Deepak K. Tempe

Pentoxifylline Therapy for Hepatopulmonary Syndrome: A Pilot Study

H epatopulmonary syndrome (HPS) is characterized by a triad of liver disease, hypoxemia, and intrapulmonary vascular dilations (IPVDs). Its prevalence is 4% to 47% in patients with cirrhosis. Patients with HPS demonstrate a significant reduction in exercise capacity due to abnormal pulmonary circulation. Anatomic arteriovenous shunts in the lung are used during exercise and lead to exercise-induced impairment in gas exchange and exercise-induced arterial hypoxemia. The pathogenesis of HPS is unclear. Cytokinemediated injury is alleged to play a key role. Endothelin-1 and tumor necrosis factor (TNF) interaction, occurring in the lung vasculature, contribute to the development of experimental HPS. Overproduction of TNF, due to endotoxin stimulation of Kupffer cells, might be a major mechanism leading to HPS. Pentoxifylline, a nonspecific phosphodiesterase-4 inhibitor, blocks TNF synthesis and TNF-induced macrophagic nitric oxide production. Pentoxifylline prevented the development of HPS and attenuated HPS in cirrhotic rats. However, to our knowledge, pentoxifylline has not been used clinically for the treatment of HPS. In this study, we tried pentoxifylline therapy in patients with HPS.

Successful nonsurgical removal of a knotted and entrapped pulmonary artery catheter

Knotting of a balloon-tipped, flow-directed catheter leading to difficulty in its removal is a rare but serious complication. Several methods have been used to remove such catheters with nonsurgical techniques. A case of knotted catheter that was also entrapped in a surgical suture in a patient undergoing emergency mitral valve replacement is presented and a method for its nonsurgical removal is described.

Myocardial protection with isoflurane during off-pump coronary artery bypass grafting: a randomized trial.

OBJECTIVES To analyze the hemodynamic effects and myocardial injury using troponin-T and creatine phosphokinase (CPK-MB) with isoflurane and compare it with a control group in patients undergoing off-pump coronary artery bypass (OPCAB) surgery. DESIGN This prospective, randomized study was performed in patients scheduled for elective OPCAB surgery during February 2007 to February 2009. SETTING Tertiary care, university teaching hospital. PARTICIPANTS Forty-five patients undergoing elective OPCAB surgery. INTERVENTIONS Patients were randomly allotted to receive either isoflurane (inspired concentration between 1.0% and 2.5%) or propofol (1.5 to 3.5 mg/kg/h) during OPCAB surgery. The concentration of these agents was titrated such that the BIS value was maintained between 50 and 60. MEASUREMENTS AND MAIN RESULTS The hemodynamic data were measured and recorded after induction of anesthesia (baseline), during the distal anastomosis of each coronary artery, and 5 and 30 minutes after giving protamine. In addition, blood samples for troponin-T and CPK-MB were obtained after induction (baseline), after 6 hours and 24 hours postoperatively. The cardiac index was significantly higher in the isoflurane group at all stages, except during distal anastomosis of the diagonal branch of the left anterior descending artery (p < 0.05). There was a significant increase in troponin-T levels at 6 and 24 hours after surgery in the propofol group (from 0.037 ± 0.013 ng/mL to 0.098 ± 0.045 ng/mL and 0.081 ± 0.025 ng/mL, respectively, p < 0.05). Significant increases in the troponin-T levels were observed at 6 hours (from 0.033 ± 0.011 ng/mL to 0.052 ± 0.025 ng/mL, (p < 0.05) in the isoflurane group, and the levels in the propofol group were significantly higher than the isoflurane group at 6 and 24 hours after surgery (p < 0.05). The CPK-MB levels increased in both groups, but were not statistically different. CONCLUSIONS Isoflurane provides protection against myocardial damage in a clinically used dosage as documented by lower levels of troponin-T in patients undergoing OPCAB surgery.

Blood conservation in small adults undergoing valve surgery

OBJECTIVES A substantial reduction in transfusion requirements for cardiac surgical procedures has been reported. Many of these reports have been described in patients undergoing coronary artery bypass grafting. Patients suffering from rheumatic heart disease in India are usually small and also anemic. This study was conducted to assess blood conservation methods for cardiac valve surgery in this subset of patients. DESIGN This was a prospective, randomized study. SETTING The study was performed in a New Delhi tertiary care hospital, and the patients were referred from the northern states of India. PARTICIPANTS One hundred fifty consecutive patients undergoing elective valve surgery using cardiopulmonary bypass were included. The mean age was 27.7 years and mean weight was 45.2 kg. INTERVENTIONS The patients were divided into three groups of 50 each. Group 1 received autologous fresh blood donated before bypass, and both a cell saver and membrane oxygenator were used. The oxygenator contents at the end of perfusion were processed by cell saver. Group 2 patients were reinfused with autologous blood only, and group 3 was a control group. In groups 2 and 3, the blood that remained in the oxygenator at the conclusion of cardiopulmonary bypass was reinfused. A hematocrit of less than 25% was considered an indication for transfusion in the postoperative period. MEASUREMENTS AND MAIN RESULTS The mean preoperative hematocrit was 35.5%. A mean of 361.1 mL of autologous blood was collected from group 1 and 303.3 mL from group 2. Group 1 required 15 units of bank blood, group 2, 90 units (p < 0.001), and group 3, 102 units (p < 0.001). Seventy-eight percent of group 1 patients did not receive any donor blood. There was no significant difference in chest tube drainage among the three groups. CONCLUSIONS In this unique group of patients whose mean body weight was only 45 kg, autologous blood alone did not decrease blood bank requirements but when combined with a cell saver and membrane oxygenator greatly reduced the need for donor blood.

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.

Closed Mitral Valvotomy and Elective Ventilation in the Postoperative Period: Effect of Mild Hypercarbia on Right Ventricular Function

OBJECTIVES It is customary to extubate patients immediately after closed mitral valvotomy. These patients often have deranged respiratory function caused by chronic lung congestion. The left ventricular function may also be subnormal after valvotomy in some patients. Therefore, elective ventilation for some duration in the postoperative period can be beneficial to these patients. This work is an attempt to find whether elective ventilation should be preferred over immediate extubation in these patients. DESIGN A prospective randomized study. SETTING The study was performed in a tertiary care hospital, and the patients are referred from the northern states of India. PARTICIPANTS One hundred patients undergoing elective closed mitral valvotomy were included in the initial part of the study. Ten more patients were studied to evaluate the effect of mild hypercarbia on right ventricular function after closed mitral valvotomy. INTERVENTIONS One hundred patients were divided into two groups of 50 each. Group 1 consisted of patients in whom the neuromuscular blockade was reversed at the end of surgery with neostigmine and atropine and the trachea was extubated. In group 2, the residual neuromuscular paralysis was not reversed and the patients were electively ventilated in the postoperative period for an average duration of 5 hours and 29 minutes +/- 1 hour and 58 minutes. In all the patients in both the groups, electrocardiogram, direct arterial blood pressure, and oxygen saturation were continuously monitored, and arterial blood gases were measured intermittently throughout the study period. Because the results showed that there was mild hypercarbia, 30 minutes after extubation in group 1, 10 more patients were studied to evaluate the effect of mild hypercarbia on right ventricular function after surgery. Patients were ventilated after surgery (F1O2 = 1) to maintain normocarbia (PaCO238.6 +/- 3.4 mmHg). Mild hypercarbia PaCO251.5 +/- 3.7 mmHg) followed by normocarbia (PaCO2 40 +/- 2.5 mmHg) was induced by adjusting the ventilator rate with a constant tidal volume. Standard hemodynamic measurements were performed at each stage. MEASUREMENTS AND MAIN RESULTS Although all the patients maintained satisfactory and stable hemodynamics in the postoperative period, the PaCO2 at the end of 30 minutes of extubation was significantly higher in group 1 (48.1 +/- 5.3 mmHg) as compared with group 2 (40.2 +/- 4.3 mmHg, p < 0.001). Mild hypercarbia significantly increased pulmonary vascular resistance (p < 0.01), mean pulmonary arterial pressure (p < 0.001), right ventricular stroke work (p < 0.01), right ventricular systolic pressure (p < 0.01), and right ventricular end-diastolic pressure (p < 0.001). The effect was not totally reversible with CO2 washout as all parameters except right ventricular end-diastolic pressure and pulmonary vascular resistance continued to remain significantly higher when normocarbia was restored. The significant changes in systemic hemodynamics produced by hypercarbia were increases in cardiac index, mean arterial pressure, and pulmonary capillary wedge pressure. CONCLUSIONS Avoidance of even mild hypercarbia, therefore, appears advisable in the early postoperative period because of potential impedence to right ventricular ejection. Continuous monitoring of end-tidal CO2 and frequent blood gas analyses should be practiced, and elective ventilation should be considered in patients with long-standing disease and pulmonary hypertension.

The success rate and safety of internal jugular vein cannulation using anatomical landmark technique in patients undergoing cardiothoracic surgery

AIMS AND OBJECTIVES Landmark-guided internal jugular vein (IJV) cannulation is a basic procedure, which every anesthetist is expected to acquire. A successful first attempt is desirable as each attempt increases the risk of complications. The present study is an analysis of 976 IJV cannulations performed in adults undergoing cardiothoracic surgery. MATERIALS AND METHODS The IJV was cannulated with a triple lumen catheter using the anatomical landmarks. The following data were recorded: Patient demographics, age, sex, body mass index, diagnosis, operative procedure, operator (resident/consultant), site of cannulation (central approach, right IJV, left IJV, external jugular vein), number of attempts and duration of cannulation, length of insertion of the catheter, number of correct placements on X-ray and any complications. RESULTS The success rate of IJV cannulation was 100%. In 809 (82.9%) patients, cannulation was performed in the first attempt. Residents performed 792 cannulations and the consultants performed 184 cannulations. In 767 patients, the residents were successful in inserting the catheter and in 25 they failed after 5 attempts, hence, they were cannulated by the consultant. The time taken for insertion of the catheter was 6.89 ± 3.2 minutes. Carotid artery puncture was the most common complication, it occurred in 22 (2.3%) patients. CONCLUSION IJV cannulation with landmark technique is highly successful with minimal complications in the adult patients undergoing cardiothoracic surgery. Basic training of cannulating the IJV by landmark technique should be imparted to all the traines as ultrasound may not be available in all locations.

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.