Sepsis in the Pediatric Cardiac Intensive Care Unit: An Updated Review.

Sepsis remains among the most common causes of mortality in children with congenital heart disease (CHD). Extensive literature is available regarding managing sepsis in pediatric patients without CHD. Because the cardiovascular pathophysiology of children with CHD differs entirely from their typical peers, the available diagnosis and management recommendations for sepsis cannot be implemented directly in children with CHD. This review discusses the risk factors, etiopathogenesis, available diagnostic tools, resuscitation protocols, and anesthetic management of pediatric patients suffering from various congenital cardiac lesions. Further research should focus on establishing a standard guideline for managing children with CHD with sepsis and septic shock admitted to the intensive care unit.

Bedside Chest Ultrasound in Postoperative Pediatric Cardiac Surgery Patients: Comparison With Bedside Chest Radiography.

OBJECTIVE: The primary objective was to study the degree of agreement between the chest ultrasound (CUS) studies and chest x-ray (CXR) studies in postoperative pediatric cardiac surgical patients regarding the diagnosis of thoracic abnormalities, and also to compare the diagnostic performance of CUS in reference to CXR for the detection of thoracic abnormalities. The secondary objective was to compare the necessity for interventions done on the basis of CUS and CXR findings in the postoperative setting. DESIGN: A prospective observational study. SETTING: At a postoperative pediatric cardiac surgical intensive care unit in a tertiary-care center. PARTICIPANTS: One hundred sixty patients between the age of 2 months to 18 years undergoing elective cardiac surgery for various congenital heart diseases. INTERVENTIONS: After obtaining permission from the institutional ethics committee, 160 pediatric cardiac surgical patients were studied prospectively in the postoperative period. On the day of surgery (postoperative day [POD] 0), bedside CXR was done in the immediate postoperative period. After bedside CXR, CUS examination was performed and then interpreted by the principal investigator. The CXR was interpreted by the surgical team. Provisional diagnosis was made by the principal investigator and surgical team. Any intervention required was decided based on CXR or CUS findings or both. The procedure was repeated in the morning of POD 1. MEASUREMENTS AND MAIN RESULTS: The degree of agreement between CUS studies and CXR studies in detecting abnormalities was evaluated by Cohen's kappa (k) statistics. The diagnostic performance of CUS was compared with that of CXR using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy. Overall, kappa analysis (k) showed substantial agreement between the findings of the CUS and CXR studies (k = 0.749). The diagnostic performance of CUS, as compared with CXR, was found to have a sensitivity of 96.9%, specificity of 84.75%, PPV of 73.4%, NPV of 98.43%, and diagnostic accuracy of 88.44%. In 94 abnormal findings, the interventions were done based on CUS or CXR findings or both. Overall, there was a substantial agreement (k = 0.787) between CUS and CXR regarding the necessity for interventions. CONCLUSIONS: The degree of agreement between CUS and CXR studies was substantial for atelectasis, interstitial edema, and diaphragmatic weakness. The degree of agreement between CUS and CXR studies was almost perfect for pneumothorax and fair for pleural effusion. More CUS studies detected intrathoracic pathologies than CXR studies. The CUS also detected abnormalities earlier than CXR and was found to be useful for the early institution of intervention therapy in patients with interstitial edema and atelectasis. It would be reasonable to conclude that CUS may be considered in some instances as an alternative to CXR.

Comparison of Four Different Techniques for Estimation of Left Ventricular Volumes Using Intraoperative Real Time Three Dimensional Transesophageal Echocardiography--A Prospective Observational Study.

OBJECTIVES: The primary objective of the present study was to compare cardiac output derived with four methods of QLab (Philips, Amsterdam, Netherlands) software using real-time three-dimensional (3D) transesophageal echocardiography, with cardiac output obtained with the 3D left ventricular outflow tract (LVOT) cardiac output method. The secondary objective was to assess left ventricular (LV) volumes, LV ejection fraction, and cardiac output derived with four different methods of real time 3D transesophageal echocardiography processed in QLab software and to determine whether these parameters differed among these four methods. DESIGN: A prospective observational study. SETTING: A tertiary referral center and a university level teaching hospital. PARTICIPANTS: The study comprised 50 patients scheduled for elective coronary artery bypass surgery without any concomitant valvular lesions. MEASUREMENTS AND MAIN RESULTS: Three-dimensional full-volume datasets were obtained in optimum conditions. The 3D datasets were analyzed using four different methods in QLab, version 9. In method A, LV volumes were derived without endocardial border adjustment. In method B, LV volumes were obtained after endocardial border adjustment in the long-axis view alone. In method C, the iSlice tool (Philips) was used to adjust the endocardial borders in 16 short-axis slices. In method D, endocardial borders were adjusted after dataset processing to obtain LV volumes. The cardiac output derived with the 3D echocardiography LVOT method was 3.93 ± 1.44 L/min, with method A was 3.26 ± 1.42 L/min, with method B was 3.51 ± 1.2 L/min, with method C was 4.01 ± 1.40 L/min, and with method D was 4.18 ± 1.58 L/min. There was a significant positive correlation between the cardiac output derived using the 3D LVOT method and method C (r = 0.71). CONCLUSIONS: Readjusting the endocardial border contours resulted in higher LV volumes than the volumes estimated using semiautomated border algorithms. The iSlice method produced the highest and the most accurate LV volumes, although it required the longest time to analyze and derive results. The ejection fraction obtained with all four methods of QLab demonstrated no statistical differences and had a strong correlation with the two-dimensional echocardiography-derived left ventricular ejection fraction.

Comparison of Three Ultrasound Views for Internal Jugular Venous Cannulation in Patients Undergoing Cardiac Surgery: A Randomized Trial.

BACKGROUND: The quality of needle visualization during ultrasound-guided internal jugular vein (IJV) cannulation determines the ease of procedure, whereas posterior IJV wall puncture is the most common risk associated. The IJV can be imaged in different views, which offer certain advantages over each other. We compared three different ultrasound views for IJV cannulation short axis (SAX), long axis (LAX), and oblique axis (OAX) with respect to the quality of needle visualization, first pass success rate, and posterior IJV wall puncture. METHODS: Two hundred ten patients undergoing elective cardiac surgery were analyzed in this prospective randomized clinical trial. Patients were randomly assigned to one of the three groups: SAX (n = 70), LAX (n = 70), and OAX (n = 70). The quality of needle visualization, first pass success rate, and incidence of posterior IJV wall puncture in each of the three ultrasound views were studied. The Chi-square test and ANOVA were used for the comparison of means and proportion between the groups. RESULTS: The quality of needle visualization was graded as good in 90% patients in OAX group, 81.4% patients in LAX group, and 14.2% patients in SAX group, respectively (P < 0.0001). OAX group had the highest first pass success rate (94.2%) followed by SAX (88.5%), and then, LAX (82.8%), but it was statistically insignificant among the groups (P = 0.105). The mean IJV access time was longer in LAX group when compared to OAX and SAX group (P < 0.0001).The incidence of IJV posterior wall puncture was 14.2% patients in SAX group and none in other groups (P = 0.0011). CONCLUSION: The results suggest that OAX view can be adopted as standard approach during ultrasound-guided IJV cannulation as it safe and reliable.

Criteria for Postoperative Mechanical Ventilation After Thymectomy in Patients With Myasthenia Gravis: A Retrospective Analysis.

OBJECTIVE: To determine the criteria for postoperative mechanical ventilation after thymectomy in patients with Myasthenia Gravis. DESIGN: Retrospective study. SETTING: Teritiary care centre. PARTICIPANTS: 77 Myasthenia gravis patients operated for thymectomy were studied. INTERVENTIONS: After obtaining clearance from Institutional ethics committee, medical records of 77 patients with MG, who were operated for thymectomy between January 2005 and December 2015 were reviewed in a retrospective manner. Perioperative variables collected from the patient records were demographic data, duration of the disease, Osserman and Genkin classification, Anti-acetylcholine antibody (AChR) positivity, preoperative daily dose of drug, history of preoperative myasthenic crisis, preoperative vital capacity, technique of anesthesia, drugs used for anesthesia, perioperative complications, and duration of postoperative mechanical ventilation. The patients were divided into two groups, group I and group II consisting of those who required postoperative ventilation for < 300 minutes and > 300 minutes, respectively. The determinants of prolonged postoperative ventilation were studied. MEASUREMENTS AND MAIN RESULTS: The requirement of mechanical ventilation was higher in patients with higher Osserman's grade of myasthenia gravis. Duration of the disease had no effect on the duration of mechanical ventilation in myasthenic patients post thymectomy (p = 0.89). The patients with a preoperative history of myasthenic crisis had a requirement for prolonged mechanical ventilation (p=0.03). Patients with preoperative vital capacity < 2.9 litres and preoperative CT scan showing thymoma had a requirement for prolonged mechanical ventilation with p values < 0.001 and 0.035, respectively. Patients who showed positivity for anti-acetylcholine antibodies had a prolonged mechanical ventilation (p=0.026). Preoperative dose of pyridostigmine and the choice of continuation or discontinuation of antcholinesterases on the day of surgery had no influence on the duration of mechanical ventilation (p value of 0.19 and 0.36 respectively). Epidural analgesia intra and postoperatively significantly reduced the requirement of mechanical ventilation (p=0.006). CONCLUSION: The predictors of postoperative ventilation in myasthenic patients undergoing thymectomy as per our study are: 1. Grade of myasthenia; 2. History of preoperative myasthenic crisis; 3. Anti-acetylcholine antibodies positivity; 4. Presence of thymoma; and 5. a vital capacity < 2.9 litres. Use of thoracic epidural as a part of combined anesthetic technique helps to reduce the need of mechanical ventilation in these patients.

Intraoperative Transesophageal and Postoperative Transthoracic Echocardiographic Evaluation of a Mechanical Heart Valve Prosthesis Implanted at Aortic Position.

OBJECTIVE: The aims of this study were to evaluate the intraoperative transesophageal echocardiographic (iTEE) characteristics and Doppler flow profile of aortic Chitra heart valve prosthesis (CHVP) under stable hemodynamic and loading conditions, and to compare and correlate the iTEE data with the postoperative transthoracic echocardiography (TTE) data obtained at 48 hours (TTE1) and 3 months (TTE2) after the surgery. DESIGN: Prospective, observational study. SETTING: University-level tertiary referral hospital. PARTICIPANTS: Forty patients between 18 years and 65 years of age undergoing elective aortic valve replacement (AVR) using CHVP during the period January 2015 to August 2016. INTERVENTIONS: After obtaining permission from institutional ethics committee, 40 patients undergoing elective AVR were studied prospectively. The iTEE examination was performed in the pre-cardiopulmonary bypass (CPB) and post-CPB period in all the study subjects. CHVP was subjected to iTEE two-dimensional (2D) echo, color Doppler, and spectral Doppler evaluation under stable hemodynamic and loading condition in the post-CPB period after the administration of protamine. The CHVP were re-evaluated using TTE in all the patients 48 hours after the surgery (TTE1) and 3 months after the surgery (TTE2). The iTEE and postoperative TTE Doppler values were compared and correlated. MEASUREMENTS AND MAIN RESULTS: The CHVP could be imaged adequately and interrogated with Doppler in all the patients. None of the patients had restriction of occluder mobility or unstable seating of the valve. The intraoperative flow dependent (peak velocity [PV] and mean pressure gradient [MPG]) and less flow dependent (Doppler velocity index, acceleration time, acceleration time/ejection time, effective orifice area [EOA] and indexed EOA) Doppler parameters of CHVP were measured as per the American Society of Echocardiography recommendations. The PV and MPG of CHVP measured by iTEE showed no statistical difference (p > 0.05) and were in limits of agreement when compared with TTE1 and TTE2 data. CONCLUSION: The iTEE features of CHVP were found compliant with the criteria set by the ASE defining normal functioning of an aortic valve prosthesis. The iTEE Doppler parameters obtained under stable loading conditions strongly predicted the postoperative values of Doppler parameters on TTE examination. The iTEE Doppler values can be used as the reference values for the postoperative follow up studies.

Multiple unruptured aortic sinus of Valsalva aneurysms: A rare presentation.

Aneurysms of sinus of Valsalva, usually a rare presentation, account for 0.1%-3.5% of congenital heart defects. They rarely present unless rupture occurs. There are very few cases of unruptured sinus of Valsalva aneurysms that presented with myocardial ischemia, symptomatic cardiac dysfunction, and conduction abnormalities. We present a case of multiple unruptured sinus of Valsalva aneurysms with particular emphasis on the transesophageal echocardiography.

Sevoflurane requirement to maintain bispectral index-guided steady-state level of anesthesia during the rewarming phase of cardiopulmonary bypass with moderate hypothermia.

OBJECTIVES: The authors aimed to quantify any increase and the extent of the increase in sevoflurane requirements for maintaining hypnosis during hypothermic cardiopulmonary bypass (CPB) with the bispectral index (BIS) maintained between 40 and 50. DESIGN: An observational prospective study. SETTING: A single-center tertiary referral center at a university hospital. PARTICIPANTS: Fifty patients undergoing elective coronary artery bypass graft surgery with CPB. INTERVENTIONS: End-tidal oxygenator expiratory gas concentrations were used to quantify sevoflurane requirements while maintaining a BIS level between 40 and 50 during the rewarming phase. RESULTS: Sevoflurane requirements progressively increased as temperature increased. The difference in sevoflurane requirement at 35°C and 29°C was compared using analysis of variance for repeated measures, which was statistically significant. When relating temperature and sevoflurane requirement, the Pearson correlation coefficient was 0.67. Linear regression analysis using temperature as the independent variable and expiratory sevoflurane as the dependent variable showed a temperature ß-coefficient of 0.11 and a constant of -2.34. Other parameters like fresh gas flows and pump flows were correlated to find out if they affected end-tidal sevoflurane levels on CPB. They were not significant in multivariate analysis. CONCLUSIONS: The sevoflurane requirement increases during the rewarming phase of hypothermic CPB. The percent increase in the requirement for sevoflurane is uniform and follows a particular pattern, which may be predicted.

Factors predicting difficulty in insertion of real-time-three-dimensional transesophageal echocardiography probe in adult patients undergoing cardiac surgery.

Background: Transesophageal echocardiography (TEE) probe insertion may be associated with many complications. Demographic factors and airway conditions such as high Mallampati scores (MMC) and Cormack-Lehane grades (MCLG) are likely to have an impact on its ease of insertion. The primary aim of this study was to identify the predictive factors for difficult real-time-three-dimensional TEE probe insertion. Methods: A total of 153 adult patients undergoing cardiac surgery were prospectively evaluated. The upper airway manipulations required for TEE probe placement were jaw thrust, reverse Sellick's maneuver, and laryngoscopy. All the patients who required airway manipulations were grouped under difficult TEE probe placement group. We evaluated the patients' predictive factors such as demographic characteristics and factors related to difficult intubation. Results: Out of 153 patients, 123 were males and 30 were females. Overall, 27.5% (n = 42) patients had difficulty in probe placement. About 31.7% (n = 39) males had difficulty in TEE probe placement against 13% (n = 4) females (P-value 0.045). Difficulty in TEE probe placement was found in 72.7% (n = 16) of obese patients (body mass index [BMI] > 30), compared to 18.6% (n = 17) in the patients with BMI less than 25 (P-value < 0.001). Probe insertion was significantly more difficult in the presence of MMC III and IV (50%, n = 18) compared to class I (19.2%, n = 10) (P-value 0.001) and MCLG III (73.3%, n = 22) compared to grade I (11.1%, n = 7) (P-value 0.001). Conclusion: Male gender, obesity, higher grades of MMC and MCLG were found to be the risk factors for difficult TEE probe placement in anesthetized patients.

Atrial septal defect occluder device embolization: Experience of a tertiary care cardiac center.

Background: Percutaneous device closure of atrial septal defect (ASD) has become an increasingly popular procedure as it offers several advantages. However, it is associated with infrequent, but life-threatening complications such as device embolization. Objective: To analyze the risk factors, common sites of embolization, associated complications, timing of embolization, and the treatment executed. Settings and Design: A retrospective study was performed at a tertiary referral center for cardiac services. Material and Methods: Pre-procedure, intra-procedure, and post-procedure data of patients whose ASD device embolized was collected retrospectively and analyzed for risk factors, common sites of embolization, associated complications, timing of embolization, and the treatment executed. Results: Thirty devices were embolized, out of which 13 were retrieved percutaneously in the Catheter laboratory, whereas 17 patients underwent surgery. Fourteen patients had an unfavorable septal morphology for device closure. Ten devices were embolized in the catheter laboratory, five in the intensive care unit, and two in the ward. The devices were embolized to almost all chambers of the heart and great vessels. One patient had an inferior vena cava rim tear while attempting percutaneous retrieval. One patient required a short period of total circulatory arrest (TCA) for retrieval of the device from ascending aorta, while another required a lateral position for retrieval from descending aorta. One patient required re-exploration for bleeding, while another had an air embolism and succumbed. Conclusions: Once embolization occurs, the risks associated increase manifold. Most of the surgical extractions are uneventful; however, there could be certain complications that may need repair of valvular apparatus, the institution of TCA, or the need for the lateral position. Air embolization though very rare can occur which could be fatal.

Comparison of effects of sevoflurane versus propofol on left ventricular longitudinal global and regional strain in patients undergoing on-pump coronary artery bypass grafting.

Background: Assessment of myocardial deformation by quantifying peak systolic longitudinal strain (PSLS) is a sensitive and robust index to detect subclinical myocardial dysfunction. We hypothesize that sevoflurane by virtue of anesthetic preconditioning preserves myocardial function better than propofol. Aims: The authors have assessed the effects of sevoflurane and propofol on global longitudinal strain (GLS) as a primary outcome in patients undergoing on-pump coronary artery bypass grafting. Our secondary aim was to assess the pattern of regional distribution of segmental PSLS between the groups. Materials and Methods: Fifty patients with normal left ventricular function undergoing coronary artery bypass grafting were analyzed in this prospective observational study. Consecutive patients received either propofol (P) or sevoflurane (S) anesthesia. Measurements: Trans-esophageal echocardiographic images (mid-esophageal four-chamber, two-chamber, and three-chamber (long-axis)) were recorded during the precardiopulmonary bypass (CPB) and post-CPB period. Strain analysis (GLS/segmental PSLS) was done offline by investigators blinded to the study. The inotropic score, duration of inotropic support, and mechanical ventilation required were recorded. Results: Following cardiopulmonary bypass and coronary revascularization, GLS reduced significantly in both the groups (P < 0.05). In the S-group, significant reduction in segmental strain was observed only in apical segments including apex, whereas in P-group significant reduction in segmental strain was seen in mid- and apical segments. The postoperative VIS, duration of inotropes/vasopressor required, and mechanical ventilation were similar in both the groups. Conclusions: There are no significant differences in global left ventricular function as assessed by GLS between patients anesthetized with sevoflurane or propofol. However, regional PSLS was better preserved in the S-group compared to P-group.

Intraoperative comparison of 2D versus 3D transesophageal echocardiography for quantitative assessment of mitral regurgitation.

Background: Effective regurgitant orifice area (EROA) can be represented by 3D echocardiographic vena contracta cross-sectional area (3D-VCA) as a reference method for the quantification of mitral regurgitation (MR) without making any geometrical assumptions. EROA can also be derived from 3D PISA technique with a hemispherical (HS) or hemielliptical (HE) assumption of the proximal flow convergence. However, it is not clear whether HS-PISA and HE-PISA has better agreement with 3D-VCA. Aims: This study was conducted to compare the EROA and Rvol obtained from 3D-VCA with those obtained from 2D-VC, 2D-HS-PISA, 3D-HS-PISA, and 3D-HE-PISA. Setting: Tertiary care hospital. Design: Prospective observational study. Materials and Methods: After anesthesia induction, 43 consecutive patients were evaluated with RT-3D-TEE after acquiring images from midesophegeal views and performing the offline analysis of volume dataset. 3D-VCA was measured using multiplanar reconstruction mode and EROA and regurgitant volume were estimated using HS-PISA and HE-PISA methods. The HE-PISA was calculated by using the Knud Thomsen formula. Statistical Analysis: Agreement between methods to estimate EROA and regurgitant volumes were tested using Bland-Altman analysis. The interobserver variability and intraobserver variability were assessed using an intraclass correlation coefficient. Results: The EROA estimated by 3D-VCA was larger than EROA obtained by 2D-HS-PISA and 3D-HS-PISA, which were significantly greater than 3D-HE-PISA. 3D-HS-PISA-EROA showed the best agreement with 3D-VCA (bias: 0.21; limits of agreement: -0.01 to 0.41; SD: 0.1). Correlation between various methods as compared to 3D-VCA was better in the organic MR group than functional MR group. Conclusion: 3D-HS-PISA showed the best agreement with 3D-VCA compared to other PISA methods. Better correlation between PISA-EROA and 3D-VCA was observed in patients with organic MR than functional MR.