Perioperative Hemodynamic Stability Research Articles

Effect of intravenous infusion of dexmedetomidine on perioperative haemodynamic changes and postoperative recovery: A study with entropy analysis

Background:Dexmedetomidine, an α2 agonist, when used as an adjuvant in general anaesthesia attenuates stress response to various noxious stimuli, maintains perioperative haemodynamic stability and provides sedation without significant respiratory depression postoperatively.Methods:Sixty patients were randomly divided into two groups of 30 each. In group A, fentanyl 2 μg/kg and in group B dexmedetomidine were given intravenously as loading dose of 1 μg/kg over 10 min prior to induction. After induction with thiopentone, in group B, dexmedetomidine was given as infusion at a dose of 0.2–0.8 μg/kg. Sevoflurane was used as inhalation agent in both groups. Haemodynamic variables and entropy (response entropy and state entropy) were recorded continuously. Postoperative sedation and recovery were assessed by sedation score and modified Aldrete's score, respectively.Results:Dexmedetomidine significantly attenuates stress response at intubation with lesser increase in heart rate (10% vs. 17%), systolic blood pressure (6% vs. 23%) and diastolic blood pressure (7% vs. 20%) as compared to the control group (P<0.05). Intraoperatively, an average of 8% fall in systolic blood pressure and 8.16% fall in diastolic pressure in the test group as compared to 3.6% rise in systolic and 3.3% in diastolic pressure of the control group was observed. Postoperatively, the test group showed significant sedation at 2 h as compared to the control group (P=0.00) and recovery was better in the control group for the first 2 h post extubation.Conclusion:Dexmedetomidine attenuates various stress responses during surgery and maintains the haemodynamic stability when used as an adjuvant in general anaesthesia. Also, the sedative action of dexmedetomidine delays recovery for the first few hours post extubation.

A randomized double-blind placebo-controlled clinical study on the effects of gabapentin premedication on hemodynamic stability during laparoscopic cholecystectomy

Background:Carbon dioxide pneumoperitoneum for laparoscopic surgery increases arterial pressures, heart rate, and systemic vascular resistance. In this randomized double-blind placebo-controlled clinical study, we investigated the efficacy of gabapentin premedication to provide perioperative hemodynamic stability in patients undergoing laparoscopic cholecystectomy.Materials and Methods:Sixty patients, of either sex (18–65 years of age) undergoing elective laparoscopic cholecystectomy were randomly allocated to two groups of 30 patients each. Patients of group G received oral gabapentin 900 mg 2 h before induction of anesthesia, while patients in group P received placebo at the same time.Results:Mean arterial pressure in patients of group G were significantly lower (P < 0.05) after tracheal intubation and pneumoperitoneum and remained lower, as compared to group P, throughout the pneumoperitoneum. Similarly, heart rate in group G was significantly lower (P < 0.05) after tracheal intubation and pneumoperitoneum and remained lower, in comparison to group P, throughout the peumoperitoneum. Intravenous labetalol was required, to control intraoperative hypertension, in 33.3% (10 out of 30) patients in group P. There was no significant difference in the incidence of adverse effects between the two groups.Conclusion:Gabapentin premedication provided perioperative hemodynamic stability during laparoscopic surgery.

A Randomised Study of Perioperative Esmolol Infusion for Haemodynamic Stability during Major Vascular Surgery; Rationale and Design of DECREASE-XIII

Objectives This article describes the rationale and design of the DECREASE-XIII trial, which aims to evaluate the potential of esmolol infusion, an ultra-short-acting beta-blocker, during surgery as an add-on to chronic low-dose beta-blocker therapy to maintain perioperative haemodynamic stability during major vascular surgery. Design A double-blind, placebo-controlled, randomised trial. Materials & methods A total of 260 vascular surgery patients will be randomised to esmolol or placebo as an add-on to standard medical care, including chronic low-dose beta-blockers. Esmolol is titrated to maintain a heart rate within a target window of 60–80 beats per minute for 24 h from the induction of anaesthesia. Heart rate and ischaemia are assessed by continuous 12-lead electrocardiographic monitoring for 72 h, starting 1 day prior to surgery. The primary outcome measure is duration of heart rate outside the target window during infusion of the study drug. Secondary outcome measures will be the efficacy parameters of occurrence of cardiac ischaemia, troponin T release, myocardial infarction and cardiac death within 30 days after surgery and safety parameters such as the occurrence of stroke and hypotension. Conclusions This study will provide data on the efficacy of esmolol titration in chronic beta-blocker users for tight heart-rate control and reduction of ischaemia in patients undergoing vascular surgery as well as data on safety parameters.

Renal effects of dexmedetomidine during coronary artery bypass surgery: a randomized placebo-controlled study

BackgroundDexmedetomidine, an alpha2-adrenoceptor agonist, has been evaluated as an adjunct to anesthesia and for the delivery of sedation and perioperative hemodynamic stability. It provokes dose-dependent and centrally-mediated sympatholysis. Coronary artery bypass grafting (CABG) with extracorporeal circulation is a stressful procedure increasing sympathetic nervous system activity which could attenuate renal function due the interrelation of sympathetic nervous system, hemodynamics and renal function. We tested the hypothesis that dexmetomidine would improve kidney function in patients undergoing elective CABG during the first two postoperative days.MethodsThis was a double-blind, randomized, parallel-group study. Patients with normal renal function and scheduled for elective CABG were randomized to placebo or to infusion of dexmedetomidine to achieve a pseudo steady-state plasma concentration of 0.60 ng/ml. The infusion was started after anesthesia induction and continued until 4 h after surgery. The primary endpoint was creatinine clearance. Other variables included urinary creatinine and output, fractional sodium and potassium excretion, urinary potassium, sodium and glucose, serum and urinary osmolality and plasma catecholamine concentrations. The data were analyzed with repeated-measures ANOVA or Cochran-Mantel-Haenszel test.ResultsSixty-six of 87 randomized patients were evaluable for analysis. No significant between-group differences were recorded for any indices of renal function except for a mean 74% increase in urinary output with dexmedetomidine in the first 4 h after insertion of a urinary catheter (p < 0.001). Confidence interval examination revealed that the sample size was large enough for the no-difference statement for creatinine clearance.ConclusionsUse of intravenous dexmedetomidine did not alter renal function in this cohort of relatively low-risk elective CABG patients but was associated with an increase in urinary output.This study was carried out in 1994-1997 and was thus not registered.

Perioperative management of combined heart-liver transplantation in patients with cirrhosis, renal insufficiency, or pulmonary hypertension

STATING THE MAIN PROBLEM: Only few reports have detailed perioperative management and outcome of combined heart and liver transplantation (CHLT), and none describe the long-term renal function. Three patients presented clinical signs of cardiomyopathy with reduced ejection fraction and proven cirrhosis with evidence of portal hypertension. Two of them presented renal failure, and the other pulmonary hypertension. After cardiac transplantation and closure of the sternum, liver transplantation was performed using systematically venovenous double-limb (portal and caval) bypass. Mean cold ischemic time for heart and liver was 2 h 46 min and 12 h 47 min, respectively. Intraoperative hemodynamics remained grossly stable during surgery. Mean transfusions were 12 red blood cell packs. All three patients received anti-R-Il2 antibodies at post-operative day 1 and 4. Mean plasma creatinine concentration was 90 ± 8 μmol/L one yr post-CHLT, vs 160 ± 62 μmol/L pre-CHLT. All three patients are alive with functional grafts after a mean follow-up of 26 months (12-38). CHLT could be performed safely through two consecutive and independent usual procedures. Perioperative hemodynamic stability, minimal blood loss, and routine splanchnic decompression are probably major determinants of a favorable outcome and good long-term renal function.

Effect of oral clonidine premedication on perioperative haemodynamic response and post-operative analgesic requirement for patients undergoing laparoscopic cholecystectomy

Clonidine has anti-hypertensive properties and augments the effects of anaesthesia, hence we considered it to be an ideal agent to contain the stress response to pneumoperitoneum. We studied the clinical efficacy of oral clonidine premedication in patients undergoing laparoscopic cholecystectomies. Fifty patients scheduled for elective laparoscopic cholecystectomy under general anaesthesia were randomly allocated to receive premedication with either oral clonidine 150 μg (Group I, n = 25) or placebo (Group II, n = 25) 90 minutes prior to induction. The patients were managed with a standard general anaesthetic. The two groups were compared with respect to haemodynamic parameters, isoflurane concentration, pain and sedation scores, time to request of analgesic and cumulative analgesic requirements. Oral clonidine was found to be significantly better in terms of maintaining stable haemodynamics, having an isoflurane sparing effect and having a prolonged time interval to the first request of analgesia postoperatively compared to the control group. Administration of oral clonidine 150 μg as a pre-medicant in patients undergoing laparoscopic cholecystectomy results in improved perioperative haemodynamic stability and a reduction in the intra-operative anaesthetic and post-operative analgesic requirements.

General anesthesia in a patient with idiopathic orthostatic hypotension

Idiopathic orthostatic hypotension (formerly known as Shy-Drager syndrome) is a multiple system atrophy, which is characterized by autonomic dysregulation. Providing perioperative hemodynamic stability during narcosis is therefore a particular challenge. The effects of general anesthesia on systemic vascular resistance and cardiac output in a patient with idiopathic orthostatic hypotension undergoing retropubic prostatectomy will be reported. In the case presented perioperative hemodynamic stability was achieved by aggressive volume therapy guided by global end-diastolic volume measurement and low-dose catecholamine therapy.

Effect of Low Concentration Isoflurane with Thiopental Sodium for Craniotomies of Intracranial Space Occupying Lesion

The primary objective of anaesthesia is to facilitate surgery at minimal risk to the patient and to ensure safe optimal recovery following the procedure. The minimal risk to the neurosurgical patient can be achieved with meticulous attention to the detail of intraoperative systemic and brain homeostasis. Safe early recovery from craniotomy necessitates an anaesthetic technique pharmacology adequate to permit early awakening. The present study was designed to observe the effect of different anaesthetic technique that permits early recovery and hemodynamic stability. A total number of thirty patients both male and female age range 18 to 60 yrs having ASA grade-I &amp; II and were randomly selected. They were equally divided into two groups. Group A received TPS infusion and group B received isoflurane inhalation with low dose of TPS infusion. Other drugs remained same for both group. Group A Received induction dose of TPS 4 - 5 mg/kg, maintained by TPS (4 - 5 mg/kg/h infusion), fentanyl (3 mgm/kg bolus, 1 - 2 mgm/ kg/h infusion), oxygen/N2O mixture FiO2 being 0.3. Group B- Received induction dose of TPS 4 - 5 mg/kg and maintained by isoflurane 0.5%, oxygen/ N2O mixture FiO2 being 0.3, fentanyl (3 mgm/kg bolus, 1 - 2 mgm/kg/h infusion), and low dose TPS (1 - 2 mg/kg/h) infusion. In all patients induction was done with TPS 4 - 5 mg/kg and vecuronium (0.1 mg/kg) was used for tracheal intubation, muscle relaxation was maintained by vecuronium 0.01 mg/kg intermittently. Both groups received midazolam (0.1 mg/kg), lignocaine 1.5 mg/kg 2 minutes before induction. Both groups received frusemide 1 mg/ kg just after induction and mannitol 1 gm/kg when scalp incision was given. Anaesthetic procedure was performed with monitoring of hemodynamic variable pulse, blood pressure, SPO2, ETCO2, temperature, urine output. Hemodynamic variable pulse, blood pressure were measure before induction, at intubation, every 15 min. interval and before extubation. Data were analyzed by paired and unpaired student's t-test as appropriate using SPSS software. Hemodynamic response to intubation does not differ significantly between the two groups. But it was observed that at intubation in both groups the pulse and mean arterial blood pressure was raised in compare to baseline, which gradually came down as anaesthetic depth increased and then remained stable all through the procedure. Recovery was evaluated using Aldrete score. Total score significantly differ between two groups up to 30 min after extubation. Group A showed delay recovery up to 30 min in compare to group B. But after 30 min there was no significant difference in scoring between two groups. Total cost of main anaesthetic agent used significantly lower in group A. This study showed that the total infusion of TPS technique was as equally effective as using low concentration of isoflurane with conjunction of low dose TPS regarding perioperative hemodynamic stability. But the cost was minimal in thiopental sodium infusion group with the expense of a little bit delayed recovery. Journal of BSA, Vol. 21, No. 1, January 2008 21-28

The Influence of the alpha-2 Agonist Clonidine on Perioperative Haemodynamic Stability, Sedation, Anxiety and Analgesia in Medium Amplitude Abdominal Surgery

The Influence of the alpha-2 Agonist Clonidine on Perioperative Haemodynamic Stability, Sedation, Anxiety and Analgesia in Medium Amplitude Abdominal Surgery

Dexmedetomidine increases perioperative haemodynamic stability, and may decrease intraoperative opioid analgesic requirements

Dexmedetomidine increases perioperative haemodynamic stability, and may decrease intraoperative opioid analgesic requirements

Dexmedetomidine as an anaesthetic adjuvant in patients undergoing intracranial tumour surgery: a double-blind, randomized and placebo-controlled study

Dexmedetomidine (DEX) has been shown to provide good perioperative haemodynamic stability with decreased intraoperative opioid requirements. It may have neural protective effects, and thus may be a suitable anaesthetic adjuvant to neurosurgical anaesthesia. Fifty-four patients scheduled for elective surgery of supratentorial brain tumour were randomized to receive in a double-blind manner a continuous DEX infusion (plasma target concentration 0.2 or 0.4 ng ml(-1)) or placebo, beginning 20 min before anaesthesia and continuing until the start of skin closure. The DEX groups received fentanyl 2 microg kg(-1) at the induction of anaesthesia and before the start of operation, the placebo group 4 microg kg(-1), respectively. Anaesthesia was maintained with nitrous oxide in oxygen and isoflurane. The median times from the termination of N2O to extubation were 6 (3-27), 3 (0-20) and 4 (0-13) min in placebo, DEX-0.2 and DEX-0.4 groups, respectively (P<0.05 anova all-over effect). The median percentage of time points when systolic blood pressure was within more or less than 20% of the intraoperative mean was 72, 77 and 85, respectively (P<0.01), DEX-0.4 group differed significantly from the other groups. DEX blunted the tachycardic response to intubation (P<0.01) and the hypertensive response to extubation (P<0.01). DEX-0.4 group differed in the heart rate variability from placebo (93 vs 82%, P<0.01). DEX increased perioperative haemodynamic stability in patients undergoing brain tumour surgery. Compared with fentanyl, the trachea was extubated [corrected] faster without respiratory depression.

Hypertension and anesthesia

There are still many controversies about perioperative management of hypertensive patients. This review aims to provide relevant instruction based on evidence regarding the treatment of those patients. Mild to moderate hypertension is not independently responsible for perioperative cardiac complications. The position is less clear for severely hypertensive patients. A randomized study shows no benefit of the traditional practice of delaying elective surgery in severely hypertensive patients until better control of blood pressure is achieved. Perioperative use of beta-blockers or alpha-2 agonists has been shown to maintain perioperative hemodynamic stability and thereby to prevent major cardiac complications. Delaying surgery only for the purpose of blood pressure control may not be necessary, especially in the case of mild to moderate hypertension. Strict care, however, should be taken to ensure perioperative hemodynamic stability because labile hemodynamics, rather than preoperative hypertension per se, appears to be more closely associated with adverse cardiovascular complications. Delaying surgery in hypertensive patients may be justified if target organ damage exists that can be improved by such a delay or if (suspected) target organ damage should be evaluated further before the operation.

Effect of Dexmedetomidine on Haemodynamic Responses to Laryngoscopy and Intubation

Dexmedetomidine reduces the dose requirements for opioids and anaesthetic agents. The purpose of this study was to evaluate the effect of a single pre-induction intravenous dose of dexmedetomidine 1 microg/kg on cardiovascular response resulting from laryngoscopy and endotracheal intubation, need for anaesthetic agent and perioperative haemodynamic stability. Fifty patients scheduled for elective minor surgery were randomised into two groups (dexmedetomidine group and placebo group, n = 25 in each group). During and after drug administration, the Ramsey sedation scale was applied every 5 minutes. Fentanyl 1 microg/kg was administered to all patients and thiopental was given until lash reflex disappeared. Anaesthesia continuation was maintained with 50% : 50%, oxygen : nitrous oxide. Sevoflurane concentration was adjusted to maintain systolic blood pressure within 20% of preoperative values. After extubation, the Steward awakening score was applied at 5 and 10 minutes. Haemodynamic parameters and adverse effects were recorded every 10 minutes for 1 hour after surgery. During intubation the need for thiopental and sevoflurane concentration were decreased by 39% and 92%, respectively, in the dexmedetomidine group compared with the placebo group. In all groups, blood pressure and heart rate increased after tracheal intubation; both were significantly lower in the dexmedetomidine group than in the placebo group (p < 0.05). Fentanyl requirement during the operation was 74.20 +/- 10.53microg in the dexmedetomidine group and 84.00 +/- 27.04microg in the placebo group (p < 0.05). At 5 minutes, the Steward scores were >6 in 56% of the dexmedetomidine group and in 4% of the placebo group (p < 0.05). At 10 minutes, sedation scores were > or =4 in all patients in the dexmedetomidine group (p < 0.05). Arterial blood pressure and heart rate in the postoperative period were significantly lower in the dexmedetomidine group compared with the placebo group (p < 0.05). Preoperative administration of a single dose of dexmedetomidine resulted in progressive increases in sedation, blunted the haemodynamic responses during laryngoscopy, and reduced opioid and anaesthetic requirements. Furthermore, dexmedetomidine decreased blood pressure and heart rate as well as the recovery time after the operation.

Dexmedetomidine-Remifentanil or Propofol-Remifentanil Anesthesia in Patients Undergoing Intracranial Surgery

Abstract: Dexmedetomidine has been shown to provide good perioperative hemodynamic stability with decreased intraoperative opioid requirements. This study was conducted to compare the effect of dexmedetomidine-remifentanil (DR) anesthesia and propofol-remifentanil (PR) anesthesia on perioperative hemodynamics and postanesthesia recovery profiles in patients undergoing intracranial surgery. After receiving Ethics Committee approval and informed patient consent, 78 American Society of Anesthesiologists physical status I or II patients between the ages of 19 and 70 years with a Glasgow Coma Scale score 14 or 15 who were scheduled for elective intracranial surgery with general anesthesia were recruited. Anesthesia induction was provided by intravenous remifentanil (0.5 μg/kg) and propofol (1.5-2 mg/kg) in both groups and maintained with infusion of DR (0.6-1.2 mg/kg/h and 0.25 μg/kg/min)-nitrous oxide/oxygen (n2o/o2) in the DR group (n = 39) and infusion of PR (3-10 mg/kg/h and 0.25 μg/kg/min)-n2o/o2 in the PR group (n = 39). Hemodynamic variables were recorded before surgery, during the induction of anesthesia, after intubation, and during application of the headholder and skin incision; brain relaxation was also recorded. Times to extubation and awakening, eye opening, and response to commands as well as analgesic requirements were recorded after surgery. No significant difference was found in systolic blood pressure and mean arterial pressure throughout the study period except at the time of the dural incision (P 0.05). Time to extubation was significantly shorter in patients receiving PR anesthesia than in patients receiving DR anesthesia (3.6 minutes vs. 5.5 minutes). Analgesic requirements were significantly higher in the PR group than in the DR group (P = 0.013). No significant side effects were reported in the 2 groups (P > 0.05). In conclusion, dexmedetomidine (0.6-1.2 μg/kg−1/h−1) plus remifentanil (0.25 μg/kg−1 min−1) anesthesia offered lower analgesic requirements, a longer extubation time, and better hemodynamic stability compared with PR anesthesia for patients undergoing intracranial surgery.

Perioperative hemodynamic stability in patients with pheochromocytoma – laparoscopic vs. open surgery

Perioperative hemodynamic stability in patients with pheochromocytoma – laparoscopic vs. open surgery

Effects of flow rate on hemodynamic parameters and agent consumption in low-flow desflurane anesthesia: An open-label, prospective study in 90 patients

Background: In surgical patients, decreasing the fresh gas flow rate in anesthesia may minimize costs, reduce environmental pollution, and preserve heat and humidity in the respiratory system. Objective: The aim of this study was to investigate the effects of 3 low-flowdesflurane rates on perioperative hemodynamic stability, end-tidal desflurane concentration, emergence and recovery characteristics, and agent consumption. Methods: This open-label, prospective study was conducted at the Departmentof Anesthesiology and Reanimation, University of Gaziantep, Gaziantep, Turkey. Nonpremedicated adult patients scheduled to undergo surgery (ureterolithotomy, cholecystectomy, pyelolithotomy, or thyroidectomy) were enrolled. Patients were anesthetized with propofol and fentanyl and intubated after neuromuscular blockade with vecuronium. Patients were randomly allocated to 1 of 3 groups according to the fresh gas flow rate: medium flow (2 L/min), low flow (1 L/min), and minimal flow (0.5 L/min). Intraoperative fentanyl volume was recorded. Heart rate, mean arterial pressure, and end-tidal desflurane concentration were recorded before (baseline) and after anesthesia induction; immediately before incision; and 5, 10, 15, 30, 45, and 60 minutes after incision. Emergence time and desflurane consumption after extubation were recorded. Aldrete scores were recorded at 5, 15, and 30 minutes after extubation. Results: Ninety patients (46 women, 44 men; mean [SD] age, 39.74 [13.73] years; 30 patients per treatment group) participated in the study. Means of hemodynamic parameters, intraoperative volume of fentanyl, end-tidal desflurane concentration, emergence time, and Aldrete score were statistically similar between the 3 groups. Mean (SD) desflurane consumption was significantly higher in the medium-flow group compared with the low- and minimal-flow groups (110.43 [28.18] g vs 98.40 [23.62] g and 79.80 [17.54] g, respectively; both, P < 0.01). Mean (SD) desflurane consumption was also significantly higher in the low-flow group compared with the minimal-flow group ( P < 0.01). Conclusion: The results of the present study in adult surgical patients suggestthat desflurane may be used in low-flow anesthesia, even with the minimal fresh gas flow rate.

New strategies to control the inflammatory response in cardiac surgery

To present and interpret data from recent clinical studies (July 2002-August 2003) of strategies to control the inflammatory response after cardiac surgery. Off-pump coronary artery bypass techniques, which avoid the need for extracorporeal circulation, attenuate the inflammatory response and appear to confer clinical benefit. Concerns regarding the quality of the revascularization after off-pump coronary artery bypass appear to have been allayed. At present, ventricular assist devices do not enhance the efficacy of off-pump coronary artery bypass. In patients undergoing cardiopulmonary bypass, heparin-coated circuits, hypothermic pulmonary perfusion, normoxic reperfusion after aortic unclamping, and modified ultrafiltration hold promise. Strategies to maintain perioperative haemodynamic stability, such as enoximone therapy, may be beneficial, particularly in elderly patients. Aprotinin may have important beneficial anti-inflammatory actions in higher-risk adult and paediatric patients. The therapeutic potential of corticosteroids, particularly when administered in multiple dosages is increasingly clear. Direct anti-mediator therapies that focus upon key effector molecules and pathways of the inflammatory response offer future therapeutic options. The potential for strategies that inhibit the inflammatory response to improve outcome after cardiac surgery is clear. Large-scale multicentre trials investigating the most promising strategies, including off-pump coronary artery bypass, heparin-coated circuits, and perioperative corticosteroid and aprotinin therapy, are urgently needed. These trials need to be restricted to the high-risk patient groups most likely to experience benefit. In the interim, the optimal strategy to minimize the inflammatory response to cardiac surgery will remain elusive.

Anaesthesia and isolated systolic hypertension--pathophysiology and anaesthesia risk.

This review examines the pathophysiology of isolated systolic hypertension, changing medical perspectives on this condition as a cardiovascular risk factor in the community and evolving evidence of it being an independent risk factor for perioperative morbidity and mortality. Hypertension is regarded as an added risk in anaesthesia. Continuation of antihypertensive medication through the perioperative period is an established principle. Studies supporting this practice have demonstrated greater perioperative haemodynamic stability in association with general anaesthesia and surgery in patients with treated hypertension compared to untreated hypertension. Therapy has historically focused on control of diastolic blood pressure, rather than systolic blood pressure. Recent clinical trial data and data from large observational studies show a closer association of systolic hypertension with both coronary heart disease and stroke compared with diastolic hypertension. This has led to recommendations for aggressive treatment of isolated systolic hypertension, especially in patients over 65 years old. The association between decreased compliance of the central systemic arteries and isolated systolic hypertension is well understood. The fact that this same pathology, lack of compliance of central arteries, can cause a decrease in diastolic blood pressure is not so well recognised. This means that, in patients with isolated systolic hypertension, decreasing diastolic blood pressure can be associated with worsening arterial disease and that systolic minus diastolic blood pressure may give a better indication of the problem. Anaesthetic assessment and technique should be studied and potentially revised in the light of these changes in perspective on isolated systolic hypertension.

Priorities in perioperative geriatrics.

T he aging of the baby-boom population and the decreases in adult mortality seen in the last few decades will dramatically increase the age of Americans between 2010 and 2030. During that time, the population older than age 65 yr is expected to grow by 75%, whereas between 1995 and 2050, the cumulative growth of the population older than 85 yr is expected to exceed 400% (1). Furthermore, it has been reported that the increased demand for surgery in this population may exceed the rate of population growth (2). The implications of an aging population for the practice of anesthesiology are profound. Age-related changes in physiology and pharmacology can affect every aspect of perioperative care. The changes in surgical demographics will compel the anesthesiologist to become familiar with the physiology and clinical care of the aged. This review will serve as an introduction. First, some of the physiologic changes that occur with aging will be presented. Second, the preoperative assessment of the older surgical patient will be discussed. Third, some of the research related to intraoperative management of the geriatric surgical patient will be described. In the fourth section, we will discuss some geriatric-specific issues related to postoperative management.

Preoperative Intravenous Dose of Clonidine for Perioperative Sedation and Hemodynamic Stability

Preoperative Intravenous Dose of Clonidine for Perioperative Sedation and Hemodynamic Stability