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Biomedical subjects

E F Christensen

Publications and source records attributed to E F Christensen.

At least 19 recordsLinked to original sources
PubMed2006

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.

Cohort Studies↗
PubMed2005

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.

Accidents↗
PubMed2002

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.

Adult↗
PubMed1998

[Severely traumatized patients admitted to Aarhus Community Hospital 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.

Adolescent↗
PubMed1998

[Mechanical ventilation in acute respiratory insufficiency in patients with chronic obstructive lung diseases].

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.

Acute Disease↗
PubMed1998

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.

Animals↗
PubMed1996

[Testing a medically-staffed ambulance in Aarhus. A pilot study].

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.

Adult↗
PubMed1996

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.

Administration, Rectal↗
PubMed1995

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.

Equipment Design↗
PubMed1994

Contamination of central venous catheters: use of infusion-lines does not increase catheter-contamination.

In a prospective controlled trial we compared the rates of intraluminal contamination between the two lumens of a double-lumen central venous catheter. One lumen was used for repeat infusions and injections, and the other was permanently connected to a slow infusion of 0.9% NaCl. The study was designed so that the patient was his own control. Twenty-eight catheters were examined and comparison with catheter-tip cultures was performed in 24. Intraluminal culture was performed 67-77 h after insertion of the catheter and catheter-tip culture was performed on removal of the catheter. The contamination rate from catheter-tips was 20.8%, which is acceptable compared with other studies. There was only one positive intraluminal culture in each group (3.6%), and thus no correlation was found between contamination rate and the number of times the infusion-line had been interrupted for use. As for catheter-tip contamination, we found no correlation between infusion of blood-products or parenteral nutrition and contamination rates.

Blood Transfusion↗
PubMed1993

Myocardial ischaemia and spinal analgesia in patients with angina pectoris.

We have studied prospectively myocardial ischaemic events by Holter monitoring of ST-segment depression in patients with angina pectoris given spinal analgesia for minor surgery compared with a reference day of normal daily activities. Monitoring was undertaken continuously for 24 h on both days, starting just before anaesthesia on the day of surgery. On the reference day, seven of 14 patients had 27 ischaemic events with mean max ST-depression of 0.15 mV and total duration of 143 min, compared with 10 of 14 patients with 70 ischaemic events with mean max ST-depression of 0.22 mV and total duration of 1078 min (P < 0.01 for all). On the day of surgery, the first ischaemic event occurred a mean 338 min (range 75-480 min) after spinal analgesia, and the duration of all first events was 480 min. On this day, the first ischaemic event was associated with increased heart rate (103 beat min-1 (range 66-131 beat min-1) compared with 92 (60-122) beat min-1 during all events (P = 0.011)). In patients with angina pectoris, myocardial ischaemia did not occur immediately after the onset of spinal analgesia, but several hours later, corresponding to the cessation of block. This could be explained by increased cardiac pre- and afterload, probably further aggravated by the volume load.

Aged↗
PubMed1993

Inhaled beta 2-agonist and positive expiratory pressure in bronchial asthma. Influence on airway resistance and functional residual capacity.

INTRODUCTION: Positive expiratory airway pressure seems to dilate narrowed or collapsed airways, but this may be accompanied by a maintained and harmful increase in resting lung volume in obstructive pulmonary disease. PURPOSE: To evaluate the influence of inhaled terbutaline and positive expiratory pressure (PEP) on airway resistance (Raw) and functional residual capacity (FRC) in bronchial asthma. DESIGN: Randomized crossover design, single blind with regard to inhaled medication, open with regard to PEP (PEP can be felt). MATERIAL AND METHODS: Ten patients with bronchial asthma inhaled placebo and terbutaline in doses of 0.125 mg, 0.5 mg, and 1.5 mg by cone spacer combined with a facemask giving 0, 10, or 15 cm H2O PEP on separate days. FRC and Raw were measured by body plethysmography before and after inhalations. Data were analyzed by analysis of variance with terbutaline dose and PEP as factor levels. RESULTS: The effect of terbutaline: Raw decreased significantly (p < 0.0001) after 0.125 mg and 1.5 mg. The FRC did not change significantly. The effect of PEP: Raw decreased, but significantly only when the dose of 1.5 mg terbutaline was excluded from the analysis. Raw decreased with PEP 10 and 15 cm H2O, mean 0.6 (95 percent CI: -1.1, -0.2) and 0.9 (95 percent CI: -1.3, -0.4) cm H2O/L/s. The FRC did not change significantly with the PEP level. CONCLUSION: PEP only had influence on Raw when insufficient doses of terbutaline were inhaled, whereas once an efficient dose of terbutaline was administered, significant bronchodilation was achieved with or without PEP. Positive expiratory pressure did not increase FRC.

Administration, Inhalation↗
PubMed1992

[Continuous positive airway pressure (CPAP)--does the equipment live up to its name?].

The purpose of this study was to evaluate the in- and expiratory pressures achieved by the use of different continuous positive airway pressure (CPAP) delivery systems. The study was performed on ten healthy adults breathing spontaneously with: 1) "simple CPAP", consisting of a fresh gas flow around 40 l/min and reservoir balloons of 2, 6 and 10 l and expiration against a water column, 2) a high-flow system CR60 CPAP, designed for home treatment and 3) another high-flow system Down's CPAP. Both high-flow systems used a venturi device (Downs Flow Generator, Vital Signs) giving flows around 90 and 170 l/min in our set-up, and the same PEEP valves (Vital signs) were used. All systems were tested with expiratory pressures set at 5, 10 and 20 cm H2O. Individual responses were found, but in general the simple CPAP with a 10 l latex balloon reservoir gave optimal CPAP. The high-flow systems were not found to provide better CPAP, however, CR60 CPAP was found also to be optimal with 5 and 10 cm H2O. Down's CPAP provided 3-5 cm higher expiratory pressure than the intended CPAP level. We recommend measurement of the pressure during the CPAP treatment to ensure that the intended CPAP is achieved.

Adult↗
PubMed1992

Increased urinary loss of uric acid in adults with acute respiratory failure requiring mechanical ventilation.

INTRODUCTION: The purpose of this study was to test a hypothesis of increased urinary excretion of uric acid as an indicator of adenosine triphosphate (ATP) degradation in adult patients with acute respiratory failure, and to look for a correlation to the clinical outcome. STUDY DESIGN: Prospectively 31 patients with acute respiratory failure were studied. The patients were divided into two groups according to the clinical outcome: the need for solely supplemental oxygen (group 1), death or mechanical ventilation (group 2). METHODS: Uric acid was determined by spectrophotometry. RESULTS: Mean uric acid excretion was 39 mumol/kg (range, 7 to 92 mumol/kg) body weight/per 24 h in group 1 (16 patients) compared with 65 mumol/kg/24 h (range, 8 to 253 mumol/kg/24 h) in group 2 (13 patients were mechanically ventilated, and two patients died). The difference was highly significant (p less than 0.0001). CONCLUSION: Increased amount of urinary uric acid was related to the severity of acute respiratory failure in adults.

Acute Disease↗
PubMed1991

[Long-term treatment of chronic bronchitis with pulmonary physiotherapy with and without positive expiratory pressure].

In a prospective, randomized, controlled study, treatment of chronic bronchitis with self-administered chest physiotherapy alone (control) or with positive expiratory pressure (PEP) by mask was studied. Forty-three patients completed the study (n = 20 PEP, and n = 23 control). After instruction, the treatments were self-administered twice daily for 12 months (34 patients) and five months (9 patients). The patients completed a diary concerning symptoms twice weekly. An acute exacerbation (AE) was defined as the appearance of mucopurulent or purulent sputum and increasing cough and one or more of the following symptoms: temperature greater than or equal to 38 degrees C, general malaise, increased dyspnea, increased mucus production, increased thickness of mucus or increased difficulty in expectoration. The number of AE were calculated from the diaries. The incidence of AE was significantly lower in the PEP group (p less than 0.0005). In the PEP group, three patients had a total of six AE, compared to 12 patients with 28 AE in the control group. The PEP group also used less antibiotics (p less than 0.005). Treatment with a simple PEP device can reduce morbidity in patients with chronic bronchitis.

Adult↗