Pulmonary blood volume measured by contrast enhanced ultrasound : a comparison with transpulmonary thermodilution

Background Blood volume quantification is essential for haemodynamic evaluation guiding fluid management in anaesthesia and intensive care practice. Ultrasound contrast agent (UCA)-dilution measured by contrast enhanced ultrasound (CEUS) can provide the UCA mean transit time (MTT) between the right and left heart, enabling the assessment of the intrathoracic blood volume (ITBVUCA). The purpose of the present study was to investigate the agreement between UCA-dilution using CEUS and transpulmonary thermodilution (TPTD) in vitro and in vivo. Methods In an in vitro setup, with variable flows and volumes, we injected a double indicator, ice-cold saline with SonoVue®, and performed volume measurements using transesophageal echo and thermodilution by PiCCO®. In a pilot study, we assigned 17 patients undergoing elective cardiac surgery for pulmonary blood volume (PBV) measurement using TPTD by PiCCO® and ITBV by UCA-dilution. Correlation coefficients and Bland-Altman analysis were performed for all volume measurements. Results In vitro, 73 experimental MTT's were obtained using PiCCO® and UCA-dilution. The volumes by PiCCO® and UCA-dilution correlated with true volumes; rs=0.96 (95% CI, 0.93–0.97; P<0.0001) and rs=0.97 (95% CI, 0.95–0.98; P<0.0001), respectively. The bias of PBV by PiCCO® and ITBVUCA were −380 ml and −42 ml, respectively. In 16 patients, 86 measurements were performed. The correlation between PBV by PiCCO® and ITBVUCA was rs=0.69 (95% CI 0.55–0.79; P<0.0001). Bland-Altman analysis revealed a bias of −323 ml. Conclusions ITBV assessment with CEUS seems a promising technique for blood volume measurement, which is minimally-invasive and bedside applicable

The hemodynamic effects of different pacing modalities after cardiopulmonary bypass in patients with reduced left ventricular function

Objectives: Patients with decreased left ventricular function undergoing cardiac surgery have a greater chance of difficult weaning from cardiopulmonary bypass and a poorer clinical outcome. Directly after weaning, interventricular dyssynchrony, paradoxical septal motion, and even temporary bundle-branch block might be observed. In this study, the authors measured arterial dP/dtmax, mean arterial pressure (MAP), and cardiac index using transpulmonary thermodilution, pulse contour analysis, and femoral artery catheter and compared the effects between right ventricular (A-RV) and biventricular (A-BiV) pacing on these parameters. Design: Prospective study. Setting: Single-center study. Participants: The study comprised 17 patients with a normal or prolonged QRS duration and a left ventricular ejection fraction ≤35% who underwent coronary artery bypass grafting with or without valve replacement. Interventions: Temporary pacing wires were placed on the right atrium and both ventricles. Different pacing modalities were used in a standardized order. Measurements and Main Results: A-BiV pacing compared with A-RV pacing demonstrated higher arterial dP/dtmax values (846 ± 646 mmHg/s v 800 ± 587 mmHg/s, p = 0.023) and higher MAP values (77 ± 19 mmHg v 71 ± 18 mmHg, p = 0.036). Conclusion: In patients with preoperative decreased left ventricular function undergoing coronary artery bypass grafting, A-BiV pacing improve the arterial dP/dtmax and MAP in patients with both normal and prolonged QRS duration compared with standard A-RV pacing. In addition, arterial dP/dtmax and MAP can be used to evaluate the effect of intraoperative pacing. In contrast to previous studies using more invasive techniques, transpulmonary thermodilution is easy to apply in the perioperative clinical setting

Systems that prevent unwanted represcription of drugs withdrawn because of adverse drug events: A systematic review

Represcription of medication that was withdrawn after the occurrence of an adverse drug event (including allergy), is a recognized medication safety issue on a patient level. We performed a systematic review to identify systems (electronic and nonelectronic) that can prevent the represcription of drugs withdrawn because of an adverse drug event and the effects of these systems. The review was performed using PRISMA and Cochrane guidelines. PubMed and Embase were searched for articles describing systems that can prevent represcription of drugs that had been withdrawn for causing an adverse drug event. Information on the characteristics of the studies, systems, and if present results achieved with such systems, was extracted. The results showed that of 6793 articles screened, 137 full-text articles were assessed for eligibility. A total of 45 studies describing 33 systems (28 electronic) were included. The five nonelectronic systems used allergy bracelets or allergy labels on hospital medical records or on drug orders. Systems differed in the way adverse drug events were documented and how users were alerted to drug represcription. Most systems functioned within a specific healthcare setting. Of 12 studies that compared pre- and post-intervention periods or wards with and without intervention, 7 showed a reduction in represcription after adverse drug event. In conclusion, several systems have been developed that can prevent the represcription of drugs that elicited an adverse drug event, but the evidence that these systems are effective is limited