Combination effect of low dose fentanyl and propofol on emergence agitation in children following sevoflurane anesthesia

To investigate the combination effect of low dose fentanyl and subhypnotic dose of propofol on emergence agitation in children receiving sevoflurane for adenotonsillectomy procedure. After ethical approval, a prospective, randomized, clinical study was performed in Saad Specialist Hospital, Al-Khobar, Kingdom of Saudi Arabia in 2007-2008. One hundred and twenty children in physical status of I according to the American Society of Anesthesiologists, aged 2-6 years, scheduled for adentonsillectomy under general anesthesia were allocated into 3 groups randomly. Anesthesia was induced and maintained by sevoflurane in all groups. Children received 0.1 ml.kg-1 normal saline at the end of surgery in group C [n=40], 1.5 mcg.kg-1 fentanyl during induction, and 0.1 ml.kg-1 normal saline at the end of surgery in group F [n=40], and 1.5 mcg.kg-1 fentanyl during induction and 1 mg.kg-1 propofol at the end of surgery in group FP [n=40]. Postoperative agitation was recorded, if any, for the first postoperative hour. Three groups were comparable with regard to demographic data. Twenty-one patients [53%] in the control group, 14 patients [35%] in group F and 7 [18%] patients in group FP experienced postoperative agitation. The combination of low dose fentanyl before surgery and propofol at the end of surgery decreases the incidence and level of emergence agitation in children after adenotonsillectomy procedure under sevoflurane anesthesia

impact of preemptive phosphodiesterase III inhibition on left ventricular diastolic performance after valve replacement for aortic stenosis

Left ventricular diastolic dysfunction [LVDD] in aortic stenosis is an important independent risk factor for early and late postoperative mortality. We hypothesized that enoximone or milrinone, administered after releasing the aortic cross-clamp improved the diastolic function of the left ventricle as assessed by transesophageal echocardiography [TEE] in patients with aortic stenosis undergoing aortic valve replacement. Forty-five adult patients with valvular aortic stenosis and preserved systolic function scheduled for primary aortic valve replacement were randomly assigned to one of three equal groups; in group M [milrinone group, n = 15] patients received milrinone with a loading dose of 50 microg/kg followed by an infusion of 0.5 microg/kg/min for 6 hours. In group E [enoximone group, n = 15] patients were given enoximone after release of aortic cross-clamp, with an initial bolus of 0.5 mg/kg followed by a continuous infusion of 2.5 microg/kg/min for 6 hours, and in group C [control group, n = 15] patients received saline bolus and infusion at the same time and interval as the first two groups. Hemodynamic parameters and transesophageal echocardiographic assessment of left ventricular end-diastolic area [EDA], transmitral inflow velocity, and tissue doppler imaging [TDI] of the mitral annulus parameters were assessed pre-bypass [Tl], post-bypass [12] after administration of the test drug and separation from CPB, and at the end of the operation after chest closure [T3]. Cardiac index showed a statistically significant increase [p < 0.05], while the systemic vascular resistance showed statistically significant decrease [p < 0.05] in T2 and T3 compared to Tl in the three groups. Cardiac index was significantly higher [p < 0.05] and the systemic vascular resistance was significantly lower [p < 0.05] in T2 and T3 in both the milrinone and enoximone groups compared to the control group at the same intervals. Left ventricular end-diastolic area showed a decrease in all groups which was statistically significant [p < 0.05] comparing T2 and T3 to Tl but without intergroup difference. Peak E-wave velocity, peak A-wave velocity and E/A ratio of the transmitral flow were comparable in the three groups. E-wave deceleration time was significantly decreased [p < 0.05] in T2 and T3 in the three groups. Tissue Doppler analysis of the peak early mitral annular velocity revealed no significant difference between the three groups. The administration of milrinone or enoximone after release of aortic cross-clamp in valve replacement for aortic stenosis did not improve ventricular diastolic function and failed to show increase in the indices of compliance and relaxation compared to the control

Comparative study between the effects of clevidipine and nitroglycerine in patients with pulmonary hypertension undergoing mitral valve replacement

Pulmonary hypertension [PHT] is commonly found in patients undergoing mitral valve replacement [MVR]. Various pharmacologic agents have been used to decrease the pulmonary artery pressure in pulmonary hypertensive patients. Clevidipine is a third-generation IV dihydropyridine calcium channel blocker, specific arterial dilator, with rapid onset and offset. The aim of the present study was to compare between the effects of clevidipine and nitroglycerine on pulmonary and systemic hemodynamics as well as pulmonary oxygenation. Thirty patients with PHT scheduled for elective MVR were enrolled in this study and randomly allocated into 2 groups. Patients received either nitroglycerin infusion at 0.25-10 microg/kg/min [NTG group] or clevidipine infusion at 0.4-8 microg/kg/min [CLV group]. Pulmonary and systemic hemodynamic parameters as well as oxygenation data were measured after induction of anesthesia, after weaning from CPB before the start of the study medication, and after 30 minutes, 2 hours, and 4 hours from the start of the study medication. The incidence of postoperative atrial fibrillation and total ICU and hospital length of stays were also recorded. The mean pulmonary artery pressure [MPAP], pulmonary vascular resistance [PVR], pulmonary capillary wedge pressure [PCWP], mean arterial blood pressure [MAP], and systemic vascular resistance [SVR] were significantly lower in the CLV group compared to the NTG group. In both groups, these parameters were significantly lower at 30 min, 2 hours, and 4 hours after drug administration compared to pre-drug administration values. There was no statistical significant change in the heart rate [HR] in the CLV group, however, it was significantly increased at 30 min, 2 hours, and 4 hours after drug administration compared to pre-drug administration values in the NTG group. The cardiac index [Cl] was significantly increased at 30 min, 2 hours, and 4 hours after drug administration compared to pre-drug administration values in CLV group and was statistically higher than NTG group. There was a non significant decrease in the PaO[2]/Fi0[2] and no significant change in PaCO[2] and SvO[2] at 30 min, 2 hours, and 4 hours after drug administration compared to pre-drug administration values in both groups with no statistical difference between the two groups. Clevidipine is a valuable alternative to nitroglycerine in the treatment of PHT in patients undergoing MVR as it showed better pulmonary and systemic hemodynamic profiles and did not worsen pulmonar] oxygenation

Management of low systemic vascular resistance hypotension following CPB. a comparative study between low dose vasopressin and norepinephrine

Post-cardiopulmonary bypass [CPB] low systemic vascular resistance [SVR] hypotension is attributed mainly to CPB activated systemic inflammatory response together with long CPB duration, long-term preoperative use angiotensin-converting enzyme [ACE] inhibitors or beta blockers, and inappropriate low vasopressin secretion. Vasopressin is a potent vasoconstrictor in various hypotensive states including post CPB vasodilatation. The aim of the present study was to compare the effects of low dose vasopressin infusion with norepinephrine on systemic hemodynamics, myocardial performance, internal mammary artery [IMA] graft blood flow, renal function, and clinical outcome. In patients undergoing elective on-pump coronary artery bypass grafting [CABG], hemodynamic variables were measured after weaning from CPB, and patients who had SVR < 800 dyne.s.cm-5, and systolic systemic blood pressure [SBP] < 80 mmHg or mean systemic blood pressure [MAP] < 60 mmHg despite proper volume resuscitation were enrolled in the study and were randomly allocated into 2 groups with 15 patients in each group. These patients received either vasopressin at 0.01-0.1 U/min [VP group], or norepinephrine at 0.01-0.2 microg/kg/min [NE group] to maintain MAP >70 mmHg. Hemodynamic variables were measured before; 1, 4, and 12 hours after the start of study drugs. Blood flow through IMA graft was measured before and 1 hour after infusion of the study drugs. Creatine kinase MB [CK-MB] serum concentrations were obtained immediately after surgery and at 24 hours and 48 hours postoperatively. Arterial lactate concentrations were measured before and at 1, and 4 hours after the start of study drugs. Serum creatinine was measured before and 24 hours and 48 hours after the start of the study drugs. Urine output was measured before and 4 hours after the start of the study drugs. The duration of vasopressor infusion and complications such as stroke or tachyarrhythmias were recorded. Extubation times, intensive care unit [ICU] and hospital length of stay were also recorded. Vasopressin compared to norepinephrine caused a significant increase in Cl, LVSWI, and postoperative urine output together with significant decrease in HR, postoperative CK-MB, duration of vasopressor infusion, and shorter extubation time. Both drugs resulted in a significant increase in MAP and SVR, a significant decrease in arterial lactate, together with non significant change-in IMA blood flow, postoperative serum creatinine, ICU and hospital length of stay, and the incidence of postoperative complications. low dose vasopressin infusion was found to be a valuable alternative to norepinephrine in management of low SVR hypotension after CPB

Comparative study between different routes of n-acetylcysteine administration for patients undergoing coronary artery bypass grafting

Reactive oxygen species [ROS] have been shown to contribute to myocardial stress in patients undergoing coronary artery bypass surgery [CABG] with cardiopulmonary bypass [CPB]. N-acetylcysteine [NAC], a potent anti-inflammatory and antioxidant agent, is known to decrease the production ROS after CPB. The present study was designed to compare the effect of different routes of NAC administration in patients undergoing CABG using CPB on myocardial protection, renal function and clinical outcome. Forty five adult patients scheduled for elective CABG with CPB were randomly allocated to one of three equal groups [15 patients each]. Patients received NAC either intravenously as a bolus of 100 mg/kg over a 15 minute period immediately before skin incision, followed by infusion at 20 mg / kg / h until the end of CPB [Intravenous NAC Group], or received 100 mg / kg into the CPB prime, followed by infusion at 20 mg / kg / h until the end of CPB [NAC in CPB prime Group], or received NAC at a dose of 100 mg / kg within the antegrade cardioplegia [NAC in cardioplegia Group]. Hemodynamic and transesophageal echo [TEE] measurements were recorded before and after separation from CPB. Serial serum creatine kinase MB [CK-MB], Cardiac troponin I [CTnl], Malondialdehyde [MDA] and creatinine levels were evaluated perioperatively over 2 days. Several clinical variables were evaluated after surgery including death, myocardial infarction, bleeding, cerebrovascular accidents, arrhythmias, atrial fibrillation, and intensive care unit [ICU] and hospital lengths of stay. Compared to baseline measurements, CTnl and MDA levels were comparable among the three study groups at the 6th, 24th and 48th postoperative hours. At the Gthand 24th postoperative hours, CTnl and MDA levels were statistically higher in the intravenous group compared to the CPB prime and cardioplegia groups. There was no significant difference between the three groups regarding serum creatinine, serum CK-MB, global LV function and postoperative clinical variables. NAC administration into the CPB prime or within the cardioplegia for patients undergoing CABG using CPB resulted in better myocardial protection compared to intravenous administration. There was no significant change in the clinical outcome and renal function between the three groups

prognostic value of alveolar recruitment strategy during the intra and postoperative periods in off pump coronary artery bypass surgery

In Off Pump Coronary Artery Bypass [OPCAB] surgery, there is a high incidence of deterioration in lung mechanics and arterial oxygenation. This study aimed at assessing the effect of alveolar recruitment on lung mechanics and oxygenation in patients undergoing OPCAB surgery. In this study, we performed a randomized controlled trial between 2 groups of patients undergoing OPCAB surgery. Group A: patients received a PEEP of 5 cm H20 only. Group 3: Alveolar Recruitment Strategy [ARS] was applied after finishing the proximal anastomotic procedure and repeated in the postoperative period in the ICU. The ARS consisted of raising the peak inspiratory Pressure [PIP] to 30 cm H20 and setting PEEP at 10 cm H20 and maintaining them for 1 minute. Then, both PIP and PEEP were increased to 40 and 15 cm H20 respectively and maintained for another minute. After arrival to the ICU, all patients received 5 cm H20 PEEP, then after 1 hour, the patients received either PEEP only or with the same previous strategy as in O.R. to their groups. In the OR, lung compliance as well as arterial oxygenation were measured after induction of anesthesia, before, and after setting both PEEP and ARS. In the ICU, arterial oxygenation was measured before both PEEP and ARS, as well as one and four hours later. Postoperative pulmonary complications including hypoxemia, hypercapnia, atelectasis, prolonged intubation, pulmonary congestion, pulmonary infection, total ICU stay and mortality werq recorded. There was a significant rise in lung compliance and arterial oxygenation in the ARS [Group B] than in the PEEP group [Group A]. As regards the Arterial Oxygen Tension, there was a continuous statistically significant rise in group B than in group A, 30 minutes after starting the ARS in the OR, before starting the ARS in the ICU, 30 minutes, 1 and 4 hours later [206.5 +/- 23.9,192.2 +/- 23.5, 250.7 +/- 31.9, 211.9 +/- 21.3 mmHg and 195.3 +/- 24.5 mm/Hg respectively in group B versus 126.9 +/- 10.1, 128.7111.6, 129.1 +/- 10.4, 129.8 +/- 9.4 mmHg and 130.1 +/- 9.7 mm/Hg respectively in group A] [P< 0.0001]. Additionally, there was a marked reduction in the postoperative hypoxemia, hypercarnia, atelectasis, prolonged intubation, infection and prolonged ICU stay in the ARS group. OPCAB patients in whom there is a reduction in lung compliance owing to the large volumes of intravenous fluids and compression of the right chest by the rotated heart during revascularization of the postero-lateral coronary vessels, applying an ARS in those patients greatly improves lung mechanics and arterial oxygen tension

Effects of dexmedetomidine in morbidly obese patients undergoing laparoscopic gastric bypass

Obese patients may be sensitive to the respiratory depressant effect of opioid analgesics. Alternative methods for analgesia may be beneficial for management of bariatric surgery. We evaluated the effect of dexmedetomidine on anesthetic requirements during surgery, hemodynamic, recovery profile and morphine use in the postoperative period. Eighty adult patients scheduled for elective laparoscopic Roux-en-Y gastric bypass surgery were randomly assigned to one of two study groups; Group D [40 patients] received dexmedetomidine [0.8-micro g/kg bolus, 0.4 micro g.kg[-1]. h[-1] and Group P [40 patients] received normal saline [placebo] in the same volume and rate. Intraoperative and postoperative mean blood pressure and heart rate were recorded. The total amount of intraoperative fentanyl and propofol required to maintain anesthesia were measured. Recovery profile, pain score and total amount of morphine used via patient controlled analgesia [PCA] were assessed. During surgery, dexmedetomidine decreased the total amount of intraoperative fentanyl and propofol required for maintenance of anesthesia compared to placebo. Patients who received dexmedetomidine showed significant decrease of intraoperative and postoperative mean blood pressure, heart rate. In the postoperative period, dexmedetomidine decreased pain scores and PCA morphine use significantly and showed better recovery profile as compared to the placebo group. There was no difference in the incidence of postoperative nausea and vomiting [PONV] between both groups. The intraoperative infusion of dexmedetomidine decreased the total amount of propofol and fentanyl required to maintain anesthesia, offered better control of intraoperative and postoperative hemodynamics, decreased postoperative pain level, decreased the total amount of morphine used and showed better recovery profile compared with placebo