Respiratory and circulatory insufficiency during emergent long-distance critical care interhospital transports to tertiary care in a sparsely populated region: a retrospective analysis of late mortality risk.

OBJECTIVES: To test if impaired oxygenation or major haemodynamic instability at the time of emergency intensive care transport, from a smaller admitting hospital to a tertiary care centre, are predictors of long-term mortality. DESIGN: Retrospective observational study. Impaired oxygenation was defined as oxyhaemoglobin %-inspired oxygen fraction ratio (S/F ratio)<100. Major haemodynamic instability was defined as a need for treatment with norepinephrine infusion to sustain mean arterial pressure (MAP) at or above 60 mm Hg or having a mean MAP <60. Logistic regression was used to assess mortality risk with impaired oxygenation or major haemodynamic instability. SETTING: Sparsely populated Northern Sweden. A fixed-wing interhospital air ambulance system for critical care serving 900 000 inhabitants. PARTICIPANTS: Intensive care cases transported in fixed-wing air ambulance from outlying hospitals to a regional tertiary care centre during 2000-2016 for adults (16 years old or older). 2142 cases were included. PRIMARY AND SECONDARY OUTCOME MEASURES: All-cause mortality at 3 months after transport was the primary outcome, and secondary outcomes were all-cause mortality at 1 and 7 days, 1, 6 and 12 months. RESULTS: S/F ratio <100 was associated with increased mortality risk compared with S/F>300 at all time-points, with adjusted OR 6.3 (2.5 to 15.5, p<0.001) at 3 months. Major haemodynamic instability during intensive care unit (ICU) transport was associated with increased adjusted OR of all-cause mortality at 3 months with OR 2.5 (1.8 to 3.5, p<0.001). CONCLUSION: Major impairment of oxygenation and/or major haemodynamic instability at the time of ICU transport to get to urgent tertiary intervention is strongly associated with increased mortality risk at 3 months in this cohort. These findings support the conclusion that these conditions are markers for many fold increase in risk for death notable already at 3 months after transport for patients with these conditions.

Total Mission Time and Mortality in a Regional Interhospital Critical Care Transport System: A Retrospective Observational Study.

OBJECTIVE: We assessed the mortality risk related to the time for intensive care unit transport in a geographically large regional health care system. METHODS: Patient-level data from critical care ambulance missions were analyzed for 2,067 cases, mission time, and relevant patient factors. Mission time was used as a surrogate for the "distance" to tertiary care, and mortality at 7 days and other intervals was assessed. RESULTS: No increased mortality risk was found at 7 days in an unadjusted regression analysis (odds ratio = 1.00; range, 0.999-1.002; P = .66). In a secondary analysis, an increased mortality risk was observed in longer mission time subgroups and at later mortality assessment intervals (> 375 mission minutes and 90-day mortality; adjusted hazard ratio = 1.56; range, 1.07-2.28; P = .02). Negative changes in oxygenation and hemodynamic status and transport-related adverse events were associated with the longest flight times. Measurable but small changes during flight were noted for mean arterial pressure and oxygenation. CONCLUSION: The main finding was that there was no overall difference in mortality risk based on mission time. We conclude that transport distances or accessibility to critical care in the tertiary care center in a geographically large but sparsely populated region is not clearly associated with mortality risk.

Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation.

BACKGROUND: Post-craniotomy intracranial air can be present in patients scheduled for air ambulance transport to their home hospital. We aimed to assess risk for in-flight intracranial pressure (ICP) increases related to observed intracranial air volumes, hypothetical sea level pre-transport ICP, and different potential flight levels and cabin pressures. METHODS: A cohort of consecutive subdural hematoma evacuation patients from one University Medical Centre was assessed with post-operative intracranial air volume measurements by computed tomography. Intracranial pressure changes related to estimated intracranial air volume effects of changing atmospheric pressure (simulating flight and cabin pressure changes up to 8000 ft) were simulated using an established model for intracranial pressure and volume relations. RESULTS: Approximately one third of the cohort had post-operative intracranial air. Of these, approximately one third had intracranial air volumes less than 11 ml. The simulation estimated that the expected changes in intracranial pressure during 'flight' would not result in intracranial hypertension. For intracranial air volumes above 11 ml, the simulation suggested that it was possible that intracranial hypertension could develop 'inflight' related to cabin pressure drop. Depending on the pre-flight intracranial pressure and air volume, this could occur quite early during the assent phase in the flight profile. DISCUSSION: These findings support the idea that there should be radiographic verification of the presence or absence of intracranial air after craniotomy for patients planned for long distance air transport. CONCLUSIONS: Very small amounts of air are clinically inconsequential. Otherwise, air transport with maintained ground-level cabin pressure should be a priority for these patients.

Evacuation Preparedness in the Event of Fire in Intensive Care Units in Sweden: More is Needed.

Introduction Hospitals, including intensive care units (ICUs), can be subject to threat from fire and require urgent evacuation. Hypothesis The hypothesis was that the current preparedness for ICU evacuation for fire in the national public hospital system in a wealthy country was very good, using Sweden as model. METHODS: An already validated questionnaire for this purpose was adapted to national/local circumstances and translated into Swedish. It aimed to elicit information concerning fire response planning, personnel education, training, and exercises. Questionnaire results (yes/no answers) were collected and answers collated to assess grouped responses. Frequencies of responses were determined. RESULTS: While a written hospital plan for fire response and evacuation was noted by all responders, personnel familiarity with the plan was less frequent. Deficiencies were reported concerning all categories: lack of written fire response plan for ICU, lack of personnel education in this, and lack of practical exercises to practice urgent evacuation in the event of fire. CONCLUSIONS: These findings were interpreted as an indication of risk for worse consequences for patients in the event of fire and ICU evacuation among the hospitals in the country that was assessed, despite clear regulations and requirements for these. The exact reasons for this lack of compliance with existing laws was not clear, though there are many possible explanations. To remedy this, more attention is needed concerning recognizing risk related to lack of preparedness. Where there exists a goal of high-quality work in the ICU, this should include general leadership and medical staff preparedness in the event of urgent ICU evacuation. Löfqvist E , Oskarsson A , Brändström H , Vuorio A , Haney M . Evacuation preparedness in the event of fire in intensive care units in Sweden: more is needed. Prehosp Disaster Med. 2017;32(3):317-320.

Simulated flying altitude and performance of continuous positive airway pressure devices.

INTRODUCTION: Continuous positive airway pressure (CPAP) is used in air ambulances to treat patients with impaired oxygenation. Differences in mechanical principles between CPAP devices may affect their performance at different ambient air pressures, as will occur in an air ambulance during flight. METHODS: Two different CPAP systems, a threshold resistor device and a flow resistor device, at settings of 5 and 10 cm H2O were examined. Static pressure, static airflow, and pressure during simulated breathing were measured at ground level and at three different altitudes [2400 m (7874 ft), 3000 m (9843 ft), and 10,700 m (35,105 ft)]. RESULTS: When altitude increased, the performance of the two CPAP systems differed during both static and simulated breathing pressure measurements. With the threshold resistor CPAP, measured pressure levels were close to the preset CPAP level. Static pressure decreased 0.71 ± 0.35 cm H2O at CPAP 10 cm H2O compared to ground level and 35,105 ft (10,700 m). With the flow resistor CPAP, as the altitude increased, CPAP produced pressure levels increased. At 35,105 ft (10,700 m), the increase was 5.13 ± 0.33 cm H2O at CPAP 10 cm H2O. DISCUSSION: The velocity of airflow through the flow resistor CPAP device is strongly influenced by reduced ambient air pressure, leading to a higher delivered CPAP effect than the preset CPAP level. Threshold resistor CPAP devices seem to have robust performance regardless of altitude. Thus, the threshold resistor CPAP device is probably more appropriate for CPAP treatment in an air ambulance cabin, where ambient pressure will vary during patient transport.

Regional intensive care transports: a prospective analysis of distance, time and cost for road, helicopter and fixed-wing ambulances.

BACKGROUND: There are three different types of ambulance systems, all of which can manage the same secondary intensive care patient transport mission: road ambulance, rotor-wing ambulance, and fixed-wing ambulance. We hypothesized that costs for specific transport distances would differ between systems. We aimed to analyze distances and observed times for ambulance intensive care secondary transport missions together with system costs to assess this. METHODS: We prospectively collected data for consecutive urgent intensive care transports into the regional tertiary care hospital in the northern region of Sweden. Distances and transport times were gathered, and a cost model was generated based on these together with fixed and operating costs from the three different ambulance systems. Distance-cost and time-cost estimations were then generated for each transport system. RESULTS: Road ambulance cost relatively less for shorter distances (within 250 kilometers/155 miles) but were relatively time ineffective. The rotor-wing systems were most expensive regardless of distance; but were most time-effective up to 400-500 km (248-310 miles). Fixed-wing systems were more cost-effective for longer distance (300 km/186 miles), and time effective for transports over 500 km (310 miles). CONCLUSIONS: In summary, based on an economic model developed from observed regional ICU patient transports, and cost estimations, different ambulance system cost-distances could be compared. Distance-cost and time results show that helicopters can be effective up to moderate ICU transport distances (400-500), though are expensive to operate. For longer ICU patient transports, fixed-wing transport systems are both cost and time effective compared to helicopter-based systems.

Accidental cold-related injury leading to hospitalization in northern Sweden: an eight-year retrospective analysis.

BACKGROUND: Cold injuries are rare but important causes of hospitalization. We aimed to identify the magnitude of cold injury hospitalization, and assess causes, associated factors and treatment routines in a subarctic region. METHODS: In this retrospective analysis of hospital records from the 4 northernmost counties in Sweden, cases from 2000-2007 were identified from the hospital registry by diagnosis codes for accidental hypothermia, frostbite, and cold-water drowning. Results were analyzed for pre-hospital site events, clinical events in-hospital, and complications observed with mild (temperature 34.9 - 32°C), moderate (31.9 - 28°C) and severe (<28°C), hypothermia as well as for frostbite and cold-water drowning. RESULTS: From the 362 cases, average annual incidences for hypothermia, frostbite, and cold-water drowning were estimated to be 3.4/100,000, 1.5/100,000, and 0.8/100,000 inhabitants, respectively. Annual frequencies for hypothermia hospitalizations increased by approximately 3 cases/year during the study period. Twenty percent of the hypothermia cases were mild, 40% moderate, and 24% severe. For 12%, the lowest documented core temperature was 35°C or higher, for 4% there was no temperature documented. Body core temperature was seldom measured in pre-hospital locations. Of 362 cold injury admissions, 17 (5%) died in hospital related to their injuries. Associated co-factors and co-morbidities included ethanol consumption, dementia, and psychiatric diagnosis. CONCLUSIONS: The incidence of accidental hypothermia seems to be increasing in this studied sub-arctic region. Likely associated factors are recognized (ethanol intake, dementia, and psychiatric diagnosis).

Autonomic nerve system responses for normal and slow rewarmers after hand cold provocation: effects of long-term cold climate training.

PURPOSE: Differences among individuals concerning susceptibility to local cold injury following acute cold exposure may be related to function of the autonomic nervous system. We hypothesized that there are differences in heart rate variability (HRV) between individuals with normal or more pronounced vasoconstriction following cold exposure and that there is an adaptation related to prolonged cold exposure in autonomic nervous system response to cold stimuli. METHODS: Seventy-seven young men performed a cold provocation test, where HRV was recorded during cold hand immersion and recovery. Forty-three subjects were re-examined 15 months later, with many months of cold weather training between the tests. Subjects were analyzed as 'slow' and 'normal' rewarmers according to their thermographic rewarming pattern. RESULTS: For the 'pre-training' test, before cold climate exposure, normal rewarmers had higher power for low-frequency (PLF) and high-frequency (PHF) HRV components during the cold provocation test (ANOVA for groups: p = 0.04 and p = 0.005, respectively). There was an approximately 25 % higher PHF at the start in normal rewarmers, in the logarithmic scale. Low frequency-to-high frequency ratio (PLF/PHF) showed lower levels for normal rewarmers (ANOVA for groups: p = 0.04). During the 'post-training' cold provocation test, both groups lacked the marked increase in heart rate that occurred during cold exposure at the 'pre-training' setting. After cold acclimatization (post-training), normal rewarmers showed lower resting power values for the low-frequency and high-frequency HRV components. After winter training, the slow rewarmers showed reduced low-frequency power for some of the cold provocation measurements but not all (average total PLF, ANOVA p = 0.05), which was not present before winter training. CONCLUSIONS: These HRV results support the conclusion that cold adaptation occurred in both groups. We conclude that further prospective study is needed to determine whether cold adaptation provides protection to subjects at higher risk for cold injury, that is, slow rewarmers.

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.

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.

KAMEDO Report No. 91: 2004 tsunami disaster in Asia--home transport and emergency care in Sweden.

This is a descriptive report of the Swedish authorities' responses to the tsunami that affected Southeast Asia in December 2004. The main focus is the care of survivors and the injured during their transportation from Thailand and their return to Sweden. The psychological and physical after-effects also are presented based on a poll conducted one year after the tsunami.

KAMEDO Report 90: terrorist attacks in Madrid, Spain, 2004.

This is a descriptive study of the medical responses to the bombings by terrorists in Madrid on 11 March 2004. The nature of the event, the human damage, and the responses are described. It describes the: (1) nature and operations associated with the alarm; (2) assignment of responding units and personnel; (3) establishment and operations of casualty collection points; (4) medical transport and distribution of injured victims; (5) prioritization and command; (6) hospital care; (7) psychosocial care; (8) identification of the dead; and (9) police investigation and actions. Each of these descriptions is discussed in terms of what currently is known and the implications for future planning, preparedness, and response.

KAMEDO Report 89: terrorist attack in Bali, 2002.

On 12 October 2002, two bombs exploded on the island of Bali in Indonesia, destroying two bars in the tourist district of the holiday resort Kuta Beach. The explosions killed 202 people from 21 different countries, and >300 people were injured. A team of observers conducted structured and unstructured interviews, and lessons learned from the experience were identified. This report summarizes various elements of the response including: (1) prehospital care; (2) coordination; (3) hospital response; and (4) Australia's efforts in air evacuation.

KAMEDO report no. 85: collapse of building during wedding reception in Jerusalem, 2001.

What is now known as the "Versailles Disaster" began as a wedding celebration in Jerusalem on 24 May 2001. The reception was held in the third floor banqueting hall of a hotel, the floor of which subsequently collapsed, crashing through the second and first floors of the building. Four hundred people fell with the floor, and 310 injured people were evacuated using the scoop-and-run principle. The total number of dead was 23, which was less than might have been expected. Israel's on-site disaster management system of giving control to the first paramedic on the scene appeared to work well; however, the other emergency services did not act in coordination with the paramedics. The hospitals managed patients efficiently and social workers were mobilized quickly to assist people experiencing psychological trauma.

KAMEDO report no. 88: floods in the Czech Republic and Southeastern Germany, 2002.

Severe flooding in August 2002 devastated villages, towns, large areas of arable land, streets, roads, and industrial areas in the Czech Republic and Southeastern Germany. In the Czech Republic, 48,000 people were evacuated from Prague. Due to electrical outages, communication and the care of hospital patients suffered. Sanitation services and refuse collection also were not available, which increased the potential for the spread of disease. In Germany, five hospitals required evacuation. Electrical outages were problematic here as well, and it is recommended that the procedures for the long-distance transportation of a large number of severely ill or injured people be clarified in national plans.

KAMEDO report no. 77: sinking of the MS Sleipner, 26 November 1999.

The catamaran HS Sleipner struck a rock and sunk in bad weather and heavy seas on 26 November 1999. Rescue efforts were provided by helicopters and other ships. A total of 68 victims were rescued alive and 16 died, mostly by drowning. Problems were encountered with evacuation, life jackets, and life rafts. Most of those rescued alive suffered from hypothermia. Response times for rescue helicopters should be improved. Emphasis should be placed on correct manifest lists of passengers and crew. Special emphasis must be placed on media relations and cross-boundary issues. Exercises should focus on cooperation and coordination.

KAMEDO report no. 82: explosion at the fireworks warehouse in the Netherlands in 2000.

A fire and subsequent explosions occurred in a fireworks warehouse on 13 May 2000. A total of 947 persons were injured and 21 persons died, including four firefighters and one reporter. Communication networks became overloaded and impaired notification chains. The hospital disaster plan was followed, but was proved inadequate. Public information was a high priority. A counselling center was established early and was planned to continue operation for five years. The command function did not perform to expectations. Hospital triage was impaired as many responsible left the triage area. Short-term psychosocial support evolved to long-term programs. Liability issues were examined.

Air transport of patients with intracranial air: computer model of pressure effects.

INTRODUCTION: Air is commonly trapped within the skull in patients who have been treated for trauma or intracranial hemorrhage. In Sweden, when such a patient is transported by air ambulance it is standard procedure to maintain sea-level pressure in the cabin to prevent increased intracranial pressure (ICP). However, this type of flight operation is more difficult and expensive. Maintenance of sea-level cabin pressure is not common practice all over the world, and the criteria supporting the choice of pressurization during transport are inadequate and in need of evaluation. The purpose of this study was to develop and evaluate a model to simulate the influence of intracranial air on ICP during air transport. METHODS: We identified an existing nonlinear model of the cerebral spinal fluid and intracranial pressure dynamics, then added intracranial air as a new component and evaluated the model through simulations. RESULTS: The model behaved as expected, and the simulations indicated that under normal flying conditions with decreased cabin pressure the initial intracranial air volume will increase by approximately 30% at normal maximum cabin altitude, 8000 ft. The increase in ICP depends upon both the initial air volume and the rate of change in cabin altitude. For an intracranial air volume of 30 ml the estimated worst-case increments of ICP from sea level to maximum altitude would be from 10 mm Hg to 21.0 mm Hg, or from 20 mm Hg to 31.8 mm Hg. DISCUSSION: Our results support the need for maintenance of sea-level pressure during air transport of patients with suspected intracranial air, since an ICP increment could potentially impair the patient's clinical condition.