Rohan Magoon

Goal-directed therapy improves the outcome of high-risk cardiac patients undergoing off-pump coronary artery bypass

Background: There has been a constant emphasis on developing management strategies to improve the outcome of high-risk cardiac patients undergoing surgical revascularization. The performance of coronary artery bypass surgery on an off-pump coronary artery bypass (OPCAB) avoids the risks associated with extra-corporeal circulation. The preliminary results of goal-directed therapy (GDT) for hemodynamic management of high-risk cardiac surgical patients are encouraging. The present study was conducted to study the outcome benefits with the combined use of GDT with OPCAB as compared to the conventional hemodynamic management. Material and Method: Patients with the European System for Cardiac Operative Risk Evaluation ≥3 scheduled for OPCAB were randomly divided into two groups; the control and GDT groups. The GDT group included the monitoring and optimization of advanced parameters, including cardiac index (CI), systemic vascular resistance index, oxygen delivery index, stroke volume variation; continuous central venous oxygen saturation (ScVO 2 ), global end-diastolic volume, and extravascular lung water (EVLW), using FloTrac™ , PreSep™ , and EV-1000 ® monitoring panels, in addition to the conventional hemodynamic management in the control group. The hemodynamic parameters were continuously monitored for 48 h in Intensive Care Unit (ICU) and corrected according to GDT protocol. A total of 163 patients consented for the study. Result: Seventy-five patients were assigned to the GDT group and 88 patients were in the control group. In view of 9 exclusions from the GDT group and 12 exclusions from control group, 66 patients in the GDT group and 76 patients in control group completed the study. Conclusion: The length of stay in hospital (LOS-H) (7.42 ± 1.48 vs. 5.61 ± 1.11 days, P < 0.001) and ICU stay (4.2 ± 0.82 vs. 2.53 ± 0.56 days, P < 0.001) were significantly lower in the GDT group as compared to control group. The duration of inotropes (3.24 ± 0.73 vs. 2.89 ± 0.68 h, P = 0.005) was also significantly lower in the GDT group. The two groups did not differ in duration of ventilated hours, mortality, and other complications. The parameters such as ScVO 2 , CI, and EVLW had a strong negative and positive correlation with the LOS-H with r values of − 0.331, −0.319, and 0.798, respectively. The study elucidates the role of a goal-directed hemodynamic optimization for improved outcome in high-risk cardiac patients undergoing OPCAB.

Delirium after cardiac surgery: A pilot study from a single tertiary referral center

Background: Advances in cardiac surgery has shifted paradigm of management to perioperative psychological illnesses. Delirium is a state of altered consciousness with easy distraction of thoughts. The pathophysiology of this complication is not clear, but identification of risk factors is important for positive postoperative outcomes. The goal of the present study was to prospectively identify the incidence, motoric subtypes, and risk factors associated with development of delirium in cardiac surgical patients admitted to postoperative cardiac intensive care, using a validated delirium monitoring instrument. Materials and Methods: This is a prospective, observational study. This study included 120 patients of age 18-80 years, admitted to undergo cardiac surgery after applying inclusion and exclusion criteria. Specific preoperative, intraoperative, and postoperative data for possible risk factors were obtained. Once in a day, assessment of delirium was done. Continuous variables were measured as mean ± standard deviation, whereas categorical variables were described as proportions. Differences between groups were analyzed using Student′s t-test, Mann-Whitney U-test, or Chi-square test. Variables with a P < 0.1 were then used to develop a predictive model using stepwise logistic regression with bootstrapping. Results: Delirium was seen in 17.5% patients. The majority of cases were of hypoactive delirium type (85.72%). Multiple risk factors were found to be associated with delirium, and when logistic regression with bootstrapping applied to these risk factors, five independent variables were detected. History of hypertension (relative risk [RR] =6.7857, P = 0.0003), carotid artery disease (RR = 4.5000, P < 0.0001) in the form of stroke or hemorrhage, noninvasive ventilation (NIV) use (RR = 5.0446, P < 0.0001), Intensive Care Unit (ICU) stay more than 10 days (RR = 3.1630, P = 0.0021), and poor postoperative pain control (RR = 2.4958, P = 0.0063) was associated with postcardiac surgical delirium. Conclusions: Patients who developed delirium had systemic disease in the form of hypertension and cerebrovascular disease. Delirium was seen in patients who had higher postoperative pain scores, longer ICU stay, and NIV use. This study can be used to develop a predictive tool for diagnosing postcardiac surgical delirium.

Perioperative utility of goal-directed therapy in high-risk cardiac patients undergoing coronary artery bypass grafting: “A clinical outcome and biomarker-based study”

Goal-directed therapy (GDT) encompasses guidance of intravenous (IV) fluid and vasopressor/inotropic therapy by cardiac output or similar parameters to help in early recognition and management of high-risk cardiac surgical patients. With the aim of establishing the utility of perioperative GDT using robust clinical and biochemical outcomes, we conducted the present study. This multicenter randomized controlled study included 130 patients of either sex, with European system for cardiac operative risk evaluation ≥3 undergoing coronary artery bypass grafting on cardiopulmonary bypass. The patients were randomly divided into the control and GDT group. All the participants received standardized care; arterial pressure monitored through radial artery, central venous pressure (CVP) through a triple lumen in the right internal jugular vein, electrocardiogram, oxygen saturation, temperature, urine output per hour, and frequent arterial blood gas (ABG) analysis. In addition, cardiac index (CI) monitoring using FloTrac™ and continuous central venous oxygen saturation (ScVO2) using PreSep™ were used in patients in the GDT group. Our aim was to maintain the CI at 2.5–4.2 L/min/m2, stroke volume index 30–65 ml/beat/m2, systemic vascular resistance index 1500–2500 dynes/s/cm5/m2, oxygen delivery index 450–600 ml/min/m2, continuous ScVO2 >70%, and stroke volume variation <10%; in addition to the control group parameters such as CVP 6–8 mmHg, mean arterial pressure 90–105 mmHg, normal ABG values, oxygen saturation, hematocrit value >30%, and urine output >1 ml/kg/h. The aims were achieved by altering the administration of IV fluids and doses of inotropes or vasodilators. The data of sixty patients in each group were analyzed in view of ten exclusions. The average duration of ventilation (19.89 ± 3.96 vs. 18.05 ± 4.53 h, P = 0.025), hospital stay (7.94 ± 1.64 vs. 7.17 ± 1.93 days, P = 0.025), and Intensive Care Unit (ICU) stay (3.74 ± 0.59 vs. 3.41 ± 0.75 days, P = 0.012) was significantly less in the GDT group, compared to the control group. The extra volume added and the number of inotropic dose adjustments were significantly more in the GDT group. The two groups did not differ in duration of inotropic use, mortality, and other complications. The perioperative continuation of GDT affected the early decline in the lactate levels after 6 h in ICU, whereas the control group demonstrated a settling lactate only after 12 h. Similarly, the GDT group had significantly lower levels of brain natriuretic peptide, neutrophil gelatinase-associated lipocalin levels as compared to the control. The study clearly depicts the advantage of GDT for a favorable postoperative outcome in high-risk cardiac surgical patients.

Studying diastology with speckle tracking echocardiography: The essentials

Diastolic dysfunction is common in cardiac disease and an important finding independent of systolic function as it contributes to the signs and symptoms of heart failure. Tissue Doppler mitral early diastolic velocity (Ea) combined with peak transmitral early diastolic velocity (E) to obtain E/Ea ratio provides an estimate of the left ventricular (LV) filling pressure. However, E/Ea has a significant gray zone and less reliable in patients with preserved ejection fraction (>50%). Two-dimensional echocardiographic speckle tracking measure myocardial strain and strain rate (Sr) avoiding the Doppler-associated angulation errors and tethering artifacts. Global myocardial peak diastolic strain (Ds) and diastolic Sr (DSr) at the time of E and isovolumic relaxation combined with E (E/Ds and E/10 DSr) have been recently proposed as novel indices to determine LV filling pressure. The present article elucidates the methodology of studying diastology with strain echocardiography along with the advantages and limitations of the novel technique in light of the available literature.

Pharmacological update: New drugs in cardiac practice: A critical appraisal

Cardiac practice involves the application of a range of pharmacological therapies. An anesthesiologist needs to keep pace with the rampant drug developments in the field of cardiovascular medicine for appropriate management in both perioperative and intensive care set-up, to strengthen his/her role as a perioperative physician in practice. The article reviews the changing trends and the future perspectives in major classes of cardiovascular medicine.

Bleeding in the lung complicates a routine intracardiac repair: What went wrong!!!

Cyanotic congenital heart disease presents an increased tendency to bleed in view of subtle coagulation defects. Airway bleeding can be particularly difficult to manage while maintaining an adequate ventilation. An isolated lung bleed with the exclusion of possible traumatic, medical and surgical causes of bleeding, should alert the attending anesthesiologist to the possibility of the collateral-related bleeding. Preoperative coil embolization remains an important initial management step in a case of tetralogy of Fallot (TOF) with major aortopulmonary collaterals. Nevertheless, the coiling of the collaterals in certain specific case scenarios is not feasible, rendering the management of a lung bleed, all the more challenging. We, hereby discuss a case of a 7-year-old girl with a massive endotracheal bleed at the time of weaning from cardiopulmonary bypass after corrective surgery for TOF. The subsequent approach and management are discussed. The optimal management of tetralogy with collaterals mandates an effective communication among the cardiologist, radiologist, anesthesiologist, and the surgeon.

Anaesthesia for emergency caesarean section in a morbidly obese achondroplastic patient with PIH: Feasibility of Neuraxial anaesthesia?

A 25‐year‐old primigravida was referred to our hospital at 38 ± 3 week gestation with meconium stained liquor for emergency caesarean section (CS). She weighed 90 Kg with a height of 104 cm and body mass index (BMI 80 kg/m2, morbid obesity). She was a diagnosed case of pregnancy induced hypertension (PIH), not on medications. She had complaints of fever, productive cough and dyspnea (NYHA III) since10 days and was on antibiotics. She was afebrile, pale with stable vitals. Systemic examination revealed lumbar lordosis, pedal edema and crepitations in lung bases. She had an anticipated difficult airway in view of short neck, limited neck extension, large tongue and Mallampatti grade 3. Her haemoglobin was 7 gm% but coagulation, renal and liver functions were normal. Chest X‐ray demonstrated bilateral lower zones haziness, and increased bronchovesicular markings. ECG showed sinus rhythm and 2‐D echocardiography revealed left ventricular ejection fraction 55‐60%.

Airway management of the cardiac surgical patients: Current perspective

The difficult airway (DA) is a common problem encountered in patients undergoing cardiac surgery. However, the challenge is not only just establishment of airway but also maintaining a definitive airway for the safe conduct of cardiopulmonary bypass from initiation to weaning after surgical correction or palliation, de-airing of cardiac chambers. This review describes the management of the DA in a cardiac theater environment. The primary aims are recognition of DA both anatomical and physiological, necessary preparations for (and management of) difficult intubation and extubation. All patients undergoing cardiac surgery should initially be considered as having potentially DA as many of them have poor physiologic reserve. Making the cardiac surgical theater environment conducive to DA management is as essential as it is to deal with low cardiac output syndrome or acute heart failure. Tube obstruction and/or displacement should be suspected in case of a new onset ventilation problem, especially in the recovery unit. Cardiac anesthesiologists are often challenged with DA while inducing general endotracheal anesthesia. They ought to be familiar with the DA algorithms and possess skill for using the latest airway adjuncts.

Methylene blue for post-cardioplumonary bypass vasoplegic syndrome

First, in the author’s study methylene blue was administered in a dose of 1–2 mg/kg bolus over 10 min and the median time until a maximum hemodynamic response was 2 h after drug administration. Out of 88 patients who received methylene blue, only 39 (44.3%) showed a positive hemodynamic response to the drug. We believe that if the bolus of methylene blue was followed by a continuous infusion of the drug, it would have produced even better results. Evora et al. have reviewed 20 years of vasoplegic syndrome treatment in heart surgery and found that the most used dosage of methylene blue is 2 mg/kg as an intravenous bolus, followed by the same dose in continuous infusion because its plasma concentration sharply decreases in the first 40 min.[2,3]

Aortic valve homograft for revision surgery - transesophageal echocardiography considerations.

Aortic root surgical anatomy and knowledge of the various homograft implantation techniques is of paramount importance to the attending anesthesiologist for echocardiographic correlation, estimation and accurately predicting aortic annular dimensions for the valve replacement in a case of diseased homograft.