Does Military High-speed Boat Slamming Cause Severe Injuries and Disability?

BACKGROUND: Many operators of professional high-speed boats suffer severe, acute, and permanent injuries caused by slamming-induced hull impacts. As the number of professional high-speed boats and their speed capabilities increase, operators are reporting increasing numbers and severity of injuries. However, the actual incidence rate of acute injuries and the prevalence of chronic musculoskeletal disorders are still unknown. QUESTIONS/PURPOSES: We sought to investigate, among professional high-speed boat operators, (1) the self-reported incidence rate of impact-induced injuries, (2) the most common types of injuries or injury locations, (3) what impact characteristics were reported, and (4) the prevalence of self-reported sick leave, disability, and medical or orthopaedic treatment. METHODS: This study was an internet-based survey among retired military high-speed boat operators. The survey was given to members of the Combatant Craft Crewman Association online user group (360 members). Participants answered questions on demographics, service branch, service years and capacity, boat type, types of events, injury location, severity, pain, disability, and need for treatment. Values are presented as the mean ± SD and proportions. Incidence rates are presented as injuries per person-year. A total of 214 members of the Combatant Craft Crewman Association participated in the survey (213 men, mean age 50 ± 9 years, mean BMI 29 ± 4 kg/m 2 ). A total of 59% (214 of 360) of those we surveyed provided responses; all provided complete survey responses. RESULTS: The self-reported incidence rate of impact-induced injuries was 1.1 injuries per person-year served onboard. A total of 32% (775 of 2460) of respondents reported injuries that affected the back, and 21% (509 of 2460) reported injuries that affected the neck. Among those who responded, 33% (70 of 214) reported loss of consciousness onboard, and 70% (149 of 214) reported having experienced impaired capacity to perform their job onboard because of impact exposure. A total of 49% (889 of 1827) of the reported injuries were attributed to impacts containing lateral forces, 18% (333 of 1827) to frontal impacts, and 12% (218 of 1827) were attributed to purely vertical impacts. Finally, 67% (144 of 214) of respondents reported at least one occasion of sick leave from training or missions. Seventy-two percent (155 of 214) applied for a Veterans Affairs disability rating, and 68% (105 of 155) of these had a rating of 50% or higher. Additionally, 39% (84 of 214) reported having had surgery during active duty, and 34% (72 of 214) reported surgery after leaving active service. CONCLUSION: The results suggest that in the investigated military population, exposure to slamming-induced impacts onboard high-speed boats may cause more injuries than previously reported. Most reported injuries are musculoskeletal, but the high number of reported slamming-induced events of unconsciousness is concerning. LEVEL OF EVIDENCE: Level IV, prognostic study.

Navigation system for percutaneous tracheotomy.

BACKGROUND: Percutaneous dilatational tracheotomy (PDT) is a well-established method. The prerequisite is to identify anatomical landmarks of the neck. We introduce a three-dimensional navigation system - SafeTrach. AIMS/OBJECTIVES: We present an alternative technique using internal landmarks that can be used in patients with difficult anatomy. MATERIAL AND METHODS: The device is a forceps-like instrument with an outer and an inner shank. The later serves as a ventilation lumen and stabilizes the orotracheal tube in the midline of trachea. The outer shank acts as a three-dimensional guide for the puncturing needle. RESULTS: Out of 48 patients we have determined the level of puncture in 20 patients by using intraoperative measurements. The distance from the vocal cords to the puncture site was about 50 mm for men and 40 mm for women. In 13 of the patients who had had CT scans, we studied the distance between the vocal cords and the optimal puncture site and found the median distance for men 45 mm and for women 42 mm. CONCLUSIONS AND SIGNIFICANCE: With the studied navigation system one may use external or internal landmarks to indicate the puncture level in PDT. The device may minimize the risk of injuring the posterior tracheal wall.

Biomarkers for oxidative stress and organ injury during Transnasal Humidified Rapid-Insufflation Ventilatory Exchange compared to mechanical ventilation in adults undergoing microlaryngoscopy: A randomised controlled study.

BACKGROUND: Apnoeic oxygenation using Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) during general anaesthesia prolongs the safe apnoeic period. However, there is a gap of knowledge how THRIVE-induced hyperoxia and hypercapnia impact vital organs. The primary aim of this randomised controlled trial was to characterise oxidative stress and, secondary, vital organ function biomarkers during THRIVE compared to mechanical ventilation (MV). METHODS: Thirty adult patients, American Society of Anesthesiologists (ASA) 1-2, undergoing short laryngeal surgery under general anaesthesia were randomised to THRIVE, FI O2 1.0, 70 L min-1 during apnoea or MV. Blood biomarkers for oxidative stress, malondialdehyde and TAC and vital organ function were collected (A) preoperatively, (B) at procedure completion and (C) at PACU discharge. RESULTS: Mean apnoea time was 17.9 (4.8) min and intubation to end-of-surgery time was 28.1 (12.8) min in the THRIVE and MV group, respectively. Malondialdehyde increased from 11.2 (3.1) to 12.7 (3.1) µM (P = .02) and from 9.5 (2.2) to 11.6 (2.6) µM (P = .003) (A to C) in the THRIVE and MV group, respectively. S100B increased from 0.05 (0.02) to 0.06 (0.02) µg L-1 (P = .005) (A to C) in the THRIVE group. No increase in TAC, CRP, leukocyte count, troponin-T, NTproBNP, creatinine, eGFRcrea or NSE was demonstrated during THRIVE. CONCLUSION: While THRIVE and MV was associated with increased oxidative stress, we found no change in cardiac, inflammation or kidney biomarkers during THRIVE. Further evaluation of stress and inflammatory response and cerebral and cardiac function during THRIVE is needed.

Lung volume changes in Apnoeic Oxygenation using Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) compared to mechanical ventilation in adults undergoing laryngeal surgery.

BACKGROUND: Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) using high-flow 100% oxygen during apnoea has gained increased use during difficult airway management and laryngeal surgery due to a slower carbon dioxide rise compared to traditional apnoeic oxygenation. We have previously demonstrated high arterial oxygen partial pressures and an increasing arterial-alveolar carbon dioxide difference during THRIVE. Primary aim of this study was to characterise lung volume changes measured with electrical impedance tomography during THRIVE compared to mechanical ventilation. METHODS: Thirty adult patients undergoing laryngeal surgery under general anaesthesia were randomised to THRIVE or mechanical ventilation. Subjects were monitored with electrical impedance tomography and repeated blood gas measurement perioperatively. The THRIVE group received 100% oxygen at 70 l min-1 during apnoea. The mechanical ventilation group was intubated and normoventilated with an FiO2 of 0.4. RESULTS: Mean age were 48.2 (19.9) and 51.3 (12.3) years, and BMI 26.0 (4.5) and 26.0 (3.9) in the THRIVE and mechanical ventilation group respectively. Mean apnoea time in the THRIVE group was 17.9 (4.8) min. Mean apnoea to end-of-surgery time was 28.1 (12.8) min in the mechanical ventilation group. No difference in delta End Expiratory Lung Impedance was seen between groups over time. In the THRIVE group all but three subjects were well oxygenated during apnoea. THRIVE was discontinued for the three patients who desaturated. CONCLUSIONS: No difference in lung volume change over time, measured by electrical impedance tomography, was detected when using THRIVE compared to mechanical ventilation during laryngeal surgery.

A New Technique for Percutaneous Tracheotomy.

The objective of this study was to investigate a new technique for tracheal puncture during percutaneous dilatational tracheotomy (PDT). A new invention, known as SafeTrach, was used: this instrument allows exact localization of the puncture site with built-in protection of the posterior tracheal wall. Surgery was performed on 17 patients with this technique, and our experience is described in this report. The results showed that this new technique minimizes known risk factors compared with existing PDT techniques, including patients with disadvantageous anatomy.

Sedation with Dexmedetomidine or Propofol Impairs Hypoxic Control of Breathing in Healthy Male Volunteers: A Nonblinded, Randomized Crossover Study.

BACKGROUND: In contrast to general anesthetics such as propofol, dexmedetomidine when used for sedation has been put forward as a drug with minimal effects on respiration. To obtain a more comprehensive understanding of the regulation of breathing during sedation with dexmedetomidine, the authors compared ventilatory responses to hypoxia and hypercapnia during sedation with dexmedetomidine and propofol. METHODS: Eleven healthy male volunteers entered this randomized crossover study. Sedation was administered as an intravenous bolus followed by an infusion and monitored by Observer's Assessment of Alertness/Sedation (OAA/S) scale, Richmond Agitation Sedation Scale, and Bispectral Index Score. Hypoxic and hypercapnic ventilatory responses were measured at rest, during sedation (OAA/S 2 to 4), and after recovery. Drug exposure was verified with concentration analysis in plasma. RESULTS: Ten subjects completed the study. The OAA/S at the sedation goal was 3 (3 to 4) (median [minimum to maximum]) for both drugs. Bispectral Index Score was 82 ± 8 and 75 ± 3, and the drug concentrations in plasma at the sedation target were 0.66 ± 0.14 and 1.26 ± 0.36 µg/ml for dexmedetomidine and propofol, respectively. Compared with baseline, sedation reduced hypoxic ventilation to 59 and 53% and the hypercapnic ventilation to 82 and 86% for dexmedetomidine and propofol, respectively. In addition, some volunteers displayed upper airway obstruction and episodes of apnea during sedation. CONCLUSIONS: Dexmedetomidine-induced sedation reduces ventilatory responses to hypoxia and hypercapnia to a similar extent as sedation with propofol. This finding implies that sedation with dexmedetomidine interacts with both peripheral and central control of breathing.

A new safe and cost-effective percutaneous dilatational tracheotomy: SafeTrach.

Conclusion SafeTrach is a new simplified and safe technique to perform percutaneous dilatational tracheotomy (PDT) that eliminates known risk factors compared with existing percutaneous techniques. In the present clinical study, also patients with disadvantageous anatomy not suitable for conventional PDT (CPDT) were treated without complications using SafeTrach. PDT with SafeTrach (STPDT) offers an excellent solution for patients who need tracheotomy in connection with elective ear, nose, and throat (ENT) surgery. Objectives To assess a new technique for percutaneous tracheotomy. Methods Seventeen patients were tracheotomized with STPDT using SafeTrach for the initial penetration sequence and single step dilatational techniques for the dilatational sequence. The patients represented a variety of different neck anatomies. Fifteen patients were head- and neck cancer patients that were subjects of free flap transplants. Results This study showed that STPDT was safe and easy to perform and time-efficient. The median duration of the procedure was 11.5 min and the puncture was in all cases located in the midline of the trachea either between the 2nd and 3rd tracheal ring (n = 13) or between the 3rd and 4th ring (n = 4).

A randomized simultaneous comparison of acceleromyography with a peripheral nerve stimulator for assessing reversal of rocuronium-induced neuromuscular blockade with sugammadex.

BACKGROUND AND OBJECTIVE: We investigated the relationship between acceleromyography and a peripheral nerve stimulator for measuring reversal in patients administered sugammadex following rocuronium. METHODS: In this randomized, active and within-participant controlled study, patients received rocuronium 0.6 mg kg for intubation with 0.15 mg kg maintenance doses as required. Single-dose sugammadex 4.0 or 1.0 mg kg was given 15 min after the last rocuronium dose. Neuromuscular monitoring was performed simultaneously: acceleromyography on one forearm and a peripheral nerve stimulator on the other. The peripheral nerve stimulator assessor was blinded to acceleromyography results. The primary efficacy end point was the difference between time from start of sugammadex 4.0 mg kg administration to recovery of the train-of-four ratio to 0.9 (acceleromyography) and time to reappearance of the fourth twitch (T4) (peripheral nerve stimulator). RESULTS: Sixty-one patients received sugammadex 4.0 mg kg. With acceleromyography, mean (SD) recovery time to a train-of-four ratio of at least 0.9 was 1.5 (0.7) min. With both the peripheral nerve stimulator and acceleromyography, mean (SD) time to T4 reappearance was 0.8 (0.3) min. Mean (95% confidence interval) difference between time to T4 reappearance (peripheral nerve stimulator) and recovery to a train-of-four ratio of at least 0.9 (acceleromyography) was 0.8 (0.6-0.9) min. CONCLUSION: T4 is detected at similar times when measured by a peripheral nerve stimulator or acceleromyography following sugammadex 4.0 mg kg administration 15 min after rocuronium. The mean interval between T4 reappearance (peripheral nerve stimulator) and recovery to a train-of-four ratio of at least 0.9 (acceleromyography) was 0.8 min. These findings provide guidance for evaluating the reversal effect of sugammadex in clinical situations.

Cerebral influences of sodium and angiotensin II on cardiovascular function in hypotensive hemorrhage.

During progressive blood loss several mechanisms act in concert to compensate for the reduced intravascular volume with the overall aim to provide sufficient blood supply to vital organs. The hemodynamic responses in this situation follow a characteristic course of events in conscious individuals with an initial phase of largely maintained blood pressure and tachycardia followed by an abrupt fall in pressure, accompanied by bradycardia and widespread inhibition of sympathetic nervous activity when 20-30% of the blood volume is lost. Our research has focussed on Na+ and angiotensin II effects on the brain for the cardiovascular compensatory mechanisms in response to hypotensive hemorrhage in sheep. We have found that intracerebroventricular infusion of hypertonic NaCl solution improves the tolerance to blood loss, i.e., increases the amount of blood loss needed to induce hypotension. Inhalation anesthesia abolished this effect of the infusion. Similarly, corresponding infusions of angiotensin II also increased the resistance to blood loss in conscious animals only, although accompanied by different hemodynamic compensatory mechanisms. The effects of intracerebroventricular hypertonic NaCl infusion on cardiovascular compensation during hemorrhage are similar to those achieved with treatment of hemorrhagic shock with intravenous infusions of small volumes of hypertonic NaCl solutions. We therefore suggest that a substantial part of the beneficial effect of that treatment is mediated via direct effects of the hypernatremia on the brain. These observations also illustrate the need for further elucidation of more possible influences on autonomic functions by increased Na+ concentration which, together with hypovolemia, is a hallmark of dehydration.

A new approach to the mouse arm syndrome.

OBJECTIVES: The study validates a new computer mouse concept. The tested device is a small mouse with a pivoting pen-shaped handle. The hypothesis behind the design is the assumptions that the pen grip requires less static tension than the normal mouse grip and that fine-motor, high precision tasks normally are done with finger movements with forearm at rest. METHODS: Four muscles were monitored with electromyography (EMG) during work with a new mouse and with a traditional mouse. RESULTS: EMG activity was significant lower, in M. pronator teres--46%, M. extensor digitorum--46%, M. trapezius--69%, and M. levator scapulae--82%, during work with the new mouse as compared to the traditional mouse. CONCLUSION: Altering the design of the computer mouse can significantly reduce muscular tension.