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ABSTRACTIntroduction: Freezing Cold Injuries (FCI) have been associated with long-term sequelae including vasospasm. The aims of the pilot study are to explore the research methodology and investigate the tolerability and safety of treatment with Botulinum Toxin-A (BTX-A) in FCI Sequelae.Methodology: This pilot study tests the logistics, the treatment setting and the follow-up procedure in an early-phase, double-blinded, randomized, controlled trial study-design. The variables in the study were subjective symptoms, peripheral micro-vascularization/rewarming, somatosensory responsiveness, and generic measure of health status.Results: No major challenges or difficulties were noticed according to the protocol or the study methodology. The monitoring of tolerability and safety of treatment with BTX-A did not reveal any major unwanted and/or adverse reactions among the patients in the pilot study and no challenges occurred during data collection of endpoints. The study revealed an inaccuracy of the 2nd degree FCI diagnosis and uncover a need for relevant and sufficient clinical information for FCI classification.Conclusions: This pilot study showed the study methodology with minor adjustments is feasible in a future full-scale clinical trial. The recruitment process needs to be more refined to ensure that the eligible study participants are a homogenous group of FCI patients.

Background:. Dynamic infrared thermography (DIRT) is a noninvasive imaging technique that can provide indirect and real-time information on skin perfusion by measuring skin temperature. Although used in flap surgery, there are no reports on its value in procedures using a pedicled thoracodorsal artery perforator (TDAP) flap. The aim of this study was to assess the usefulness of DIRT in preoperative perforator mapping and in monitoring intra- and postoperative flap perfusion of pedicled TDAP flaps. Methods:. This prospective study comprised 21 patients (21 flaps) scheduled for reconstructive surgery with a TDAP flap. Perforator mapping was done by DIRT, handheld unidirectional Doppler ultrasound, and computer tomography angiography. Intra- and postoperative flap perfusion was assessed by clinical signs and with the use of DIRT and handheld unidirectional Doppler ultrasound. Results:. Perforator mapping with DIRT showed that first-appearing bright hotspots were always associated with arterial Doppler sounds and suitable perforators intraoperatively. Computer tomography angiography presented useful information on the thoracodorsal artery branching pattern but was less beneficial for perforator mapping. Intra- and postoperative flap monitoring with DIRT was more useful than handheld unidirectional Doppler ultrasound and clinical signs to detect early arterial and venous perfusion problems. DIRT demonstrated that TDAP flap perfusion is a dynamic process with an increase in perfusion during the first operative days. Nineteen flaps survived, of which 3 sustained distal necrosis. Two flaps were lost due to inadequate blood perfusion. Conclusion:. DIRT provides valuable real-time information for perforator mapping and for monitoring TDAP flap perfusion intra- and postoperatively.

Exposure to cold climate is an inevitable consequence of military training in Norway. Adequate peripheral microcirculation in the extremities is important to maintain temperature, and to protect against freezing cold injuries. The aim of this study was to investigate the variability in skin rewarming ability. The study subjects consisted of 260 healthy Norwegian army conscripts, following a mild cold provocation test (hands immersed in 20°C water for 1 min) using dynamic infrared thermography (DIRT). Thermal images were obtained to investigate any differences in skin rewarming ability of the hand (fingers). DIRT took place under standardised and stable study conditions. Conscripts were characterised as either slow, intermediate or rapid rewarmers. While 90% could recover, partially or completely, within 4 min to the skin temperature values before the provocation test, 10% showed a slow rewarming pattern. In the slow rewarmers, the rewarming ability was correlated with a low average temperature of the hands prior to the cooling test. The healthy young army conscripts in this study showed a large variability in their rewarming ability following a standardised mild cold provocation test.

Background:. Wound healing problems at the donor site in free abdominal flap breast reconstruction cause significant morbidity to patients. No studies have investigated what impact the use of the internal mammary artery in free abdominal flap breast reconstruction has on abdominal skin perfusion. We hypothesized that harvesting the internal mammary vessels (IMV) has a negative effect on abdominal skin perfusion. Methods:. The abdomen and anterior thoracic wall of 17 patients scheduled for secondary free abdominal flap breast reconstruction using IMV was pre-, intra-, and postoperatively examined with dynamic infrared thermography. Qualitative and quantitative analyses of the rate and pattern of recovery in Huger’s vascular zones were made with each patient being its own control. Zone III on the side where IMV were used was numbered zone IV. The contralateral zone III was used as reference. Results:. Postoperative abdominal skin perfusion in zone IV was always significantly reduced compared with zone III (1-tailed t test, P < 0.05). The difference between zones II and III was statistically significant for day 1 and 3, but not for day 6 (2-tailed t test, P < 0.05). Skin perfusion in zones II and IV increased during consecutive postoperative days with an increase of hot spots in these areas. Conclusions:. Using the IMV in free abdominal flap breast reconstruction had a significant effect on abdominal skin perfusion and may contribute to abdominal wound healing problems. The reperfusion of the abdominal skin was a dynamic process showing an increase in perfusion in the affected areas during the postoperative days.

A method is described whereby it is possible to alter total body core temperature independently of environmetal temperature and/or exercise in conscious reindeer. The method employs the use of a simple heat exchanger introduced through a permanent rumen fistula. The heat exchanger consists of a 7 m long coil of flexible plastic tubing (OD, 10.0 mm, ID, 8.0 mm). By perfusing the tubing with thermostatically controlled water, heat can be added to or subtracted from the body core at rates equalling several times resting heat production. It is suggested that the method could be used in any large ruminant species. En intra-rumenal varmeveksler til bruk i større, uanesteserte dyr. Abstract in Norwegian / Sammendrag: Vi har i denne undersøkelsen beskrevet en metode for hvordan kroppstemperatur hos uanesteserte reinsdyr kan endres uavhengig av omgivelsestemperatur og om dyret løper eller ikke. Metoden innebærer bruk av en enkel varmeveksler som plasseres i dyrets vom gjennom en permanent vom-fistel. Varmeveksleren består av en 7 m lang kveil av fleksibel plastslange (ytre diameter 10.0 mm, indre diameter 8.0 mm). Ved å perfundere slangen med vann av en bestemt temperatur er det mulig å fjerne eller tilføre kroppen en varmemengde som tilsvarer flere ganger dyrets varmeproduksjon. Vi mener at denne metoden kan tilpasses alle store drøvtyggere. Potsiin asetettavan låmpotilan muuttajan kåytto suurilla nukkumattomilla elåimillå. Abstract in Finnish / Yhteenveto: Tutkimuksessa olemme kuvanneet menetelman, jolla voidaan muuttaa nukuttamattoman poron ruumiinlåmpotilaa riippumatta ulkolampotilasta tai siita juokseeko elåin vai ei. Menetelmassa kåytaan yksinkertaista låmpotilan muuttajaa, joka asetetaan elaimeen pysyyan potsifistulan kautta. Låmpotilan muuttaja kasittåa 7 m pitkan muoviletkurullan (letkun halkaisija 10.6 mm, reian halkaisija" 8.0 mmJTTayttåmålla letku tietyn lampoisellå vedella on mahdollista joko laskea tai nostaa ruumiin lampomååråa niin, etta se vastaa moninkertaisesti elaimen omaa låmmontuottoa. Oletamme, etta menetelmåa voidaan kayttaå kaikille suurille mårehtijoille.

This article analyzes the coherence of low-mode signals at ranges of 3515 and 5171 km using data from the Acoustic Thermometry of Ocean Climate (ATOC) and Alternate Source Test (AST) experiments. Vertical line arrays at Hawaii and Kiritimati received M-sequences transmitted from two sources: the 75-Hz bottom-mounted ATOC source on Pioneer Seamount and the near-axial dual-frequency (28/84 Hz) AST source deployed nearby. This study demonstrates that the characteristics of the mode signals at 5171-km range are quite similar to those at 3515-km range. At 75 Hz the mode time spreads are on the order of 1.5 s, implying a coherence bandwidth of 0.67 Hz. The time spread of the 28-Hz signals is somewhat lower, but these signals show significantly less frequency-selective fading than the 75-Hz signals, suggesting that at the lower frequency the multipaths are temporally resolvable. Coherence times for mode 1 at 75 Hz are on the order of 8 min for the 3515-km range and 6 min for 5171-km range. At 28 Hz mode 1 is much more stable, with a magnitude-squared coherence of greater than 0.6 for the 20-min transmission period. 2005 Acoustical Society of America. [ABSTRACT FROM AUTHOR]

The statistics of low-frequency, long-range acoustic transmissions in the North Pacific Ocean are presented. Broadband signals at center frequencies of 28, 75, and 84 Hz are analyzed at propagation ranges of 3252 to 5171 km, and transmissions were received on 700 and 1400 m long vertical receiver arrays with 35 m hydrophone spacing. In the analysis we focus on the energetic finale region of the broadband time front arrival pattern, where a multipath interference pattern exists. A Fourier analysis of 1 s regions in the finale provide narrowband data for examination as well. Two-dimensional (depth and time) phase unwrapping is employed to study separately the complex field phase and intensity. Because data sampling occured in 20 or 40 min intervals followed by long gaps, the acoustic fields are analyzed in terms of these 20 and 40 min and multiday observation times. An analysis of phase, intensity, and complex envelope variability as a function of depth and time is presented in terms of mean fields, variances, probability density functions (PDFs), covariance, spectra, and coherence. Observations are compared to a random multipath model of frequency and vertical wave number spectra for phase and log intensity, and the observations are compared to a broadband multipath model of scintillation index and coherence. 2005 Acoustical Society of America. [ABSTRACT FROM AUTHOR]

Predictions of transverse horizontal spatial coherence from path integral theory are compared with measurements for two ranges between 2000 and 3000 km. The measurements derive from a low-frequency (75 Hz) bottom-mounted source at depth 810 m near Kauai that transmitted m-sequence signals over several years to two bottom-mounted horizontal line arrays in the North Pacific. In this paper we consider the early arriving portion of the deep acoustic field at these arrays. Horizontal coherence length estimates, on the order of 400 m, show good agreement with lengths calculated from theory. These lengths correspond to about 1 in horizontal arrival angle variability using a simple, extended, spatially incoherent source model. Estimates of scintillation index, log-amplitude variance, and decibel intensity variance indicate that the fields were partially saturated. There was no significant seasonal variability in these measures. The scintillation index predictions agree quite well with the dataset estimates; nevertheless, the scattering regime predictions (fully saturated) vary from the regime classification (partially saturated) inferred from observation. This contradictory result suggests that a fuller characterization of scattering regime metrics may be required. 2005 Acoustical Society of America. [ABSTRACT FROM AUTHOR]

This review is based on a multiple database survey on published literature to determine the effects on health following voluntary exposure to cold-water immersion (CWI) in humans. After a filtering process 104 studies were regarded relevant. Many studies demonstrated significant effects of CWI on various physiological and biochemical parameters. Although some studies were based on established winter swimmers, many were performed on subjects with no previous winter swimming experience or in subjects not involving cold-water swimming, for example, CWI as a post-exercise treatment. Clear conclusions from most studies were hampered by the fact that they were carried out in small groups, often of one gender and with differences in exposure temperature and salt composition of the water. CWI seems to reduce and/or transform body adipose tissue, as well as reduce insulin resistance and improve insulin sensitivity. This may have a protective effect against cardiovascular, obesity and other metabolic diseases and could have prophylactic health effects. Whether winter swimmers as a group are naturally healthier is unclear. Some of the studies indicate that voluntary exposure to cold water has some beneficial health effects. However, without further conclusive studies, the topic will continue to be a subject of debate.

A common effort for both military and civil healthcare is to achieve knowledge-based health care in cold weather injuries and fatal accidents in harsh arctic environment. The Cold Weather Operations Conference in November 2021, having more than 300 participants from 20 countries, was addressing the prevention and treatment of injuries and trauma care in cold weather conditions and the challenges for military prehospital casualty care. The intention of the programme was to stimulate further research and systematic knowledge-based clinical work. The abstracts from the conference present cold weather research and clinical experience relevant for readers of the International Journal of Circumpolar Health.

Background:. There are no in vivo studies that evaluate the effect of perforator dissection on the perfusion territory of a perforator (perforasome). In this study, indocyanine green fluorescence angiography (ICG-FA) and infrared thermography (IRT) were used intraoperatively to evaluate perforasome perfusion in hemi-DIEP flaps. Methods:. Patients selected for DIEP breast reconstruction were prospectively included in the study. Preoperative perforator mapping was performed with CTA and handheld Doppler ultrasound. In general anesthesia, perforasome perfusion was evaluated with ICG-FA and IRT both before surgery and after flap dissection with preserved dominant perforators. Results:. Thirty hemi-DIEP flaps were dissected in 15 patients (average BMI 26.6 kg/m2), of which 40% had been operated on in the lower abdomen. Fluorescence spots from ICG were associated with infrared radiation hotspots on IRT and these corresponded with the locations of the selected perforators. IRT and ICG-FA demonstrated similar patterns in perforasome perfusion before and after perforator dissection. Perforator dissection changed the perforasome perfusion. IRT made it possible to continuously monitor the perforator activity during surgery. ICG-FA easily identified areas with impaired flap perfusion due to previous surgery. Conclusions:. Perforasome perfusion is a dynamic process that changes with perforator dissection. ICG-FA and IRT are reproducible techniques for in vivo evaluation of perforasome perfusion and produce comparable results.

Background:. Wound healing problems following abdominoplasty may be a result of impaired tissue perfusion. This study evaluated the impact a standard abdominoplasty may have on abdominal skin perfusion. Methods:. A standard abdominoplasty was performed in 16 patients. Dynamic infrared thermography (DIRT) using a mild and a stronger cold challenge was performed pre-, intra-, and postoperatively on day 1, 2, and in week 6. The abdomen was divided into Huger’s vascular zones. A two-tailed t test was used to evaluate differences in mean temperature between zones. Statistical significance was defined as P < 0.05. Results:. Two patients suffered wound healing problems. Abdominal skin perfusion showed a hyperaemic state on day 1, day 2, and week 6, postoperatively. Hotspots in zones I and II had all disappeared at the end of surgery and on day 1, except in the cranial part of zone I. Hotspots reappeared in zones I and II during day 2. A statistically significant difference between zones I and II was seen on day 1 and 2, with zone II being cooler. This difference had disappeared in week 6 for the mild cold challenge but not for the stronger cold challenge. Conclusions:. A standard abdominoplasty has a significant impact on abdominal skin perfusion. The skin perfusion is a dynamic process with a gradual improvement over time. The strongest effect was seen in zone II near the lower transverse incision line, where skin perfusion was the least. Such may contribute to impaired wound healing at this site.