Nurses versus physician-led interhospital critical care transport: a randomized non-inferiority trial.

PURPOSE: Regionalization and concentration of critical care increases the need for interhospital transport. However, optimal staffing of ground critical care transport has not been evaluated. METHODS: In this prospective, randomized, open-label, blinded-endpoint non-inferiority trial, critically ill patients on mechanical ventilation transported by interhospital ground critical care transport were randomized between transport staffed by a dedicated team comprising a critical care nurse and paramedic (nurses group) or a dedicated team including a critical care physician (nurses + physician group). The primary outcome was the number of patients with critical events, both clinical and technical, during transport. Clinical events included decrease in blood pressure, oxygen saturation, or temperature, blood loss, new cardiac arrhythmias, or death. Non-inferiority was assumed if the upper limit of the two-sided 90 % confidence interval (CI) for the between-group difference lies below the non-inferiority margin of 3 %. RESULTS: Of 618 eligible transported critically ill patients, 298 could be analyzed after randomization and allocation to the nurses group (n = 147) or nurses + physician group (n = 151). The percentages of patients with critical events were 16.3 % (24 incidents in 147 transports) in the nurses group and 15.2 % (23 incidents in 151 transports) in the nurses + physician group (difference 1.1 %, two-sided 90 % CI [-5.9 to 8.1]). Critical events occurred in both groups at a higher than the expected (0-1 %) rate. In the nurses group consultations for physician assistance were requested in 8.2 % (12 in 147 transports), all of which were performed prior to transport. CONCLUSIONS: The number of patients with critical events did not markedly differ between critical care transports staffed by a critical care nurse and paramedic compared to a team including a critical care physician. However, as a result of an unexpected higher rate of critical events in both groups recorded by an electronic health record, non-inferiority of nurse-led interhospital critical transport could not be established ( http://www.controlled-trials.com/ISRCTN39701540 ).

Improved communication in post-ICU care by improving writing of ICU discharge letters: a longitudinal before-after study.

BACKGROUND: The discharge letter is the primary means of communication at patient discharge, yet discharge letters are often not completed on time. A multifaceted intervention was performed to improve communication in patient hand-off from the intensive care unit (ICU) to the wards by improving the timeliness of discharge letters. METHODS: A management directive was operationalised by a working group of ICU staff in a longitudinal before-after study. The intervention consisted of (a) changing policy to require a letter for use as a transfer note at the time of ICU discharge, (b) changing the assignment of responsibility to an automatic process, (c) leveraging positive peer pressure by making the list of patients in need of letters visible to colleagues and (d) provision of decision support, through automatic copying of important content from the patient record to the letter and email reminders if letters were not written on time. Statistical process control charts were used to monitor the longitudinal effect of the intervention. RESULTS: The intervention resulted in a 77.9% absolute improvement in the proportion of patients with a complete transfer note at the time of discharge, and an 85.2% absolute improvement in the number of discharge letters written. Statistical process control shows that the effect was sustained over time. CONCLUSIONS: A multifaceted intervention can be highly effective for improving discharge communication from the ICU.

Electromagnetic interference from radio frequency identification inducing potentially hazardous incidents in critical care medical equipment.

CONTEXT: Health care applications of autoidentification technologies, such as radio frequency identification (RFID), have been proposed to improve patient safety and also the tracking and tracing of medical equipment. However, electromagnetic interference (EMI) by RFID on medical devices has never been reported. OBJECTIVE: To assess and classify incidents of EMI by RFID on critical care equipment. DESIGN AND SETTING: Without a patient being connected, EMI by 2 RFID systems (active 125 kHz and passive 868 MHz) was assessed under controlled conditions during May 2006, in the proximity of 41 medical devices (in 17 categories, 22 different manufacturers) at the Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. Assessment took place according to an international test protocol. Incidents of EMI were classified according to a critical care adverse events scale as hazardous, significant, or light. RESULTS: In 123 EMI tests (3 per medical device), RFID induced 34 EMI incidents: 22 were classified as hazardous, 2 as significant, and 10 as light. The passive 868-MHz RFID signal induced a higher number of incidents (26 incidents in 41 EMI tests; 63%) compared with the active 125-kHz RFID signal (8 incidents in 41 EMI tests; 20%); difference 44% (95% confidence interval, 27%-53%; P < .001). The passive 868-MHz RFID signal induced EMI in 26 medical devices, including 8 that were also affected by the active 125-kHz RFID signal (26 in 41 devices; 63%). The median distance between the RFID reader and the medical device in all EMI incidents was 30 cm (range, 0.1-600 cm). CONCLUSIONS: In a controlled nonclinical setting, RFID induced potentially hazardous incidents in medical devices. Implementation of RFID in the critical care environment should require on-site EMI tests and updates of international standards.

Decision making in interhospital transport of critically ill patients: national questionnaire survey among critical care physicians.

OBJECTIVE: This study assessed the relative importance of clinical and transport-related factors in physicians' decision-making regarding the interhospital transport of critically ill patients. METHODS: The medical heads of all 95 ICUs in The Netherlands were surveyed with a questionnaire using 16 case vignettes to evaluate preferences for transportability; 78 physicians (82%) participated. The vignettes varied in eight factors with regard to severity of illness and transport conditions. Their relative weights were calculated for each level of the factors by conjoint analysis and expressed in beta. The reference value (beta = 0) was defined as the optimal conditions for critical care transport; a negative beta indicated preference against transportability. RESULTS: The type of escorting personnel (paramedic only: beta = -3.1) and transport facilities (standard ambulance beta = -1.21) had the greatest negative effect on preference for transportability. Determinants reflecting severity of illness were of relative minor importance (dose of noradrenaline beta = -0.6, arterial oxygenation beta = -0.8, level of peep beta = -0.6). Age, cardiac arrhythmia, and the indication for transport had no significant effect. CONCLUSIONS: Escorting personnel and transport facilities in interhospital transport were considered as most important by intensive care physicians in determining transportability. When these factors are optimal, even severely critically ill patients are considered able to undergo transport. Further clinical research should tailor transport conditions to optimize the use of expensive resources in those inevitable road trips.

Individual and joint expert judgments as reference standards in artifact detection.

OBJECTIVE: To investigate the agreement among clinical experts in their judgments of monitoring data with respect to artifacts, and to examine the effect of reference standards that consist of individual and joint expert judgments on the performance of artifact filters. DESIGN: Individual judgments of four physicians, a majority vote judgment, and a consensus judgment were obtained for 30 time series of three monitoring variables: mean arterial blood pressure (ABPm), central venous pressure (CVP), and heart rate (HR). The individual and joint judgments were used to tune three existing automated filtering methods and to evaluate the performance of the resulting filters. MEASUREMENTS: The interrater agreement was calculated in terms of positive specific agreement (PSA). The performance of the artifact filters was quantified in terms of sensitivity and positive predictive value (PPV). RESULTS: PSA values between 0.33 and 0.85 were observed among clinical experts in their selection of artifacts, with relatively high values for CVP data. Artifact filters developed using judgments of individual experts were found to moderately generalize to new time series and other experts; sensitivity values ranged from 0.40 to 0.60 for ABPm and HR filters (PPV: 0.57-0.84), and from 0.63 to 0.80 for CVP filters (PPV: 0.71-0.86). A higher performance value for the filters was found for the three variable types when joint judgments were used for tuning the filtering methods. CONCLUSION: Given the disagreement among experts in their individual judgment of monitoring data with respect to artifacts, the use of joint reference standards obtained from multiple experts is recommended for development of automatic artifact filters.

Interference by new-generation mobile phones on critical care medical equipment.

INTRODUCTION: The aim of the study was to assess and classify incidents of electromagnetic interference (EMI) by second-generation and third-generation mobile phones on critical care medical equipment. METHODS: EMI was assessed with two General Packet Radio Service (GPRS) signals (900 MHz, 2 W, two different time-slot occupations) and one Universal Mobile Telecommunications System (UMTS) signal (1,947.2 MHz, 0.2 W), corresponding to maximal transmit performance of mobile phones in daily practice, generated under controlled conditions in the proximity of 61 medical devices. Incidents of EMI were classified in accordance with an adjusted critical care event scale. RESULTS: A total of 61 medical devices in 17 categories (27 different manufacturers) were tested and demonstrated 48 incidents in 26 devices (43%); 16 (33%) were classified as hazardous, 20 (42%) as significant and 12 (25%) as light. The GPRS-1 signal induced the most EMI incidents (41%), the GRPS-2 signal induced fewer (25%) and the UMTS signal induced the least (13%; P < 0.001). The median distance between antenna and medical device for EMI incidents was 3 cm (range 0.1 to 500 cm). One hazardous incident occurred beyond 100 cm (in a ventilator with GRPS-1 signal at 300 cm). CONCLUSION: Critical care equipment is vulnerable to EMI by new-generation wireless telecommunication technologies with median distances of about 3 cm. The policy to keep mobile phones '1 meter' from the critical care bedside in combination with easily accessed areas of unrestricted use still seems warranted.

Beat-to-beat noninvasive stroke volume from arterial pressure and Doppler ultrasound.

The proper understanding of the cardiovascular mechanisms involved in complaints of short-lasting dizziness and the evaluation of unexplained recurrent syncope requires continuous monitoring of cardiac stroke volume (SV) in addition to blood pressure and heart rate. The primary aim of the present study was to evaluate a pulse wave analysis method that calculates beat-to-beat flow from non-invasive arterial pressure by simulating a non-linear, time-varying model of human aortic input impedance (Modelflow; MF), by comparing MF stroke volume (SV(MF)) to Doppler ultrasound (US) flow velocity SV (SV(US)). A second purpose was to compare the two methods under two different conditions: the supine and head-up tilt (30 degrees ) position. SV(US) and SV(MF) with non-invasive arterial pressure (Finapres) as input to the aortic model were measured beat-to-beat during spontaneous supine breathing and in the passive 30 degrees head-up tilt (HUT30) position in six normotensive healthy humans [three females, mean age 24 (21-26) years]. There were variations in supine SV track between the two methods with zero difference and a SD of the beat-to-beat difference (MF-US) of 4.2%. HUT30 induced a systematic difference of 10.5% and an increase in SD to 6.9%, which was reproducible. Beat-to-beat changes in SV in the supine resting condition were equally well assessed by both methods. Systematic differences appear during HUT30 and show opposite signs. The difference between the two methods upon a change in body position may be attributed to limitations in each method.