The effect of computerised decision support alerts tailored to intensive care on the administration of high-risk drug combinations, and their monitoring: a cluster randomised stepped-wedge trial.

BACKGROUND: Drug-drug interactions (DDIs) can harm patients admitted to the intensive care unit (ICU). Yet, clinical decision support systems (CDSSs) aimed at helping physicians prevent DDIs are plagued by low-yield alerts, causing alert fatigue and compromising patient safety. The aim of this multicentre study was to evaluate the effect of tailoring potential DDI alerts to the ICU setting on the frequency of administered high-risk drug combinations. METHODS: We implemented a cluster randomised stepped-wedge trial in nine ICUs in the Netherlands. Five ICUs already used potential DDI alerts. Patients aged 18 years or older admitted to the ICU with at least two drugs administered were included. Our intervention was an adapted CDSS, only providing alerts for potential DDIs considered as high risk. The intervention was delivered at the ICU level and targeted physicians. We hypothesised that showing only relevant alerts would improve CDSS effectiveness and lead to a decreased number of administered high-risk drug combinations. The order in which the intervention was implemented in the ICUs was randomised by an independent researcher. The primary outcome was the number of administered high-risk drug combinations per 1000 drug administrations per patient and was assessed in all included patients. This trial was registered in the Netherlands Trial Register (identifier NL6762) on Nov 26, 2018, and is now closed. FINDINGS: In total, 10 423 patients admitted to the ICU between Sept 1, 2018, and Sept 1, 2019, were assessed and 9887 patients were included. The mean number of administered high-risk drug combinations per 1000 drug administrations per patient was 26·2 (SD 53·4) in the intervention group (n=5534), compared with 35·6 (65·0) in the control group (n=4353). Tailoring potential DDI alerts to the ICU led to a 12% decrease (95% CI 5-18%; p=0·0008) in the number of administered high-risk drug combinations per 1000 drug administrations per patient, after adjusting for clustering and prognostic factors. INTERPRETATION: This cluster randomised stepped-wedge trial showed that tailoring potential DDI alerts to the ICU setting significantly reduced the number of administered high-risk drug combinations. Our list of high-risk drug combinations can be used in other ICUs, and our strategy of tailoring alerts based on clinical relevance could be applied to other clinical settings. FUNDING: ZonMw.

Cardiac output measured by uncalibrated arterial pressure waveform analysis by recently released software version 3.02 versus thermodilution in septic shock.

To evaluate the 3.02 software version of the FloTrac/Vigileo™ system for estimation of cardiac output by uncalibrated arterial pressure waveform analysis, in septic shock. Nineteen consecutive patients in septic shock were studied. FloTrac/Vigileo™ measurements (COfv) were compared with pulmonary artery catheter thermodilution-derived cardiac output (COtd). The mean cardiac output was 7.7 L min(-1) and measurements correlated at r = 0.53 (P < 0.001, n = 314). In Bland-Altman plot for repeated measurements, the bias was 1.7 L min(-1) and 95 % limits of agreement (LA) were -3.0 to 6.5 L min(-1), with a %error of 53 %. The bias of COfv inversely related to systemic vascular resistance (SVR) (r = -0.54, P < 0.001). Above a SVR of 700 dyn s cm(-5) (n = 74), bias was 0.3 L min(-1) and 95 % LA were -1.6 to 2.2 L min(-1) (%error 32 %). Changes between consecutive measurements (n = 295) correlated at 0.67 (P < 0.001), with a bias of 0.1 % (95 % limits of agreement -17.5 to 17.0 %). All changes >10 % in both COtd and COfv (n = 46) were in the same direction. Eighty-five percent of the measurements were within the 30°-330° of the polar axis. COfv with the latest software still underestimates COtd at low SVR in septic shock. The tracking capacities of the 3.02 software are moderate-good when clinically relevant changes are considered.

Hemodynamic changes during a combined psoas compartment-sciatic nerve block for elective orthopedic surgery.

BACKGROUND: Hemodynamic variables can theoretically be influenced by a combined psoas compartment-sciatic nerve block (CPCSNB) owing to a relatively high systemic absorption of local anesthetics and extended vasodilatation in the anesthetized limb (hemisympatectomy). In this study we assessed and documented hemodynamic changes during CPCSNB for elective orthopedic surgery. METHODS: Twenty consecutive patients scheduled for a total hip arthroplasty revision surgery were subjected to a CPCSNB with 150 mg bupivacaine (with epinephrine 1:200.000) 90 minutes before surgery (2 separate single-injection blocks: 30 mg bupivacaine for the sciatic nerve block and 120 mg bupivacaine for the psoas compartment block). Cardiac index, invasive arterial blood pressure, and heart rate were measured at baseline and 60 minutes after puncture using a minimally invasive cardiac output monitoring device (FloTrac/Vigileo™ system (Edwards Lifesciences, Irvine, CA)). RESULTS: Cardiac index did not change after a CPCSNB (preblock cardiac index 2.98 ± 0.54 l · min(-1) · m(-2) versus postblock cardiac index 2.99 ± 0.60 l · min(-1) · m(-2)). There was a significant reduction in mean arterial blood pressure (108 ± 16 mm|Hg vs. 99 ± 16 mm|Hg (P < 0.001)) and diastolic blood pressure (75 ± 9 mm|Hg vs. 68 ± 10 mm|Hg (P = 0.001)). Heart rate increased significantly (68 ± 9 beats · min(-1) vs. 73 ± 10 beats · min(-1) (P = 0.001)). CONCLUSION: CPCSNB did not affect cardiac index. Changes in arterial blood pressure and heart rate, although statistically significant, remained within an acceptable clinical range (<10% variation). CPCSNB does not appear to induce clinically significant hemodynamic changes in this group of patients.

Cardiac output derived from arterial pressure waveform analysis without calibration vs. thermodilution in septic shock: evolving accuracy of software versions.

BACKGROUND AND OBJECTIVE: We studied the evolution of software in the accuracy of the FloTrac/Vigileo system to measure cardiac output less invasively from arterial pressure waveform analysis without calibration, in comparison with pulmonary artery catheter-derived thermodilution measurements, in patients with septic shock and presumed alterations in vascular tone. METHODS: Nine patients who received a pulmonary artery catheter and were on mechanical ventilation and in sinus rhythm were monitored by the FloTrac/Vigileo. Paired cardiac output measurements by both techniques were analysed for 86 measurements in four patients using the 1.07 software version and 73 measurements in five subsequent patients using the later 1.10 version. RESULTS: For the 1.07 version, bias was -1.6 L min, precision 1.6 L min, limits of agreement -4.8-1.5 L min and error 48%. Measurements correlated at partial r equal to 0.32 (P = 0.003). For the 1.10 version, bias was -1.2 L min, precision 1.1 L min, limits of agreement -3.5-1.0 L min and error 32%. Measurements correlated at partial r equal to 0.90 (P < 0.001 vs. version 1.07). Differences were inversely related to mean cardiac output (P < 0.001, generalized estimating equations), particularly for software version 1.07 vs. 1.10 (P = 0.017, generalized estimating equation). Changes in thermodilution cardiac output over the course of time were also better tracked by the FloTrac/Vigileo when applying the latest software (P < 0.001, generalized estimating equation). CONCLUSIONS: Evolving software versions are thus better able to account for the effect of vascular tone on cardiac output measurements by less invasive waveform analyses without calibration (FloTrac/Vigileo), so that the latter may become useful in the haemodynamic monitoring of septic shock.

The efficacy of levobupivacaine, ropivacaine, and bupivacaine for combined psoas compartment-sciatic nerve block in patients undergoing total hip arthroplasty.

BACKGROUND AND OBJECTIVES: The aim of our study was to compare postoperative analgesic efficacy, and the extent of sensory and motor blockade of levobupivacaine, ropivacaine, and bupivacaine administered in a combined psoas compartment-sciatic nerve block (PCSNB) for total hip arthroplasty. METHODS: Forty-five patients undergoing total hip arthroplasty under general anesthesia combined with PCSNB, were randomly assigned to receive either 50 mL levobupivacaine 3 mg/mL, 50 mL ropivacaine 4.5 mg/mL or 50 mL bupivacaine 3 mg/mL with epinephrine. Postoperative, the pain intensity at rest, the degree of motor block (Modified Bromage Scale) and the extent of sensory block (pin prick test) were recorded at 4, 8, 12, 24, and 48 hours following initial injection in a double blind fashion. RESULTS: The postoperative pain intensity was low and did not differ between groups, except for a significantly lower pain intensity in group ropivacaine compared with group levobupivacaine at 4 hours. Five patients (11%), equally divided over three groups, needed parenteral rescue opiates postoperatively. The extent of sensory block was not different between the three groups. In each group the majority of patients showed no sensory block in dermatome L1. Group levobupivacaine initially showed the least motor impairment. Motor impairment was found to be significantly higher in bupivacaine group compared with both ropivacaine and levobupivacaine groups at 12 (P = 0.012) and 48 hours (P = 0.003). CONCLUSIONS: Levobupivacaine, bupivacaine and ropivacaine are equally effective for PCSNB in patients undergoing total hip arthroplasty. Residual pain may be due to the lack of sensory block in dermatome L1, suggesting that modification of this technique should be considered for this type of surgery.