Haemodynamic management in brain death donors: Influence of aetiology of brain death

BACKGROUND

In brain death donors (BDDs), donor management is the key in the complex donation process. Donor management goals, which are standards of care or clinical parameters, have been considered an acceptable barometer of successful donor management.

AIM

To test the hypothesis that aetiology of brain death could influence haemodynamic management in BDDs.

METHODS

Haemodynamic data (blood pressure, heart rate, central venous pressure, lactate, urine output, and vasoactive drugs) of BDDs were recorded on intensive care unit (ICU) admission and during the 6-h observation period (Time 1 at the beginning; Time 2 at the end).

RESULTS

The study population was divided into three groups according to the aetiology of brain death: Stroke (n = 71), traumatic brain injury (n = 48), and postanoxic encephalopathy (n = 19). On ICU admission, BDDs with postanoxic encephalopathy showed the lowest values of systolic and diastolic blood pressure associated with higher values of heart rate and lactate and a higher need of norepinephrine and other vasoactive drugs. At the beginning of the 6-h period (Time 1), BDDs with postanoxic encephalopathy showed higher values of heart rate, lactate, and central venous pressure together with a higher need of other vasoactive drugs.

CONCLUSION

According to our data, haemodynamic management of BDDs is affected by the aetiology of brain death. BDDs with postanoxic encephalopathy have higher requirements for norepinephrine and other vasoactive drugs.

Early postoperative blood pressure and blood loss after cardiac surgery: A retrospective analysis

BACKGROUND

Increased blood loss after cardiac surgery is a risk factor for patient morbidity and mortality. Guidelines for postoperative haemodynamics management recommend normotensive blood pressure to avoid increased chest drain volumes. The aim of this study was to verify the correlation of early postoperative hypertension and blood loss in patients after cardiac surgery during the early postoperative period.

METHODS

Postoperative mean blood pressure values and chest drain volumes of 431 patients were registered by an intensive care monitoring system during first 60minutes after intensive care admission. Correlation between blood pressure and blood loss was calculated by linear regression analysis.

RESULTS

In the entire patient cohort and in various subgroup analyses (body-mass-index, type of surgery, comorbidity, emergency surgery, preoperative anticoagulation therapy) no association between early mean blood pressure >80mmHg and increased blood loss was evident in simple regression analysis. Merely, after aortic surgery a correlation of hypertension and blood loss was found. Multiple regression revealed postoperative INR values >1.5 and thrombocyte counts <100.000/nL to impact blood loss in contrast to postoperative hypertension.

CONCLUSION

Evidence for strict blood pressure management to reduce blood loss after cardiac surgery is scarce. Instead, in face of higher INR and low thrombocytes increasing postoperative blood loss, achieving and maintaining a physiological coagulation is essential.

Perioperative optimal blood pressure as determined by ultrasound tagged near infrared spectroscopy and its association with postoperative acute kidney injury in cardiac surgery patients

OBJECTIVES

Perioperative blood pressure management by targeting individualized optimal blood pressure, determined by cerebral blood flow autoregulation monitoring, may ensure sufficient renal perfusion. The purpose of this study was to evaluate changes in the optimal blood pressure for individual patients, determined during cardiopulmonary bypass (CPB) and during early postoperative period in intensive care unit (ICU). A secondary aim was to examine if excursions below optimal blood pressure in the ICU are associated with risk of cardiac surgery-associated acute kidney injury (CSA-AKI).

METHODS

One hundred and ten patients undergoing cardiac surgery had cerebral blood flow monitored with a novel technology using ultrasound tagged near infrared spectroscopy (UT-NIRS) during CPB and in the first 3 h after surgery in the ICU. The correlation flow index (CFx) was calculated as a moving, linear correlation coefficient between cerebral flow index measured using UT-NIRS and mean arterial pressure (MAP). Optimal blood pressure was defined as the MAP with the lowest CFx. Changes in optimal blood pressure in the perioperative period were observed and the association of blood pressure excursions (magnitude and duration) below the optimal blood pressure [area under the curve (AUC) < OptMAP mmHgxh] with incidence of CSA-AKI (defined using Kidney Disease: Improving Global Outcomes criteria) was examined.

RESULTS

Optimal blood pressure during early ICU stay and CPB was correlated (r = 0.46, P < 0.0001), but was significantly higher in the ICU compared with during CPB (75 ± 8.7 vs 71 ± 10.3 mmHg, P = 0.0002). Thirty patients (27.3%) developed CSA-AKI within 48 h after the surgery. AUC < OptMAP was associated with CSA-AKI during CPB [median, 13.27 mmHgxh, interquartile range (IQR), 4.63-20.14 vs median, 6.05 mmHgxh, IQR 3.03-12.40, P = 0.008], and in the ICU (13.72 mmHgxh, IQR 5.09-25.54 vs 5.65 mmHgxh, IQR 1.71-13.07, P = 0.022).

CONCLUSIONS

Optimal blood pressure during CPB and in the ICU was correlated. Excursions below optimal blood pressure (AUC < OptMAP mmHgXh) during perioperative period are associated with CSA-AKI. Individualized blood pressure management based on cerebral autoregulation monitoring during the perioperative period may help improve CSA-AKI-related outcomes.