National consensus on communication in prehospital trauma care, the DENIM study.

BACKGROUND: In the Netherlands prehospital trauma care is provided by emergency medical services (EMS) nurses. This care is extended by Physician staffed Helicopter Emergency Medical Services (P-HEMS) for the more severely injured patient. Prehospital communication is a factor of influence on the identification of these patients and the dispatch of P-HEMS. Though prehospital communication it is often perceived to be incomplete and unstructured. To elucidated factors of influence on prehospital triage and the identification of the severely injured patient a Delphi study was performed. METHODS: A three round modified Delphi study was designed to explore concepts amongst experts in prehospital trauma care. P-HEMS physicians/nurses, trauma surgeons, EMS nurses and dispatch center operators where asked to state their opinion regarding identification of the poly trauma patient, trauma patient characteristics, prehospital communication and prehospital handover. RESULTS: Seventy-one panellist completed all three rounds. For the first round seven cases and 13 theses were presented. From the answers/argumentation the second round was build, in which 68 theses had to be ranked within four principle themes: factors that influence prehospital communication, critical information for proper handover, factors influencing collaboration and how training/education can influence this. Out of these answers the third survey was build, focussing on determining the exact content of a prehospital trauma handover. The majority of the panellists agreed to a set of parameters resulting in a new model of inter-professional hand over regarding prehospital trauma patients. DISCUSSION: Exact identification of the poly trauma patient in need of care by P-HEMS is difficult though prehospital communication and the prehospital handover may be improved. CONCLUSION: The respondents report that prehospital communication needs to be unambiguous to improve trauma care. Consensus was reached on a set of ten parameters that should minimally be handed over with regard to a prehospital trauma patient. This to facilitate prehospital communication between the Dispatch centre, EMS, P-HEMS and the receiving hospital.

The Hypoxia Alarm of a Multigas Analyzer Is Triggered During Helicopter Takeoffs in Helicopter Emergency Medical Services Operations.

OBJECTIVE: Safety in helicopter emergency medical services (HEMS) settings might be enhanced by the routine use of portable multigas analyzers to indicate hypoxic ambient air mixtures and the presence of hazardous gases. METHODS: In our HEMS (EC-135, Lifeliner 1, Amsterdam, The Netherlands), we introduced a professional multigas analyzer (Gas Alert Max XT II; Honeywell Analytics, Lincolnshire, IL) to prospectively detect possible hazardous gas mixtures. This analyzer measures ambient oxygen percentage (FO2, 0%-30%), carbon monoxide (CO, 0-1,000 ppm), hydrogen sulfide (H2S, 0-200 ppm), and combustibles (lower explosive limit, %). RESULTS: Before 12 HEMS flights, we measured a stable baseline ambient FO2 of 20.9%. However, in all flights, takeoff to cruising altitude (500-1,000 ft) markedly decreased the measured FO2 to 19.1% ± 0.1% (mean ± standard deviation; Wilcoxon signed rank test, P = .002) with a minimum of 18.8%. This triggered the optoacoustic hypoxia alarm (preset to 19.5% to comply with international guidelines) in all cases. Maintaining cruise altitude restored measured FO2 slowly back to 20.9%. In contrast, CO, H2S, and combustibles remained unchanged during takeoff and flight. CONCLUSIONS: The hypoxia alarm of multigas analyzers is reproducibly triggered during helicopter takeoff. This observation may be explained by properties of certain multigas analyzers using a capillary controlled concentration sensor for FO2 measurement. Flight crews, increasingly equipped with those multigas analyzers, should be aware of this fact.

Airway obstruction due to aspiration of muddy water.

We report a case of complete airway obstruction due to aspiration of muddy water. An innovative approach to clear the airway is described, which may be a potentially life saving manoeuver in similar cases of suspected muddy water aspiration.

Helicopter Emergency Medical Services save lives: outcome in a cohort of 1073 polytraumatized patients.

BACKGROUND: In many Western countries, Helicopter Emergency Medical Services (HEMS) have become standard in the prehospital care of severely injured patients. Several studies have shown that HEMS have a positive effect on patient's outcome, although it remains unclear which specific patients benefit most from its care. The aim of this study was to assess the effect of HEMS on the outcome of a large polytraumatized (Injury Severity Score≥16) population. METHODS: All polytraumatized patients treated at the scene of the accident by EMS and/or HEMS and presented in the VU University Medical Center during a period of 6 years were included and retrospectively analyzed. The total population was divided into two groups according to the presence of HEMS on-scene. Prehospital, in-hospital, and outcome parameters were compared. The Trauma Injury Severity Score method was used to calculate the probability of survival. RESULTS: Almost 60% of all included patients (n=1073) were treated only by an EMS crew on-scene. The remaining 446 patients received additional HEMS care. Significant differences between these two groups were observed in the demographic characteristics, showing that the HEMS group was more severely injured. The predicted survival was calculated using the Trauma Injury Severity Score method, as well as the observed survival, both showing a significantly higher outcome for the EMS group (0.88 vs. 0.66% and 87.7 vs. 71.3%). However, the Z-statistic showed a significant positive difference between the predicted and the observed survival for the HEMS group (P<0.005) and no significant differences for the EMS group (P>0.1), indicating that the chance of surviving in the HEMS group was higher. Per 100 HEMS dispatches, 5.4 additional lives were saved. A correlation of the observed survival with the first measured Revised Trauma Score on-scene showed a positive effect for the HEMS group when the Revised Trauma Score reached a value of 9 or lower. CONCLUSION: On-scene HEMS care has a positive effect on the survival of polytraumatized patients, saving 5.4 additional lives per 100 HEMS deployments. This positive effect is especially observed in patients with abnormal vital signs (respiratory and hemodynamically). Research and revision of dispatch criteria are important to reach patients that benefit most from HEMS care.

Criteria for cancelling helicopter emergency medical services (HEMS) dispatches.

INTRODUCTION: In The Netherlands there is no consensus about criteria for cancelling helicopter emergency medical services (HEMS) dispatches. This study assessed the ability of the primary HEMS dispatch criteria to identify major trauma patients. The predictive power of other early prehospital parameters was evaluated to design a safe triage model for HEMS dispatch cancellations. METHODS: All trauma-related dispatches of HEMS during a period of 6 months were included. Data concerning prehospital information and inhospital treatment were collected. Patients were divided into two groups (major and minor trauma) according to the following criteria: injury severity score 16 or greater, emergency intervention, intensive care unit admission, or inhospital death. Logistic regression analysis was used to design a prediction model for the early identification of major trauma patients. RESULTS: In total, 420 trauma-related dispatches were evaluated, of which 155 concerned major trauma patients. HEMS was more often cancelled for minor trauma patients than for major trauma patients (57.7% vs 20.6%). Overall, HEMS dispatch criteria had a sensitivity of 87.7% and a specificity of 45.3% for identifying major trauma patients. Significant differences were found for vital sign abnormalities, anatomical components and several parameters of the mechanism of injury. A triage model designed for cancelling HEMS correctly identified major trauma patients (sensitivity 99.4%). CONCLUSION: The accuracy of the current HEMS dispatch criteria is relatively low, resulting in high cancellation rates and low predictability for major trauma. The new HEMS cancellation triage model identified all major trauma patients with an acceptable overtriage and will probably reduce unjustified HEMS dispatches.

Is a maximum Revised Trauma Score a safe triage tool for Helicopter Emergency Medical Services cancellations?

INTRODUCTION: The Revised Trauma Score is used worldwide in the prehospital setting and provides a snapshot of patient's physiological state. Several studies have shown that the reliability of the RTS is high in trauma outcomes. In the Netherlands, Helicopter Emergency Medical Services (HEMS) are mostly used for delivery of specialized trauma teams on-scene and occasionally for patient transportation. In our trauma system, the Emergency Medical Services crew performs triage after arrival on-scene and cancels the HEMS-dispatch if deemed unnecessary. In this study we assessed the ability of a maximum on-scene Revised Trauma Score (RTS=12) to be used as a triage tool for HEMS cancellation. METHODS: All patients with a maximum on-scene RTS after blunt trauma (with or without receiving HEMS care) who were presented in the trauma resuscitation room of two Level-1 trauma centers during a period of 6 months, were included. Information concerning prehospital and in-hospital vital parameters, severity and localization of the injuries, and the in-hospital course were analyzed. Major trauma patients were classified using the following parameters: Injury Severity Score of at least 16, emergency intervention, Intensive Care Unit admission, and in-hospital death. RESULTS: Four-hundred and forty blunt trauma patients having a maximum RTS were included between 1 July and 31 December 2006. Eighty patients received on-scene HEMS care. Almost 16% of the total population concerned major trauma patients, of which only 25 (36%) received HEMS care. In 17 patients (3.9%), the RTS deteriorated during transportation. Major trauma patients sustained more injuries to the chest, abdomen, and lower extremities. CONCLUSION: The RTS alone is not a reliable triage tool for HEMS cancellations in our trauma system and will lead to a considerable rate of undertriage with one in every six cancellations being incorrect. Other criteria based on patient's vital signs, combined with anatomical and mechanism of injury parameters should be developed to safely minimize triage errors.

Cancellations of (helicopter-transported) mobile medical team dispatches in the Netherlands.

BACKGROUND: The trauma centre of the Trauma Center Region North-West Netherlands (TRNWN) has consensus criteria for Mobile Medical Team (MMT) scene dispatch. The MMT can be dispatched by the EMS-dispatch centre or by the on-scene ambulance crew and is transported by helicopter or ground transport. Although much attention has been paid to improve the dispatch criteria, the MMT is often cancelled after being dispatched. The aim of this study was to assess the cancellation rate and the noncompliant dispatches of our MMT and to identify factors associated with this form of primary overtriage. METHODS: By retrospective analysis of all MMT dispatches in the period from 1 July 2006 till 31 December 2006 using chart review, we conducted a consecutive case review of 605 dispatches. Four hundred and sixty seven of these were included for our study, collecting data related to prehospital triage, patient's condition on-scene and hospital course. RESULTS: Average age was 35.9 years; the majority of the patients were male (65.3%). Four hundred and thirty patients were victims of trauma, sustaining injuries in most cases from blunt trauma (89.3%). After being dispatched, the MMT was cancelled 203 times (43.5%). Statistically significant differences between assists and cancellations were found for overall mortality, mean RTS, GCS and ISS, mean hospitalization, length and amount of ICU admissions (p < 0.001). All dispatches were evaluated by using the MMT-dispatch criteria and mission appropriateness criteria. Almost 26% of all dispatches were neither appropriate, nor met the dispatch criteria. Fourteen missions were appropriate, but did not meet the dispatch criteria. The remaining 318 dispatches had met the dispatch criteria, of which 135 (30.3%) were also appropriate. The calculated additional costs of the cancelled dispatches summed up to a total of 34,448 euro, amounting to 2.2% of the total MMT costs during the study period. CONCLUSION: In our trauma system, the MMT dispatches are involved with high rates of overtriage. After being dispatched, the MMT is cancelled in almost 50% of all cases. We found an undertriage rate of 4%, which we think is acceptable. All cancellations were justified. The additional costs of the cancelled missions were within an acceptable range. According to this study, it seems to be possible to reduce the overtriage rate of the MMT dispatches, without increasing the undertriage rate to non-acceptable levels.

The association of hemodilution and transfusion of red blood cells with biochemical markers of splanchnic and renal injury during cardiopulmonary bypass.

BACKGROUND: Hemodilution is the main cause of a low hematocrit concentration during cardiopulmonary bypass. This low hematocrit may be insufficient for optimal tissue oxygen delivery and often results in packed cell transfusion. Our objective in this study was to find a relationship between intraoperative hematocrit and allogeneic blood transfusion on release of postoperative injury markers from the kidneys and the splanchnic area. METHODS: Fifty consecutive patients undergoing coronary artery bypass grafting with cardiopulmonary bypass were included. Systemic tissue hypoxia was assessed by lactate concentrations. Kidney and splanchnic ischemia were assessed by the measurement of N-acetyl-beta-D-glucosaminidase (NAG) and intestinal fatty acid binding protein (IFABP) in urine. Patients were retrospectively placed into groups according to their lowest hematocrit concentration on bypass (<24% or >or=24%). RESULTS: The intraoperative lactate and the postoperative NAG and IFABP concentrations were higher in the low hematocrit group (<24%) than in the high hematocrit group (>or=24%; P < 0.05). Low hematocrit correlated with higher lactate concentrations (R(2) = 0.150, P < 0.01) and with higher NAG concentrations (R(2) = 0.138, P < 0.01) and IFABP concentrations (R(2) = 0.107, P < 0.01) postoperatively. Transfusion of packed cells during cardiopulmonary bypass correlated with higher lactate (R(2) = 0.089, P < 0.05), NAG (R(2) = 0.431, P < 0.01), and IFABP concentrations (R(2) = 0.189, P < 0.01). CONCLUSIONS: The results support the concept that hemodilution below an intraoperative hematocrit of 24% and consequently transfusion of red blood cells is related to release of injury markers of the kidneys and splanchnic area.

Evaluation of repatriation parameters: does medical history matter?

BACKGROUND: Aeromedical repatriation of patients is an expanding service due to the growing number of travelers worldwide. Of these repatriated patients, a small number require specialized transportation due to severe medical complications. We evaluated the medical in-flight records of Dutch patients with severe disease or polytrauma who were repatriated by air from 1998 to 2002 via one of the largest Dutch alarm centers. We questioned how this Dutch population of repatriated patients is demographically distributed and whether this population is a priori at high risk for acute medical complications that need specialized medical attention. RESULTS: Seventy-seven of 115 repatriated patients were 50 years and older, of which most were male (73%). Fifty patients had no significant medical history, whereas the remaining 65 patients suffered from comorbidities such as cardiovascular disease or cancer. In patients aged 18 to 49 years, one third of all patients were repatriated due to traumatic fractures. In the older age category, the main reasons for repatriation were cardiopulmonary incidents. There was an equal distribution in the primary medical reason for repatriation as defined by need for trauma/neurological support and ventilation or circulatory support. Of note, 82% of the 65 patients who traveled with a chronic disease condition were repatriated due to worsening of this particular condition. CONCLUSIONS: The present study shows that an aeromedical repatriation service is frequently employed by travelers with a history of chronic disease who develop medical complications. The growing number of repatriated elderly patients and/or patients with preexisting comorbidities requires development of secure pretravel risk assessment and adaptation of the medical service level in foreign countries.

Cardiac response is greater for colloid than saline fluid loading after cardiac or vascular surgery.

OBJECTIVE: To study the effects on volume expansion and myocardial function of colloids or crystalloids in the treatment of hypovolaemic hypotension after cardiac and major vascular surgery. DESIGN AND SETTING: A single-centre, single-blinded, randomized clinical trial at the intensive care unit of a university hospital. PATIENTS AND METHODS: Patients (n=67) were subjected to a 90-min filling pressure-guided fluid challenge with saline 0.9% or the colloids gelatin 4%, hydroxyethyl starch 6% or albumin 5%. Biochemical variables and haemodynamics (transpulmonary thermodilution) were measured. RESULTS: An amount of 1800 (1300-1800) ml of saline or 1600 (750-1800) ml of colloid solution (P< 0.005) was infused. Colloid osmotic pressure (COP) decreased in the saline group and increased in the colloid groups (P< 0.001). Plasma volume increased by 3.0% (-18 to 24) in the saline versus 19% (-11 to 50) in the colloid groups (P< 0.001). Cardiac index increased by median 13% (ns) in the saline group and by 22% in the colloid groups (P<0.005). The rise in left ventricular stroke work index was greater in the colloid than in the saline groups. The different colloids were equally effective. The rise in cardiac index related to the rise in plasma volume and global end-diastolic volume, confirming plasma volume and preload augmentation by the fluid loading. CONCLUSION: After cardiac or major vascular surgery, the pressure- and time-guided fluid response is dependent on the type of fluid used. Colloid fluid loading leads to a greater increase in preload-recruitable cardiac and left ventricular stroke work indices than that with saline, because of greater plasma volume expansion following an increase in plasma COP.

Percutaneous dilatational tracheostomy in the ICU: optimal organization, low complication rates, and description of a new complication.

STUDY OBJECTIVES: To assess short-term and long-term complications of bronchoscopy-guided, percutaneous dilatational tracheostomy (PDT) and surgical tracheostomy (ST) and to report a complication of PDT that has not been described previously. DESIGN: Prospective survey. SETTING: University teaching hospital. PATIENTS: Two hundred eleven critically ill patients in our ICU. INTERVENTIONS: PDT was performed in 174 patients, under bronchoscopic guidance in most cases. ST was performed in 40 patients. RESULTS: No procedure-related fatalities occurred during PDT or ST. The incidence of significant complications (eg, procedure-related transfusion of fresh-frozen plasma, RBCs, or platelets, malpositioning or kinking of the tracheal cannula, deterioration of respiratory parameters lasting for > 36 h following the procedure, or stomal infection) in patients undergoing PDT was 4.0% overall and 3.0% when bronchoscopic guidance was used. No cases of paratracheal insertion, pneumothorax, pneumomediastinum, tracheal laceration, or clinically significant tracheal stenosis occurred in patients undergoing PDT. We attribute this low rate of complications to procedural and organizational factors such as bronchoscopic guidance, performance by or supervision of all PDTs by physicians with extensive experience in this procedure, and airway management by physicians who were well-versed in (difficult) airway management. In addition, an ear-nose-throat surgeon participated in the procedure in case conversion of the procedure to an ST should become necessary. We observed a complication that, to our knowledge, has not been reported previously. Five patients developed intermittent respiratory difficulties 2 to 21 days (mean, 8 days) after undergoing PDT. The cause turned out to be the periodic obstruction of the tracheal cannula by hematoma and the swelling of the posterior tracheal wall, which had been caused by intermittent pressure and chafing of the cannula on the tracheal wall. In between the episodes of obstruction, the cannula was open and functioning normally, which made the diagnosis difficult to establish. CONCLUSIONS: Bronchoscopy-assisted PDT is a safe and effective procedure when performed by a team of experienced physicians under controlled circumstances. The intermittent obstruction of the cannula caused by swelling and irritation of the posterior tracheal wall should be considered in patients who develop unexplained paroxysmal respiratory problems some time after undergoing PDT or ST.