Fatal hypothermia: an analysis from a sub-arctic region

Objectives

To determine the incidence as well as contributing factors to fatal hypothermia.

Study design

Retrospective, registry-based analysis.

Methods

Cases of fatal hypothermia were identified in the database of the National Board of Forensic Medicine for the 4 northernmost counties of Sweden and for the study period 1992–2008. Police reports, medical records and autopsy protocols were studied.

Results

A total of 207 cases of fatal hypothermia were noted during the study period, giving an annual incidence of 1.35 per 100,000 inhabitants. Seventy-two percent occurred in rural areas, and 93% outdoors. Many (40%) were found within approximately 100 meters of a building. The majority (75%) occurred during the colder season (October to March). Some degree of paradoxical undressing was documented in 30%. Ethanol was detected in femoral vein blood in 43% of the victims. Contributing co-morbidity was common and included heart disease, earlier stroke, dementia, psychiatric disease, alcoholism, and recent trauma.

Conclusions

With the identification of groups at high risk for fatal hypothermia, it should be possible to reduce risk through thoughtful interventions, particularly related to the highest risk subjects (rural, living alone, alcohol-imbibing, and psychiatric diagnosis-carrying) citizens.

Reconstructive vascular surgery in diabetic patients with peripheral arterial insufficiency

Peripheral arterial insufficiency in diabetic patients is for vascular surgeons a special problem as there even may be a distal diabetic angiopathy in the leg arteries. Preoperative adequate evaluation and selection of the patients is necessary before vascular reconstruction. Of 100 consecutive patients operated on with femoropopliteal bypass 33 were diabetic and 67 nondiabetic. Eleven of the diabetic patients were one year later asymptomatic, eight improved but eight were amputated.

Hand cold recovery responses before and after 15 months of military training in a cold climate

INTRODUCTION

The ability of fingers to rapidly rewarm following cold exposure is a possible indicator of cold injury protection. We categorized the post-cooling hand-rewarming responses of men before and after participation in 15 mo of military training in a cold environment in northern Sweden to determine: 1) if the initial rewarming category was related to the occurrence of local cold injury during training; and 2) if cold training affected subsequent hand-rewarming responses.

METHODS

Immersion of the dominant hand in 10 degrees C water for 10 min was performed pre-training on 77 men. Of those, 45 were available for successful post-training retests. Infrared thermography monitored the dorsal hand during 30 min of recovery. Rewarming was categorized as normal, moderate, or slow based on mean fingertip temperature at the end of 30 min of recovery (TFinger,30) and the percentage of time that fingertips were vasodilated (%VD).

RESULTS

Cold injury occurrence during training was disproportionately higher in the slow rewarmers (four of the five injuries). Post-training, baseline fingertip temperatures and cold recovery variables increased significantly in moderate and slow rewarmers: TFinger30 increased from 21.9 +/- 4 to 30.4 +/- 6 degrees C (Moderate), and from 17.4 +/- 0 to 22.3 +/- 7 degrees C (Slow); %VD increased from 27.5 +/- 16 to 65.9 +/- 34% (Moderate), and from 0.7 +/- 2 to 31.7 +/- 44% (Slow).

CONCLUSIONS

Results of the cold recovery test were related to the occurrence of local cold injury during long-term cold-weather training. Cold training itself improved baseline and cold recovery in moderate and slow rewarmers.

The effects of a 1-year physical exercise programme on development of fatigue during a simulated ambulance work task

The aim of the study was to evaluate the effects of individually prescribed physical exercise programmes on development of fatigue during the carrying of a loaded stretcher up and down the stairs. Nineteen ambulance personnel performed the training for 1 year. Testing occurred before and after 1 year of the training. Both the training group (n = 19) and the control group (n = 15) were assessed for physical capacity and lactate concentration in blood and ratings of perceived exertion during carrying a stretcher on the stairs. When comparisons were made between those who had been training three times/week for 1 year and the control group, lactate concentration was significantly decreased. In conclusion, markers of fatigue during stretcher carrying can be reduced by the use of individually prescribed physical exercise programmes.

Characteristics of cardiac arrest and resuscitation by age group: an analysis from the Swedish Cardiac Arrest Registry

AIM

The objective of this study was to describe patients who experienced an out-of-hospital cardiac arrest (OHCA) by age group.

METHODS

All patients who suffered from an OHCA between 1990 and 2005 and are included in the Swedish Cardiac Arrest Registry (n = 40,503) were classified into the following age groups: neonates, younger than 1 year; young children, between 1 and 4 years; older children, between 5 and 12 years; adolescents, between 13 and 17 years; young adults, between 18 and 35 years; adults not retired, between 36 and 64 years; adults retired, between 65 and 79 years; and older adults, 80 years or older.

RESULTS

Ventricular fibrillation was lowest in young children (3%) and highest in adults (35%). Survival to 1 month was lowest in neonates (2.6%) and highest in older children (7.8%). Children (<18 years), young adults (18-35 years), and adults (>35 years) survived to 1 month 24.5%, 21.2%, and 13.6% of cases, respectively (P = .0003 for trend) when found in a shockable rhythm. The corresponding figures for nonshockable rhythms were 3.8%, 3.2%, and 1.6%, respectively (P < .0001 for trend).

CONCLUSIONS

There is a large variability in characteristics and outcome among patients in various age groups who experienced an OHCA. Among the large age groups, there was a successive decline in survival with increasing age in shockable and nonshockable rhythms.

Stress monitoring of ambulance personnel during work and leisure time

OBJECTIVES

The aim of the present study was to assess physiological and subjective stress markers during a 24-h ambulance work shift and during the next two work-free days, and relate these parameters to self-reported health complaints.

METHODS

Twenty-six ambulance personnel were followed during a 24-h work shift and during the next two work-free days with electrocardiogram, cortisol assessments and diary notes. The ambulance personnel also performed tests of autonomic reactivity before and at the end of the work shift. The subjects were categorized into two groups according to their number of health complaints.

RESULTS

In general, stress markers did not show differences between the work shift and leisure time. However, a modest deviation in heart rate variability pattern and higher morning cortisol values during work in comparison with work-free days were observed in personnel with many health complaints.

CONCLUSIONS

Subjective and physiological characteristics of ambulance personnel did not indicate distinctive stress during the 24-h work shift. Relationships between frequent health complaints and specific work-related factors require further prospective studies.

Relationships between Work‐related Factors and Disorders in the Neck‐shoulder and Low‐back Region among Female and Male Ambulance Personnel

This cross-sectional study on a random sample of 1,500 ambulance personnel investigated the relationships between self-reported work-related physical and psychosocial factors, worry about work conditions, and musculoskeletal disorders among female and male ambulance personnel. Three different outcomes, complaints, activity limitation, and sick leave, for the neck-shoulder and low-back region, respectively, were chosen. Among the female personnel, physical demands was significantly associated with activity limitation in the neck-shoulder (OR 4.13) and low-back region (OR 2.17), and psychological demands with neck-shoulder (OR 2.37) and low-back (OR 2.28) complaints. Among the male personnel, physical demands was significantly associated with low-back complaints (OR 1.41) and activity limitation (OR 1.62). Psychological demands and lack of social support were significantly associated with neck-shoulder complaints (OR 1.86 and OR 1.58, respectively) and activity limitation (OR 3.46 and OR 1.71) as well as activity limitation due to low-back complaints (OR 2.22 and OR 1.63). Worry about work conditions was independently associated with activity limitation due to low-back complaints among the female (OR 5.28), and to both neck-shoulder and low-back complaints (OR 1.79 and OR 2.04, respectively) and activity limitation (OR 2.32 and OR 1.95) among the male personnel. In conclusion, the association patterns between physical and psychological demands and MSDs suggest opportunities for intervention.

Efficacy of bystander CPR: Intervention by lay people and by health care professionals

BACKGROUND

Early cardiopulmonary resuscitation (CPR) by bystanders prior to the arrival of the rescue team has been shown to be associated with increased survival after out-of-hospital cardiac arrest. The aim of this survey was to evaluate the impact on survival of no bystander CPR, lay bystander CPR and professional bystander CPR.

METHODS

Patients suffering an out-of-hospital cardiac arrest in Sweden between 1990 and 2002 who were given CPR and were not witnessed by the ambulance crew were included.

RESULTS

In all, 29,711 patients were included, 36% of whom received bystander CPR prior to the arrival of the rescue team. Among the latter, 72% received CPR from lay people and 28% from professionals. Survival to 1 month was 2.2% among those who received no bystander CPR, 4.9% among those who received bystander CPR from lay people (p<0.0001) and 9.2% among those who received bystander CPR from professionals (p<0.0001 compared with bystander CPR by lay people). In a multivariate analysis, lay bystander CPR was associated with improved survival compared to no bystander CPR (OR: 2.04; 95% CI: 1.72-2.42), and professional bystander CPR was associated with improved survival compared to lay bystander CPR (OR: 1.37; 95% CI: 1.12-1.67).

CONCLUSION

Among patients suffering an out-of-hospital cardiac arrest, bystander CPR by lay persons (excluding health care professionals) is associated with an increased chance of survival. Furthermore, there is a distinction between lay persons and health care providers; survival is higher when the latter perform bystander CPR. However, these results may not be explained by differences in the quality of CPR.

Work-related psychosocial factors, worry about work conditions and health complaints among female and male ambulance personnel

This study aimed at investigating the relationships between work-related psychosocial factors, worry about work conditions and health complaints (sleeping problems, headache and stomach symptoms) among female and male ambulance personnel. Out of 4000 ambulance personnel in Sweden, 1500 (300 female and 1200 male personnel) were randomly selected. They answered a questionnaire including items on self-reported health complaints, individual characteristics, work-related psychological demands, decision latitude, social support and worry about work conditions. Twenty-five per cent of the female and 20% of the male ambulance personnel reported two or more health complaints sometimes or often. According to the demand-control-support questionnaire, ambulance personnel reported a generally positive psychosocial work environment, although psychological demands were associated with sleeping problems, headache and stomach symptoms among both female and male ambulance personnel. Another factor that was significantly associated with health complaints among both genders was worry about work conditions. When worry about work conditions was added to the regression models, this variable took over the role from psychological demands as a predictor for health complaints among the female ambulance personnel. The prevalence of sleeping problems, headache and stomach symptoms were significantly associated with psychological demands among both female and male ambulance personnel. Notably, worry about work conditions seems to be an important risk factor for health complaints. This suggests that worry about work conditions should not be neglected when considering risk factors among ambulance personnel.

Changes in demographic factors and mortality after out-of-hospital cardiac arrest in Sweden

OBJECTIVE

To describe changes between 1992 and 2003 in age, sex, factors at resuscitation and survival among patients suffering from out-of-hospital cardiac arrest in Sweden.

METHODS

This was a prospective observational study including various ambulance organizations in Sweden. Patients suffering from out-of-hospital cardiac arrest between 1992 and 2003 included in the Swedish Cardiac Arrest Registry were followed for survival to 1 month.

RESULTS

In all 19 791 cases took part in the survey. There was a slight increase in mean age from 68 to 70 years (P = 0.025) and an increase of females from 29 to 32% (P = 0.0001). There was a change in witnessed status (P < 0.0001) with an increase in crew-witnessed cases and a decrease in non-witnessed cases. There was a decrease in cases of a cardiac etiology from 75 to 61% (P < 0.0001) and a decrease in the percentage found in ventricular fibrillation from 36 to 25% (P < 0.0001). When crew-witnessed cases were excluded the proportion receiving bystander cardiopulmonary resuscitation (CPR) increased from 30 to 42% (P < 0.0001). There was a slight increase in the overall proportion of patients hospitalized alive from 16 to 20% (P = 0.032). There was no significant change in the overall proportion of survivors at 1 month after cardiac arrest (4.5% in 1992 and 5.0% in 2003).

CONCLUSIONS

Among patients suffering from out-of-hospital cardiac arrest in Sweden some changes took place. The most important ones were a decrease in the proportion of patients found in ventricular fibrillation and an increase in the proportion of patients receiving bystander CPR. The proportion of patients admitted alive to hospital increased moderately, whereas the proportion of patients alive after 1 month remained unchanged.

Factors associated with an increased chance of survival among patients suffering from an out-of-hospital cardiac arrest in a national perspective in Sweden

AIM

To describe factors associated with an increased chance of survival among patients suffering from an out-of-hospital cardiac arrest in Sweden.

PATIENTS AND METHODS

All patients suffering from an out-of-hospital cardiac arrest, which were not crew witnessed, in Sweden and in whom cardiopulmonary resuscitation (CPR) was attempted and who were registered in the Swedish Cardiac Arrest Registry. This registry covers about 85% of the Swedish population and has been running since 1990.

RESULTS

In all, 33,453 patients, 71% of whom had a cardiac etiology, were included in the survey. The following were independent predictors for an increased chance of survival in order of magnitude: (1) patients found in ventricular fibrillation (odds ratio [OR] 5.3, 95% confidence limits [CL] 4.2-6.8), (2) the interval between call for and arrival of the ambulance less than or equal to the median (OR 3.6, 95% CL 2.9-4.6), (3) cardiac arrest occurred outside the home (OR 2.2, 95% CL 1.9-2.7), (4) cardiac arrest was witnessed (OR 2.0, 95% CL 1.6-2.7), (5) bystanders performing CPR before the arrival of the ambulance (OR 2.0, 95% CL 1.7-2.4), and (6) age less than or equal to the median (OR 1.6, 95% CL 1.4-2.0). When none of these factors were present, survival to 1 m was 0.4%; when all factors were present, survival was 23.8%.

CONCLUSION

Among patients suffering from an out-of-hospital cardiac arrest, which were not crew witnessed, in Sweden and in whom CPR was attempted, 6 factors for an increased chance of survival could be defined. These include (1) initial rhythm, (2) delay to arrival of the rescue team, (3) place of arrest, (4) witnessed status, (5) bystander CPR, and (6) age.

Decrease in the occurrence of ventricular fibrillation as the initially observed arrhythmia after out-of-hospital cardiac arrest during 11 years in Sweden

AIM

To describe the change in the occurrence of ventricular fibrillation as initially observed arrhythmia among patients suffering from out-of-hospital cardiac arrest in Sweden.

PATIENTS

All patients included in the Swedish cardiac arrest registry between 1991 until 2001. The registry covers 85% of the population in Sweden.

METHODS

All patients with bystander witnessed out-of-hospital cardiac arrest included in the Swedish Cardiac Arrest Registry between 1991 and 2001 from the same ambulance organisation each year were included in the survey.

RESULTS

Over 11 years, among patients in Sweden with a bystander witnessed out-of-hospital cardiac arrest in whom cardiopulmonary resuscitation (CPR) was attempted (n = 9666), the occurrence of ventricular fibrillation as the initially obseved arrhythmia decreased from 45% in 1991 to 28% in 2001 (P < 0.0001) if the arrest occurred at home, and from 57% to 41% if the arrest occurred outside home (P < 0.0001). This was found despite the fact that the proportion who received bystander CPR increased from 29% in 1991 to 39% in 2001 if the arrest occurred at home (P < 0.0001) and from 54% to 60% if the arrest occurred outside home (NS). There was a significant increase in age among patients with out-of-hospital cardiac arrest at home, no change in the estimated interval between collapse and call but an increase in the interval between call and arrival of the ambulance among patients with out-of-hospital cardiac arrest outside home.

CONCLUSION

During 11 years in Sweden, there was a marked decrease in the proportion of patients found in ventricular fibrillation among patients with a bystander witnessed cardiac arrest regardless whether the arrest occurred at home or outside home. A modest increase in age and interval between call for, and arrival of, the ambulance was associated with these findings.

Is female sex associated with increased survival after out-of-hospital cardiac arrest?

AIM

To evaluate survival after out-of-hospital cardiac arrest in relation to sex.

METHODS

All patients with out-of-hospital cardiac arrest included in the Swedish Cardiac Arrest Registry between 1990 and 2000 in whom cardiopulmonary resuscitation (CPR) was attempted and who did not have a crew witnessed arrest were included. The registry covers 85% of the inhabitants of Sweden (approximately 8 million inhabitants). P-values were adjusted to differences in age. Survival was defined as patients being hospitalised alive and being alive one month after cardiac arrest. In all, 23,797 patients participated in the survey of which 27.9% were women.

RESULTS

Among women 16.4% were hospitalised alive versus 13.2% among men ( P<0.001). After one month 3.0% among women were alive versus 3.4% among men (NS). In a multivariate analysis considering differences in age and various factors at resuscitation female sex was an independent predictor for patients being hospitalised alive (odds ratio 1.66; 95% confidence limits 1.49-1.84) and for being alive after one month (odds ratio 1.27; 95% confidence limits 1.03-1.56). Women differed from men as they were older ( P<0.001 ), had a lower prevalence of witnessed cardiac arrest ( P=0.01), a lower occurrence of bystander CPR (P<0.001), a lower occurrence of ventricular fibrillation as initial arrhythmia (P<0.001) and a lower occurrence of cardiac disease judged to be the cause of cardiac arrest ( P<0.0001 ). On the other hand they had a cardiac arrest at home more frequently ( P<0.001 ).

CONCLUSION

Among patients suffering out-of-hospital cardiac arrest in Sweden which was not crew witnessed and in whom resuscitation efforts were attempted, female sex was associated with an increased survival.

A short delay from out of hospital cardiac arrest to call for ambulance increases survival

AIM

To describe the relative impact on survival of the delay from estimated time of collapse to call for an ambulance among patients who suffer from a bystander witnessed out of hospital cardiac arrest of a cardiac aetiology.

METHODS

A majority of all ambulance organizations in Sweden (covering 85% of Sweden inhabitants) participate in a National survey of out of hospital cardiac arrest.

RESULTS

In all there were 9340 patients with a bystander witnessed cardiac arrest of a cardiac aetiology in whom cardiopulmonary resuscitation (CPR) was attempted participating in this survey. Survival at one month among patients with a delay between estimated time of collapse and call for ambulance of < or =4 min (median) was 6.9% versus 2.8% among patients with a median of >4 min (P<0.0001). When adjusting for age, sex, initial rhythm, estimated interval between collapse and start of CPR, place of arrest and the interval between call for ambulance and arrival of the rescue team, the odds ratio for survival was 0.70 (0.95% CI. 0.58-0.84) per unit increase of the natural logarithm of delay in minutes between collapse and call.

CONCLUSION

Among patients with a bystander witnessed out of hospital cardiac arrest of a cardiac aetiology increased delay from estimated time of collapse to call for an ambulance decreased the chance of survival.

Presence of Chlamydia pneumoniae in abdominal aortic aneurysms is not associated with increased activity of matrix metalloproteinases

OBJECTIVE

to test the hypothesis that the presence of Chlamydia pneumoniae (C. pneumoniae) in the wall of abdominal aortic aneurysms (AAA) is associated with increased activity of matrix metalloproteinase (MMP)-2 and/or MMP-9.

DESIGN

case-control study.

MATERIAL AND METHODS

in a series of 40 patients with AAA > or =5cm in maximal cross-sectional diameter, C. pneumoniae-DNA was identified in the aneurysm wall by nested PCR in 14 (35%) patients. Another 14 C. pneumoniae-DNA-negative AAA patients from the same series, matched for gender and aneurysm diameter, were used as controls. In each group there were 7 asymptomatic (aAAA) and 7 ruptured (rAAA) aneurysms. MMP-2 and -9 activity was estimated in AAA wall biopsies by gelatin zymography.

RESULTS

patients with a C. pneumoniae-DNA-positive aneurysm wall specimen showed an over-all lower activity of MMP-2 and MMP-9 (pro- and active enzyme) compared to the C. pneumoniae-DNA negative patients. However, there were no statistically significant differences in MMP activity between the two groups of patients with aAAA. Among patients with rAAA both pro-MMP-9 (p=0,026) and active-MMP-9 (p=0.007) were significantly lower in C. pneumoniae-DNA-positive patients compared to C. pneumoniae-DNA-negative patients, whereas there were no significant differences in pro-MMP-2 or active-MMP-2.

CONCLUSION

this preliminary study does not support the hypothesis that the presence of C. pneumoniae in the AAA wall is associated with increased activity of MMP-2 and MMP-9.

Intestinal pHi studied with continuous saline tonometry during ischaemia and reperfusion in the pig

OBJECTIVE

To evaluate continuous saline tonometry for detection of progressive intestinal ischaemia and reperfusion in a porcine model.

DESIGN

In eight anaesthetised pigs, small bowel mucosal pCO2 was recorded by means of two identical equipments for continuous saline tonometry and a standard tonometry balloon during ischaemia and reperfusion.

RESULTS

Both systems of saline tonometry functioned stably during the four hour protocol ischaemia, although not significant until after 45 min for one of the tonometers.

CONCLUSION

The equipment for continuous saline tonometry has a good reactivity, an accuracy comparable with standard tonometry.

Proteolysis of the abdominal aortic aneurysm wall and the association with rupture

PURPOSE

to investigate proteolysis of the abdominal aortic aneurysm (AAA) wall and the association with rupture.

METHODS

levels of matrix metalloproteinases (MMP-2 and MMP-9) and tissue inhibitor of metalloproteinases (TIMP-1 and TIMP-2) were measured in the walls of medium-sized (5-7 cm in diameter) ruptured AAA (rAAA) (n =30) and large (> or = 7 cm in diameter) asymptomatic AAA (aAAA) (n=30).

RESULTS

MMP-2 levels (median, range) were significantly higher in the walls of large aAAA (165 ng/g AAA tissue, 50-840) than from medium-sized rAAA (110 ng/g AAA tissue, 47-547, p=0.007). MMP-9 levels were significantly higher in the walls of medium-sized rAAA (107 ng/g AAA tissue, 19-582) than from large aAAA (55 ng/g AAA tissue, 11-278, p=0.012). TIMP-1 and TIMP-2 levels were equivalent. There was a positive correlation between MMP-2 and the diameter of aAAA (r=0.54, p=0.002), but a negative correlation with MMP-9 (r= -0.44, p=0.017). No significant correlations were found between aAAA diameter and TIMP-1 or TIMP-2.

CONCLUSION

AAA rupture is associated with higher levels of MMP-9. There is no association with TIMP-1 or TIMP-2 levels. MMP-2 levels are positively, whereas MMP-9 levels are negatively, correlated with aAAA size. MMP-9 may play a role in the progression towards rupture, whereas MMP-2 may play a role in expansion.

In vitro degradation of aortic elastin by Chlamydia pneumoniae

OBJECTIVES

to investigate whether Chlamydia pneumoniae (C. pneumoniae) may increase elastin degradation in the aortic wall.

MATERIALS AND METHODS

eighteen full thickness aortic wall samples from non-aneurysmal infrarenal abdominal aortas were collected from autopsies. Two adjacent and equally large pieces were cut out of each aortic sample. From each sample, one piece was incubated in a HEp-2 cell culture infected with C. pneumoniae and the other piece was incubated in an uninfected HEp-2 cell culture. The incubation time was one week at 35 degrees C. The concentration of elastin-derived peptides (EDP) (ng/ml) in the medium of each cell culture was measured in duplicate. For each paired sample, delta-EDP (EDP in HEp-2 cell culture infected with C. pneumoniae- EDP in uninfected HEp-2 cell culture) was calculated.

RESULT

there was a significantly increased degradation of aortic elastin, estimated by EDP concentrations in cell culture conditioned medium, when aortic wall samples were incubated in C. pneumoniae cultures compared with uninfected cultures (p=0.025, Wilcoxon signed ranks test).

CONCLUSION

these results indicate that there is a relationship between the presence of C. pneumoniae and increased elastin degradation in the aortic wall in vitro. This suggests C. pneumoniae in the aortic wall directly or indirectly leads to the degradation of aortic elastin.

Validation of a novel method for continuous saline tonometry in a porcine model

Only intermittent and semi-continuous tonometric measurement of gastric and intestinal pHi is possible with the equipment available today. Earlier we developed a system for continuous saline tonometry and tested it in vitro. To assess the in vivo reliability of this method for continuous gastrointestinal saline tonometry, a standard tonometer for measurement of intestinal pCO2 and corresponding pHi was modified to allow continuous perfusion of physiological saline in a closed system and tested in a porcine model. In 11 anaesthetized and haemodynamically stable pigs, two continuous tonometry balloons were inserted into the distal small bowel, and a standard tonometry balloon was used as reference. To test long-term function of the continuous tonometers the research protocol lasted for eight hours. The two continuous saline tonometers performed well, and after an equilibration time of three hours the mean pHi values were stable between 7.35 and 7.43 and between 7.32 and 7.39 respectively. The standard tonometer measured stable pHi values. These preliminary studies indicate that continuous saline tonometry performs well over eight hours with a small bias and a good precision.

Serum levels of elastin-derived peptides in patients with ruptured and asymptomatic abdominal aortic aneurysms

OBJECTIVE

to determine whether serum elastin-derived peptides (S-EDP), are lower in patients with ruptured abdominal aortic aneurysms (rAAA) than asymptomatic (aAAA).

MATERIALS AND METHODS

serum samples were collected preoperatively from 45 consecutive patients with aAAA and 15 haemodynamically stable patients with rAAA. S-EDP (ng/ml) was measured by a competitive enzyme-linked immunosorbent assay (ELISA).

RESULTS

S-EDP (mean +/- s.d.) was significantly lower in patients with rAAA (31.6 ng/ml +/- 6.8) than in patients with aAAA (39.4 ng/ml +/- 8.0 p=0.001).

CONCLUSION

patients with rAAA had significantly lower levels of S-EDP than patients with aAAA. The possibility that S-EDP can be used to identify patients at increased risk of rupture requires further investigation.

Geriatric-based versus general wards for older acute medical patients: a randomized comparison of outcomes and use of resources

BACKGROUND

The effects of residence in an acute geriatrics-based ward (AGW) with emphasis on early rehabilitation and discharge planning for older patients with acute medical illnesses were assessed. Outcome and use of resources were compared with those of patients treated in general medical wards (MWs). A per-protocol rather than intention-to-treat analysis was performed.

METHODS

A randomized trial with 3-months follow-up. A total of 190 patients aged 70 years and older were randomized to an acute geriatrics-based ward, and 223 patients were randomized to general medical wards.

RESULTS

The two groups were comparable at inclusion. However, after care in the AGW, 71% of patients could be discharged directly home compared with 64% of those treated in MWs (relative risk 1.17; 95% CI, 0.93-1.49). The length of stay was shorter in the AGW (mean 5.9 vs 7.3 days; P = .002). The proportion of patients in geriatric or other hospital wards or in nursing homes did not differ, but the proportion of AGW patients in sheltered living tended to be lower (P = .085). At the follow-up, case fatality, ADL function, psychological well-being, need for daily personal assistance, drug consumption, need for readmission to hospital, and total health care costs after discharge did not differ between the two groups. Poor global outcome was observed in 37% of AGW and 34% of MW patients.

CONCLUSIONS

A geriatric approach with greater emphasis on early rehabilitation and discharge planning in the AGW shortened the length of hospital stay and may have reduced the need for long-term institutional living. This occurred despite patients in an acute geriatric ward not having better medical or functional outcome than older acute patients treated in general medical wards.

Activity of matrix metalloproteinase-2 and -9 in abdominal aortic aneurysms. Relation to size and rupture

OBJECTIVES

to investigate the activity of matrix metalloproteinase (MMP)-2 and -9 in asymptomatic abdominal aortic aneurysms (aAAAs) and ruptured abdominal aortic aneurysms (rAAAs).

DESIGN

cross-sectional study.

MATERIALS AND METHODS

MMP-2 and MMP-9 activity was estimated in biopsies from the anterior wall of 60 AAAs using gelatin zymography. There were 20 medium-sized (diameter 5<7 cm) aAAAs, 20 large (>57 cm) aAAAs and 20 rAAAs. MMP activity was quantified using a laser densitometer and expressed as arbitrary units (au).

RESULTS

mean (SEM) MMP-9 activity was significantly lower in large aAAAs (1190 au +/-247) than in rAAAs (2647 au +/-498, p<0.05). There was no difference in MMP-2 activity.

CONCLUSION

High MMP-9 activity in the AAA wall is associated with rupture.

A new method for continuous tonometric pCO2 measurement--in vitro studies

The available methods for tonometric pCO2 measurement only provide the possibility of performing intermittent registrations. A new method allowing continuous tonometric pCO2 measurement has been developed and tested in an in vitro model. A standard tonometer for intestinal pCO2 measurement was modified to allow continuous perfusion of the balloon with physiological saline solution in a closed system. The pCO2 in the system was determined in a specially constructed measurement chamber with a TCM20 percutaneous pCO2 monitor. In this in vitro model the tonometer balloon was placed in a saline bath with a constant pCO2 concentration and the measurements from the closed circulating system were compared with those obtained from a standard tonometer placed in the same bath. In 8 and 24 h experiments the circulating system measured the pCO2 value as accurately and reliably as traditional tonometry. This study indicates that the new method makes continuous monitoring of pCO2 possible.

A tactile sensor for detection of physical properties of human skin in vivo

A spring loaded tactile sensor with displacement sensing has been evaluated for non-invasive assessment of physical properties, stiffness and elasticity, of human skin in vivo. The tactile sensor consists of a peizoelectric vibrator (61 kHz) with a vibration pickup, electronics and PC with software for measurement of the change in frequency when the sensor is attached to an object. Integrated with the tactile sensor is a displacement sensor that shows the compression of the spring that loads the sensor element against the object during measurement. Under certain conditions (e.g. fixed contact pressure) this change in frequency monitors the acoustic impedance of the object and is related to the stiffness of soft tissue. The experimental results on silicone gum and on healthy Japanese and Swedish women indicated that the instrument was able to detect changes in stiffness and elastic related properties of human skin, related to age, day-to-day variations and application of cosmetics. The instrument was concluded to be easy to handle and suitable for field work.

Non-invasive assessment of intercompartmental fluid shifts in burn victims

Two non-invasive methods (the bioimpedance technique, BIA, and the impression method, IM) were studied, to find out whether they are sensitive enough to detect and chronicle the development of the oedema and fluid resuscitation effects (Parkland formula) that occur secondary to a major burn. Ten patients with a total burned body surface area (TBSA) of more than 10% were included in this prospective study. Total body water (TBW), as measured by the resistance (BIA) or F(0) variable (IM), reached a maximum on day 2. The tissue fluid translocation (INT) variable (IM) followed a different course, increasing slowly to reach a maximum on day 6, when it was 40% higher than the 12 h value. TBW and the interstitial translocatable fluid were still increased 1 week post-burn. The non-invasive measurements of TBW (resistance by BIA and F(0) by IM) reflected the anticipated changes in TBW. The phase angle (BIA) indicative of cellular membrane effects of burn and sepsis had its lowest values at day 1.5, and stayed significantly low until day 4. Interestingly, the phase angle was lowest in the two cases that died subsequently. The different time course of the INT value (IM), which reflected the translocatable interstitial fluid volume in skin, may be the result of resuscitation fluid remaining in this compartment, due to the excess sodium content together with a possible change in tissue compliance secondary to the early total water peak on day 2.