Entrapped central venous catheter after mitral valve replacement and its surgical retrieval.

Central venous pressure monitoring line insertion is routine prior to the conduct of cardiac surgery, and in rare instances, malposition can contribute to operative complications. We describe here how a central venous line lying in the right atrium became caught in a left atrial (LA) closure suture during a mitral valve replacement. The opening of the LA suture line is highly unsafe without cardiopulmonary bypass (CPB) because of the possibility of systemic air embolism, but by employing an ingenious method of suturing over and unravelling the continuous sutures closing the left atrium, it was possible to surgically retrieve it without the use of a CPB.

Haemodynamic response to endotracheal intubation in coronary artery disease: Direct versus video laryngoscopy.

Endotracheal intubation involving conventional laryngoscopy elicits a haemodynamic response associated with increased heart and blood pressure. The study was aimed to see if video laryngoscopy and endotracheal intubation has any advantages over conventional laryngoscopy and endotracheal intubation in patients with coronary artery disease. Thirty patients suffering from coronary artery disease scheduled for elective coronary artery bypass grafting (CABG) were studied. The patients were randomly allocated to undergo either conventional laryngoscopy (group A) or video laryngoscopy (group B). The time taken to perform endotracheal intubation and haemodynamic changes associated with intubation were noted in both the groups at different time points. The duration of laryngoscopy and intubation was significantly longer in group B (video laryngoscopy) when compared to group A patients. However, haemodynamic changes were no different between the groups. There were no events of myocardial ischaemia as monitored by surface electrocardiography during the study period in either of the groups. In conclusion, video laryngoscopy did not provide any benefit in terms of haemodynamic response to laryngoscopy and intubation in patients undergoing primary CABG with a Mallampatti grade of <2.

Influence of colloid infusion on coagulation during off-pump coronary artery bypass grafting.

This study was conducted to determine the influence of colloid infusion on coagulation in patients undergoing off-pump coronary artery bypass grafting (OP-CABG). Thirty patients undergoing elective OP-CABG received medium molecular weight hydroxyethyl starch group I (MMW-HES 200/0.5), low molecular weight hydroxyethyl starch group II (LMW-HES 130/0.4) or gelatin group III (GEL) in a prospective randomized trial. Blood samples were assessed for hemoglobin (Hb), activated coagulation time (ACT), prothrombin time (PT), activated partial thromboplastin time (aPPT), platelet count, fibrinogen and von Willebrand factor (vWF) at specified intervals. Total volume of the colloid infused and postoperative chest-time drainage was also measured. There was a significant decrease in Hb, platelet count, fibrinogen levels in all these groups, which did not warrant blood transfusion. After the colloid infusion, vWF decreased significantly to 67% from baseline in group I as compared to 85 and 79% in group II and group III, respectively. vWF levels remained lower than the baseline value in the first 24 hours in group I, whereas this factor level increased above the baseline values in groups II and III, 6 hours postoperatively. Postoperative chest tube drainage in 24 hours was significantly higher in group I (856 +/- 131 ml) as compared to group II (550 +/- 124 ml) and group III (582 +/- 159 ml). LMW-HES 130/0.4 was superior to MMW-HES 200/0.5 and gelatin in patients undergoing OP-CABG, in terms of better preservation of coagulation associated with enhanced volume effect.

Transthoracic electrical bioimpedence cardiac output: comparison with multigated equillibrium radionuclide cardiography.

INTRODUCTION: Thoracic electrical bioimpedance (TEB) for measuring cardiac output (CO) is being explored increasingly as an alternative to pulmonary artery catheter. The major advantage of this technology is that it is non-invasive and easy to perform. Several studies have compared it to thermodilution cardiac output using PA catheter, with variable correlation. Multigated radionuclide equilibrium cardiography (RNEC) method of cardiac output measurement is known to be reliable. OBJECTIVE: To compare cardiac output measured by thoracic electrical bioimpdenace with that measured by multigated radionuclide equilibrium cardiography. PATIENTS AND METHODS: CO studies were performed sequentially at a single sitting by TEB and RNEC methods among patients with cardiac symptoms referred for radionuclide study as part of their evaluation. TEB CO was measured by placing two pairs of electrodes on either side of neck and two other pairs on either side of the lower chest. Stroke volume was estimated from the sequential changes in transthoracic electrical bioimpedance induced by rhythmic aortic blood flow, using Kubicek equation. RNEC-CO was measured by intravenous injection of radio-active Technitium-tagged RBCs followed by ECG gated blood pool imaging over the chest (MUGA study). Bland-Altman analysis was used to compare the measurements. RESULTS: A total of 32 subjects with proven or suspected ischemic heart disease, but without overt cardiac failure, edema or arrhythmias were studied (M:F::26:6; mean age: 48 +/- 12 years). The mean TEB-CO was 3.54 +/- 1.052 l/min and mean RNEC-CO was 3.907 +/- 0.952 l/min. Correlation coefficient (r) for these measurements was 0.67 (p < 0.01), with bias: -0.421 l/min; precision: 1.557 l/min; and percentage error of measurement: 42.35%. CONCLUSIONS: This study observed a moderate correlation between TEB and RNEC methods of CO measurement. Further studies are indicated to explore the relative utility of TEB in comparison with RNEC as well as other methods of CO measurement before considering its use in patients with ischemic heart disease.

The efficacy of aprotinin in arterial switch operations in infants.

BACKGROUND: In the present study we assessed whether aprotinin at a total dose (40,000 kallikrein inhibitor units (KIU)/kg) is effective in reducing postoperative blood loss and blood product requirement after arterial switch operations in infants. METHODS: A prospective, double-blind, randomized study, evaluated 50 infants who underwent arterial switch operations for transposition of great arteries. Patients were randomized into a placebo group, 25 patients who received normal saline and a treatment group, 25 patients who received 20,000 KIU/kg of aprotinin after induction of anesthesia, followed by 20,000 KIU/kg of aprotinin added to pump prime. Postoperative blood loss through the thoracic chest tubes and blood product requirements (mL/kg/24 h) were measured for the first 24 h in the intensive care unit. RESULTS: Postoperative blood loss in the first 24 h was significantly (P < 0.0001) higher in the placebo group (49.7 +/- 11.9 mL/kg/24 h) as compared to the aprotinin group (37.1 +/- 3.5 mL/kg/24 h). Requirements for fresh frozen plasma (mL/kg/24 h) and use of platelet concentrate transfusion (mL/kg/24 h) were significantly less in patients who received aprotinin (P < 0.0001), but did not reduce the proportion of patients transfused with blood products. The number of total donor exposures to all allogenic blood products was less in the aprotinin group [range (median) = 2-4 (3)] than the placebo group [range (median) = 7-14 (10)]. The re-exploration for excessive bleeding was significantly less with aprotinin group (16% vs 32%) (P = 0.01). CONCLUSION: Our study concludes that aprotinin decreased the postoperative blood loss and requirement of transfusion of fresh frozen plasma and platelets (mL/kg/24 h) during the early postoperative period. Further, it reduced the number of donor exposures and re-exploration for excessive bleeding in the treatment population.

Bispectral index-guided anaesthesia for off-pump coronary artery bypass grafting.

Bispectral index (BIS) monitoring may assist reduction in utilisation of anaesthetic agents during general surgical procedures. This study was designed to test whether the use of BIS monitoring reduces the anaesthetic requirements during off-pump coronary artery bypass grafting (CABG). This prospective - clinical trial was conducted on 40 adult patients undergoing elective off-pump CABG. Patients received either isoflurane or propofol anaesthesia. BIS monitoring, which guided the dose of anaesthetic, was carried out in 50 percent of the patients. The amount of anaesthetic agent (isoflurane or propofol) administered from the start of anaesthesia to the end of surgical procedure was calculated and were compared in four groups of patients - namely Group A (I-no BIS) received isoflurane; end tidal concentration was maintained at 1-1.2% in a low flow technique throughout the procedure, Group B (I-BIS) received isoflurane in a low flow technique; inspired concentration was dictated by BIS value maintained at 50; Group C (P-no BIS) received propofol at a dose range of 4-8 mg/kg/hr and in Group D(P-BIS) the propofol infusion rate was dictated by BIS value maintained at 50. The quantity of isoflurane was significantly less for Group B (I-BIS) as compared with Group A (I-no BIS) (37 +/- 4 vs. 24 +/- 4 ml; p< 0.05) and similarly the amount of propofol infused was significantly less in Group D (P-BIS) as compared with Group C (P-no BIS) (176 +/- 9 vs. 120 +/- 6 ml; p< 0.05). BIS guided anaesthesia reduces the anaesthetic agent required for the performance of off-pump CABG. This can be extrapolated in terms of saving agent and reduced cardiac depression during off-pump CABG.

Non-invasive cardiac output by transthoracic electrical bioimpedence in post-cardiac surgery patients: comparison with thermodilution method.

OBJECTIVE: Thoracic electrical bioimpedance (TEB) cardiac output (CO) is being explored increasingly as a non-invasive alternative to the pulmonary artery catheter (PAC). This study compared TEB-CO measured using a new instrument--NICOMON (Larsen & Toubro Ltd. India) with thermodilution (Td) CO in post-cardiac surgery patients. METHODS: Postoperative cardiac surgical patients requiring a PAC for their management were studied. TEB-CO was measured by passing a 4 mA RMS alternating current across the chest and measuring the analog bioimpedence across the thorax. Kubicek equation was used to estimate TEB-CO. Td-CO was measured using a PAC. Bland-Altman analysis was used to compare paired data. RESULTS: One hundred and ninety-seven pairs of CO measurements were made by the two methods among 35 patients. Mean TEB-CO was 5.15 +/- 1.27 l/min and mean Td-CO was 5.22 +/- 1.28 l/min. Pearson correlation coefficient (r) for these measurements was 0.856 (P < 0.01), with bias -0.0651 l and precision: +/-1.37 l/min. The percentage error of measurement of this precision was 26.44%. Cardiac index also correlated among the two methods (r = 0.789; P = 0.01). CONCLUSIONS: Thoracic electrical bioimpedance cardiac output compares favorably with thermodilution method among post-cardiac surgery patients. Further studies are indi- cated with this instrument to validate its efficacy in various clinical situations and utility in monitoring hemodynamic interventions.

Severe pulmonary oedema following therapeutic embolization with Onyx for cerebral arteriovenous malformation.

Acute respiratory distress syndrome (ARDS) is characterized by sudden onset of respiratory distress, infiltrates on radiographs consistent with pulmonary oedema, hypoxaemia and increased work in breathing. Infiltrates on radiographs are bilateral, but may be patchy or diffuse and fluffy or dense. It is associated with absence of left heart failure and a PaO2/FiO2 ratio of < or =200. Ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide (DMSO), which was approved by the US FDA in July 2005, is used as an embolic agent for cerebral arteriovenous malformation (AVM). It is a biocompatible liquid polymer that precipitates and solidifies on contact with blood, thus forming a soft and spongy embolus. We report a case of ARDS following therapeutic embolization with ethylene vinyl alcohol copolymer for cerebral AVM under general anaesthesia. Experienced perioperative physicians adopted standard anaesthetic technique and monitoring for this procedure. Acute respiratory distress and hypoxaemia developed in the patient following extubation of the trachea. Infiltrates seen on postprocedural chest radiographs were consistent with pulmonary oedema. DMSO, the solvent for the ethylene vinyl alcohol copolymer, is excreted via the lungs after administration and we postulate that DMSO was the possible cause of ARDS in this patient. Monitoring of haemodynamic parameters (invasive blood pressure, electrocardiography) and ventilatory parameters (ETCO2, SpO2, airway pressure monitoring) are important in the recognition of this possible event. One should be vigilant and anticipate this complication following therapeutic embolization with ethylene vinyl alcohol polymer for the treatment of cerebral AVM.

Ultra low dose aprotinin decreases blood loss and transfusion requirements in high risk two valve replacement surgery.

The efficacy of ultra-low-dose-aprotinin (ULDA) in 'high-risk' two valve replacement surgery, was evaluated in this prospective, randomized, double-blind study. Forty adult high-risk patients undergoing elective two valve replacement surgery, were included. The patients were divided into 2 groups of 20 each. In Group I, aprotinin in a dose of 1,000,000 KIU was administered from the end of anaesthesia induction to the time of sternotomy after a 1 ml of test dose. In Group II (control), 100 ml of normal saline was administered in a similar fashion. Coagulation parameters, blood loss, and amount of transfusion of blood / blood products were measured at specific intervals. The postoperative chest tube drainage in the first 24 hours was significantly less 203+/-35 ml (p<0.05) in Group I as compared with 490+/-104 ml in group II and consequently, Group I patients received significantly less (p<0.05) red cell concentrates and platelet transfusion. There was a significant decrease in the length of postoperative elective ventilation, intensive care unit (ICU) stay and direct costs involved in the hospital expenses with the use of ULDA. We conclude that ULDA is safe and effective in 'high-risk' two-valve replacement surgery to reduce postoperative bleeding, postoperative length of intubation and ICU stay; use of ULDA is associated with significant direct cost savings.