The effect of combined conventional and modified ultrafiltration on mechanical ventilation and hemodynamic changes in congenital heart surgery.

BACKGROUND: Cardiopulmonary bypass is associated with increased fluid accumulation around the heart which influences pulmonary and cardiac diastolic function. The aim of this study was to compare the effects of modified ultrafiltration (MUF) versus conventional ultrafiltration (CUF) on duration of mechanical ventilation and hemodynamic status in children undergoing congenital heart surgery. MATERIALS AND METHODS: A randomized clinical trial was conducted on 46 pediatric patients undergoing cardiopulmonary bypass throughout their congenital heart surgery. Arteriovenous MUF plus CUF was performed in 23 patients (intervention group) and sole CUF was performed for other 23 patients (control group). In MUF group, arterial cannula was linked to the filter inlet through the arterial line, and for 10 min, 10 ml/kg/min of blood was filtered and returned via cardioplegia line to the right atrium. Different parameters including hemodynamic variables, length of mechanical ventilation, Intensive Care Unit (ICU) stay, and inotrope requirement were compared between the two groups. RESULTS: At immediate post-MUF phase, there was a statistically significant increase in the mean arterial pressure, systolic blood pressure, and diastolic blood pressure (P < 0.05) only in the study group. Furthermore, there was a significant difference in time of mechanical ventilation (P = 0.004) and ICU stay (P = 0.007) between the two groups. Inotropes including milrinone (P = 0.04), epinephrine (P = 0.001), and dobutamine (P = 0.002) were used significantly less frequently for patients in the intervention than the control group. CONCLUSION: Administration of MUF following surgery improves hemodynamic status of patients and also significantly decreases the duration of mechanical ventilation and inotrope requirement within 48 h after surgery.

Comparison of the Effect of Heparinized Normal Saline Solution Versus Saline Solutions in Arterial and Central Venous Catheters on Complete Blood Count After Cardiac Surgery.

Background: Heparinized and saline solutions can prevent clot formation in arterial and central venous catheters. However, heparin can decrease the platelet count and induce thrombocytopenia. Patients undergoing cardiac surgeries are more likely to develop heparin-induced thrombocytopenia. Objectives: This study aimed to investigate the effect of heparinized and saline solutions of arterial and central venous catheters on complete blood count (CBC) after cardiac surgery. Methods: This randomized controlled trial was conducted on 100 participants. All subjects underwent cardiac surgery at Rajaie Cardiovascular, Medical, and Research Center, Tehran, Iran. Patients were randomly divided into two groups intervention (A) for whom heparinized normal saline solution was used to maintain central arterial and venous catheters, and control (B) for whom normal saline solution was used. The CBC of subjects was monitored for three days (before surgery and the first and second days after surgery). Results: In the present study, there were no significant differences between CBC, white blood cell differential count, prothrombin time, partial thromboplastin time (PTT), and international normalized ratio in groups A and B. However, we found significant differences in platelet count (P = 0.049), red blood cell count (P = 0.0001), hemoglobin (P = 0.0001), and hematocrit (P = 0.0001) between before surgery and the second day after surgery in group A. Platelet count (P = 0.027) and PTT (P = 0.0001) before and after surgery were significantly different in group B. Conclusions: According to the results of this study, normal saline solution catheters have fewer side effects and can be a suitable replacement for heparinized catheters.

Cardiovascular responses to orotracheal intubation in patients undergoing coronary artery bypass grafting surgery. Comparing fiberoptic bronchoscopy with direct laryngoscopy.

BACKGROUND: The intubation by using fiberoptic brochoscop (FOB) can avoid the mechanical stimulus to oropharyngolaryngeal structures thereby it is likely to attenuate hemodynamic response during orotracheal intubation. Based on this hypothesis, we compared the hemodynamic responses to orotracheal intubation using an FOB and direct laryngoscope (DLS) in patients undergoing general anesthesia for coronary artery bypass grafting (CABG) surgery. METHODS: Fifty patients with ASA physical status II and Mallampati score I and II were scheduled for elective CABG surgery under general anesthesia requiring orotracheal intubation were randomly allocated to either DLS group (n = 25) or FOB group (n = 25). The same protocol of anesthetic medications was used. Invasive systolic and diastolic blood pressure (SBP & DBP) and heart rate (HR) were recorded before and after anesthesia induction, during intubation and in the first and second minutes after intubation. The differences among the hemodynamic variables recorded over time and differences in the circulatory variables between the two study groups were compared. RESULTS: Duration of intubation was shorter in DLS group (19.3 +/- 4.7 sec) compared with FOB group (34.9 +/- 9.8 sec; p = 0.0001). In both study groups basic SBP and DBP and HR were not significantly different (P > 0.05). During the observation, there were no significant differences between the two groups in BP or HR at any time points or in their maximal values (all p values > 0.05). CONCLUSION: We conclude that the FOB had no advantage in attenuating the hemodynamic responses to orotracheal intubation in patients undergoing CABG surgery.

Acute respiratory distress syndrome: rapid and significant response to volume-controlled inverse ratio ventilation--a case report.

Pulmonary complications following cardiopulmonary bypass (CPB) are relatively common, with up to 12% of patients experiencing acute lung injury (ALI). The treatment for ALI or acute respiratory distress syndrome (ARDS) is primarily supportive with specific modes of mechanical ventilation. We report a 46-year-old man withARDS after cardiac surgery whose arterial oxygenation was surprisingly improved 1 hour after using volume-controlled inverse ratio ventilation (VC-IRV).

Can preoperative anesthesia consultation clinic help to reduce operating room cancellation rate of cardiac surgery on the day of surgery?

BACKGROUND: Many surgical procedures are delayed or cancelled due to inadequate preoperative assessment and preparation. Case cancellations can be decreased by improved preoperative patient evaluation, improved communication between physician and patient, and modified schedule design. Because of importance of the high cost associated with operating room cancellations; healthcare providers have exerted efforts to decrease case cancellations on the day of surgery. The aim of this study was to evaluate the role of"pre-anesthesia consultation clinic" in reducing operating room cancellation. METHODS: We prospectively studied cancellation rate in 1716 scheduled cases for open heart surgery during a 4 months period in a teaching hospital. Of the 1716 patients, 866 cases were scheduled for operation before establishment of pre-anesthesia consultation clinic (Group 1) and 850 cases were scheduled after establishment of those clinics (Group 2). The data collected included patient age, ASA physical status and date of the preoperative assessment. RESULTS: Of the 1716 patients studied, 15.03% of cases were cancelled in the two groups. Cancellation rate in Group 1 was 146 (16.8%) and cancellation rate in Group 2 was 113 (13.29%). This difference was statistically significant (p = 0.046). The most common cause of cancellation in the two groups was incomplete medical work-up (32%) [group 1 (19.8%) more than group 2 (12.6%)]. CONCLUSION: Since the most common cause of cancellation in the two groups was incomplete medical work-up, then visitation of patients to the pre-anesthesia consultation clinic would minimize cancellation rate on the day of surgery.

Hemodynamic Responses to Two Different Anesthesia Regimens in Compromised Left Ventricular Function Patients Undergoing Coronary Artery Bypass Graft Surgery: Etomidate-Midazolam Versus Propofol-Ketamine.

BACKGROUND: Various methods have been suggested to prevent hemodynamic instability caused by propofol and adverse effects caused by etomidate induction. The current study evaluated hemodynamic effects of propofol-ketamine mixture in comparison to etomidate-midazolam mixture during anesthesia induction. OBJECTIVES: The aim of this study was to evaluate the hemodynamic effects of etomidate-midazolam by comparing it with propofol-ketamine for the induction of anesthesia in patients with left ventricular dysfunction undergoing coronary artery bypass graft surgery. PATIENTS AND METHODS: One-hundred patients aged between 40 and 65 with coronary artery disease and low ejection fraction scheduled for elective coronary artery bypass surgery participated in this study. The patients were randomly allotted to one of the two groups to receive either propofol-ketamine or etomidate-midazolam combination. Two groups were compared for pain on injection and myoclonus, Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), Cardiac Index (CI) and Systemic Vascular Resistance (SVR), before and one minute after induction of anesthesia, and one, three and five minutes after intubation. RESULTS: Incidence of pain on injection (2 - 4%) and myoclonus (10%) was less in both groups. The hemodynamic response was similar in the two groups for all variables over the time interval, except for CI at one and three minutes after intubation (P = 0.024 and P = 0.048, respectively), and SVR in five minutes after intubation (P = 0.009), with differences being statistically significant. CONCLUSIONS: Both anesthetic regimens were acceptable for induction in patients with coronary artery disease and left ventricular dysfunction undergoing coronary artery bypass graft surgery.

Heparinized and Saline Solutions in the Maintenance of Arterial and Central Venous Catheters After Cardiac Surgery.

BACKGROUND: Heparinized saline solution is used to prevent occlusion in the arterial catheters and central venous pressure monitoring catheters. Even at low dose, heparin administration can be associated with serious complications. Normal saline solution can maintain patency of arterial catheters and central venous pressure monitoring catheters. OBJECTIVES: The current study aimed to compare the efficacy of normal saline with that of heparinized one to maintain patency of arterial and central venous catheters after cardiac surgery. PATIENTS AND METHODS: In the current randomized controlled trial, 100 patients, with an age range of 18 - 65 years of valve and coronary artery surgery were studied in Rajaie heart center, Tehran, Iran. Patients were randomized to receive either heparinized saline (n = 50) or normal saline flush solutions (n = 50). In the study, arterial catheters and central venous pressure monitoring catheters were daily checked for any signs of occlusion in three postoperative days as primary end-point of the study. RESULTS: According to the information obtained from the study, four (8%) arterial catheters in the saline group (P value: 0.135) and three (6%) arterial catheters in the heparin group (P value = 0.097) were obstructed. Statistical analysis showed that the incidence of obstruction and changes in all other parameters between the two groups during the three-day follow-up was not significant (all P values > 0.05). CONCLUSIONS: It seems that there is no difference in the use of heparinized and normal saline solutions to prevent catheter occlusion of arterial and central venous pressure.

Sedative efficacy of propofol in patients intubated/ventilated after coronary artery bypass graft surgery.

BACKGROUND: Sedation after open heart surgery is important in preventing stress on the heart. The unique sedative features of propofol prompted us to evaluate its potential clinical role in the sedation of post-CABG patients. OBJECTIVES: To compare propofol-based sedation to midazolam-based sedation after coronary artery bypass graft (CABG) surgery in the intensive care unit (ICU). PATIENTS AND METHODS: Fifty patients who were admitted to the ICU after CABG surgery was randomized into two groups to receive sedation with either midazolam or propofol infusions; and additional analgesia was administered if required. Inclusion criteria were as follows: patients 40-60 years old, hemodynamic stability, ejection fraction (EF) more than 40%; exclusion criteria included patients who required intra-aortic balloon pump or inotropic drugs post-bypass. The same protocol of anesthetic medications was used in both groups. Depth of sedation was monitored using the Ramsay sedation score (RSS). Invasive mean arterial pressure (MAP) and heart rate (HR), arterial blood gas (ABG) and ventilatory parameters were monitored continuously after the start of study drug and until the patients were extubated. RESULTS: The depth of sedation was almost the same in the two groups (RSS=4.5 in midazolam group vs 4.7 in propofol group; P = 0.259) but the total dose of fentanyl in the midazolam group was significantly more than the propofol group (12.5 mg/hr vs 4 mg/hr) (P = 0.0039). No significant differences were found in MAP (P = 0.51) and HR (P = 0.41) between the groups. The mean extubation time in patients sedated with propofol was shorter than those sedated with midazolam (102 ± 27 min vs 245 ± 42 min, respectively; P < 0.05) but the ICU discharge time was not shorter (47.5 hr vs 36.3 hr, respectively; P = 0.24). CONCLUSIONS: Propofol provided a safe and acceptable sedation for post-CABG surgical patients, significantly reduced the requirement for analgesics, and allowed for more rapid tracheal extubation than midazolam but did not result in earlier ICU discharge.

Significance of preoperative total lymphocyte count as a prognostic criterion in adult cardiac surgery.

BACKGROUND: Evaluation of operational risk is a consequential goal in perioperative management of patients in cardiac surgery. Preoperative total lymphocyte count (PTLC) is a prognostic criterion of adverse major cardiovascular outcomes. OBJECTIVES: The purpose of this study was to investigate the prognostic value of PTLC as an independent predictor of postoperative morbidity and mortality in cardiac surgery. PATIENTS AND METHODS: Of 1604 patients scheduled for cardiac surgery between September, 2012 and March, 2013, a total of 1171 consecutive patients underwent elective primary valvular heart surgery and coronary artery bypass grafting. The patients were divided to three groups according to their PTLCs. The baseline characteristics and postoperative mortality and morbidity of the patients as well as the intensive care unit (ICU) stay according to the PTLCs were recorded and analyzed. The only inclusion criterion was a preoperative complete blood count. Exclusion criteria included: ages under 18 or over 80 years old, emergency surgery, adult patients with congenital heart disease and previous open heart surgery, and patients with any bacterial or viral infection during two weeks before the surgery. Protocol of anesthetic medications was used in all the patients similarly and according to standard. All the patients were admitted to the ICU after the surgery. RESULTS: A PTLC < 1500 cells/µL was associated with significantly high mortality and morbidity (P = 0.0001). In-hospital mortality and major composite morbidity were 9.65% and 28.4%, respectively. Low PTLC was associated with more frequent need for inotropic and intra-aortic balloon pump (IABP) support (P < 0.001), dialysis-dependent acute renal failure (P = 0.0001), postoperative superficial wound infections (P = 0.0001) and prolong ICU stay (P = 0.0001). CONCLUSIONS: Our study results showed that low PTLC was an independent, valuable prognostic criterion, with high sensitivity and specificity for evaluation of postoperative morbidity and mortality in cardiac surgery.

Cardiac variables as main predictors of endotracheal reintubation rate after cardiac surgery.

BACKGROUND: Reintubation in patients after cardiac surgery is associated with undesirable consequences. The purpose of the present study was to identify variables that could predict reintubation necessity in this group of patients. METHODS: We performed a prospective study in 1000 consecutive adult patients undergoing cardiac surgery with cardiopulmonary bypass. The patients who required reintubation after extubation were compared with patients not requiring reintubation regarding demographic and preoperative clinical variables, including postoperative complications and in-hospital mortality. RESULTS: Postoperatively, 26 (2.6%) of the 1000 patients studied required reintubation due to respiratory, cardiac, or neurological reasons. Advanced age and mainly cardiac variables were determined as univariate intra- and postoperative predictors of reintubation (all p values < 0.05). Multiple logistic regression analysis revealed lower preoperative (p = 0.014; OR = 3.00, 95%CI: 1.25 - 7.21), and postoperative ejection fraction (p = 0.001; OR = 11.10, 95%CI: 3.88 - 31.79), valvular disease (p = 0.043; OR = 1.84, 95%CI: 1.05 - 3.96), arrhythmia (p = 0.006; OR = 3.84, 95%CI: 1.47 - 10.03), and postoperative intra-aortic balloon pump requirement (p = 0.019; OR = 4.20, 95%CI: 1.26 - 14.00) as the independent predictors of reintubation. CONCLUSIONS: These findings reveal that cardiac variables are more common and significant predictors of reintubation after cardiac surgery in adult patients than are respiratory variables. The incidence of this complication, reintubation, is low, although it could result in significant postoperative morbidity and mortality.

Early hemodynamic changes after mitral valve replacement in patients with severe and mild pulmonary artery hypertension.

PURPOSE: to assess the early hemodynamic changes after elective mitral valve replacement (MVR) in patients with severe and mild pulmonary arterial hypertension (PAH). METHODS: a total of 45 consecutive patients, who were candidate for elective MVR, were enrolled in this prospective observational study. Patients were divided into two groups based on the absence (group A, 20 patients) or presence (group B, 25 patients) of severe pulmonary artery hypertension (PAH) defined as systolic pulmonary artery pressure ≥50 mmHg measuring by catheterization. MVR was performed using standard cardiopulmonary bypass (CBD) technique. The hemodynamic and arterial blood gas assessments were carried out at baseline before the induction of general anesthesia, in the operating room immediately after MVR, and then continued after stabilization of hemodynamic status with 2 hr interval up to 24 hours. RESULTS: The mean CPB and aortic cross-clamp times were similar in two groups (95.3 ± 49.5 and 61.8 ± 36.3 minutes in group A and 103.1 ± 34.7and 61.9 ± 20.0 minutes in group B). In group A, the mean PAP showed an increase immediately after the operation (from 40.4 ± 7.3 to 43.10 ± 6.2 mmHg) and then decreased significantly to 32.5 ± 3.9 mmHg (P <0.05). In group B, the mean PAP showed no significant reduction immediately after MVR, but it decreased significantly below the range of severe PAP over the first 24 hours. CONCLUSION: MVR is safe and effective even in patients with severe PAH. The anesthetic technique and postoperative cares can be useful in improving the outcome in such patients.

Relationship between gender and in-hospital morbidity and mortality after coronary artery bypass grafting surgery in an Iranian population.

BACKGROUND: Many previous studies have investigated the influence of gender on coronary artery bypass grafting surgery (CABG) outcomes. Despite the great volume of reports on this issue, it is still not clear whether it is the gender of the patient or pre-existing comorbid conditions that is the best predictor for the different outcomes seen between men and women. Multiple studies have shown that women are at higher risk of postoperative complications than men, particularly in the perioperative period. OBJECTIVES: The goal of this study was to determine whether sex differences exist in preoperative variables between men and women, and to evaluate the effect of gender on short-term mortality and morbidity after CABG in an Iranian population. PATIENTS AND METHODS: Data were collected prospectively from 690 consecutive patients (495 men and 195 women) who underwent isolated CABG. Preoperative, intraoperative, and postoperative variables, major complications and death were compared between the male and female patients until hospital discharge using multivariate analysis. RESULTS: Women were older (P = 0.020), had more diabetes (P = 0.0001), more obesity (P = 0.010), a higher New York Heart Association functional class (P = 0.030), and there was less use of arterial grafts (P = 0.016). Men had more tobacco smokers (P = 0.0001) and lower preoperative ejection fractions (EF) (P = 0.030). After surgery, women had a higher incidence of respiratory complications (P = 0.003), higher creatine kinase (CK) - MB levels (P = 0.0001), and higher inotropic support requirements (P = 0.030). They also had a higher incidence of decreased postoperative EF versus preoperative values (P = 0.020). The length of ICU stay, incidence of return to ICU and postoperative death, were similar between men and women. Nevertheless, after adjusting for age and diabetes, female gender was still independently associated with higher morbidity in patients over 50 years of age. CONCLUSIONS: Women had more risk factors, comorbidities, and postoperative complications. Women older than 50 years of age were at a higher risk of postoperative complications than men. This difference decreased with younger age. In-hospital mortality rates were not influenced by sex, as there was no difference found between the two groups (2.5% women vs. 2.2% men; P > 0.05).