Impact On The Cycle In The Sustained Release Tables Of Metoprolol In Hypertensive Patients During The Induction Of Anesthesia

Objective:During the induction of general anesthesia,the anesthesia drugswill inhibit sympathetic and lead to decrease the blood pressure and heartrate;placing a laryngoscope to stir up the epiglottis,tracheal intubation or cuffinflated will stimulate the sympathetic and lead to the high blood pressure,rapidheart rate.Making the patient’s hemodynamic changes in a short period,suchchanges are mostly transient,it’s the generally tolerable for normal,but for thepatients with hypertension may be a serious cirulation complications. Appro-priate pre-anesthetic medication has the great significance for hemody-namicstability. Sustained release tables of metoprolol is slow-release, long-acting β1receptor blocker for the treatment of a variety of cardiovascular diseases.Thisstudy aimed to observe the impact of blood pressure and heart rate in thepre-anesthetic using of sustained release tables of metoprolol in hypertensivepatients,provide the basis for the hypertensive patients premedication.Test methods: Choose who underwent surgery （including liver, gallb-ladder,esophagus,stomach,intestines,lungs,total hip and other parts of thesurgery） and had been taking the sustained release tablets of metoprololsuccinate（producted by AstraZeneca AB,trade name as metoprolpl,J20050061）for the treatment,47.5⁹5mg qd for more than4weeks in40patients withhypertension,23males and17females,aged45⁸2years, weight49⁸2kg,ASA â… ^â…¡, with no cardiovascular system,respiratory system,central nervoussystem and endocrine system diseases.The patients are divided into2groupsrandomly,each group has20patients.Control group:stop taking metoprolol inthe morning of the surgery.Test group:go on taking metoprolol in the morningof the surgery.The age,sex ratio,body weight between the two groups had no significant difference（P＞0.05）.After the patient enter the operating room,piercing the left radial artery to monitor blood pressure, routine monitoringECG, Pulse oximetry and end-tidal carbon dioxide,opening the venousaccess,giving penehyclidine1mg to intravenous drip slowly before20min ofanesthesia. Before induce,give the sodium lactate ringer10¹2ml/kg tointravenous drip.Induction of anesthesia:midazolam2mg,vecuronium0.1mg/kg,propofol1-2mg/kg,sufentanil0.3μg/kg.When the patient losses of sanity,fastenthe mask positive pressure ventilation to oxygen3minutes,then trachealintubation,mechanical ventilation in conjunction with the anesthesiamachine, set the tidal volume （VT）8-10ml/kg, respiratory rate（RR）12-15/min,inspiratory to expiratory ratio（I/E）1:2.Two groups of patients were recordedbefore induction of T₀, after induction of T1,after intubation of T2,afterintubation3minutes of T3the heart rate （HR）, systolic blood pressure （SBP）,diastolic blood pressure （DBP）.Use atropine when bradycardia and ephedrinewhen hypotension. All the data presented as mean±standard deviation（±s）,useSPSS17statistical software for statistical treatment,in the group were comparedusing t test and the two groups were compared using single factor analysis ofvariance.P＜0.05means significant difference.Blood pressure and heart rate to determine:（1）Low blood pressure: bloodpressure is25ï¼…lower than T₀or SBP＜90mmHg;（2）High blood pressure:blood pressure is increased＞30mmHg than T₀;（3）tachycardia: heart rate＞100/min;（4）bradycardia:heart rate＜50/min.Results:The blood pressure:two groups of patients’SBP and DBP weresignificantly decreased at T1, SBP and DBP were significantly increased at T2than T1.In the test group SBP and DBP has no significant change between T2and T₀with no significant difference（P＞0.05）.In the control group SBP andDBP is significantly higher at T2than T₀with significant differences（P＜ 0.05）.Compared with the test group,SBP and DBP of the control group felleven more sharply at T₁with significant differences（P＜0.05）;SBP and DBP ofthe control group increased more than the test group at T2with significantdifferences（P＜0.05）.There has17cases of hypotension in the control group atT₁and6cases of hypotension in the test group at T₁,it has significantdifferences（P＜0.05）.The heart rate:HR of the two groups of patients wassignificantly slowed down at T₁and significantly faster at T2than T₁withsignificant differences（P＜0.05）. And HR was significantly faster at T2than T₀with significant differences （P＜0.05）.The rate of decline at T₁and the rate ofincrease at T2has no significant differences（P＞0.05） between the two groupsof patients. There has2cases of bradycardia in the control group at T₁and1case of bradycardia in the test group at T₁with no significant difference （P＞0.05）.Conclusion:The blood pressure of test group decreased after induction andrised after intubation in a relatively small amplitude,and there is a relativelylow incidence of hypotension after the induction,the heart rate compared withthe control group showed no significant difference,by the application ofephedrine and atropine,all of hypotension and bradycardia patients’ bloodpressure and heart rate returned to normal. So the hypertensive patients whohave been taking the sustained release tablets of metoprolol before surgeryshould continue taking metoprolol tablets in the morning of the surgery, makehemodynamics more stable during induction of anesthesia and reduce theincidence of anesthetic accidents.