The current study shows that preoperative carbohydrate given 4 h prior to anesthesia could improve well-being feelings of cirrhotic patients without increasing gastro-oesphageal reflux and aspiration pneumonia risk, suggesting the safety and promising role of POC applied in cirrhotic patients. This study also suggests that the intake of POC had beneficial effects on hemodynamic stability. Other aspects studied showed no significant differences regardless of gastric peristalsis and postoperative complication.
Preoperative fasting strategies have undergone various modifications over the past few decades. Guidelines for sedation and anesthesia in gastrointestinal endoscopy indicate that patients without a propensity for delayed gastric emptying should fast a minimum of 2 hours after ingestion of clear liquids and 6 hours after ingestion of light meals before anesthesia (9). However, patients with liver cirrhosis often show gastric dysmotility associated with prolonged gastric emptying and decreased gastric wall compliance. Previous studies suggest that parasympathetic hypofunction, sympatheic hyperfunction, portal blood flow and gastrointestinal hormones are closely related with gastric motility in cirrhotic patients (23). Delayed gastric emptying also appears to cause disturbance in postprandial glucose, insulin and ghrelin levels, and further results in low energy intake contributing to malnutrition and increased morbidity (24, 25). Up to now, there is no data to support a direct relationship between duration of fasting and the risk of pulmonary aspiration in cirrhotic patients. And there is also no practice standard for pre-procedural fasting that has been universally accepted for cirrhotic patients. Initial promising reports using preoperative carbohydrate intake have been published to reduce perioperative discomfort, but it has not been a well-defined approach in cirrhotic patients. The best timing for the use of preoperative carbohydrate in this population has been a topic of discussion that has recently been revitalized with the availability of carbohydrate beverages. Thus, understanding the evidence-based preoperative carbohydrate recommendations that might impact on well-being feelings and clinical outcomes of cirrhotic patient is utmost importance.
For the first time, we conducted randomized controlled trial to recommend the timing for oral intake before anesthesia in cirrhotic patients. This study was designed to test whether preoperative carbohydrate application, when performed 2 h or 4 h before endoscopic therapy, could improve the well-being feelings of patients without increasing risk of reflux and aspiration. In situations where gastric emptying is impaired such as in cirrhotic patients, the potential for pulmonary aspiration of gastric contents must be considered in determining a specific time period of fasting before anesthesia (10). Therefore, in this study, to confirm the safety of preoperative carbohydrate in cirrhotic patients, endoscopic examiner would perform gastroscopy to suck stomach content before anesthesia. We then measured and analysed, as primary outcome parameter, the volume of gastric content, which is an important factor in estimating the severity of aspiration and regurgitation. Interestingly, we found no patient had residual fluid more than 1.5 ml/kg in control and 4 h group. It is, however, definitely worth pointing out that six patients (11%) reached a residual volume of more than 1.5 ml/kg in 2 h group, indicating at high risk of regurgitation. Based on these findings, we suggest that preoperative carbohydrate administered 4 h rather than 2 h prior to anesthesia may be safely applied for cirrhotic patients. Our study adds knowledge for preoperative fasting guidelines in anesthesia for cirrhotic patients.
Malnutrition is common in cirrhotic patients with a reported prevalence as high as 80%. Low energy intake and poor nutritional status have been reported to facilitate the development of hepatic encephalopathy, which is associated with a poor prognosis in cirrhotic patients (26). Hypermetabolism is a characteristic of patients with liver cirrhosis who should ensure energy intake is adequate. (27). Thus, avoiding long-term fasting is fundamental for appropriate management in these patients (28, 29). However, for examination and treatment of complications including gastric esophageal varices among cirrhotic patients, endoscopy intervention is commonly used that requires preoperative fasting. Determining a specific time period of fasting before anesthesia is thereby considered to be of central importance in perioperative management of patients with liver cirrhosis. Based on our findings, we recommend that preoperative fasting time for cirrhotic patients could reduce to 4 h instead of standard 8 h. The concept that reducing fasting time to 4 h may have long-term beneficial effect on cirrhotic patients is an interesting one and should prompt further research.
On the other hand, previous study has demonstrated that 200 kcal supplement could reduce both self-assessment of physical and mental stresses that exist for examination associated fasting in cirrhotic patients requiring contrast-enhanced CT or contrast-enhanced MRI (26). In this study, we further examine the effect of preoperative carbohydrate supplement on stresses caused by endoscopy examination associated fasting in cirrhotic patients. Our second significant finding was that lower preoperative VAS scores for thirst, hunger, mouth dryness, nausea, vomit and fatigue were reported in the carbohydrated group than in control group, which suggests that preoperative carbohydrate loading is better accepted. This is in accordance with previous reports that found patients had effectively reduced thirst, hunger, nausea and vomiting, as main components in preoperative discomfort, when taking carbohydrate before surgery (30, 31).
To date, esophageal and gastric variceal bleedings have been considered the major cause of upper gastrointestinal hemorrhage in cirrhotic patients, with a high risk of mortality and poor prognosis. It is therefore essential that patients who are with liver cirrhosis should not only receive intervetion to survive from acute variceal hemorrhage, but also undergo secondary prophylaxis (32). The advancements in multidisciplinary approaches that include pharmacological therapy, endoscopic intervention, transjugular intrahepatic portosystemic shunt and surgery have improved outcomes of cirrhotic patients. Endoscopic intervention has great clinical value in achieving hemostasis and preventing first as well as recurrent bleeding from esophageal and isolated gastric varices for cirrhotic patients (33–35). Although endoscopy intervention is at rapid development, the choice of sedation and anesthesia selected for cirrhotic patients continues to be a controversial issue. In our study, we used propofol in combination with opioids to keep patients in moderate or deep sedation during endoscopic operation. Among 117 patients, no gastro-oesphageal reflux and aspiration pneumonia was caused, indicating propofol-based sedation with appropriate monitoring seems to be a safe procedure during endoscopy therapy in cirrhotic patients. This is in accordance with previous reports that found during colonoscopy and ERCP, the use of propofol for sedation was safe in patients with liver cirrhosis (36).
There are some limitations in this study. Firstly, the effect of preoperative carbohydrate on long term is unclear in patients with liver cirrhosis. Large multicenter RCTs will be needed to further strengthen whether propofol-based sedation is the best choice for this subgroup of patients.