Neurological prognostication tools in out-of-hospital cardiac arrest patients in Danish intensive care units from 2005 to 2013.

BACKGROUND: Neurological prognostication is an essential part of post-resuscitation care in out-of-hospital cardiac arrest (OHCA). This study aims to assess the use of computed tomography (CT) and magnetic resonance imaging (MR) of the head, electroencephalography (EEG), and somatosensory evoked potentials (SSEP) in neurological prognostication in resuscitated OHCA patients and factors associated with their use in Danish tertiary and non-tertiary centers from 2005 to 2013 and associations with outcome. METHODS: We used the Danish Cardiac Arrest Registry to identify patients ≥18 years of age admitted to intensive care units due to OHCA of presumed cardiac etiology. CT 0-20 days and MR, SSEP, and EEG ≥2-20 days post OHCA were considered related to prognostication. Incidence and factors associated with procedures were assessed by multiple Cox regression with death as competing risk. RESULTS: Use of CT, MR, EEG, and SSEP increased during the study period (CT: 51%-67%, HRCT : 1.06, CI: 1.03-1.08, MR: 2%-5%, P = .08, EEG: 6%-33%, HREEG : 1.25, CI: 1.19-1.30, SSEP: 4%-15%, HRSSEP : 1.23, CI: 1.15-1.32). EEG and SSEP were more used in tertiary centers than non-tertiary (HREEG : 1.86, CI: 1.51-2.29, HRSSEP : 4.44, CI: 2.86-6.89). Use of CT, SSEP, and EEG were associated with higher 30-day mortality, and MR was associated with lower (HRCT : 1.15, CI: 1.01-1.30, HRMR : 0.53, CI: 0.37-0.77, HRSSEP : 1.90, CI: 1.57-2.32, HREEG : 1.75, CI: 1.49-2.05). CONCLUSION: Use of neurological prognostication procedures increased during the study period. EEG and SSEP were more used in tertiary centers. CT, EEG and SSEP were associated with increased mortality.

Efficacy and safety of intravenous fentanyl administered by ambulance personnel.

BACKGROUND: Management of pain in the pre-hospital setting is often inadequate. In 2011, ambulance personnel were authorized to administer intravenous fentanyl in the Central Denmark Region. The aim of this study was to evaluate the efficacy and safety of intravenous fentanyl administered by ambulance personnel. METHODS: Pre-hospital medical charts from 2348 adults treated with intravenous fentanyl by ambulance personnel during a 6-month period were reviewed. The primary outcome was the change in pain intensity on a numeric rating scale (NRS) from before fentanyl treatment to hospital arrival. Secondary outcomes included the number of patients with reduction in pain intensity during transport (NRS ≥ 2), the number of patients with NRS > 3 at hospital arrival, and potential fentanyl-related side effects. RESULTS: Fentanyl reduced pain from before treatment (8, IQR 7-9) to hospital arrival (4, IQR 3-6) (NRS reduction: 3, IQR 2-5; P = 0.001), 79.3% of all patients had a reduction in > 2 on the NRS during transport, and 58.4% of patients experienced pain at hospital arrival (NRS > 3). Twenty-one patients (0.9%) had oxygen saturation < 90%. A decrease in Glasgow Coma Scale was seen in 31 patients (1.3%) and hypotension observed in 71 patients (3.0%). CONCLUSION: Intravenous fentanyl caused clinically meaningful pain reduction in most patients and was safe in the hands of ambulance personnel. Many patients had moderate to severe pain at hospital arrival. As the protocol allowed higher doses of fentanyl, feedback on effect and safety should be part of continuous education of ambulance personnel.

Can public health registry data improve Emergency Medical Dispatch?

BACKGROUND: Emergency Medical Dispatchers make decisions based on limited information. We aimed to investigate if adding demographic and hospitalization history information to the dispatch process improved precision. METHODS: This 30-day follow-up study evaluated time-critical emergencies in contact with the emergency phone number 112 in Denmark during 18 months. 'Time-critical' was defined as suspected First Hour Quintet (FHQ) (cardiac arrest, chest pain, stroke, difficulty breathing, trauma). The association of age, sex, and hospitalization history with adverse outcomes was examined using logistic regression. The predictive ability was assessed via area under the curve (AUC) and Hosmer-Lemeshow tests. RESULTS: Of 59,943 patients (median age 63 years, 45% female), 44-45.5% had at least one chronic condition, 3880 (6.47%) died the day or the day after (primary outcome) calling 112. Age 30-59 was associated with increased adjusted odds ratio (OR) of death on day 1 of 3.59 [2.88-4.47]. Male sex was associated with an increased adjusted OR of death on day 1 of 1.37 [1.28-1.47]. Previous hospitalization with nutritional deficiencies (adjusted OR 2.07 [1.47-2.92]) and severe chronic liver disease (adjusted OR 2.02 [1.57-2.59]) was associated with a higher risk of death. For trauma patients, the discriminative ability of the model showed an AUC of 0.74 for death on day 1. CONCLUSION: Increasing age, male sex, and hospitalization history was associated with increased risk of death on day 1 for FHQ 112 callers. Additional efforts are warranted to clarify the role for risk prediction tools in emergency medical dispatch.

Antipsychotics and associated risk of out-of-hospital cardiac arrest.

Antipsychotic drugs have been associated with sudden cardiac death, but differences in the risk of out-of-hospital cardiac arrest (OHCA) associated with different antipsychotic drug classes are not clear. We identified all OHCAs in Denmark (2001-2010). The risk of OHCA associated with antipsychotic drug use was evaluated by conditional logistic regression analysis in case-time-control models. In total, 2,205 (7.6%) of 28,947 OHCA patients received treatment with an antipsychotic drug at the time of the event. Overall, treatment with any antipsychotic drug was associated with OHCA (odds ratio (OR) = 1.53, 95% confidence interval (CI): 1.23-1.89), as was use with typical antipsychotics (OR = 1.66, CI: 1.27-2.17). By contrast, overall, atypical antipsychotic drug use was not (OR = 1.29, CI: 0.90-1.85). Two individual typical antipsychotic drugs, haloperidol (OR = 2.43, CI: 1.20-4.93) and levomepromazine (OR = 2.05, CI: 1.18-3.56), were associated with OHCA, as was one atypical antipsychotic drug, quetiapine (OR = 3.64, CI: 1.59-8.30).

Reporting of data from out-of-hospital cardiac arrest has to involve emergency medical dispatching--taking the recommendations on reporting OHCA the Utstein style a step further.

OBJECTIVES: As a part of the chain of survival, the emergency medical communication centre (EMCC) and the emergency medical dispatcher (EMD) has an important role in early identification of out-of-hospital cardiac arrests (OHCA). The EMD may provide instructions to the caller and thereby initiate cardiopulmonary resuscitation in a substantial number of subjects and thus contribute to increased survival. The EMCC provides a response with first responders, ambulances, physician manned units and potentially other health care providers. EMCC in many cases initiates the communication with experts in the referral hospital and provide added value to the post resuscitation care by providing advanced transport, logistics and follow up. In research there is a growing focus on the EMCC/EMDs impact on survival in OHCA. The lack of standards in reporting results from medical dispatching is an obstacle for thorough evaluation of results in this area and comparison of data. The objective for this paper is to introduce a framework for uniform reporting of the dispatching process for quality improvement, collecting and reporting data and exchanging information regarding OHCA.

Recommended guidelines for reporting on emergency medical dispatch when conducting research in emergency medicine: the Utstein style.

OBJECTIVES: To establish a uniform framework describing the system and organisation of emergency medical response centres and the process of emergency medical dispatching (EMD) when reporting results from studies in emergency medicine and prehospital care. DESIGN AND RESULTS: In September 2005 a task force of 22 experts from 12 countries met in Stavanger; Norway at the Utstein Abbey to review data and establish a common terminology for medical dispatch centres including core and optional data to be used for health monitoring, benchmarking and future research.

Evaluation of pre-hospital trauma triage criteria: a prospective study at a Danish level I trauma centre.

BACKGROUND: The aim of the present study was to evaluate the precision of our trauma triage protocol [based on the American College of Surgeons, Committee on Trauma (ACS COT)] in identifying severely injured defined as an injury severity score (ISS) > 15. Our hypothesis was that isolated mechanism-of-injury criteria were responsible for a significant over-triage leading to over-use of our trauma team. DESIGN: A prospective cohort study. SETTING: A level I trauma centre, Aarhus, Denmark. PATIENTS AND PARTICIPANTS: Among all injured patients admitted during a 6-month period in 2003 we identified severely injured. During the study period, trauma team activations were consecutively registered and triage criteria were prospectively collected. Sensitivity, specificity, positive predictive value, over-triage and under-triage were calculated. RESULTS: Out of 15,162 patients in the emergency department, 848 injured patients were included and 59 (7%) were severely injured. We had 242 trauma team activations with 54 (22%) severely injured. Sensitivity was 92%, specificity 76%, giving an over-triage of 24% and an under-triage of 8%. The positive predictive value was 22%. Among 60 patients with mechanism-of-injury as the only criterion, five were severely injured in contrast to 12 out of 20 patients with mechanism-of-injury combined with physiological and/or anatomical criteria. CONCLUSION: The positive predictive value of our triage protocol was low, only 22%. This was mainly as a result of a significant over-triage from isolated mechanism-of-injury criteria. We recommend revision of the triage protocol and reallocation of our trauma team resources.

Accuracy in identifying patients with loss of consciousness in a police-operated emergency call centre - first step in the chain of survival.

BACKGROUND: The first link in the 'chain of survival' is the activation of Emergency Medical Services (EMS). In the major part of Denmark, police officers operate the alarm 1-1-2 centre, including calls for EMS. Our aim was to study the police 1-1-2 operators' accuracy in identifying calls concerning patients with loss of consciousness as a key symptom of life-threatening conditions. 'Unconsciousness' was defined as patients with a Glasgow Coma Scale (GCS) score of < 9, scored by the on-scene anaesthesiologist from the Mobile Emergency Care Unit (MECU). METHODS: This study was an observational cohort study based on data from the Police 1-1-2 Database and the Aarhus County Pre-hospital Database containing data from MECU cases during 6 months in 2004-05. RESULTS: Two thousand, three hundred and forty-three emergency calls with MECU dispatch were identified. In 1655 cases, both 1-1-2 data and the GCS score were recorded. Two hundred and ninety-five patients were found with a GCS score of < 9 at MECU arrival, 243 of whom were reported 'unconscious' by 1-1-2, giving a sensitivity of 82%. One thousand, three hundred and sixty patients were found with a GCS score of > or = 9, 972 of whom were reported 'awake', giving a specificity of 72%. The positive predictive value (percentage of patients found with a GCS score of < 9 at MECU arrival amongst patients reported as 'unconscious') was 39%. CONCLUSIONS: The accuracy was moderate with room for improvement. The positive predictive value was low, indicating over-triage of MECU.

A study of police operated dispatch to acute coronary syndrome cases arising from 112 emergency calls in Aarhus county, Denmark.

BACKGROUND: The accuracy of the Danish police operated "112" emergency call system was studied. Dispatch of the anaesthesiologist staffed mobile emergency care unit (MECU) to acute coronary syndrome (ACS) cases was used as an indicator of accuracy of dispatch to life threatening emergencies. METHODS: This was an observational cohort study of patients given a 112 system report of heart attack and patients with a provisional diagnosis of ACS made on scene by the MECU. Sensitivity, specificity, and positive predictive value with 95% confidence intervals (CI) were calculated. RESULTS: There were 341 reports of "heart attack" and 205 patients with ACS. Sensitivity was 75% (95% CI 68% to 80%) specificity 90% (89% to 92%) and positive predictive value 45% (40% to 50%). CONCLUSION: The accuracy of 112 dispatch of the MECU was found to be moderate. We suggest more training of dispatch staff and medical supervision.

Ethical and practical problems in blood sampling for research purposes during pre-hospital emergencies.

BACKGROUND: Research in the pre-hospital phase of emergencies involves certain ethical and practical challenges. Severely ill or injured patients are not able to give informed consent in the immediate stressful situation. The aim of this pilot study was to find an ethically acceptable method to carry out research in acutely ill or injured patients before any treatment was given in order to be able to study the acute and unmodified systemic inflammatory response to trauma. METHODS: Younger physicians were assigned to the mobile emergency care unit (MECU) on a volunteer basis. They drew blood samples 'at the scene' from patients exposed to accidental injury or from patients with acute medical emergencies. The ethical committee accepted that informed consent to blood analyses could be postponed until later or given by relatives. Pro- and anti-inflammatory cytokines, catecholamines and cortisol were measured. RESULTS: During 6 months, the study group accompanied the MECU on approximately 500 call-outs. Blood samples were drawn from 42 patients. Consent to the analysis of blood samples was obtained in 30 cases. In 20 cases, it was not possible to draw the blood sample before medication. CONCLUSION: This pilot study showed that it was possible to conduct blood sampling from acutely ill patients 'at the scene'. However, the present legislation on informed consent makes this type of research very time consuming. When patients die in hospital and no relatives can be found, consent cannot be obtained, and information from these severely affected patients is lost.

Acute myocardial infarction: does pre-hospital treatment increase survival?

The aim of this study was to assess the impact of a mobile emergency care unit (MECU) staffed with an anaesthetist, in terms of increased survival among patients with acute myocardial infarction (MI). The setting was an urban area with 330 000 inhabitants. This was a quasi-experimental before-and-after-study including consecutive emergency calls during September to November 1996 (Period 1, without the MECU) and September to November 1997 (Period 2, including the MECU). Fifty-four ambulance patients had their MI diagnosis confirmed at hospital during Period 1, and another 54 in Period 2. The 28-day mortality was collected from relevant registers. Twenty-four (44%) of Period 2 patients were transported by the MECU. MECU patients had lower systolic blood pressure (SBP) than other patients, both before and after hospital admission. Nitroglycerine treatment was relatively frequent in MECU patients, and cardioversion, anaesthesia and intubation was applied exclusively in these patients. After arrival at hospital, MECU patients had thrombolysis relatively often (46% versus 23% in other Period 2 patients) but percutaneous transluminal coronary angioplasty (PTCA) relatively infrequently (21% vs 30%). The total mortality was significantly lower in Period 2 than in Period 1 patients (11% vs 21%, <0.025), irrespective of differences in the distribution of age, gender, pulse and SBP, measured at hospital. Also, the more specific MECU use, alone and in combination with subsequent PTCA treatment, was found to be associated with prolonged survival. Pre-hospital treatment by an MECU staffed by an anaesthetist and/or having a PTCA seems to be associated with prolonged survival in acute MI patients. It must be underscored that these observations have been based on quasi-experimental rather than randomized experimental data.

Prospective measure of serum 3-nitrotyrosine levels in systemic lupus erythematosus: correlation with disease activity.

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease. Overproduction of nitric oxide (NO) has been implicated in its pathogenesis. Several retrospective studies have indicated a correlation between serum nitrate and nitrite (NOx) and disease activity. This measure of NO production can be falsely elevated by exogenous dietary and medication sources of NOx and variably reduced by serum thiols. These variables can make NOx a less reliable tool for studying the role of NO in SLE. Peroxynitrite, a by-product of NO and superoxide, nitrates tyrosine moieties. The resulting 3-nitrotyrosine (3NT) serves as a long-term indicator of NO-mediated protein modifications that is not affected by exogenous sources of NOx or serum thiols. We hypothesized that for these reasons serum 3NT levels would correlate with lupus disease activity more significantly than serum NOx. To address this hypothesis, we prospectively evaluated lupus disease activity, serum protein 3NT levels, and NOx levels in a cohort of lupus patients at 3-month intervals. Serum 3NT correlated with disease activity among African-Americans, while NOx correlated with disease activity among Caucasians. Subjects with active lupus nephritis had higher levels of serum 3NT than those without renal disease. Immunohistochemical analysis of renal biopsies from subjects with active proliferative lupus nephritis revealed renal expression of inducible NO synthase. The results of this study suggest that overproduction of NO may play a pathogenic role in SLE and lupus nephritis. Serum 3NT may be a useful, new tool for studying the contributions of NO to the pathogenesis of SLE.

[Severely traumatized patients admitted to Aarhus Community Hospital 1994-1995]. / Svaert tilskadekomne patienter indbragt til Arhus Kommunehospital 1994-1995.

In Denmark, only few studies have addressed the problem of severe trauma. In relation to establishing a trauma manual at our hospital we studied trauma patients requiring immediate anaesthesiological assistance. Patients from the preceeding years, 1994-1995 were identified. The injuries were scored according to the Abbreviated Injury Scale (AIS), and Injury Severity Scores (ISS) were calculated. Two hundred and fifty-eight trauma patients were identified, 132 of these were severely injured, defined as having ISS > or = 15. Of these, 75 patients were multitraumatised, defined as AIS > or = 3 in at least two regions. None of the patients with ISS < or = 15 died. Mortality was 49% among severely injured but not multitraumatised patients, while mortality was 56% among the multitraumatised patients. Head injuries were the most frequently found severe injury (AIS > or = 3), followed by injuries to the thorax and extremities. The anaesthesiologist and the orthopaedic surgeon were involved in initial diagnosis and treatment in all patients, and beyond these a variety of medical specialties were involved. In the light of this study we have revised our procedures and registration concerning severe trauma patients.

[Mechanical ventilation in acute respiratory insufficiency in patients with chronic obstructive lung diseases]. / Mekanisk ventilation ved akut respirationsinsufficiens hos patienter med kronisk obstruktiv lungesygdom.

Chronic obstructive lung disease (COLD) is a common disease and cause of death. At an advanced stage, acute respiratory failure will repeatedly arise and mechanical ventilation may be the only solution. The best result of treatment is a return to the habitual condition. In this article a survey is presented regarding the course and survival following mechanical ventilation of acute exacerbation of COLD. Survival rate after mechanical ventilation was 50-70% compared to a survival rate of 75-95% in patients not mechanically ventilated. Mechanical ventilation influenced factors were taken into consideration. The severity of baseline COLD and comorbidity had significant influence on survival. These factors together with the quality of nursing were predictors of successful ventilator weaning. Knowledge of the patient before the need for mechanical ventilation arises is of decisive importance.

P1,P4-diadenosine 5' tetraphosphate induces nitric oxide release from bovine aortic endothelial cells.

Since the infusion of P1,P4-diadenosine 5' tetraphosphate (Ap4A) into animal models induces vasodilation [1,2], the present study was performed to determine whether Ap4A induces the release of nitric oxide (NO) from endothelial cells. Ap4A induced NO release was 4.2-fold greater than the amount of NO released under basal condition. Ap4A induced NO release was inhibited by NG-nitro-L-arginine (L-NNA) and this inhibition was reversed by L-Arg. In addition, EGTA inhibits Ap4A induced NO release. These data are consistent with Ap4A inducing the release of NO from endothelial cells through the activation of endothelial nitric oxide synthase.

[Testing a medically-staffed ambulance in Aarhus. A pilot study]. / Forsøg med indsaettelse af laegeambulance i Arhus. En pilotundersøgelse.

As an attempt to assess the value of a medically-staffed mobile emergency care unit in Aarhus City, we carried out a seven-day experiment (17 hours per day) with an anaesthesiologist and a nurse on duty in a fully equipped vehicle. Aarhus City is an area of approximately 300 km2, with a population of 330,000. The unit responded to emergency calls in 106 patients (38% of all emergency calls during this week). In 31% of all cases the response-time was less than five minutes. Medical disease was diagnosed in 73 patients. Twenty-three patients were suffering from trauma and in three cases the reason for the emergency call was attempted suicide. Fifty-seven percent were treated immediately by the emergency unit, and in 4% of these the treatment was lifesaving. Twenty percent of the patients had their treatment completed outside the hospital. Eighty percent were brought to hospital, 47% with medical assistance. We conclude that there seems to be a basis for a medically-staffed mobile emergency care unit in Aarhus City.

The value of continuous blockade of the lumbar plexus as an adjunct to acetylsalicyclic acid for pain relief after surgery for femoral neck fractures.

In a randomized, double-blind investigation the analgesic effect of continuous blockade of the lumbar plexus as an adjunct to acetylsalicyclic acid by suppository after surgery for femoral neck fractures under spinal anaesthesia was examined in 20 patients. Before surgery, a catheter was inserted into the femoral nerve sheath. The patients were allocated randomly to receive bupivacaine or saline by bolus and then continuous infusion, started immediately after the operation. No statistically significant differences in additional morphine requirements, visual analogue pain scores or adverse effects were observed between the two treatment groups. It is concluded that continuous blockade of the lumbar plexus as an adjunct to rectal acetylsalicyclic acid offers no major additional pain relief after surgery for femoral neck fractures under spinal anaesthesia.

Flow-dependent properties of positive expiratory pressure devices.

Valves for positive expiratory pressure (PEP) can be characterized as threshold resistors, ideally providing pressure independent of the expiratory flow, or as flow-dependent resistors. The aim of the study was to evaluate the flow-dependence properties of PEP devices of the flow resistor type compared to threshold resistor devices. Pressures were measured on three different flow resistor valves: the PEP-mask, the Pari-PEP-System and the System 22-PEP with orifice diameters of 1.5-5.0 mm; and on three threshold resistors, the underwater seal, the Ambu Positive End-Expiratory Pressure (PEEP) valve and the Vital Signs PEEP valve with pressures of 0, 5, 10, 15 and 20 cmH2O. All devices were studied with constant flows of 3, 6, 9, 12, 15, 18, 30, 60, 90, 120 and 150 l.min-1. The PEP-mask, the Pari-PEP and the System 22-PEP showed the typical pattern of flow resistors, i.e. a pressure increasing with flow, dependent on the diameter of the orifice. The underwater seal and the Vital Signs PEEP valves acted as almost ideal threshold resistors. The Ambu PEEP valves acted as threshold resistors at the lower flows, but showed flow-dependency at higher flows. The Vital Signs PEEP valves gave lower pressures and Ambu PEEP valves gave higher pressures compared with indicated values, whereas the underwater seal gave the intended pressure. In clinical use of PEP treatment the actual pressure should be measured to ensure the intended pressure, no matter which type of resistor is used.