A Study Of Perioperative Ventilation And Postoperative Oxygenation Management In Liver Cancer Patients With Hepatopulmonary Syndrome Undergoing Liver Cancer Resection

In recent years,the perioperative management of hepatopulmonary syndrome（HPS）attracted more and more attention of the anesthesiology and liver disease experts at home and abroad;However,the number of reports on perioperative management of HPS patients so far is limited,so it is urgent to go further in this field.China is a country known for large numbers of liver disease patients,and many surgical patients with HPS.At the same time,HPS in China mainly comes from post-hepatitis cirrhosis,which is significantly different from alcoholic cirrhosis in Europe and America.Therefore,the study on perioperative management of HPS in China helps to improve the perioperative management level of such patients and reduce the incidence rate of postoperative complications,which is of great clinical significance.During a surgery,mechanical ventilation is an important link to maintain oxygen supply for HPS patients under anesthesia,among which pressure controlled ventilation（PCV）and volume controlled ventilation（VCV）are the two main ventilation modes nowadays.It is generally considered that Positive end-expiratory pressure（PEEP）is often used in the surgery operation to maintain the state of alveolar expansion and increase the pressure in the alveoli,thus effectively preventing alveolar collapse and ultimately improving PaO2.But does PEEP also help to improve oxygenation in HPS patients,and what is the optimal PEEP range?These questions remain unclear.The liver cancer patients with ASAⅡorⅢscore for Hepatectomy patients,when they are fully awake,have recovered respiratory function after surgery,and under the condition of adequate sputum excretion,they usually aren’t given oxygen back to the ward,or just given a short period of time（2-8）h oxygen.Some hospitals even don’t have clear regulations for the oxygen duration of this kind of surgery patients.This has no significant effect on patients without concurrent HPS,while for patients with concurrent HPS,"intermittent potential hypoxemia"may occur,leading to a sharply increased risk of postoperative pulmonary complications.48 hours after surgery is the golden time for the recovery of patients and the prevention of complications,and prolonged postoperative oxygen intake may be beneficial to postoperative recovery of HPS patients,mainly used to prevent"intermittent potential hypoxemia".The key to ensure perioperative oxygen supply for HPS patients is to adopt proper perioperative management measures to avoid aggravation of ventilation/blood flow ratio imbalance and promote oxygen molecular dispersion.Therefore,this study is on the ventilation mode and postoperative oxygenation management in hepatocellular carcinoma resection in patients with hepatopulmonary syndrome,to provide new research evidence for the perioperative management strategy of HPS.Part one:The study on the ventilation mode during hepatocellular carcinoma resection in HPS patientsObjective:To study and compare the ventilation effect of PCV,VCV and PEEP during hepatocellular carcinoma resection in HPS patients.Methods:123 elective hepatocellular carcinoma patients in the First Affiliated Hospital of the Third Military Medical University from 2015 to 2016,in accordance with the random number table,were divided into four groups:31 cases in ventilating group with simple PCV;30 cases in Group PCV+PEEP（3-5mmhg）;PCV+PEEP（7-9 MMHG）group included 30 cases.At different time points:before the house（T1）,5 min after intubation induction（T2）,1 h（T3）after surgical operation began,2 h（T4）after surgical operation began,10 min before the end of surgery（T5）,record respectively the PaO2,Ppeak,Pplat,Pmean,Raw,MVi,Mve and PETCO2 for continuous monitoring,do a blood gas analysis once every half an hour in order to konw the patient’s pH,PaO2,etc;Result:There was no significant difference between VCV and PCV in T1 and T2 time points（P>.05）.In terms of PaO2,PCV was significantly higher than that of VCV group at T3\4\5（P<0.05）.In lactic acid value,PCV was significantly lower than that of VCV group at T3\4\5（P<0.05）.It indicates that the ventilation mode of PCV is better than VCV in perioperative management of HPS.Compared with Simple PCV or PCV+PEEP（7-9mmHg）,the PCV+PEEP（3-5 mmHg）group had the highest PaO₂ and the lowest lactic acid content in the blood.The results showed that PCV+PEEP（3-5 mmHg）had the best effect on improving perioperative oxygen supply in HPS patients.Conclusion:For the HPS patient,the mode of PCV with PEEP（3-5mmHg）is helpful to maintain intraoperative oxygen supply in the perioperative,It is especially suitable for HPS patients with old age,severe disease and low partial arterial oxygen pressure.Part two:A Study on prolonging low-flow oxygen after liver cancer resection in patients with hepatopulmonary syndromeObjective: To evaluate the effects of prolonged oxygen inhalation time on systemic inflammatory response,intrapulmonary shunt and prognosis after hepatectomy under general anesthesia in hepatopulmonary syndrome patients.Methods: Seventy-two hepatopulmonary syndrome patients with ASA Ⅱ-Ⅲ scheduled for liver cancer resection under general anesthesia were randomized into two groups: the control group（n=36）inhaled low flow oxygen（2-3L/min）8h after operation;the research group（n=36）inhaled low flow oxygen（2-3L/min）48h after operation.Arterial blood and mixture venous blood gases were analyzed during preoperative（T1）,after operation（T2）,8h after operation（T3）,24 h after operation（T4）,48 h after operation（T5）,72 h after operation（T6）in all patients,respectively.Partial pressure of oxygen（Pa O2）,and alveolar arterial difference of oxygen（A-a DO2）were recorded at each time point were recorded at each time point.Peripheral blood white blood cell count,neutrophil percentage,CRP,TNF-α,LPS in peripheral blood and exhaled NO were measured.The incidence of postoperative pulmonary complications and hospitalization time were recorded.Results: Compared with control group,Pa O2 of research group at T4 and T5 increased markedly,and A-a DO2 were lower（P<0.05）;lower plasma levels of LPS、TNF-α and exhaled NO were observed in research group than those in control group at T4 and T5（P<0.05）;Compared with T1 timepoint,Pa O2 of research group at T4 and T5 were significantly increased,but A-a DO2,LPS,TNF-α and exhaled NO were significantly decreased（P<0.05）;on the contrary,Pa O2 of research group at T4 and T5 were significantly decreased,but A-a DO2,LPS,TNF-α and exhaled NO were significantly increased（P<0.05）.Prolonged oxygen inhalation time alleviated systemic inflammatory response,reduced the intrapulmonary shunt and the incidence of postoperative pulmonary complications and hospitalization time（P<0.05）.Conclusion: Compared with conventional oxygen inhalation（8h）,48 h after operation continuous low flow oxygen inhalation can effectively promote the recovery of gastrointestinal function,reduce the incidence of complications in HPS patients,which will be beneficial to patients recovery.