Mahesh Vakamudi

The effects of dexmedetomidine on attenuation of stress response to endotracheal intubation in patients undergoing elective off-pump coronary artery bypass grafting.

This study was designed to study the efficacy of intravenous dexmedetomidine for attenuation of cardiovascular responses to laryngoscopy and endotracheal intubation in patients with coronary artery disease. Sixty adult patients scheduled for elective off-pump coronary artery bypass surgery were randomly allocated to receive dexmedetomidine (0.5 mcg/kg) or normal saline 15 min before intubation. Patients were compared for hemodynamic changes (heart rate, arterial blood pressure and pulmonary artery pressure) at baseline, 5 min after drug infusion, before intubation and 1, 3 and 5 min after intubation. The dexmedetomidine group had a better control of hemodynamics during laryngoscopy and endotracheal intubation. Dexmedetomidine at a dose of 0.5 mcg/kg as 10-min infusion was administered prior to induction of general anaesthesia attenuates the sympathetic response to laryngoscopy and intubation in patients undergoing myocardial revascularization. The authors suggest its administration even in patients receiving beta blockers.

The effects of preemptive pregabalin on attenuation of stress response to endotracheal intubation and opioid- sparing effect in patients undergoing off-pump coronary artery bypass grafting

The clinical study was designed to evaluate and compare single preoperative dose of pregabalin to a placebo regarding hemodynamic responses to laryngoscopy and endotracheal intubation, to assess perioperative fentanyl requirement and any side-effects. It was a randomized, double-blind, placebo-controlled, parallel assignment, efficacy study. The study was done at a tertiary university hospital. This study was a comparison between two groups of 30 adult patients scheduled for elective off pump coronary artery bypass surgery. In the control group, the patients were given placebo capsules, and in the pregabalin group, the patients were given pregabalin 150 mg capsule orally 1 h before surgery. The patients were compared for hemodynamic changes before the start of the surgery, after induction, 1, 3, and 5 min after intubation. Additionally, fentanyl requirement during surgery and the first postoperative day was also compared. The present study shows that a single oral dose of 150 mg pregabalin given 1 h before surgery attenuated the pressor response to tracheal intubation in adults, but the drug did not show any effect on perioperative opioid consumption and was devoid of side-effects in the given dose.

A comparison of hemodynamic effects of levosimendan and dobutamine in patients undergoing mitral valve repair / replacement for severe mitral stenosis

AIMS AND OBJECTIVES We aimed to compare the hemodynamic effects of levosimendan and dobutamine in patients undergoing mitral valve surgery on cardiopulmonary bypass (CPB). MATERIALS AND METHODS Sixty patients were divided into 2 groups of 30 each. Group-L patients received levosimendan 0.1 μg/kg/min and Group-D patients received dobutamine 5 μg/kg/min while weaning off CPB. Additional inotrope and/or vasoconstrictor were started based on hemodynamic parameters. Hemodynamic data were collected at the end and at 30 minutes after CPB, thereafter at 6, 12, 24, and 36 hours post-CPB. Mean arterial pressure (MAP), central venous pressure (CVP), heart rate (HR), cardiac index (CI), systemic vascular resistance index (SVRI), and lactate levels were measured. RESULTS Group-L showed increased requirement of inotropes and vasoconstrictors. The SVRI, CVP, and MAP were reduced more in Group-L. The CI was low in Group-L in the initial period when compared to Group-D. Later Group-L patients showed a statistically significant increase in CI even after 12 hrs of discontinuation of levosimendan infusion. The HR was increased more in Group-D. Lactate levels, intensive care unit stay, and duration of ventilation were similar in both groups. CONCLUSIONS Levosimendan 0.1 μg/kg/min compared to dobutamine 5 μg/kg/min showed more vasodilation and lesser inotropic activity in patients undergoing mitral valve surgery for mitral stenosis. Levosimendan compared to dobutamine showed a statistically significant increase in CI even after 12 hrs of discontinuation. The requirement of another inotrope or vasopressor was frequent in levosimendan group.

Effect of levosimendan on hemodynamic changes in patients undergoing off-pump coronary artery bypass grafting: A randomized controlled study

AIMS AND OBJECTIVE We tested the hypothesis that use of levosimendan would be associated with better perioperative hemodynamics and cardiac function during off-pump coronary artery bypass grafting (OPCAB) in patients with good left ventricular function. MATERIALS AND METHODS Thirty patients scheduled for OPCAB were randomized in a double-blind manner to receive either levosimendan 0.1 μg/kg/min or placebo after induction of general anesthesia. The hemodynamic variables were measured after induction of anesthesia, at 6 minute after application of tissue stabilizer for the anastomoses of left anterior descending artery, diagonal artery, left circumflex artery, and right coronary artery and at 6, 12, 18, and 24 hours after completion of surgery. RESULTS Compared with placebo group, cardiac index (CI) was significantly higher and systemic vascular resistance index (SVRI) was significantly lower at 6, 12, 18, and 24 hour after surgery in levosimendan group. Norepinephrine was infused in 60% of the patients in the levosimendan group compared to 6.7% in the control group ( P < 0.05). Lactate and mixed venous oxygen saturation were not significantly different between groups. CONCLUSIONS Levosimendan significantly increased CI and decreased SVRI after OPCAB but it did not show any outcome benefit in terms of duration of ventilation and intensive care unit stay.

Lower ministernotomy and fast tracking for atrial septal defect.

We report our experience with a 3–5-cm lower ministernotomy incision for closure of atrial septal defect in 53 patients. Fibrillatory arrest was used in 19 patients, and crossclamping with cardioplegia in 33. One patient had to be converted from fibrillatory arrest to crossclamping with cardioplegic arrest. The mean bypass time was 39.6 ± 13.1 min, arrest time was 9.9 ± 4.5 min, and crossclamp time was 20.7 ± 8.69 min. All patients recovered without adverse events. They were fast tracked to recovery and extubated after 63.4 ± 9.2 min. The mean intensive care unit stay was 1.07 ± 0.33 days, and hospital stay was 3.07 ± 0.38 days. The ministernotomy approach was used successfully in 51 patients; in the other 2, it had to be converted to a full sternotomy because of technical difficulties. Our experience confirms that this technique offers satisfactory cosmetic results, stable sternal reconstruction, good surgical exposure, minimal interference with respiratory mechanics, and minimal pain, allowing extubation in the operating room and a speedy recovery.

Efficacy of clonidine as an adjuvant to ropivacaine for caudal analgesia in children undergoing subumbilical surgery

Context: The use of clonidine as an adjuvant to ropivacaine in different concentrations through the caudal space has been shown to improve the analgesic efficacy of local anesthetics. Aims: The purpose of our study was to compare the efficacy of ropivacaine 0.1% with clonidine 1 mcg/kg to that of plain 0.1% and 0.2% ropivacaine for caudal analgesia in children. Settings and Design: Prospective, double blind, randomized controlled trial. Materials and Methods: Sixty children in the age group of 1–6 years undergoing subumbilical surgeries were included in the study. Group A received 1 ml/kg of 0.1% ropivacaine, group B received 1 ml/kg of 0.1% ropivacaine with clonidine 1 mcg/kg, and group C received 1 ml/kg of 0.2% ropivacaine. Results: The mean duration of analgesia was 243.7 ± 99.29 min in group A, 590.25 ± 83.93 min in group B, and 388.25 ± 82.35 min in group C. The duration of analgesia was significantly prolonged in group B compared to groups A and C with the P value of 0.001. At 8 h, all the 20 children in group A had received the first rescue analgesic compared to 18 children in group C and 3 children in group B. The duration of motor blockade after extubation was 30.6 ± 7.8 min and was noted only in group C. Only 1 child in group B received two rescue medications compared to 15 (75%) children in group A and 8 (40%) children in group C. None of the groups were treated for bradycardia or hypotension and no significant sedation was noted. Conclusions: Clonidine 1 mcg/kg with ropivacaine 0.1% prolongs the duration and quality of analgesia compared to plain ropivacaine 0.1% and 0.2% without any significant sedation.

Anaesthetic management of total craniopagus twins for magnetic resonance imaging and cerebral angiography

We describe the anaesthetic management of 4-yr-old total craniopagus twins for radiological investigations. There are some unique anaesthetic problems associated with this condition. These include cross-circulation between the twins that results in induction of both the twins after the administration of i.v. induction agent to one twin and difficulty in mask ventilating both the twins simultaneously due to the angle between the heads; different arterial pressures in the two children complicate pharmacological management and underline the importance of physiological measures to control arterial pressure. Adequate preparation and teamwork is the keystone to the management of these patients.

Scimitar Syndrome: Experience with 6 Patients

Scimitar syndrome is a rare congenital anomaly characterized by anomalous pulmonary venous drainage to the inferior vena cava, causing a left-to-right shunt. Six patients with scimitar syndrome were diagnosed in our hospital between 2002 and 2008. There were 4 girls and 2 boys; 4 < 5 kg in weight, 2 < 8 kg in weight. Scimitar syndrome was suspected in 5 cases because of dextroversion, and diagnosed by color Doppler echocardiography in all 6 when a scimitar vein was detected entering the inferior vena cava. Computed tomography confirmed the diagnosis in all patients. Two patients had horseshoe lung, 2 had a unilobar right lung, 1 had a hypoplastic right lung, and 1 had a hypoplastic right lower lobe. Three patients had severe pulmonary arterial hypertension, 2 had moderate pulmonary arterial hypertension, and one had normal pulmonary arterial pressure. All patients had lower respiratory tract infections, volume loss of the right lung, a normal or hyperinflated left lung, dextroversion of the heart, and scimitar arteries from the descending aorta. Pneumonectomy was performed in 3 patients, lobectomy in 1, ligation of anomalous vessels in 1, and 1 died before surgery.

Nasal fiberoptic-guided oral tracheal intubation in neonates and infants with Pierre Robin sequence.

Sir—Neonates with the Pierre Robin sequence present with a difficult airway because of micrognathia. They may also have severe respiratory difficulty in the newborn period, and tongue lip adhesion surgery is necessary to relieve the upper airway obstruction in some of these children. Induction of anesthesia and tracheal intubation in these children is a challenging task. We describe a method of intubation using the pediatric fiberoptic bronchoscope in three children with Pierre Robin sequence.

Efficacy of clonidine as an adjuvant to bupivacaine for caudal analgesia in children undergoing sub-umbilical surgery

Caudal epidural analgesia with bupivacaine is very popular in paediatric anaesthesia for providing intra- and postoperative analgesia. Several adjuvants have been used to prolong the action of bupivacaine. We evaluated the efficacy of clonidine added to bupivacaine in prolonging the analgesia produced by caudal bupivacaine in children undergoing sub-umbilical surgery. One hundred children, age one to three years, undergoing sub-umbilical surgery, were prospectively randomized to one of two groups: caudal analgesia with 1 ml/kg of 0.25% bupivacaine in normal saline (Group A) or caudal analgesia with 1 ml/kg of 0.25% bupivacaine with 1 µg/kg of clonidine in normal saline (Group B). Post-operative pain was assessed for 24 hours using the FLACC scale. The mean duration of analgesia was significantly longer in Group B (593.4 ± 423.3 min) than in Group A (288.7 ± 259.1 min); P < 0.05. The pain score assessed using FLACC scale was compared between the two groups, and children in Group B had lower pain scores, which was statistically significant. The requirement of rescue medicine was lesser in Group B. Clonidine in a dose of 1 µg/kg added to 0.25% bupivacaine for caudal analgesia, during sub-umbilical surgeries, prolongs the duration of analgesia of bupivacaine, without any side effects.