Effect of positive cumulative fluid balance on postoperative complications after living donor liver transplantation: A retrospective analysis

Background and Aims:

Fluid administration during liver transplant (LT) surgery is controversial. Although adverse outcomes following positive intraoperative fluid balance have been reported, studies presenting the influence of cumulative postoperative fluid balance (CFB) on complications following LT are sparse. Patients with chronic liver disease tend to receive more fluid during and after surgery due to their unique physiological disease state. The aim of this study was to evaluate the influence of 48-hour CFB on the development of acute kidney injury (AKI) and pulmonary complications on day 4 after live donor LT.

Methods:

This retrospective study included 230 patients undergoing live donor LT. The effect of CFB on day 2 on AKI and pulmonary complications was analysed. Chi-square test, Fisher's exact test, samples t-test, Mann-Whitney U-test were used.

Results:

Bivariate analysis showed a lower graft vs recipient weight ratio (GRWR), sepsis (P < 0.001) and a higher 48-hour CFB after surgery significantly increased the development of AKI. For pulmonary complications, higher Model for End- stage Liver Disease-Na(MELD-Na) score, higher peak arterial lactate, higher 48-hour CFB (P = 0.016) and sepsis (P = 0.003) were found to be statistically significant. Upon multivariate analysis, CFB at 48 hours was significantly higher in patients suffering from pulmonary complications, and GRWR and sepsis were significant for AKI. For every one litre increase in CFB on day 2, the odds of pulmonary complications increased by 37%.

Conclusion:

A more positive CFB on day 2 increased the development of pulmonary complications and lower GRWR and sepsis increased the development of AKI.

Hypercoagulability on thromboelastography after living donor hepatectomy-The true side of the coin

Background and Aims:

Coagulation dynamics after donor hepatectomy are complex. Having complete knowledge of the actual changes in the coagulation status during donor hepatectomy is important to prevent complications such as pulmonary embolism, deep vein thrombosis, and bleeding. Hence, the present study aimed to study the coagulation dynamics following open donor hepatectomy both by thromboelastography (TEG) and conventional coagulation tests (CCT).

Methods:

A total of 50 prospective liver donors were included. TEG and CCT [activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalised ratio (INR), fibrinogen, and platelet counts] were performed for each patient before surgery (baseline), on postoperative day (POD) 0, 1, 2, 3, 5, and 10.

Results:

TEG showed hypercoagulability in 28%, 38%, 30%, 46%, 42%, and 48% patients; in contrast INR showed hypocoagulability in 58%, 63%, 73%, 74%, 20%, and 0% patients on POD 0,1,2,3,5, and 10, respectively. Patients demonstrating hypercoagulability on TEG had significantly decreased reaction time (P = 0.004), significantly increased maximum amplitude (P < 0.001), and alpha angle value (P < 0.001). Postoperatively, INR, PT, and aPTT values increased significantly, while platelets and fibrinogen levels decreased significantly when compared to their baseline values. There was no coagulation-related postoperative complication in any of the patients.

Conclusion:

Hypercoagulability after donor hepatectomy is common. TEG showed hypercoagulability and did not show any hypocoagulability as suggested by the CCT. In patients undergoing donor hepatectomy, CCT may not reflect the actual changes incoagulation status and tests such as TEG should be performed to know the correct nature of changes in coagulation following donor hepatectomy.

Guidelines of the Indian Association of Cardiovascular and Thoracic Anaesthesiologists and Indian College of Cardiac Anaesthesia for perioperative transesophageal echocardiography fellowship examination

During current medical care, perioperative transesophageal echocardiography (TEE) has become a vital component of patient management, especially in cardiac operating rooms and in critical care medicine. Information derived from echocardiography has an important bearing on the patient's outcome. The Indian Association of Cardiovascular and Thoracic Anaesthesiologists (IACTA) has promoted the use of TEE during routine clinical care of patients undergoing cardiac surgery. An important mission of IACTA is to oversee training and certify anesthesiologists in the perioperative and intensive care use of TEE. The provision of “Fellowship” is by way of conducting IACTA – TEE fellowship (F-TEE) examination. This has been done annually for the past 7 years using well-established curriculums by accredited national and international societies. Now, with the transformation and reconstitution of IACTA education and research cell into the newly formed Indian College of Cardiac Anaesthesia, F-TEE is bound to meet international standards. To ensure that the examinations are conducted in a transparent and foolproof manner, the guideline committee (formulated in 2010) of IACTA has taken the onus of formulating the guidelines for the same. These guidelines have been formally reviewed and updated since 2010 and are detailed here to serve as a guide to both the examinee and examiner ensuring standardization, efficiency, and competency of the IACTA F-TEE certification process.

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.

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.

Myocardial depressant effect of nitrous oxide after valve surgery

We have studied the cardiovascular effects of 50% nitrous oxide after cardiopulmonary bypass in 14 patients undergoing valve surgery. All patients received morphine as the principal anaesthetic. Nitrous oxide administration for 5 min caused a decrease in mean arterial pressure from 82 +/- 10 to 71 +/- 12.7 mmHg (P < 0.001), cardiac index (2.8 +/- 0.5 to 2.4 +/- 0.5 litres min-1 m-2, P < 0.01), heart rate (104 +/- 17 to 99 +/- 18 beats min-1, P < 0.05), left ventricular stroke work index (29.4 +/- 8.1 to 22 +/- 8.7 gm-m beat-1 mm-1, P < 0.001), stroke volume (45.3 +/- 11.6 to 40 +/- 12.8 ml beat-1, P < 0.05) and an increase in pulmonary vascular resistance from 106.4 +/- 53.9 to 143.9 +/- 81.0 dynes s cm-5 (P < 0.01) and right atrial pressure (1.42 +/- 2.09 to 1.71 +/- 2.21 mmHg, P < 0.05). There was no change in systemic vascular resistance. When nitrous oxide was discontinued all the parameters started to recover within 3 min. Mean arterial pressure returned to control value in 5 min, but cardiac index and pulmonary vascular resistance returned to control value in 10 min. Our results suggest a direct myocardial depression and that the use of nitrous oxide is not recommended immediately after valve surgery and cardiopulmonary bypass.

Blood conservation in valve surgery

Blood utilization in 40 patients undergoing elective valve surgery was prospectively studied. The patients had valvular lesions of rheumatic origin with a mean age of 29.1 years and a mean preoperative hematocrit of 35.23 +/- 4.16. Blood was removed from all patients after induction of anesthesia and reinfused after bypass (mean 365.12 +/- 66.96 ml). Membrane oxygenator was used in all the patients. All discard suction was routed through a regionally heparinised collecting and processing system, and the resulting red cell concentrate was transfused. At the conclusion of bypass, all blood remaining in the pump oxygenator was also processed by cell saver and used for subsequent reinfusion. Normovolemic anemia was accepted in hemodynamically stable patients. Thirty two patients (80%) received no bank blood or blood products during their entire hospital course. A total of twelve units of whole blood was transfused into eight patients.

Cannulation of the internal jugular vein in patients undergoing open heart surgery

A total of 476 internal jugular vein cannulations performed between June 1990 to August 1991 were prospectively evaluated. The patients' age ranged between ten days to 61 years. We achieved a high success rate of cannulation (97.9%). We describe the use of two single lumen catheters inserted through right internal jugular vein as an alternative to the popular multilumen catheters. We also suggest that low approach should be tried more often in children, if the central approach fails.

Surgical management of cardiac myxomas

Cardiac myxomas are rare cardiac lesions, though they are the commonest tumours of the heart. Seventeen cases of cardiac myxomas have been operated during the last one decade. Exertional dyspnoea, palpitation and chest pain were the main presenting symptoms. Echocardiographic assessment was the only definitive diagnostic investigation required prior to surgery. Early surgical excision was planned in all the cases. Irrespective of the exposure techniques, removal of the tumour with wide excision of its base was practised. There was one early death due to low cardiac output in a patient brought in a shock like state. Follow up study has revealed 14 patients in NYHA class I and two patients are having class II symptoms. Periodic echocardiographic follow up study has not revealed any recurrence till date. It is concluded that an early diagnosis and surgery gives excellent long term results in these cases.