Alexandru Gottlieb

Normal saline versus lactated Ringer's solution for intraoperative fluid management in patients undergoing abdominal aortic aneurysm repair: an outcome study.

Metabolic acidosis and changes in serum osmolarity are consequences of 0.9% normal saline (NS) solution administration. We sought to determine if these physiologic changes influence patient outcome. Patients undergoing aortic reconstructive surgery were enrolled and were randomly assigned to receive lactated Ringer’s (LR) solution (n = 33) or NS (n = 33) in a double-blinded fashion. Anesthetic and fluid management were standardized. Multiple measures of outcome were monitored. The NS patients developed a hyperchloremic acidosis and received more bicarbonate therapy (30 ± 62 mL in the NS group versus 4 ± 16 mL in the LR group; mean ± sd), which was given if the base deficit was greater than −5 mEq/L. The NS patients also received a larger volume of platelet transfusion (478 ± 302 mL in the NS group versus 223 ± 24 mL in the LR group; mean ± sd). When all blood products were summed, the NS group received significantly more blood products (P = 0.02). There were no differences in duration of mechanical ventilation, intensive care unit stay, hospital stay, and incidence of complications. When NS was used as the primary intraoperative solution, significantly more acidosis was seen on completion of surgery. This acidosis resulted in no apparent change in outcome but required larger amounts of bicarbonate to achieve predetermined measurements of base deficit and was associated with the use of larger amounts of blood products. These changes should be considered when choosing fluids for surgical procedures involving extensive blood loss and requiring extensive fluid administration.

The hemodynamic and adrenergic effects of perioperative dexmedetomidine infusion after vascular surgery.

UNLABELLED We tested dexmedetomidine, an alpha(2) agonist that decreases heart rate, blood pressure, and plasma norepinephrine concentration, for its ability to attenuate stress responses during emergence from anesthesia after major vascular operations. Patients scheduled for vascular surgery received either dexmedetomidine (n = 22) or placebo (n = 19) IV beginning 20 min before the induction of anesthesia and continuing until 48 h after the end of surgery. All patients received standardized anesthesia. Heart rate and arterial blood pressure were kept within predetermined limits by varying anesthetic level and using vasoactive medications. Heart rate, arterial blood pressure, and inhaled anesthetic concentration were monitored continuously; additional measurements included plasma and urine catecholamines. During emergence from anesthesia, heart rate was slower with dexmedetomidine (73 +/- 11 bpm) than placebo (83 +/- 20 bpm) (P = 0.006), and the percentage of time the heart rate was within the predetermined hemodynamic limits was more frequent with dexmedetomidine (P < 0.05). Plasma norepinephrine levels increased only in the placebo group and were significantly lower for the dexmedetomidine group during the immediate postoperative period (P = 0.0002). We conclude that dexmedetomidine attenuates increases in heart rate and plasma norepinephrine concentrations during emergence from anesthesia. IMPLICATIONS The alpha(2) agonist, dexmedetomidine, attenuates increases in heart rate and plasma norepinephrine concentrations during emergence from anesthesia in vascular surgery patients.

Massive subcutaneous emphysema and severe hypercarbia in a patient during endoscopic transcervical parathyroidectomy using carbon dioxide insufflation.

Increasingly, laparoscopic surgeries are being performed to treat a number of conditions. The technical aspects of specific laparoscopic procedures can increase the risk of certain complications that, although they are of concern in conventional procedures, may be more likely or may occur with greater severity during laparoscopic procedures. We report the anesthetic course and complications that were encountered during laparoscopic parathyroidectomy, a procedure that to our knowledge, has not previously been performed. Although the surgery was successful, the patient developed signs and symptoms of sustained carbon dioxide (CO,) absorption: supraventricular tachycardia, massive subcutaneous emphysema, hypercarbia, and acidosis.

Analysis of risk factors for myocardial infarction and cardiac mortality after major vascular surgery

Background Patients undergoing vascular surgical procedures are at high risk for perioperative myocardial infarction (PMI). This study was undertaken to identify predictors of PMI and in-hospital death in major vascular surgical patients. Methods From the Vascular Surgery Registry (6,948 operations from January 1989 through June 1997) the authors identified 107 patients in whom PMI developed during the same hospital stay. Case–control patients (patients without PMI) were matched at a 1×:×1 ratio with index cases according to the type of surgery, gender, patient age, and year of surgery. The authors analyzed data regarding preoperative cardiac disease and surgical and anesthetic factors to study association with PMI and cardiac death. Results By using univariable analysis the authors identified the following predictors of PMI: valvular disease (P = 0.007), previous congestive heart failure (P = 0.04), emergency surgery (P = 0.02), general anesthesia (P = 0.03), preoperative history of coronary artery disease (P = 0.001), preoperative treatment with &bgr;-blockers (P = 0.003), lower preoperative (P = 0.03) and postoperative (P = 0.002) hemoglobin concentrations, increased bleeding rate (as assessed from increased cell salvage;P = 0.025), and lower ejection fraction (P = 0.02). Of the 107 patients with PMI, 20.6% died of cardiac cause during the same hospital stay. The following factors increased the odds ratios for cardiac death: age (P = 0.001), recent congestive heart failure (P = 0.01), type of surgery (P = 0.04), emergency surgery (P = 0.02), lower intraoperative diastolic blood pressure (P = 0.001), new intraoperative ST-T changes (P = 0.01), and increased intraoperative use of blood (P = 0.005). Patients who underwent coronary artery bypass grafting, even more than 12 months before index surgery, had a 79% reduction in risk of death if they had PMI (P = 0.01). Multivariable analysis revealed preoperative definitive diagnosis of coronary artery disease (P = 0.001) and significant valvular disease (P = 0.03) were associated with increased risk of PMI. Congestive heart failure less than 1 yr before index vascular surgery (P = 0.0002) and increased intraoperative use of blood (P = 0.007) were associated with cardiac death. The history of coronary artery bypass grafting reduced the risk of cardiac death (P = 0.04) in patients with PMI. Conclusions The in-hospital cardiac mortality rate is high for patients who undergo vascular surgery and experience clinically significant PMI. Stress of surgery (increased intraoperative bleeding and aortic, peripheral vascular, and emergency surgery), poor preoperative cardiac functional status (congestive heart failure, lower ejection fraction, diagnosis of coronary artery disease), and preoperative history of coronary artery bypass grafting are the factors that determine perioperative cardiac morbidity and mortality rates.

Perioperative cardiovascular morbidity in patients with coronary artery disease undergoing vascular surgery after percutaneous transluminal coronary angioplasty

OBJECTIVE Patients with coronary artery disease (CAD) who undergo noncardiac surgery are at increased risk for perioperative myocardial infarction (PMI). Undergoing successful coronary artery bypass grafting (CABG) before such surgery has been shown to decrease perioperative cardiac morbidity and mortality. Percutaneous transluminal coronary angioplasty (PTCA) is an alternative treatment for these patients. Perioperative cardiac morbidity in patients with CAD who underwent PTCA before their vascular surgery was reviewed. SETTING A tertiary care referral center for patients with cardiovascular heart disease. PARTICIPANTS Review of vascular surgery database for patients who underwent vascular surgery preceded by PTCA between 1984 and 1995. Patients were excluded if they had a history of CABG within 2 years of surgery, had PTCA more than 18 months before surgery, or had incomplete data. MEASUREMENTS Data were collected concerning cardiac history, left ventricular (LV) function, perioperative cardiac morbidity (angina, MI, congestive heart failure [CHF], and arrhythmias). MAIN RESULTS Of 194 patients who underwent aortic abdominal surgery, carotid endarterectomy (CEA), or peripheral vascular surgery preceded by PTCA, 104 (54%) had a previous MI. Twenty-six patients (13.4%) had perioperative cardiac morbidity. Only one patient had an MI (0.5%; 95% confidence interval [CI], 0.0 to 2.8), whereas one patient died of CHF followed by multisystem organ failure (0.5%). The median interval between PTCA and surgery was 11 days (interquartile range, [IQR] 3 to 49 days). Patients who developed perioperative cardiac morbidity were older than those who did not (p = 0.02). Patients who had a history of CABG (before PTCA) had a higher incidence of postoperative angina (p = 0.04). The degree of preoperative LV dysfunction was linearly related to the incidence of new postoperative CHF (p = 0.01). Arrhythmias were more common in patients undergoing abdominal vascular surgery (17.9%) than in those undergoing CEA (2.5%; p = 0.03) or peripheral vascular surgery (5.2%; p = 0.02). CONCLUSION High-risk cardiac patients undergoing vascular surgery who have had PTCA performed up to 18 months preoperatively have a low incidence of perioperative cardiac morbidity. Prophylactic PTCA may be beneficial in patients with CAD who are at high risk for perioperative cardiac complications.

The hyperglycemic response to major noncardiac surgery and the added effect of steroid administration in patients with and without diabetes.

BACKGROUND:The pattern and magnitude of the hyperglycemic response to surgical stress, the added effect of low-dose steroids, and whether these differ in diabetics and nondiabetics remain unclear. We therefore tested 2 hypotheses: (1) that diabetics show a greater increase from preoperative to intraoperative glucose concentrations than nondiabetics; and (2) that steroid administration increases intraoperative hyperglycemia more so in diabetics compared with nondiabetics. METHODS:Patients scheduled for major noncardiac surgery under general anesthesia were enrolled and randomized to preoperative IV 8 mg dexamethasone or placebo, stratified by diagnosis of diabetes. Patients were part of a larger underlying trial (the Dexamethasone, Light Anesthesia and Tight Glucose Control [DeLiT] Trial). IV insulin was given when glucose concentration exceeded 215 mg/dL. The primary outcome measure was the change in glucose from the preoperative to maximal intraoperative glucose concentration. We also report the time-dependent pattern of intraoperative hyperglycemia. RESULTS:Ninety patients (23% with diabetes) were randomized to dexamethasone, and 95 (29% with diabetes) were given placebo. The mean ± SD change from preoperative to maximal intraoperative glucose concentration was 63 ± 69 mg/dL in diabetics and 72 ± 45 mg/dL in nondiabetics. The mean covariable-adjusted change (95% confidence interval) in nondiabetics was 29 (13, 46) mg/dL more than in diabetics (P < 0.001). For all patients combined, mean glucose increased slightly from preoperative to incision, substantially from incision to surgery midpoint, and then remained high and fairly stable through emergence, with nondiabetic patients showing a greater increase (P < 0.001). For nondiabetics, the mean increase in glucose concentration (97.5% CI) was 29 (9, 49) mg/dL more in patients given dexamethasone than placebo (P = 0.0012). However, there was no dexamethasone effect in diabetics (P = 0.99). CONCLUSIONS:Treatment of intraoperative hyperglycemia should account for the hyperglycemic surgical stress response trend depending on the stage of surgery as well as the added effects of steroid administration. Denying steroid prophylaxis for postoperative nausea and vomiting for fear of hyperglycemic response should be reconsidered given the limited effect of steroids on intraoperative blood glucose concentrations.

The Effects of Carotid Sinus Nerve Blockade on Hemodynamic Stability After Carotid Endarterectomy

OBJECTIVE To determine whether intraoperative administration of bupivacaine reduces the incidence of hypotension after carotid endarterectomy (CEA). DESIGN Prospective, double-blinded, randomized controlled trial. SETTING A single-institute, tertiary-care medical center. PARTICIPANTS Patients (n = 135) who were referred for CEA without prior ipsilateral CEA, diabetes mellitus, or allergies to local anesthetics. INTERVENTIONS 2 mL of 0.25% bupivacaine or 2 mL NaCl (control) injected by the surgeon at the carotid sinus immediately after CEA. MEASUREMENTS AND MAIN RESULTS Blood pressure and heart rate were measured before induction, before carotid reperfusion, 2 minutes after reperfusion, before carotid sinus injection, and every 15 minutes thereafter for 2 hours. Anesthesia was induced and maintained with fentanyl, pancuronium, and 0.5% to 1% enflurane. Hypertension was defined as a systolic blood pressure 30% above baseline or greater than 180 mmHg. Hypotension was defined as a systolic blood pressure 30% below baseline or less than 100 mmHg. Postoperative incidences of hypertension, hypotension, and the associated use of corrective medications were compared in both groups using the chi-squared test to determine statistical significance. Patients in the bupivacaine group (n = 61) had a similar incidence of postoperative hypotension as controls (n = 74) but a higher incidence of hypertension (40% v 24%; p = 0.043). The bupivacaine group required vasodilators more often (33% v 18%; p = 0.04). Baseline hypertension and preoperative use of beta-blockers also were predictive of postoperative hypertension. CONCLUSIONS Carotid sinus area infiltration with bupivacaine after CEA does not reduce the incidence of postoperative hypotension but significantly increases the incidence of postoperative hypertension. Thus, its routine use cannot be recommended in carotid endarterectomy.

Bleeding in a patient receiving platelet aggregation inhibitors.

IMPLICATIONS We describe a patient who experienced intraoperative bleeding after being treated with platelet receptor glycoprotein IIb/IIIa antagonist eptifibatide. We used Sonoclot and Thrombelastograph to monitor antiplatelet effects of eptifibatide.

The hemodynamic responses to an intravenous test dose in vascular surgical patients

The study was designed to investigate the hemodynamic responses to intravenous (IV) injections of various epidural test doses in vascular surgical patients to determine whether previously established criteria in healthier populations were valid in this inherently sicker population.A double-blind, prospective randomized study was performed on 50 patients, not receiving beta-adrenergic antagonists, presenting for vascular surgery and requiring an arterial line. Patients were randomly assigned to receive a 3-mL injection of one of five solutions, either saline (Group 1), lidocaine 45 mg (Group 2), lidocaine 45 mg and epinephrine 5 micro gram (Group 3), lidocaine 45 mg and epinephrine 10 micro gram (Group 4), or lidocaine 45 mg and epinephrine 15 micro gram (Group 5). After injection, a blinded observer recorded arterial blood pressure and heart rate (HR) every 15 s for 3 min. The changes in HR, systolic (SBP), mean (MBP), and diastolic (DBP) blood pressure as well as time to maximum change were analyzed both within and between groups. Only Group 5 had significant within-group changes for all hemodynamic variables measured. Only in the comparison between Groups 1 and 5 and between Groups 2 and 5 were there significant changes in both HR and SBP. The mean increase in HR and SBP within Group 5 was 17.0 +/- 5.9 bpm and 31.0 +/- 10.5 mm Hg, respectively. No differences were found between groups for time to maximum change for HR and SBP which for Group 5 were 64.5 +/- 37.4 s and 90.0 +/- 56.7 s, respectively. To achieve 100% sensitivity and specificity for HR increase, the criterion established was >or=to 9 bpm. A criterion with 100% sensitivity and specificity could not be established for SBP. The authors conclude that a test dose containing epinephrine 15 micro gram is a reliable test dose for identification of intravascular injection in the vascular surgical population when associated with an increase in HR of >or=to 9 bpm. This criterion for HR increase is less than that previously established in healthier populations. (Anesth Analg 1995;80:864-8)

Consequences of succinylcholine administration to patients using statins

Background:Statins cause structural changes in myocytes and provoke myotoxicity, myopathy, and myalgias. Thus, patients taking statins may be especially susceptible to succinylcholine-induced muscle injury. The authors tested the hypothesis that succinylcholine increases plasma concentrations of myoglobin, potassium, and creatine kinase more in patients who take statins than in those who do not and that succinylcholine-induced postoperative muscle pain is aggravated in statin users. Methods:Patients who took statins for at least 3 months and those who had never used statins were enrolled. General anesthesia was induced and included 1.5 mg/kg succinylcholine for intubation. The incidence and degree of fasciculation after succinylcholine administration were recorded. Blood samples were obtained before induction and 5 and 20 min and 24 h after succinylcholine administration. Patients were interviewed 2 and 24 h after surgery to determine the degree of myalgia. Results:The authors enrolled 38 patients who used statins and 32 who did not. At 20 min, myoglobin was higher in statin users versus nonusers (ratio of medians 1.34 [95% CI: 1.1, 1.7], P = 0.018). Fasciculations in statin users were more intense than in nonusers (P = 0.047). However, plasma potassium and creatine kinase concentrations were similar in statin users and nonusers, as was muscle pain. Conclusions:The plasma myoglobin concentration at 20 min was significantly greater in statin users than nonusers, although the difference seems unlikely to be clinically important. The study results suggest that the effect of succinylcholine given to patients taking statins is likely to be small and probably of limited clinical consequence.