Physical and cognitive performance after blood donation : A clinical study to investigate donor safety in walking blood banks

De siste 20 årene har fullblod til pasienter i blødningssjokk blitt re-lansert som foretrukket behandling. I vandrende blodbanker blir blodet oppbevart i original forpakningen inntil behovet oppstår. Konseptet har logistiske fordeler, er kost effektivt og bevarer tilgang til fullblod både når man er på oppdrag langt fra andre ressurser eller ved kriser. Vandrende blodbanker utgjør i dag grunlaget for nasjonale planer for blodberedskap i Norge. Marinejegerkommandoen etablerte vandrende blodbanker blant deres soldater for å sikre tilgang til fullblod på oppdrag med lange evakuerings akser. I den forbindelse ble det reist spørsmål om mulig reduksjon i yteevnene og soldatferdigheter like etter blodgivning. Litteratursøk gav ikke tilfredsstillende svar på spørsmålene. Derfor ble det designet en studie for å utforske hvordan blodgivning påvirket spesialsoldatenes utholdenhet og ferdigheter, samt om det var mulig å lære ikke-sanitetspersonell tappe prosedyrer. I Artikkel I fant vi hverken redusert maksimalt oksygenopptak eller reduserte ferdigheter hos uthvilte soldater. Det var og 100% suksessrate for opplæring i tappeprosedyrer. Dette førte til at Marinejegerkommandoen etablerte vandrende blodbanker blant sine soldater. Funnene var gjort hos uthvilte soldater og kunne trolig ikke overføres til slitne soldater på slagmarken. Neste studie undersøkte derfor effekten av standard blodgivning hos utslitte soldater. Artikkel II viste ett fall i maksimalt oksygen opptak på 6%, noe som var akseptabelt for Marinejegerkommandoen. I Norge kan avstander mellom sykehus være lange og været ofte utfordrende. Derfor er vandrende blodbanker brukt også sivilt. Dette gjorde det naturlig å designe en studie som undersøkte effekten av blodgivning på fysisk og kognitiv yteevne hos vanlige blodgivere, og i Artikkel III fant vi 7% reduksjon i maksimalt oksygenopptak og bevart kognitiv yteevne. Vandrende blodbanker er et trygt og effektivt system for å sikre tilgang til fullblod ved kriser eller ved lange evakuerings og forsynings akser. Å gi blod påvirker blodgiverens yteevne i begrenset grad, men å gi blod i en krisesituasjon kan sette blodgiveren i fare om han eller hun skulle bli den neste pasienten. Fremtidige studier er ønsket for å sikre funnen samt å undersøke effekten av blodgivning under andre miljømessige forhold.Whole blood transfusion for patients in hemorrhagic shock has been re-introduced over the last two decades. In walking blood banks, the blood is stored in the original container until needed. The concept is logistically feasible, cost-effective, and provides access to whole blood where blood bank services are unavailable. Walking blood banks are important in Norwegian health care`s blood preparedness plans. The Norwegian Naval Special Operations Command identified walking blood banks as the only option to ensure whole blood availability in far-forward missions. However, a major concern was that blood donation would compromise the soldiers’ skills, and the literature did not provide convincing evidence to implement the system. Therefore, a study was designed to investigate feasibility; would blood donation affect elite soldiers' endurance and shooting capabilities – and would it be possible to train non-medics in blood donation procedures? As shown in Paper I, we did not find reduced maximal oxygen consumption or impaired soldier skills in rested soldiers. There was a 100% success rate in teaching non-medics in whole blood donation and transfusion procedures. The Naval Special Operations Command approved walking blood banks based on these findings. However, as the study was conducted on rested soldiers, the results could not be transposed to soldiers in combat situations. The next study accordingly was designed to investigate the physical performance of fatigued soldiers immediately after blood donation. Paper II showed a 6% reduction in maximal oxygen consumption in fatigued soldiers, which was considered acceptable by the Command. In Norway, with long transportation distances and challenging weather conditions, a walking blood bank is considered a real possibility, also in civilian settings. It was consequently logical to include regular blood donors in the third paper: Would their physical and cognitive functions significantly reduce after blood donation? In Paper III, we report a 7% reduction in maximal oxygen consumption and that cognitive performances were maintained in regular blood donors. A standard blood donation causes a decrease in exercise physiology, does not affect cognitive physiology, and maintains performance. Therefore, walking blood banks are feasible and provide resilience. However, some of the risks involved should be acknowledged. Future quality data is warranted to reduce residual risk, especially in different environmental settings.Doktorgradsavhandlin

Validation of a point-of-care capillary lactate measuring device (Lactate Pro 2)

Background The measurement of lactate in emergency medical services has the potential for earlier detection of shock and can be performed with a point-of-care handheld device. Validation of a point-of-care handheld device is required for prehospital implementation. Aim The primary aim was to validate the accuracy of Lactate Pro 2 in healthy volunteers and in haemodynamically compromised intensive care patients. The secondary aim was to evaluate which sample site, fingertip or earlobe, is most accurate compared to arterial lactate. Methods Arterial, venous and capillary blood samples from fingertips and earlobes were collected from intensive care patients and healthy volunteers. Arterial and venous blood lactate samples were analysed on a stationary hospital blood gas analyser (ABL800 Flex) as the reference device and compared to the Lactate Pro 2. We used the Bland-Altman method to calculate the limits of agreement and used mixed effect models to compare instruments and sample sites. A total of 49 intensive care patients with elevated lactate and 11 healthy volunteers with elevated lactate were included. Results There was no significant difference in measured lactate between Lactate Pro 2 and the reference method using arterial blood in either the healthy volunteers or the intensive care patients. Capillary lactate measurement in the fingertip and earlobe of intensive care patients was 47% (95% CI (29 to 68%), p < 0.001) and 27% (95% CI (11 to 45%), p < 0.001) higher, respectively, than the corresponding arterial blood lactate. In the healthy volunteers, we found that capillary blood lactate in the fingertip was 14% higher than arterial blood lactate (95% CI (4 to 24%), p = 0.003) and no significant difference between capillary blood lactate in the earlobe and arterial blood lactate. Conclusion Our results showed that the handheld Lactate Pro 2 had good agreement with the reference method using arterial blood in both intensive care patients and healthy volunteers. However, we found that the agreement was poorer using venous blood in both groups. Furthermore, the earlobe may be a better sample site than the fingertip in intensive care patients.publishedVersio

Validation of a point-of-care capillary lactate measuring device (Lactate Pro 2)

Background The measurement of lactate in emergency medical services has the potential for earlier detection of shock and can be performed with a point-of-care handheld device. Validation of a point-of-care handheld device is required for prehospital implementation. Aim The primary aim was to validate the accuracy of Lactate Pro 2 in healthy volunteers and in haemodynamically compromised intensive care patients. The secondary aim was to evaluate which sample site, fingertip or earlobe, is most accurate compared to arterial lactate. Methods Arterial, venous and capillary blood samples from fingertips and earlobes were collected from intensive care patients and healthy volunteers. Arterial and venous blood lactate samples were analysed on a stationary hospital blood gas analyser (ABL800 Flex) as the reference device and compared to the Lactate Pro 2. We used the Bland-Altman method to calculate the limits of agreement and used mixed effect models to compare instruments and sample sites. A total of 49 intensive care patients with elevated lactate and 11 healthy volunteers with elevated lactate were included. Results There was no significant difference in measured lactate between Lactate Pro 2 and the reference method using arterial blood in either the healthy volunteers or the intensive care patients. Capillary lactate measurement in the fingertip and earlobe of intensive care patients was 47% (95% CI (29 to 68%), p < 0.001) and 27% (95% CI (11 to 45%), p < 0.001) higher, respectively, than the corresponding arterial blood lactate. In the healthy volunteers, we found that capillary blood lactate in the fingertip was 14% higher than arterial blood lactate (95% CI (4 to 24%), p = 0.003) and no significant difference between capillary blood lactate in the earlobe and arterial blood lactate. Conclusion Our results showed that the handheld Lactate Pro 2 had good agreement with the reference method using arterial blood in both intensive care patients and healthy volunteers. However, we found that the agreement was poorer using venous blood in both groups. Furthermore, the earlobe may be a better sample site than the fingertip in intensive care patients