Effect Of Hyper HAES Pretreatment Before Induction Of Elderly Patients Undergoing Colorectal Cancer Surgery

Objective: To observe the effect on hemodynamic stability of HyperHAES pretreatment ahead of anesthesia induction of elderly patientsundergoing colorectal cancer surgery.Background: Till the end of2007population aged over60of China hasreached153million, making up11.6%of the total population. It isexpected that China’s elderly population will reach248million by theyear2020. With the aging of the population, the medical staff will facea growing number of elderly patients. Most malignant tumors areprevalence in elderly people. Surgery is still a major clinical treatmentfor these diseases. The physiology is gradually changing with age andcan not be avoided. With aging, multiple systematic and organ functionswill be diminished. Elderly circulatory changes include the decline incardiac reserve and decreased vessel elasticity that make it susceptibleto generate more severe hemodynamic fluctuations under anesthesiaespecially during the intravenous induction of anesthesia. Thehemodynamic instability will affect the important organ perfusion evenhave some impact on the prognosis. So how to maintain the elderlypatients’ hemodynamic stability during induction to reduce relevantreverse effect should be focused on by the anesthesiologists. Elderly patients with decreased venous elasticity and compliance aresusceptible to hypotension induced by intravenous general anesthesia.There are many types of plasma substitutes including dextran,hydroxyethyl starches, glutins and so on. Hyper HAES is a kind ofhypertonic hydroxyethyl starch, mainly used for small volumeresuscitation (SVR). As a hypertonic solution, Hyper HAES (7.2%sodiumchloride hydroxyethyl starch200/0.5) will expand the intravascularvolume in a short period of time with relatively smaller dosage whileavoiding an increasing cardiac preload. This article will observe thetherapeutic effect and safety of this drug.Materials and Methods:60patients scheduled for elective colorectalcancer surgery patients, aged from60years old to80years old with anAmerican Society of Anesthesiologists (ASA) classification level II toIII were chosen. All patients were without significant cardiopulmonary,liver and kidney dysfunction. These patients were randomly assigned intotwo groups. Patients in group A were administrated with Hyper HAESsolution with a dose of4ml/kg20minutes before induction of anesthesia；Patients in group B took the same dose of saline as control group.Patients took midazolam0.05mg/kg, fentanyl0.003mg/kg, etomidate0.3mg/kg and cisatracurium0.15mg/kg during procedure induction and intubation. Surgery was performed under intravenous generalanesthesia. Remifentanil and propofol was continuously infused by targetcontrolled infusion for maintenance of anesthesia. Fentanyl andcisatracurium was administrated as needed.Results: there was no significant difference of the patients’general conditions of the two groups (P>0.05). The baseline ofhemodynamic parameters between group A and group B had no significantdifference (P>0.05). Heart rates in the experimental group were lowerthan that of the control group10minutes after administration. Centralvenous in group A were higher than that of group B5minutes afteradministration. During the period of induction mean arterial bloodpressure of experimental group were higher than the control group; Strokevolume variation10minutes after administration of the experimentalgroup was observed lower than that of the control group. Thesehemodynamic parameters compared between the two groups existedstatistical difference (P <0.05). Other signs including partialthromboplastin time, prothrombin time sodium, potassium, creatinine,urea nitrogen levels compared in the experiment showed no statisticaldifferences between the two groups (P>0.05). Vasopressor needed wasless in group A than the control group (P <0.05). Conclusion: Hyper HAES pretreatment would improve the circulativevolume reducing the incidence of hypotension in elderly patients withsmall single doses without obvious impact on the on the level of sodium,potassium, renal function and blood clotting function. This drug iseffective and safe as we observe in this experiment.