N Manjunatha

To evaluate dexmedetomidine as an additive to propofol for sedation for elective cardioversion in a cardiac intensive care unit: A double-blind randomized controlled trial

Introduction: Propofol may lead to patient recall and discomfort when used for sedation in elective cardioversion. The aim of the present study was to evaluate dexmedetomidine as an additive to propofol for sedation in elective cardioversion. Materials and Methods: A total of 500 patients undergoing elective cardioversion were randomized into Group 1 (n = 250) and Group 2 (n = 250) on the basis of computer-generated randomization table. Patients in Group 1 were given dexmedetomidine (1 mcg/kg) over 10 min before giving propofol (1 mg/kg), while patients in Group 2 were given only propofol (1 mg/kg). One or two additional doses of 0.5 mg/kg propofol were given if modified Ramsay Sedation Score (mRSS) was <5. Number of patients requiring additional doses were noted. Any hemodynamic or respiratory complication along with the mean time to recovery (mRSS = 1) was recorded. Patient recall, patient discomfort, and further requirement of cardioversion in the next 24 h were also noted. Results: About 10% patients in Group 1 and 64% patients in Group 2 required the first additional dose of propofol. While no patient in Group 1 required second dose, 16% patients in Group 2 required second dose of propofol. The mean time to recovery in Group 1 was 8.36 ± 3.08 min and 8.22 ± 2.38 min in Group 2 (P = 0.569). Sixty-seven patients (26.8%) in Group 1 and 129 patients (51.6%) in Group 2 reported remembering something (P < 0.0001), i.e., recall. Thirty-five patients (14%) in Group 1 and 79 patients (31.6%) in Group 2 reported dreaming during the procedure (P < 0.0001). Visual analog scale score was higher in Group 1 as compared to Group 2. Six patients in Group 1 and 24 patients in Group 2 had a requirement of repeat cardioversion in 24-h follow-up (P = 0.001). Conclusions: Dexmedetomidine is a useful adjunct to propofol for elective cardioversion.

Effect of dexmedetomidine on diseased coronary vessel diameter and myocardial protection in percutaneous coronary interventional patients.

Introduction: Dexmedetomidine is an alpha-2 agonist used for conscious sedation. It has also been shown to have a myocardial protective effect in off-pump coronary artery bypass patients. The aim of the study was to assess the effect of dexmedetomidine for myocardial protection in percutaneous coronary interventional patients. Methodology: A total of 60 patients (group dexmedetomidine, n = 30 and group normal saline, n = 30) were enrolled in the study. Dexmedetomidine infusion (1 mcg/kg) over 15 min was given as a loading dose after coronary angiography in group dexmedetomidine (D) while normal saline was given in the control group (C) and later maintenance infusion was started at 0.5 mcg/kg/h in both the groups. Coronary vessel diameter was noted before (T0) and after (T1) loading dose of dexmedetomidine/saline in each group. Troponin T (Trop T) values were noted at baseline (T0), 6 h (T2), 12 h (T3) and 24 h (T4) after starting the loading dose. Hemodynamic variables (heart rate [HR] and blood pressure) were monitored at T0, T1, and at regular intervals till 2 h postprocedure. Results: Coronary vessel diameter and HR significantly decreased in group D as compared to control group (P < 0.05) whereas the decrease in Trop T at 6 h, 12 h, and 24 h were not statistically significant between the two groups. Conclusion: Dexmedetomidine decreases the coronary vessel diameter, but maintains the myocardial oxygen demand-supply ratio by decreasing the HR. The decrease in Trop T is statistically insignificant at the doses used.

Comparison between noninvasive measurement of central venous pressure using near infrared spectroscopy with an invasive central venous pressure monitoring in cardiac surgical Intensive Care Unit.

Introduction: Central venous pressure (CVP) measurement is essential in the management of certain clinical situations, including cardiac failure, volume overload and sepsis. CVP measurement requires catheterization of the central vein which is invasive and may lead to complications. The aim of this study was to evaluate the accuracy of measurement of CVP using a new noninvasive method based on near infrared spectroscopy (NIRS) in a group of cardiac surgical Intensive Care Unit (ICU) patients. Methodology: Thirty patients in cardiac surgical ICU were enrolled in the study who had an in situ central venous catheter (CVC). Sixty measurements were recorded in 1 h for each patient. A total of 1800 values were compared between noninvasive CVP (CVPn) obtained from Mespere VENUS 2000 CVP system and invasive CVP (CVPi) obtained from CVC. Results: Strong positive correlation was found between CVPi and CVPn (R = 0.9272, P < 0.0001). Linear regression equation - CVPi = 0.5404 + 0.8875 × CVPn (r2 = 0.86, P < 0.001), Bland-Altman bias plots showed mean difference ± standard deviation and limits of agreement: −0.31 ± 1.36 and − 2.99 to + 2.37 (CVPi-CVPn). Conclusion: Noninvasive assessment of the CVP based on NIRS yields readings consistently close to those measured invasively. CVPn may be a clinically useful substitute for CVPi measurements with an advantage of being simple and continuous. It is a promising tool for early management of acute state wherein knowledge of CVP is helpful.

The Effect of Inhaled Milrinone Versus Inhaled Levosimendan in Pulmonary Hypertension Patients Undergoing Mitral Valve Surgery — A Pilot Randomized Double-Blind Study

OBJECTIVE To compare the effects of inhaled milrinone and levosimendan on pulmonary and systemic hemodynamics in patients with pulmonary hypertension. DESIGN Prospective, double-blind, randomized controlled study. SETTING Tertiary care cardiac institute with 650 beds. PARTICIPANTS The study comprised 150 adult patients with pulmonary hypertension undergoing mitral valve surgery. INTERVENTIONS Patients were assigned randomly into 1 of the following 3 groups: milrinone (M), levosimendan (L), or control (C); n = 50 per group. In group M, inhaled milrinone (50 µg/kg); in group L, inhaled levosimendan (24 µg/kg); and in group C, normal saline was administered when the patient arrived in the recovery room. Pre-inhalation and post-inhalation hemodynamics (mean arterial pressure [MAP], pulse rate, and systemic vascular resistance [SVR]) were noted until 24 hours of inhalation of the drug. The change in pulmonary artery pressures (pulmonary artery systolic pressure [PASP] and mean pulmonary artery pressure [MPAP]) and the duration for which they remained decreased compared with the control group, were noted. MEASUREMENTS AND MAIN RESULTS MAP, pulse rate, and SVR were comparable in the 3 groups at various time intervals. PASP and MPAP decreased comparably after inhalation of levosimendan and milrinone. However, they reached levels near the control group values after 2.5 to 3 hours in group L and after 0.5 hours in group M. CONCLUSIONS Because inhaled levosimendan causes a decrease in PASP and MPAP without causing a decrease in SVR and MAP, the authors conclude that inhaled levosimendan is a selective pulmonary vasodilator. It is as effective as milrinone in reducing pulmonary artery pressures. In addition, it has advantage over inhaled milrinone because it is has a longer duration of action.

Anaesthetic management of an infant posted for ventricular septal defect closure with right-sided eventration of diaphragm

Eventration of the diaphragm is a rare entity, characterised by abnormal elevation of a dome of diaphragm. In this condition, the diaphragm is composed of fibrous tissue with few or no interspersed muscle fibres. Eventration can be congenital or acquired. Congenital eventration results from inadequate development of muscles or absence of phrenic nerve. The common cause of acquired eventration is injury to the phrenic nerve from traumatic birth injury or surgery for heart disease. The perioperative anaesthetic management of diaphragmatic eventration along with ventricular septal defect with severe pulmonary hypertension makes this case both challenging and unique.

Dexmedetomidine for prevention of skeletal muscle ischaemia-reperfusion injury in patients with chronic limb ischaemia undergoing aortobifemoral bypass surgery: A prospective double-blind randomized controlled study

Background: Dexmedetomidine is a selective α-2 agonist used for sedation. It has also been shown to have myocardial protective effect and prevent ischemia-reperfusion injury in off-pump coronary artery bypass patients. The aim of our study was to assess the effect of dexmedetomidine for prevention of skeletal muscle ischemia-reperfusion injury in patients undergoing aortobifemoral bypass surgery. Methodology: Sixty adult patients (Group dexmedetomidine n = 30, Group normal saline n = 30) undergoing aortobifemoral bypass surgery were recruited over 3 months. Randomization was done using a computer-generated random table. The attending anesthesiologist would be blinded to whether the drug/normal saline was being administered. He would consider each unlabeled syringe as containing dexmedetomidine and calculate the volume to be infused via a syringe pump accordingly. Dexmedetomidine infusion (1 mcg/kg) over 15 minutes was given as a loading dose, followed by maintenance infusion of 0.5 mcg/kg/h till 2 h postprocedure in Group dexmedetomidine (D) while the same volume of normal saline was given in the control Group C till 2 h postprocedure. Creatine phosphokinase (CPK) values were noted at baseline (T0), 6 h (T1), 12 h (T2), and 24 h (T3) after the procedure. Hemodynamic variables (heart rate [HR] and mean blood pressure [MAP]) were recorded at T0, T1, T2, and T3. Results were analyzed using unpaired Students t-test, P < 0.05 was considered statistically significant. Results: MAP and HR significantly decreased in Group D as compared to control group (P < 0.05). However, the decrease was never <20% of the baseline. The CPK values at 6, 12, and 24 h were statistically significant between the two groups. Conclusion: Dexmedetomidine prevents skeletal muscle ischemia-reperfusion injury in patients undergoing aortobifemoral bypass surgery.

Anesthetic management of a case of Gilbert's syndrome for mitral and aortic valve replacement: Role of transesophageal echocardiography

Gilberts syndrome (GS) is an autosomal inherited disorder characterized by relative deficiency of glucuronyl transferase and poor uptake of unconjugated bilirubin by hepatocytes. Cardiac surgery on cardiopulmonary bypass (CPB) in these patients triggers further hepatic dysfunction. Transesophageal echocardiography (TEE) and Doppler assessment of hepatic vein help in assessing hepatic blood flow (HBF) during cardiac surgery. Here, we discuss anesthetic management and role of TEE in maintaining HBF perioperatively in a 25-year-old male patient with GS undergoing double valve replacement with tricuspid valve plasty. TEE-guided HBF monitoring and management of hepatic perfusion by modifying anesthetic and CPB protocol resulted in the favorable outcome.

Anaesthetic management of infants posted for repair of anomalous origin of left coronary artery from pulmonary artery

First described in 1908, anomalous origin of left coronary artery from pulmonary artery is a very rare congenital anomaly. Here, the right coronary artery is usually enlarged and has a normal origin from aorta. Numerous collaterals connect the two coronary arteries over right ventricular outflow tract or interventricular septum. It is one of the most common causes of myocardial ischaemia and infarction in children.

Prayer sign as a marker of increased ventilatory hours, length of intensive care unit and hospital stay in patients undergoing coronary artery bypass grafting surgery

Context: Various predictors have been used to predict diabetic patients who are likely to have increased ventilatory hours and an increased length of stay (LOS) in the Intensive Care Unit (ICU) as well as in the hospital after undergoing coronary artery bypass grafting (CABG) surgery, for example, glycosylated hemoglobin (HbA1c). The authors propose a simple bed-side test, i.e., the prayer sign to predict increased ventilatory hours and increased length of ICU and hospital stay. Aims: The aim of the present study was to assess whether any association exists between a positive prayer sign and increased ventilatory hours, length of ICU and hospital stay after CABG surgery in diabetic patients. Settings and Design: This prospective observational study was conducted in a 650-bedded tertiary cardiac center. Subjects and Methods: A total of 501 diabetic patients were recruited in the study over a period of 1 year. Group P consisted of 121 patients with prayer sign positive, whereas Group N consisted of 380 patients with prayer sign negative. HbA1c levels, ventilatory hours, LOS in the postoperative ICU and hospital were compared. Statistical Analysis Used: Unpaired Student′s t-test was used to compare the data. Results: The mean HbA1c levels in Group P were 8.01 ± 2.28% as compared to 6.52 ± 2.46% in Group N (P < 0.0001). The mean ventilatory hours in Group P were 9.52 ± 6.46 h, and in Group N were 7.42 ± 8.01 h (P = 0.013). Whereas, the mean length of ICU stay and hospital stay in Group P was 156.42 ± 32.66 h (6.51 ± 1.36 days) and 197.36 ± 32.46 h (8.22 ± 1.35 days), respectively, it was 121.12 ± 29.48 h (5.04 ± 1.22 days) and 178.52 ± 28.52 h (7.43 ± 1.18 days) in Group N (P < 0.0001). Conclusions: A positive prayer sign is a useful bedside test for predicting increased ventilatory hours and increased length of ICU and hospital stay after CABG surgery.

Effect of periradial administration of papaverine on radial artery diameter

Background: Radial artery cannulation is a skillful procedure. An experienced anesthesiologist might also face difficulty in cannulating a feeble radial pulse. Aim: The purpose of the study was to determine whether periradial subcutaneous administration of papaverine results in effective vasodilation and improvement in the palpability score of radial artery. Settings and Design: Prospective, double-blinded trial. Methodology: Thirty patients undergoing elective cardiac surgery were enrolled in the study. 30 mg of papaverine with 1 ml of 2% lignocaine and 3 ml of normal saline were injected subcutaneously 1–2 cm proximal to styloid process of the radius. Radial artery diameter before and after 20 min of injection papaverine was measured using ultrasonography. The palpability of the radial pulse was also determined before the injection of papaverine and 20 min later. Patients were monitored for hemodynamics and any complications were noted. Statistical Analysis Used: Students t-test for paired data. Results: Radial artery diameter increased significantly (P < 0.0001), and the pulse palpability score also showed statistically significant improvement (P < 0.0001) after periradial subcutaneous administration of papaverine. There was no statistically significant difference in heart rate, mean arterial blood pressure before and after papaverine injection. No complications were noted in 24 h of follow-up. Conclusion: Periradial subcutaneous administration of papaverine significantly increased the radial artery diameter and pulse palpability score, which had an impact on ease of radial artery cannulation essential for hemodynamic monitoring in cardiac surgical patients.