Effects of intranasal dexmedetomidine versus intranasal midazolam as premedication in children with tetralogy of Fallot undergoing corrective cardiac surgery: A randomized trial.

Background: This prospective, randomized, double-blind trial was done to compare intranasal dexmedetomidine and intranasal midazolam as premedication for sedation and ease of child-parent separation in pediatric patients of tetralogy of Fallot (TOF) undergoing corrective cardiac surgery. Materials and Methods: Forty children with TOF, between 1 and 10 years, undergoing corrective cardiac surgery were included in the study and, after randomization, were given intranasal midazolam (0.2 mg/kg) or intranasal dexmedetomidine (1 µg/kg), 30 min before shifting to the operation room (OR). Patients were assessed for sedation and child-parent separation, along with hemodynamic parameters, respiratory rate, and oxygen saturation (SpO2) 30 min after drug administration, at the time of shifting inside the OR, and at the time of induction of anesthesia. Results: Both groups had comparable child-parent scores, hemodynamic parameters, SpO2, and respiratory rate. However, the dexmedetomidine group had significantly better sedation levels than the midazolam group patients at the time of shifting inside the OR (dexmedetomidine group: 3.55 ± 0.82 vs. midazolam group: 2.80 ± 0.83; P = 0.007) and at the time of induction of anesthesia (dexmedetomidine group: 3.40 ± 0.75 vs. midazolam group: 2.70 ± 0.86; P = 0.009). Conclusion: Intranasal dexmedetomidine provides better sedation than midazolam, with similar child-parent separation scores and hemodynamic parameters, respiratory rate, and SpO2. No adverse events were observed in both groups. A study on a larger population will help in further establishing the safety and superiority of dexmedetomidine and will further its regular use as an intranasal premedication.

Delayed Diagnosis of Pulmonary Artery Thrombosis in a Patient Undergoing Mitral Valve Replacement.

ABSTRACT: The occurrence of pulmonary artery thrombus in association with rheumatic mitral stenosis is a rare complication. Pulmonary artery thrombus formation may worsen pulmonary artery pressures, and this may precipitate acute right heart failure. The possible mechanisms behind pulmonary artery thrombus formation during mitral valve replacement surgery could be acute coagulopathy following surgery, the presence of chronic pulmonary thromboembolism, or chronic atrial fibrillation. We report an unusual case of pulmonary artery thrombus in a patient with rheumatic MS which was diagnosed with transoesophageal echocardiography after MVR.

Comparison of Multiple Injection Costotransverse Block and Erector Spinae Plane Block for Post-Sternotomy Pain Relief in Pediatric Patients Undergoing Cardiac Surgery: A Prospective Randomized Comparative Study.

OBJECTIVE: The aim of this study was to evaluate the efficacy of ultrasound-guided multiple injection costotransverse block (MICB) and compare it with erector spinae plane block (ESPB) for poststernotomy pain relief in pediatric cardiac surgical patients. DESIGN: A prospective, randomized, double-blind, comparative study. SETTING: At a single institution tertiary referral cardiac center. PARTICIPANTS: A total of 90 children with acyanotic congenital heart disease requiring surgery via sternotomy. INTERVENTIONS: Children were allocated randomly to 1 of the 3 following groups: ESPB (group 1), MICB (group 2), or Control (group 3). Participants in groups 1 and 2 received 4 mg/kg of 0.2% ropivacaine for bilateral ultrasound-guided block after induction of anesthesia. Postoperatively, intravenous paracetamol was used for multimodal analgesia, and fentanyl/tramadol was used for rescue analgesia. MEASUREMENTS AND MAIN RESULTS: The modified objective pain score (MOPS) was evaluated at 0, 1, 2, 4, 6, 8, 10, and 12 hours postextubation. After all exclusions, 84 patients were analyzed. The MOPS score was found to be significantly lower in ESPB and MICB groups compared to the control group until 10 hours postextubation (p < 0.05), with no statistically significant difference at the 12th hour (p = 0.2198). The total intraoperative fentanyl consumption (p = 0.0005), need for fentanyl supplementation on incision (p < 0.0001), and need for rescue opioid requirement in the postoperative period (p = 0.034) were significantly lower in both the ESPB and MICB groups than the control group. There were no statistically significant differences in both primary and secondary outcomes between the ESPB and MICB groups. CONCLUSION: Ultrasound-guided MICB was effective and comparable to ESPB for post-sternotomy pain management in pediatric cardiac surgical patients.

Efficacy of Incisional Ropivacaine Infiltration by Presternal Multi-Orifice Catheter for Post-sternotomy Pain Relief in Pediatric Patients Undergoing Cardiac Surgery: A Prospective, Randomized, Controlled Study.

OBJECTIVE: To evaluate the efficacy of incisional ropivacaine infiltration by presternal multi-orifice catheter to manage poststernotomy pain in pediatric cardiac surgery. DESIGN: A prospective, randomized, and double-blind comparative study. SETTING: At a single-institution tertiary referral cardiac center. PARTICIPANTS: The study comprised 200 children undergoing cardiac surgeries through a midline sternotomy. INTERVENTIONS: Children were allocated randomly to 1 of 3 groups. Group A (n = 65) and group B (n = 64) received 0.375% ropivacaine infusion and intermittent bolus, respectively, by presternal multi-orifice catheter, whereas Group C (n = 64) did not receive any local anesthetic (LA) drug. Postoperatively, intravenous paracetamol was used for multimodal analgesia, and fentanyl was given as rescue analgesia, respectively. MEASUREMENTS AND MAIN RESULTS: Pain was assessed by a Modified Objective Pain Score (MOPS) for 48 hours postextubation. Group B had significantly lower early MOPS at the first hour, but in the later period, the mean MOPS was lower in group A. The requirement of the first rescue analgesia was 3 ± 1.51, 6.1 ± 2.26, and 2.6 ± 0.87 hours for groups A (n = 60), B (n = 60), and C (n = 60), respectively. The 48-hour fentanyl consumption was significantly lower (p < 0.001) in group A (0.5 ± 0.68 µg/kg) and group B (0.7 ± 0.86 µg/kg) than the control group (3.4 ± 0.68 µg/kg). The length of intensive care unit stay was lower (p < 0.001) in groups A and B than in group C; however, the length of hospital stay was comparable (p = 0.07). CONCLUSION: LA bolus and infusion through presternal multi-orifice catheter provided effective analgesia postoperatively. However, the bolus was more efficacious in the early phase but equivalent in later periods. Therefore, bolus and LA infusion can be used for steady poststernotomy pain relief in children undergoing cardiac surgeries.

Williams-Beuren syndrome with pseudoaneurysm of aortic arch and infective vegetations for modified broms procedure: anesthetic concerns & Echocardiographic illustrations.

Williams-Beuren syndrome is a rare genetic malformation with predilection for supravalvular aortic stenosis. Apart from cardiovascular malformation, hypocalcemia, developmental delay, and elfin facies, challenging airway make perioperative management more eventful. Association of infective endocarditis within the aortic arch and pseudoaneurysm formation is infrequent. We, hereby report a case of pseudoaneurysm formation and infective vegetation within the aortic arch in a patient with Williams syndrome and the role of transthoracic echocardiography in its perioperative management.

Haemodynamic predisposition to acute kidney injury: Shadow and light!

Acute kidney injury (AKI) could well be regarded as a sentinel complication given it is relatively common and associated with a substantial risk of subsequent morbidity and mortality. On the aegis of 'prevention is better than cure', there has been a wide interest in evaluating haemodynamic predisposition to AKI so as to provide a favourable renoprotective haemodynamic milieu to the subset of patients presenting a significant risk of developing AKI. In this context, the last decade has witnessed a series of evaluation of the hypotension value and duration cut-offs associated with risk of AKI across diverse non-operative and operative settings. Nevertheless, a holistic comprehension of the haemodynamic predisposition to AKI has been a laggard with only few reports highlighting the potential of elevated central venous pressure, intra-abdominal hypertension and high mean airway pressures in considerably attenuating the effective renal perfusion, particularly in scenarios where kidneys are highly sensitive to any untoward elevation in the afterload. Despite the inherent autoregulatory mechanisms, the effective renal perfusion pressure (RPP) can be modulated by a number of haemodynamic factors in addition to mean arterial pressure (MAP) as the escalation of renal interstitial pressure, in particular hampers kidney perfusion which in itself is a dynamic interplay of a number of innate pressures. The present article aims to review the subject of haemodynamic predisposition to AKI centralising the focus on effective RPP (over and above the conventional 'tunnel-vision' for MAP) and discuss the relevant literature accumulating in this area of ever-growing clinical interest.

Comparison of Changes in Thoracic Fluid Content Between On-Pump and Off-Pump CABG by Use of Electrical Cardiometry.

OBJECTIVES: To compare the changes in thoracic fluid content, PaO2/FIO2 ratio, plateau pressure, compliance, and postoperative ventilation duration in off-pump coronary artery bypass grafting (OPCAB) and on-pump coronary artery bypass grafting (ONCAB). DESIGN: Prospective observational study. SETTING: Tertiary-care cardiac center. PARTICIPANTS: Over an 18-month period, from December 2019 to May 2021, 111 patients who underwent CAB grafting were enrolled. Group I constituted OPCAB patients and Group II the ONCAB patients. INTERVENTIONS: After induction, the authors measured thoracic fluid content (TFC), pulmonary compliance, airway pressures, and the PaO2/FIO2 ratio before skin incision (T1) and after skin closure (T2). The input, output, as well as the duration of postoperative ventilation, also were recorded. RESULTS: At T2, the ONCAB group had a significantly higher change in TFC than the OPCAB group (5.4 ± 1.86 kOhm-1v 4.32 ± 1.84 kOhm-1, p = 0.012). The fluid balance was significantly higher in the OPCAB group compared with the ONCAB group (2,159.21 ± 108.73 mL v 1,792.50 ± 151.88 mL, p = 0.0001). The decrease in PaO2/FIO2 ratio was significantly lower in the OPCAB group compared with the ONCAB group (-71.34 ± 23.42 v -123.65 ± 36.81, p = 0.000). The increase in plateau pressure, decrease in compliance, and postoperative ventilation period were significantly higher in the patients who underwent ONCAB than the patients who underwent OPCAB (p < 0.05). CONCLUSION: The change in TFC was greater in the ONCAB group, despite the fact that the fluid balance was higher in the OPCAB group. A higher TFC in ONCAB led to lower PaO2/FIO2 ratio, lower compliance, higher plateau pressures, and longer postoperative ventilation.

Bivalirudin anticoagulation in neonates and infants undergoing cardiac surgery.

OBJECTIVES: To determine the dosage of bivalirudin as the anticoagulant for cardiac surgery in neonates and infants. DESIGN: Pilot study. SETTING: Tertiary-care hospital. PARTICIPANTS: Twenty-five neonates and infants with congenital heart disease (CHD) undergoing cardiac surgery. INTERVENTIONS: The children received a 1 mg/kg bivalirudin bolus followed by a 2.5 mg/kg/h infusion as the anticoagulant for cardiac surgery. The dose was adjusted subsequently to maintain an activated clotting time (ACT) >480 s. MEASUREMENTS AND MAIN RESULTS: The mean age and weight were 5.3 months and 5.2 kg, respectively. Out of the 25 children, 16 were cyanotic. Baseline rotational thromboelastometry (ROTEM) (Tem Innovations GmbH, Munich, Germany) analysis revealed an underlying coagulation defect across EXTEM, INTEM, FIBTEM, and ADPTEM parameters. The dose of anticoagulant required was 1 mg/kg, followed by a 2.2 ± 0.4 mg/kg/h infusion. Only 1 child required an additional bolus dose. The ACT remained elevated for 4 hours after discontinuation of infusion. The mean 24-h postoperative chest tube drainage was 92 ± 36 mL. Excessive bleeding occurred in 4 children, 1 of whom required re-exploration. The platelet count remained low for 5 days, and, postoperatively, the prothrombin time and activated partial thromboplastin time remained low for 2 days. CONCLUSIONS: Effective anticoagulation was achieved with bivalirudin in the neonates and infants undergoing cardiac surgery. The dose required to maintain an ACT >480 s was 1.0 mg/kg, followed by 2.2 ± 0.4 mg/kg/h. The ACT remained elevated for 4 h after the discontinuation of bivalirudin infusion, resulting in an increased chest-tube output in some patients. Randomized, controlled trials are needed to further evaluate the safety of bivalirudin in the neonates and infants with complex congenital heart disease undergoing cardiac surgery with cardiopulmonary bypass.

Plasmalyte-A Based del Nido Cardioplegia Versus Plain Ringer Based del Nido Cardioplegia: Double-Blind Randomized Trial.

Background: In this prospective randomized controlled trial, we compared the standard del Nido cardioplegia solution (SDN) with the modified del Nido cardioplegia solution (MDN) in which the base solution was the plain Ringer solution. Methods: A total of 80 patients aged < 12 years undergoing intracardiac repair of Tetralogy of Fallot were randomized into SDN (n = 39) or MDN (n = 41) groups. The primary outcome was a change in cardiac index (CI). Secondary outcomes were ventricular arrhythmias after the release of aortic-cross clamp, postoperative inotropic score (IS), time to peripheral rewarming, duration of mechanical ventilation, intensive care unit (ICU) length of stay, and hospital length of stay, and electron microscopic differences between the 2 groups. Cardiac Troponin-I, inflammatory markers tumor necrosis factor-α (TNF-α), and interleukin-L (IL-6) were measured. Results: Applying the noninferiority confidence interval approach, the difference between the changes in CI between the 2 groups was -0.093 L/min/m2 (95% CI: -0.46-0.27 L/min/m2) which was within the noninferiority threshold of -0.5 indicating that CI was similar in both SDN and MDN. Ventricular arrhythmias postclamp release (P = .91), IS (P = .09), duration of mechanical ventilation (P = .27), ICU length of stay (P = .50), hospital length of stay (P = .57), IL-6 (P = .19), TNF-α (P = .17), Troponin-I (P = .15), electron microscopy changes (P > .05) were not different between groups. Conclusion: MDN was shown to be noninferior to the SDN cardioplegia in terms of preservation of cardiac index. In addition, other metrics indicative of myocardial protection were similar between groups. In developing nations where SDN is not available or is expensive, MDN cardioplegia is an acceptable alternative.

Effect of change in tidal volume on left to right shunt across ventricular septal defect in children - A pilot study.

BACKGROUND: Pulmonary vascular resistance, an important determinant of shunting across ventricular septal defects (VSD), rises at both extremes of lung volume. AIMS: We sought to determine the effect of changes in tidal volumes (VT) on pulmonary blood flow (Qp), systemic blood flow (Qs), and shunt (Qp/Qs) in children with VSD. SETTING: Single-center teaching hospital. DESIGN: Prospective observational study. METHODS: Thirty children with a mean age of 11.8 ± 5 months undergoing surgical closure of VSD were studied. Hemodynamics and shunt-related parameters were assessed using transthoracic echocardiography measured at three different VT i.e. 10, 8, and 6-ml/kg keeping the minute ventilation constant. RESULTS: Reduction in VT from 10 to 8 to 6 ml/kg led to a reduction in gradient across VSD measuring 23.5, 20 and 13 mmHg respectively (P < 0.001). Similarly, right ventricluar outflow tract (RVOT) diameter, RVOT velocity time integral, Qp (57.3 ± 18.1, 50.6 ± 16.9, 39.9 ± 14.7 mL; P < 0.001), Qs (24.1 ± 10.4, 20.0 ± 8.7, 15.3 ± 6.9 mL; P < 0.001) and peak airway pressure (17.2 ± 1.5, 15.8 ± 1.3, 14.5 ± 1.2 cmHg; P < 0.001) showed progressive decline with decreasing VT from 10 to 8 to 6 ml/kg, respectively. However, Qp/Qs (2.4 ± 0.4, 2.6 ± 0.4, 2.6 ± 0.4) demonstrated a minor increasing trend. CONCLUSION: Lower VT reduces the gradient across VSD, the pulmonary blood flow, and the peak airway pressure. Hence, ventilation with lower VT and higher respiratory rate maintaining adequate minute ventilation might be preferable in children with VSD. Further studies are required to confirm the findings of this pilot study.

Modified ultrafiltration and postoperative course in patients undergoing repair of tetralogy of fallot.

BACKGROUND: Expected benefits of modified ultrafiltration (MUF) include increased hematocrit, reduction of total body water and inflammatory mediators, improved left ventricular systolic function, and improved systolic blood pressure and cardiac index (CI) following cardiopulmonary bypass (CPB). This prospective randomized trial tested this hypothesis. METHODS: Seventy-nine patients undergoing intracardiac repair of tetralogy of fallot were randomized to conventional ultrafiltration (CUF) + MUF (n = 39) or only CUF group (n = 40). The primary outcome was a change in hematocrit. Secondary outcomes were changes in peak airway pressures, ventilatory support, blood transfusions, time to peripheral rewarming, mean arterial pressure, central venous pressure, inotrope score (IS), and CI. Serum inflammatory markers were measured. RESULTS: Baseline hematocrit was 50.6 ± 10.02 in the only CUF group whereas it was 43.9 ± 5.55 in the CUF + MUF group (p = .36). Following MUF, the CUF + MUF group had higher hematocrit (44.7 ± 0.50 g/dl) compared to the only CUF group (37.2 ± 0.49 g/dl), p ≤ .001 after adjusting for baseline hematocrit. Central venous pressure (mmHg) immediately following sternal closure was 9.27 ± 3.12 mmHg in the CUF + MUF group and 10.52 ± 2.2 mmHg in the only CUF group (p = .04). In the intensive care unit (ICU), they were 11.52 ± 2.20 mmHg in the only CUF group and 10.84 ± 2.78 mmHg in the CUF + MUF group (p = .02). Time to peripheral rewarming was 6.30 ± 3.91 h in the CUF + MUF group and 13.67 ± 3.91 h in the only CUF group (p = .06). Peak airway pressures in ICU were 17 ± 2 mmHg versus 20.55 ± 2.97 mmHg in CUF + MUF group & only CUF group, respectively, p < .001). Duration of mechanical ventilation was 6.3 ± 2.7 h in CUF + MUF group compared to 14.7 ± 3.5 h in the only CUF group (p = .002). IS was 11.52 ± 2.20 in the only CUF group compared to 10.84 ± 2.78 in CUF + MUFs group. Eight of 39 (20.5%) patients in the CUF + MUF group had IS > 10 compared to 22 of 40 (55%) patients in the only CUF group (p = .02). Serum Troponin-T and interleukin-6 levels were lower in the CUF + MUF group; TNF-α and CPK-MB were similar. ICU and hospital stay were similar. CONCLUSION: Patients undergoing a combination of CUF and MUF had higher postoperative hematocrit, decreased duration of mechanical ventilation, lower need for inotropes and lower interleukin-6 and Troponin-T levels. This group had better postoperative outcomes. This study was registered with the Clinical trials registry of India (CTRI/2017/11/010512) before commencement.

Balancing a single-ventricle circulation: 'physiology to therapy'.

The parallel supply of the pulmonary and systemic circuits complicates the management of single-ventricle lesions. Achieving a balance between the two limbs of the circulation forms the basis of optimizing the systemic oxygen delivery, with the oxygen availability being highly sensitive to alterations in pulmonary/systemic blood flow ratio (Q p/Q s). The identification of a 'balanced' circulation is challenging wherein various parameters should be evaluated in close conjunction with each other. The prompt identification of circulatory maldistribution should be backed up with a sound management strategy aimed at attaining an equitable systemic and pulmonary perfusion. Any degree of ventricular dysfunction compromises the total output (Q p + Q s) supplying the two circuits explaining the role of inodilators in improving the myocardial performance in addition to lowering the systemic vascular resistance and optimizing Q p/Q s in setting of a single-ventricle physiology. Moreover, the pulmonary circulation is modulated by a multitude of factors intricately linked to the single-ventricle lesion, including anatomical characteristics unique to the underlying lesion (branch pulmonary arterial and venous stenosis), preoperative interventions, associated aortopulmonary and venovenous collaterals, plastic bronchitis, pulmonary arteriovenous fistulae, underlying ventricular dysfunction,, and many others. The article highlights the physiology, diagnosis, therapeutic optimization of a single-ventricle circulation, and the peculiarities pertaining to the pulmonary circulation of the uni-ventricular lesions.