoring and can help in the early detection of gas embolism, contributing to better patient outcomes.

By adhering to these practices and remaining vigilant during laparoscopic procedures, healthcare professionals can reduce the risk of CO₂ embolism and ensure the safety and well-being of patients undergoing such surgeries.