Amir Abramovich

Hyperbaric oxygen therapy for cutaneous/soft-tissue zygomycosis complicating diabetes mellitus.

A 24-year-old female diabetic patient was hospitalized because of ketoacidosis and a necrotic wound on the hand. Debridement and antibiotic therapy failed to halt the process. After demonstration of Mucor in cultures from the wound, the patient underwent extensive surgery and amphotericin B was administered. When the necrotic process continued despite these measures, adjunctive hyperbaric oxygen (100% O2 at 2.5 ATA for 90 minutes) was administered daily for a total of 21 treatment sessions. She gradually improved, and at 2 months follow-up most of the wound had healed. Although the mortality rate of cutaneous/soft-tissue zygomycosis is markedly lower than that of the rhinocerebral form, morbidity is still considerably high. Successful use of hyperbaric oxygen has been reported in rhinocerebral zygomycosis, and it may have been of benefit in this high-risk patient by preventing local and systemic spreading of the fungus. This report is the first case of the use of hyperbaric oxygen for cutaneous/soft-tissue zygomycosis. It is suggested that hyperbaric oxygen be considered for this indication in diabetic patients as an adjunct to surgery and amphotericin B.

Tranexamic acid at the point of injury: the Israeli combined civilian and military experience.

BACKGROUND Accumulating evidence established the benefit of tranexamic acid (TXA) for traumatic bleeding in the hospital setting. TXA use in the field (at or near the point of injury [POI]) was described in the military setting but not in the civilian one. The current study describes the Israeli combined experience (civilian and military) of administering TXA in the field. METHODS The Israel Defense Forces (IDF) and Magen David Adom (MDA) (the national Israeli civilian emergency medical service) protocols for giving TXA at the POI are presented. We then review all trauma patients who received TXA in the field in accord with either protocol. Data were abstracted from the IDF Trauma Registry and from the MDA database. RESULTS Data regarding casualties treated with TXA by the IDF Medical Corps and MDA between December 2011 and August 2013 are presented. One hundred three casualties who received TXA in the field were identified. The median age was 26.5 years, and 83 (88%) were male. The mechanism of injury was penetrating in 48 cases (51%). POI data indicate slightly higher injury severity for the group of patients treated by MDA compared with patients treated by the IDF (systolic blood pressure, 90 mm Hg vs. 110 mm Hg; Glasgow Coma Scale [GCS] score, 11 vs. 15; hemoglobin, 11.9 vs. 13.3; p < 0.05). CONCLUSION On the basis of our combined data, it appears that administering TXA in the field is feasible in the civilian and the military setting. Lessons learned in military settings are applicable to civilian medical systems. Action investigations and comparison of the different protocols may further improve treatment at or near the POI. LEVEL OF EVIDENCE Therapeutic study, level V.

Performance of Infusion Pumps during Hyperbaric Conditions

Background Many hyperbaric facilities use infusion pumps inside the chamber. It is therefore important to ensure that this equipment will perform accurately during hyperbaric conditions. The authors tested the function and accuracy of the Imed 965 and Infutec 520 volumetric infusion pumps, the Easy-pump MZ-257 peristaltic infusion pump, and the Graseby 3100 syringe pump. Methods The authors calculated the deviations of infused volumes at low and high rates (12–18 and 60–100 ml/h) on three different hyperbaric protocols (up to 2.5, 2.8, and 6 atmospheres absolute [ATA]), resembling a standard hyperbaric oxygen treatment and US Navy treatment tables used for decompression illness and for arterial gas embolism. Two examples of each pump model were examined in every experiment. Results The Easy-pump MZ-257 failed to function completely beyond a chamber pressure of 1.4 ATA, making it unsuitable for use inside the hyperbaric chamber. The Graseby 3100 failed to respond to all keyboard functions at 2.5–2.8 ATA, making it unsuitable for use in most hyperbaric treatments. The Imed 965 performed within an acceptable volume deviation (≤10%) during most hyperbaric conditions. During the compression phase of the profiles used, and for the low infusion rates only, exceptional volume deviations of 20–40% were monitored. The Infutec 520 demonstrated an acceptable deviation (within 10%) throughout all the hyperbaric profiles used, unaffected by changes in ambient pressure or infusion rate. Conclusions Commercially available infusion pumps operating during hyperbaric conditions demonstrate substantial variations in performance and accuracy. It is therefore important that the hyperbaric facility staff make a careful examination of such instruments to anticipate possible deviations in the accuracy of the equipment during use.

Effect of hyperbaric oxygen on a rat transverse rectus abdominis myocutaneous flap model

&NA; The single‐pedicle transverse rectus abdominis myocutaneous (TRAM) flap is frequently associated with partial flap necrosis. Hyperbaric oxygen has previously been shown to increase the survival of skin flaps, although there has been no investigation of possible beneficial effects of hyperbaric oxygen on survival of the TRAM flap. The present study compares the effectiveness of hyperbaric oxygen therapy, normobaric 100% oxygen, a hyperbaric air‐equivalent mixture, and no treatment at all (control group), in the prevention of TRAM flap necrosis in a rat model. Forty‐eight animals were randomly assigned to one of the four above‐mentioned groups. The surviving area of the flap was evaluated 7 days after surgery. The hyperbaric oxygen treatment protocol consisted of five 9‐minute sessions breathing 100% oxygen at a pressure of 2.5 atmospheres absolute during the first 48 hours, starting within 1 hour of surgery. The areas of surviving skin paddles ranged from 38.5 percent in the control group to 52.5 percent in the group treated with hyperbaric oxygen. One‐way analysis of variance indicated that flap area survival was significantly greater in the hyperbaric oxygen group (F = 2.69, p = 0.05). Tukeys pairwise comparison and the two‐sample t test indicated that the group treated with hyperbaric oxygen differed significantly from the control group (Tukeys critical value = 3.8, rejection level = 0.05, t test p = 0.01). Our results suggest that the hyperbaric oxygen treatment protocol used improves survival in the rat TRAM flap. However, the optimal treatment protocol to achieve this objective even in the rat seems to be variable, and further studies are required before extrapolating these data to human applications. (Plast. Reconstr. Surg. 102: 416, 1998.)

Prehospital intubation success rates among Israel Defense Forces providers: epidemiologic analysis and effect on doctrine.

BACKGROUND Advanced airway management is composed of a set of vital yet potentially difficult skills for the prehospital provider, with widely different clinical guidelines. In the military setting, there are few data available to inform guideline development. We reevaluated our advanced airway protocol in light of our registry data to determine if there were a preferred maximum number of endotracheal intubation (ETI) attempts; our success with cricothyroidotomy (CRIC) as a backup procedure; and whether there were cases where advanced airway interventions should possibly be avoided. METHODS This is a descriptive, registry-based study conducted using records of the Israel Defense Forces Trauma Registry at the research section of the Trauma and Combat Medicine Branch, Surgeon General’s Headquarters. We included all casualties for whom ETI was the initial advanced airway maneuver, and the number of ETI attempts was known. Descriptive statistics were used. RESULTS Of 5,553 casualties in the Israel Defense Forces Trauma Registry, 406 (7.3%) met the inclusion criteria. Successful ETI was performed in 317 casualties (78%) after any number of ETI attempts; an additional 46 (11%) underwent CRIC, and 43 (11%) had advanced airway efforts discontinued. ETI was successful in 45%, 36%, and 31% of the first, second, and third attempts, respectively, with an average of 28% success over all subsequent attempts. CRIC was successful in 43 (93%) of 46 casualties in whom it was attempted. Of the 43 casualties in whom advanced airway efforts were discontinued, 29 (67%) survived to hospital discharge. CONCLUSION After the first ETI attempt, success with subsequent attempts tended to fall, with minimal improvement in overall ETI success seen after the third attempt. Because CRIC exhibited excellent success as a backup airway modality, we advocate controlling the airway with CRIC if ETI efforts have failed after two or three attempts. We recommend that providers reevaluate whether definitive airway control is truly necessary before each attempt to control the airway. LEVEL OF EVIDENCE Care management, level IV.

Point-of-injury Use of Reconstituted Freeze Dried Plasma as a Resuscitative Fluid: A Special Report for Prehospital Trauma Care

Abstract : This special report describes the broader implications of prehospital fluid resuscitation in the context of what is the first reported case of point-of-injury use of reconstituted, lyophilized single-donor freeze dried plasma (FDP) as a resuscitative fluid. The Israeli Defense Force Medical Corps (IDF-MC) has deployed FDP as another step in the evolution of casualty care to bring damage-control resuscitation closer to the point of injury as part of the multidisciplinary efforts to improve trauma victims outcome.

Apples and oranges: looking forward to the next generation of combat casualty care statistics.

I combat casualty care requires continuous learning through comparing medical outcomes across battlefields. Differences in outcomes may be caused by the combat care rendered as well as weaponry, geography, and numerous other nonmedical factors. A rough understanding of battlefield lethality and medical care quality is obtained through calculation of the case fatality rate (CFR), percentage killed in action (%KIA), and percentage died of wounds (%DOW) (defined later). These standard statistics serve to isolate, at least partially, the medical care aspect of combat because only casualties (i.e., after injury) are considered. Lesswell standardized, however, are the numbers on which these statistics are based, complicating efforts to make quantitative comparisons across forces. We think it is time to identify newmeasures for assessing combat casualty care as we describe later.

Do hyperbaric oxygen-induced seizures cause brain damage?

It is commonly accepted that hyperbaric oxygen-induced seizures, the most severe manifestation of central nervous system oxygen toxicity, are harmless. However, this hypothesis has not been investigated in depth. We used apoptotic markers to determine whether cells in the cortex and hippocampus were damaged by hyperbaric oxygen-induced seizures in mice. Experimental animals were exposed to a pressure of 6 atmospheres absolute breathing oxygen, and were randomly assigned to two groups sacrificed 1h after the appearance of seizures or 7 days later. Control groups were not exposed to hyperbaric oxygen. Caspase 9, caspase 3, and cytochrome c were used as apoptotic markers. These were measured in the cortex and the hippocampus, and compared between the groups. Levels of caspase 3, cytochrome c, and caspase 9 in the hippocampus were significantly higher in the hyperbaric oxygenexposed groups compared with the control groups 1 week after seizures (p<0.01). The levels of two fragments of caspase 9 in the cortex were higher in the control group compared with the hyperbaric oxygen-exposed group 1h after seizures (p<0.01). Hyperbaric oxygen-induced seizures activate apoptosis in the mouse hippocampus. The reason for the changes in the cortex is not understood. Further investigation is necessary to elucidate the mechanism underlying these findings and their significance.

Flow resistance, work of breathing of humidifiers, and endotracheal tubes in the hyperbaric chamber

Humidification of inspired gas is critical in ventilated patients, usually achieved by heat and moisture exchange devices (HMEs). HME and the endotracheal tube (ETT) add airflow resistance. Ventilated patients are sometimes treated in hyperbaric chambers. Increased gas density may increase total airway resistance, peak pressures (PPs), and mechanical work of breathing (WOB). We tested the added WOB imposed by HMEs and various sizes of ETT under hyperbaric conditions. We mechanically ventilated 4 types of HMEs and 3 ETTs at 6 minute ventilation volumes (7-19.5 L/min) in a hyperbaric chamber at pressures of 1 to 6 atmospheres absolute (ATA). Peak pressure increased with increasing chamber pressure with an HME alone, from 2 cm H₂O at 1 ATA to 6 cm H(2)O at 6 ATA. Work of breathing was low at 1 ATA (0.2 J/L) and increased to 1.2 J/L at 6 ATA at minute ventilation = 19.5 L/min. Connecting the HME to an ETT increased PP as a function of peak flow and chamber pressure. Reduction of the ETT diameter (9 > 8 > 7.5 mm) and increase in chamber pressure increased the PP up to 27.7 cm H₂O, resistance to 33.2 cmH₂O*s/L, and WOB to 3.76 J/L at 6 ATA with a 7.5-mm EET. These are much greater than the usually accepted critical peak pressures of 25 cm H₂O and WOB of 1.5 to 2.0 J/L. Endotracheal tubes less than 8 mm produce significant added WOB and airway pressure swings under hyperbaric conditions. The hyperbaric critical care clinician is advised to use the largest possible ETT. The tested HMEs add negligible resistance and WOB in the chamber.

Effects on pulmonary function of daily exposure to dry or humidified hyperbaric oxygen.

The purpose of this study was to examine the effects of breathing dry or humidified hyperbaric oxygen on pulmonary function. Pulmonary function tests were performed before and after each of 10 hyperbaric oxygen exposures at 2.5 atmospheres absolute (ATA) for 95 min in a group of 13 patients treated daily by hyperbaric oxygen for problem wounds. Patients breathed dry oxygen during five successive sessions and humidified oxygen during the remaining five. No differences were found between forced vital capacities (FVC) and maximal expiratory flows before and after hyperbaric oxygen exposure while breathing dry or humidified oxygen. Significant differences were found for the changes in the percentage of FVC expired in 1 s (FEV1%) and mean forced mid-expiratory flow rate during the middle half of the FVC (FEF25-75%) on day 1 alone: decrements of 1.42 and 2.96%, respectively, under dry oxygen, vs. increments of 3.93 and 34.4%, respectively, for humidified oxygen. Day-to-day decrements in the percent changes in FEV1% and FEF25-75% were observed while breathing humidified hyperbaric oxygen. These results demonstrate that repeated daily exposure to humidified hyperbaric oxygen abolishes the initial beneficial effect of humidification on peripheral airways flow characteristics.