Fusion of dispatching centres into one entity: effects on performance.

BACKGROUND: Dispatching centres were fused into one of the 112 entity, which caused concerns regarding whether the medical calls could be processed effectively also in the new centre. We evaluated the effects of the reform on key performance criteria in medical calls. METHODS: This observational study in the Helsinki Dispatching Centre consisted of two periods: Period I 2 years before the reform and Period II 2 years after. The main outcome measures were answering and call processing times, accuracy of risk assessment and appropriate use of ambulances. RESULTS: In Period I (n=574,276), 92.2% of all incoming phone calls were answered within 10 s and in Period II (n=758,022) 82.8% (P<0.0001). Time to dispatch a first responding fire unit increased from 98 to 113 s (P<0.0001) and an advanced life support unit in category A calls increased from 73 to 84 s (P<0.0001). In Period I 47.7%, 34.8% and 17.5% of phone calls were completed in <3, 3-5 and >5 min and in Period II 29.8%, 36.1% and 34.1% (P<0.0001). The number of three studied non-transportation call types and unnecessary lights-and-siren responses increased significantly (P<0.0001 and 0.0001, respectively). Neither the accuracy of risk assessment in the three studied call types nor the rate of telephone-guided cardiopulmonary resuscitation changed. CONCLUSIONS: The reform increased the total number of ambulance dispatches, prolonged answering and call processing times and had a negative effect on the appropriate use of ambulances. The accuracy of risk assessment was not affected. Evidence-based data should be the basis for the future as dispatching centre processes are shown to be vulnerable during organisational reforms.

Comparison of Helsinki and European Resuscitation Council "do not attempt to resuscitate" guidelines, and a termination of resuscitation clinical prediction rule for out-of-hospital cardiac arrest patients found in asystole or pulseless electrical activity.

BACKGROUND: The outcome of out-of-hospital cardiac arrest (OHCA) with a non-shockable rhythm is poor. For patients found in asystole or pulseless electrical activity (PEA), recent guidelines or rules that may be used include "do not attempt to resuscitate" (DNAR) guidelines from Helsinki, discontinuing resuscitation in the guidelines of the European Resuscitation Council and a clinical prediction rule from Canada. We compared these guidelines and the rule using a large Scandinavian dataset. MATERIALS AND METHODS: The Swedish Cardiac Arrest Registry includes prospectively collected data on 44121 OHCA patients. We identified patients with asystole or PEA as the initial rhythm and excluded cases caused by trauma or drowning. The specificities and positive predictive values (PPVs) were calculated for the guidelines, and the clinical prediction rule for comparison. RESULTS: A total of 20484 patients with non-shockable rhythms were identified; 85% had asystole and 15% PEA. The overall survival to hospital admission was 9% (n=1.861) and 1% (n=231) were alive at 1 month from the arrest. The specificity of the Helsinki guidelines in identifying non-survivors was 71% (95% confidence interval (CI): 65-77%) and the PPV was 99.4% (95% CI: 99.3-99.5), while the corresponding values for the European Resuscitation Council (ERC) was 95% (95% CI: 91.3-97.5) and 99.9% (95% CI: 99.9-99.9) and, for the prediction rule, 99.1% (95% CI: 96.7-99.9) and 99.9% (95% CI: 99.9-100.00), respectively. CONCLUSION: In this comparison study, the Helsinki DNAR guidelines did not perform well enough in a general OHCA material to be widely adopted. The main reason for this was the unpredicted survival of patients with unwitnessed asystole. The clinical prediction rule and the recommendations of the ERC Guidelines worked well.

Overlap technique improves results of primary surgery after obstetric anal sphincter tear.

PURPOSE: This study was designed to evaluate prospectively the results of the overlap technique in primary sphincter reconstruction after obstetric tear. METHODS: Obstetric tears in 44 women were operated on with primary overlap reconstruction. These women were investigated six to nine months after the operation. Results were compared with those of a historical control group of 52 women whose obstetric sphincter rupture had been treated with the end-to-end technique. RESULTS: The overlap group had significantly more incontinence symptoms after delivery and repair of the sphincter tear than before delivery (P < 0.0001); however, their incontinence symptoms were significantly fewer than those of the end-to-end group (P = 0.004). The prevalence of persistent rupture of the external anal sphincter was significantly lower in the overlap group (6/44, 13.6 percent) than in the end-to-end group (39/52, 75 percent; P < 0.0001). Internal anal sphincter rupture occurred in 5 patients (11.4 percent) in the overlap group and in 40 patients (76.9 percent) in the end-to-end group (P < 0.0001). CONCLUSIONS: The overlap technique should be adopted as the method of choice for primary sphincter repair after obstetric tear.

Medical futility in asystolic out-of-hospital cardiac arrest.

OBJECTIVES: To study the factors associated with short- and long-term survival after asystolic out-of-hospital cardiac arrest, with a reference to medical futility. METHODS: This is a retrospective observational study conducted in Helsinki, Finland during 1 January 1997 to 31 December 2005. All out-of-hospital cardiac arrests were prospectively registered in the cardiac arrest database. Of 3291 arrests, 1455 had asystole as the first registered rhythm. These patients represent the study population. RESULTS: A short time interval to the initiation of advanced life support (ALS) was associated with a long-term benefit, but a short first responding unit (FRU) response time had only a short-term benefit. Conversion of asystole into a shockable rhythm provided only a short-term benefit. The prognosis was poor if the FRU response time was over 10 min or the ALS response time was over 11 min in bystander-witnessed arrests, and if the duration of resuscitation was over 8 min in emergency medical services (EMS)-witnessed arrests. Bystander-CPR was associated with increased 30-day mortality. The 30-day survival rate after an unwitnessed arrest (n=548) was 0.5%. All survivors in this group were either hypothermic or were victims of near-drowning. CONCLUSIONS: Resuscitation should be withheld in cases of unwitnessed asystole, excluding cases of hypothermia and near-drowning. The prognosis is poor if the FRU response time is over 10 min or the ALS response time is over 10-15 min in bystander-witnessed arrests. The decision of whether or not to attempt resuscitation should not be influenced by the presence of bystander-CPR. Early initiation of ALS should be prioritised in the treatment of out-of-hospital asystole.

Reaction kinetics of alkyl epoxides with DNA and other nucleophiles.

1,2-Epoxy alkanes from C3 to C8 were reacted with DNA, deoxyguanosine and 4-(p-nitrobenzyl) pyridine (NBP). DNA was hydrolyzed at neutral pH to release 7-alkylguanines. The products were analyzed by HPLC. The epoxides reacted largely according to the chain length, shorter epoxides being more reactive. Substitutions through carbon 1 predominated. Reactivity with NBP was almost equal between the epoxides.

Intercomparison of radiotherapy treatment planning systems for external photon and electron beam dose calculations.

Dose distributions calculated by six different treatment planning systems (TPSs), used by the hospitals in Finland or in Russia, were compared with measured dose distributions. Five typical cases of irradiation were selected: regular fields, oblique incidence, irregular field, wedge field and inhomogeneity in a water equivalent phantom. The beam data for each TPS where those pertaining to the beam where the comparative relative measurements were performed. The results indicate that the dose distributions produced by different TPSs can differ from each other as well as from the measured dose distributions up to a level which is not acceptable in terms of the ICRU recommendations. Greatest differences seem to be related to the omission or undue consideration of the scatter components of the beam.

[Recovery after ketamine-diazepam and thiopental-fentanyl-infusion anesthesia with jet-ventilation for laryngomicroscopy]. / Die Aufwachphase nach Ketamine-Diazepam und Thiopental-Fentanyl-Infusionsanaesthesie bei Injektorbeatmung zur Laryngomikroskopie.

Using two infusion anaesthesiamethods for laryngomicroscopy in 187 non-selected patients we studied the recovery phase with the aid of a special questionnaire filled in by the recovery room nurse. Premedication was with Thalamonal and atropine. Muscle relaxation was achieved by a succinylcholine drip. Induction doses: fentanyl 0.05-0.1 mg and thiopental 3-5 mg/kg bodyweight (Th-group) or diazepam 10-20 mg and ketamine 1 mg/kg bodyweight (K-group). Infusion doses: Thiopental 11.7 mg/min. (Th-group) or diazepam 0.2 mg/min. and ketamine 2 mg/min (K-group). Anaesthesia lasted for 20-30 min. We observed and noted during recovery: Breathing, cough-frequency and -quality, alertness, reaction to speech and stimulation, orientation, motor behaviour and well-being. Anaesthesia was sufficient in both groups. The patients of the K-group woke up earlier and their laryngeal reflexes seemed to stabilize quicker than in the Th-group. Because of the elevation of blood pressure caused by the stimulation of the laryngoscopy both methods are not recommended for patients at risk from high blood pressure.

Cumulative radiation damage and cumulative radiation effect.

Different mathematical formulas capable of replacing CRE have been analyzed. The purpose was to develop an expression which would yield a value identical with CRE for regular treatment schedules, but would represent more clearly and more truthfully the radiation damage of tissue. This quantity has been called cumulative radiation damage (CRD). Its unit is adequately called CRD unit. CRD does not require a separate gap correction, as does CRE, it is easy to use, explicit and unambiguous. CRE, CRD and some other formulas have been compared in different types of radiation therapy.

Impurities of 99mTc-generators.

The impurities present after use in 99Mo- 99mTc-generators produced by four different manufacturers were investigated by means of the energy spectrum and half-life measurements. The generators produced with fission contained only a few impurities, and the half-lives of their nuclides were relatively short. The only generator manufactured using neutron bombardment contained several nuclides whose half-lives were in a range of a few months, but also a 60Co nuclide whose long half-life may give rise to difficulties in destroying the generator.

CRE calculations for different combined radiation therapy schemes of uterine cervical carcinoma.

The CRE concept is not applicable to the assessment of the effect of combined radiotherapy when external and intracavitary radiations are given alternately and with unequal doses. Because of the numerous recurrences, we had to change our radiation treatment schemes for carcinoma cervix uteri, and we attempted, on a theoretical basis, to acquire the same biological effects as Joslin with his own method. In the comparison of different schemes we used as slightly modified approximate CRE and the "nominal dose" presented by Kellerer. In this paper we have presented the treatment schemes we used and the methods for calculating the biological effect in combined treatments. Moreover, we have examined the applicability and compatibility of the above methods in comparing the effects of different combined radiation treatment schemes.

[Our experiences during cannulation of the subclavian vein in children (author's transl)]. / Unsere Erfahrungen mi der Katheterisierung der V. Subclavia bei Kindern.

With 260 children under 12 years of age we tried to cannulate the subclavian vein during 3 years 455 times, and were successful 391 times (85.9%). 43.8% of the patients were younger than 1 year. The success rate correlated to the childrens' bodyweight and was less with lower weight of the patients. - In 68.8% of the cases we found the tip of the cannula in the upper caval vein, 19.9% were in the internal jugular vein, and 6.1% were in the opposite subclavian vein. - In this study participated 7 members of the staff and 8 specializing doctors; catheterizations per participant, mean = 30,2, SD 21,49, minimum 6, maximum 65. - Cannulas functioned for 5 +/- 2, max. 19 days. - The most serious complications were 2 pneumo- and one pneumo-hydrothorax, 2 times suspicion of thrombosis and 1 hemorrhage due to a not known hemophilia. None of the complications caused therapeutical problems.

Residual activity of Tc-generators.

Owing to contamination by long-lived radio-isotopes, the residual activity of an old 99Mo-99mTc generator may be large enough to prevent its disposal. The long-lived impurities of one generator were determined by energy spectrum and half-life measurements. In this generator 46Sc, 51Cr, 60 Co, 92mNb, 95Nb and 124Sb nuclides were found. Only the half-life of 60Co exceeds 3 months, thus a moderately long storage of the generator reduces the activity, and its disposal is then safe.

Methods for measuring the modulation transfer function of gamma camera systems.

The MTFs of three different gamma camera systems have been measured using two methods. In one method a step function was used as the object and the calculations were made by means of a pocket calculator. This method has been compared with a conventional line source method, where a computer is needed in performing the calculations. The methods give the same results with a fairly good accuracy. Both of the methods are well suited to a regular control of the condition and functioning of a gamma camera, provided that the camera is connected to a data-processing system so that the profile curves measured can be converted into the digital form.

Accuracy of computerized radiation treatment planning.

The accuracy of computerized dose planning depends essentially on the computer program. The quickest and simplest way to assess the accuracy of a commercial program is to compare the results of the computer calculations with measured values. The present report deals with the accuracy of the RADPLAN dose planning program in different situations easy to control. The test methods are also applicable to other corresponding systems.