Goal-directed therapy in cardiovascular surgery: A case series study

Hemodynamic and intravascular volume monitoring has been utilized and significantly improved thanks to the technology revolution. Goal-Directed Therapy (GDT) derived from this advanced monitoring is beneficial for complex surgeries, and it shifted the medical approaches from static therapy to more personalized functional treatments. Conventional monitoring methods such as blood pressure, heart rate, urinary output, and central venous pressure are commonly used. However, studies have shown these routine parameters often cannot precisely estimate the quality of tissue perfusion. Tissue hypoperfusion and hypoxia play a crucial role in initiating a systemic inflammatory response after prolonged surgeries, resulting in unstable hemodynamic condition of the patients. Several studies reported the importance of GDT in non-cardiac surgeries and there are few reports on cardiac surgeries. However, tissue perfusion and fluid management are more critical in complex and prolonged cardiovascular surgeries to avoid complications such as low cardiac output syndrome and renal or pulmonary dysfunction. Different advanced hemodynamic monitorings have been utilized perioperatively in cardiac surgery to help decision-making on inotrope and fluid management. In this article we present 5 cases of usefulness hemodynamic monitoring in patients who underwent cardiovascular surgeries.

Comparison of Bispectral Index Monitoring With the Critical-Care Pain Observation Tool in the Pain Assessment of Intubated Adult Patients After Cardiac Surgery

Background

Detecting pain is crucial in sedated and mechanically ventilated patients, as they are unable to communicate verbally.

Objectives

This study aimed to compare Bispectral index (BIS) monitoring with the Critical-care pain observation tool (CPOT) and vital signs for pain assessment during painful procedures in intubated adult patients after cardiac surgery.

Materials and Methods

Seventy consecutive patients who underwent cardiac surgery (coronary artery bypass graft or valvular surgery) were enrolled in the study. Pain evaluations were performed early after the operation in the intubated and sedated patients by using BIS and CPOT, and also checking the vital signs. The pain assessments were done at three different times: 1) baseline (immediately before any painful procedure, including tracheal suctioning or changing the patient’s position), 2) during any painful procedure, and 3) five minutes after the procedure (recovery time).

Results

The mean values for CPOT, BIS, and mean arterial pressure (MAP) scores were significantly different at different times; they were increased during suctioning or changing position, and decreased five minutes after these procedures (CPOT: 3.98 ± 1.65 versus 1.31 ± 1.07, respectively (P ≤ 0.0001); BIS: 84.94 ± 10.52 versus 63.48 ± 12.17, respectively (P ≤ 0.0001); MAP: 92.88 ± 15.37 versus 89.77 ± 14.72, respectively (P = 0.003)). Change in heart rate (HR) was not significant over time (95.68 ± 16.78 versus 93.61 ± 16.56, respectively; P = 0.34). CPOT scores were significantly positively correlated with BIS at baseline, during painful stimulation, and at recovery time, but were not correlated with HR or MAP, except at baseline. BIS scores were significantly correlated with MAP but not with HR.

Conclusions

It appears that BIS monitoring can be used for pain assessment along with the CPOT tool in intubated patients, and it is much more sensitive than monitoring of hemodynamic changes. BIS monitoring can be used more efficiently in intubated patients under deep sedation in the ICU.

A study of the efficacy of furosemide as a prophylaxis of acute renal failure in coronary artery bypass grafting patients: A clinical trial

BACKGROUND

Renal failure is a frequent event after coronary artery bypass grafting (CABG). Hemodynamic alterations during surgery as well as the underlying disease are the predisposing factors. We aimed to study intermittent furosemide therapy in the prevention of renal failure in patients undergoing CABG.

METHODS

In a single-blind randomized controlled trial, 123 elective CABG patients, 18-75 years, entered the study. Clearance of creatinine, urea and water were measured. Patients were randomly assigned into three groups: furosemide in prime (0.3-0.4 mg/kg); intermittent furosemide during CABG (0.2 mg/kg, if there was a decrease in urinary excretion) and control (no furosemide).

RESULTS

There was a significant change in serum urea, sodium and fluid balance in "intermittent furosemide" group; other variables did not change significantly before or after the operation. Post-operative fluid balance was significantly higher in "intermittent furosemide" group (2573 ± 205 ml) compared to control (1574.0 ± 155.0 ml) (P < 0.010); also, fluid balance was higher in "intermittent furosemide" group (2573 ± 205 ml) compared to "furosemide in prime" group (1935.0 ± 169.00 ml) (P < 0.010).

CONCLUSION

The study demonstrated no benefit from intermittent furosemide in elective CABG compared to furosemide in prime volume or even placebo.

Effect of obesity on mortality and morbidity after coronary artery bypass grafting surgery in Iranian patients

Background:

Recent years have witnessed the emergence of obesity as a major public health concern. The drastic rise in obesity and its concomitant co-morbidities is a reflection of the recent changes in dietary habits in Iran and many other developing countries. A recent large population study in Tehran reported that 58% and 75% of middle-aged Iranian men and women, respectively, were either overweight or obese.

Objectives:

Considering the impact of obesity on mortality and morbidity after coronary artery bypass graft surgery (CABG), we sought to investigate the association between central obesity and the body mass index (BMI) and the post-CABG mortality and morbidity in Iranian patients.

Patients and Methods:

This prospective study was on 235 adult patients scheduled for isolated CABG in a university hospital. The patients were divided in two groups according to BMI ≥ 30 (obese; n = 60) and BMI < 30 (non-obese; n = 175). In-hospital and late (after 3 months) morbidity and mortality rates were compared between obese and non-obese patients.

Results:

A total of 235 patients (135 women) with a mean age of 59 ± 9.2 years (range = 29 to 79 years), mean BMI of 27.3 ± 4.2 (range = 17 to 40), and mean waist circumference of 101.2 ± 14.7 cm (range = 55 to 145 cm) were included. By the third postoperative month, wound infection had significantly increased in patients with BMI ≥ 30 (P = 0.022). In-hospital and late morbidity and mortality rates were comparable between the two groups (P > 0.05).

Conclusions:

In our patients obesity was a risk factor for wound infection but not atelectasis or the need for intra-aortic balloon pump or re-exploration. Obesity was not associated with increased in-hospital or 3 months mortality rates after CABG.

Hyperglycemia or high hemoglobin A1C: Which one is more associated with morbidity and mortality after coronary artery bypass graft surgery?

PROPOSE

Our aim was to determine which criterion- hyperglycemia or high levels of glycosylated hemoglobin (HbA1C) is more associated with increased mortality and morbidity after coronary artery bypass graft (CABG).

METHODS

Two hundred and sixteen patients who underwent elective CABG were enrolled in this prospective study. In order to compare postoperative outcomes regarding HbA1c and fasting blood sugar (FBS) levels, the patients were divided into two groups based on plasma HbA1c levels >7% or ≤7% and FBS >126 mg/dl or ≤126 mg/dl.

RESULTS

Of 216 studied patients, 165 and 51 cases had levels of HbA1C ≤7% and HbA1c >7% respectively. Furthermore, 129 and 87 patients had levels of FBS of ≤126 mg/dl and FBS of >126 mg/dl respectively. Multivariate analyses revealed that patients with high HbA1C levels experienced significantly higher rates of postoperative re-intubation [P = 0.001, OR (95% CI) = 8.15 (2.88-23.09)], wound infection [P = 0.001, OR (95% CI) = 8.15 (2.88-23.09)] and bleeding [P = 0.027, OR (95% CI) = 2.18 (1.10-4.35)]. In addition, hyperglycemic patients had a higher frequency of arrhythmias [P = 0.001, OR (95% CI) = 3.07 (1.69-5.59)], atelectasis [P = 0.029, OR (95% CI) = 1.88 (1.07-3.30)] and wound infection [P = 0.001, OR (95% CI) = 8.75 (2.45-31.25)].

CONCLUSION

Higher levels of both HbA1C and FBS contribute to the increased risk of morbidity but not mortality rates in post-CABG surgery patients; yet further studies are required to distinguish "a better predictor" of postoperative adverse events.

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).