Vishnu Datt

Evaluation and Comparison of Early Hemodynamic Changes After Elective Mitral Valve Replacement in Patients With Severe and Mild Pulmonary Arterial Hypertension

OBJECTIVE To evaluate and compare early hemodynamic changes after elective mitral valve replacement (MVR) in patients with severe and mild pulmonary arterial hypertension (PAH). DESIGN A prospective observational study. SETTING University-affiliated hospital. PARTICIPANTS Sixty patients undergoing elective MVR. INTERVENTIONS The patients were divided into 2 equal groups based on the presence (group A) or absence (group B) of severe PAH defined as systolic pulmonary artery pressure (PAP) > or = 50 mmHg on preinduction pulmonary artery catheterization. Thiopental, fentanyl, midazolam, isoflurane, and rocuronium (or vecuronium if the heart rate >100 beats/min) were used for the induction and maintenance of anesthesia. MVR was performed using standard cardiopulmonary bypass (CPB) techniques. The therapy for PAH was electively instituted in all patients with a nitroglycerin infusion (0.5-1 microg/kg/min), deliberate hypocarbia (arterial carbon dioxide tension < or = 35 mmHg), fractional inspired oxygen concentration = 1.0, and elective ventilation for at least 12 hours in the postoperative period. Hemodynamic and arterial blood gas parameters were serially measured before induction; after intubation; after termination of CPB; after extubation; and at 6, 24, and 48 hours after surgery. Differences in these parameters were analyzed within and among the groups using appropriate statistical tests. MEASUREMENTS AND MAIN RESULTS The mean CPB and aortic cross-clamp times were similar in the 2 groups (78 +/- 33 and 50 +/- 21 minutes in group A and 63 +/- 32 and 41 +/- 23 minutes in group B). The mean PAP, pulmonary capillary wedge pressure, and pulmonary vascular resistance decreased significantly soon after CPB in both groups (p < 0.001), but the decrease was significantly lower in group A (p < 0.001). The mean PAP approached near-normal values in group A (23 +/- 8 mmHg) and normal values in group B (16 +/- 6 mmHg) immediately postoperatively. There was an increase in cardiac index (p < 0.01) after CPB in group A. A relative improvement in oxygenation occurred after MVR in group A compared with group B (p < 0.001). Patients in group A were ventilated for a longer duration (25.9 +/- 18.8 v 17.3 +/- 7.9 hours, p < 0.05). There was no significant difference in the inotropic requirement between the 2 groups. There was no mortality in either group. CONCLUSIONS PAP returns to near-normal values in patients with severe preoperative PAH and to normal values in patients with mild preoperative PAH immediately after MVR. The outcome after surgery in patients with severe PAH is comparable to those with mild PAH.

Acute normovolemic hemodilution is not beneficial in patients undergoing primary elective valve surgery.

The objective of this study was to evaluate the effectiveness of acute normovolemic hemodilution (ANH) as a sole method of reducing allogenic blood requirement in patients undergoing primary elective valve surgery. One hundred eighty eight patients undergoing primary elective valve surgery were prospectively randomized into two groups: Group I (n=100) acted as control and in Group II (n=88) autologous blood was removed (10% of estimated blood volume in patients with hemoglobin (Hb) > 12g% and 7% when the Hb was < 12g%) in the pre-cardiopulmonary bypass (CPB) period for subsequent re-transfusion after protamine administration. The autologous blood withdrawn was replaced simultaneously with an equal volume of hydroxyl-ethyl starch solution. Banked blood was transfused in both the groups when Hb was < or = 6g% on CPB and < or = 8g% after CPB. Platelets were transfused when the count fell to < 100 x 10(9)/L and fresh frozen plasma (FFP) was transfused whenever there was diffuse bleeding with laboratory evidence of coagulopathy. The two groups were comparable as regards demographic data, type of surgical procedures performed, duration of CPB and ischemia, duration of elective ventilation and re-exploration for excessive bleeding. The autologous blood withdrawn in patients with Hb > or = 12g% was 288.3+/-69.4 mL and 244.4+/-41.3 mL with Hb < 12g% (P=NS). The Hb concentration (g%) was comparable pre-operatively (Group I = 12.1+/-1.6, Group II = 12.4+/-1.4), on postoperative day 1 (Group I = 10.3+/-1.1, Group II = 10.6+/-1.2) and day 7 (Group I = 10.9+/-1.5, Group II = 10.4+/-1.5). However, the lowest Hb recorded on CPB was significantly lower in Group II (Group I = 7.7+/-1.2, Group II = 6.7+/-0.9, P < 0.05). There was no difference in the chest tube drainage (Group I = 747.2+/-276.5 mL, Group II = 527.6+/-399.5 mL), blood transfusion (Group I = 1.1+/-1.0 units vs. Group II = 1.3+/-1.0 units intra-operatively and Group I = 1.7+/-1.2 units vs. Group II = 1.7+/-1.4 units post-operatively) and FFP transfusion (Group I = 581.4+/-263.4 mL, Group II = 546.5+/-267.8 mL) in the two groups. We conclude that low volume autologous blood pre-donation does not seem to provide any added advantage as a sole method of reducing allogenic blood requirement in primary elective valve surgery.

Congenital lobar emphysema: pitfalls and management.

Congenital lobar emphysema is a rare entity presenting in the first month of life. It appears with varying degrees of respiratory distress, clinical and radiological evidence of over-aeration of the upper and middle lobes, mediastinal shift and hypoxia. Its early recognition and surgical intervention can be life-saving. Even today, despite advanced diagnostic techniques, pitfalls in diagnosis and management are not uncommon and the condition may be mistaken for pneumothorax or pneumonia. This report elucidates the anesthetic management of three such cases with a review of literature.

Anesthetic management for emergency cesarean section and aortic valve replacement in a parturient with severe bicuspid aortic valve stenosis and congestive heart failure

Asymptomatic women with mild aortic stenosis (AS) and normal left ventricular functions can successfully carry pregnancy to term and have vaginal deliveries. However, severe AS (valve area <1.0 cm2) can result in rapid clinical deterioration and maternal and fetal mortality. So, these patients require treatment of AS before conception or during pregnancy preferably in the second trimester. In suitable patients percutaneous balloon aortic valvotomy appears to carry lower risk. It can also be used as a palliative procedure allowing deferral of aortic valve replacement until after delivery. The present patient had severe critical AS with congestive heart failure that was refractory to medical therapy and the fetus was viable (>28 wks). So, combined lower segment cesarean section and aortic valve replacement were performed under opioid based general anesthesia technique to reduce the cardiac morbidity and mortality.

Mediastinitis Following Pediatric Cardiac Surgery

Mediastinitis following pediatric cardiac surgery is associated with significantly high morbidity and mortality.

Single Stage Repair of Tetralogy of Fallot Associated With Left Pulmonary Artery Sling and Tracheal Stenosis

We report a rare case of tetralogy of Fallot (TOF) with left pulmonary artery (LPA) sling with tracheal stenosis. The patient underwent successful surgery in one stage involving intracardiac repair of TOF, LPA reimplantation and resection of tracheal stenosis with end‐to‐end anastomosis. doi: 10.1111/jocs.12192 (J Card Surg 2013;28:595–598)

Irreversible loss of vision in a paediatric patient due to occipital infarction after cardiopulmonary bypass.

The level of epidural catheter placement and choice of epidural agent are very important. In Nuss procedures, local anesthetic agents and thoracic epidural anesthesia are commonly used for pain management.[1] However, hypotension and other complications that might be caused by high-dose local anesthetics are the limitations of local anesthetic use. Therefore, an adjuvant can be employed in order to reduce the incidence of complications. In Nuss procedures, pain is effective over T1-10 dermatomes and therefore achievement of an efficient analgesia requires successful pain management comprising an adequate number of those dermatomes. Another reason why we preferred morphine in our cases was that because we used the lumbar region instead of the thoracal region as the area of epidural intervention, it enabled us to affect an adequate number of dermatomes. In our cases, we applied the same morphine dose used by Kariya et al., 30 μg/kg/h, and proceeded with the same continuous infusion of morphine, 3 μg/ kg/h.[2] However, considering the fact that they failed to achieve effective analgesia after the first postoperative day, we delivered an additional local anesthetic, 0.0625% bupivacaine (3 ml/kg/h).

Anesthetic management of patient with myasthenia gravis and uncontrolled hyperthyroidism for thymectomy.

The relationship between myasthenia gravis (MG) and other autoimmune disorders like hyperthyroidism is well known. It may manifest earlier, concurrently or after the appearance of MG. The effect of treatment of hyperthyroidism on the control of MG is variable. There may be resolution or conversely, deterioration of the symptoms also. We present a patient who was diagnosed to be hyperthyroid two and half years before the appearance of myasthenic symptoms. Pharmacotherapy for three months neither improved the myasthenic symptoms nor the thyroid function tests. Thymectomy resulted in control of MG as well as hyperthyroidism. In conclusion, effective control of hyperthyroidism in the presence of MG may be difficult. The authors opine that careful peri-operative management of thymectomy is possible in a hyperthyroid state.

Dysphagia Lusoria with atrial septal defect: Simultaneous repair through midline.

An aberrant right subclavian artery from the descending aorta is almost always reported as an isolated anomaly. We present the case of a four-year-old child with an anomalous origin of the right subclavian artery from the descending aorta, associated with an ostium secundum atrial septal defect. The patient underwent simultaneous repair of both the anomalies through median sternotomy, with implantation of the subclavian artery into the right common carotid artery. We believe that median sternotomy is the optimal surgical approach for the management of these lesions. Other operative approaches are also discussed.

Healed perivalvular abscess: Incidental finding on transthoracic echocardiography

A 36-year-old male patient presented with the complaints of palpitations and breathlessness. Preoperative transthoracic echocardiography (TTE) revealed a bicuspid aortic valve; severe aortic regurgitation with dilated left ventricle (LV) and mild LV systolic dysfunction (ejection fraction 50%). He was scheduled to undergo aortic valve replacement. History was not suggestive of infective endocarditis (IE). Preoperative TTE did not demonstrate any aortic perivalvular abscess. Intraoperative transesophageal echocardiography (TEE) examination using the mid-esophageal (ME) long-axis view, showed an abscess cavity affecting the aortic valve, which initially was assumed to be a dissection flap, but later confirmed to be an abscess cavity by color Doppler examination. The ME aortic valve short-axis view showed two abscesses; one was at the junction of the non-coronary and left coronary commissure and the other one above the right coronary cusp. Intraoperatively, these findings were confirmed by the surgeons. The case report demonstrates the superiority of TEE over TTE in diagnosing perivalvular abscesses.