Marine Envenomation in Okinawa: Overview and Treatment Concept.

Okinawa prefecture is a popular tourist destination due to its beaches and reefs. The reefs host a large variety of animals, including a number of venomous species. Because of the popularity of the reefs and marine activities, people are frequently in close contact with dangerous venomous species and, thus, are exposed to potential envenomation. Commonly encountered venomous animals throughout Okinawa include the invertebrate cone snail, sea urchin, crown-of-thorns starfish, blue-ringed octopus, box jellyfish, and fire coral. The vertebrates include the stonefish, lionfish, sea snake, and moray eel. Treatment for marine envenomation can involve first aid, hot water immersion, antivenom, supportive care, regional anesthesia, and pharmaceutical administration. Information on venomous animals, their toxins, and treatment should be well understood by prehospital care providers and physicians practicing in the prefecture.

Regional Anesthesia for Symptomatic Treatment of Stingray Envenomation.

Stingray envenomation is common in coastal regions around the world and may result in intense pain that can be challenging to manage. Described therapies involve hot water immersion and potentially other options such as opioid and nonopioid analgesics, removal of the foreign body, wound debridement, antibiotics for secondary infection, and tetanus toxoid. However, for some patients, this may not be enough. Peripheral nerve blockade is a frequently used perioperative analgesic technique, but it has rarely been described in the management of stingray envenomation. Here, we report a case of stingray envenomation in an otherwise healthy 36-y-old male with pain refractory to traditional therapies. After admission for pain control, the patient received an ultrasound-guided sciatic popliteal nerve block. Upon completion of the peripheral nerve block, the patient reported rapid and complete resolution of the intense pain, which did not return thereafter.

Prolonged Brackish Water Exposure: A Case Report.

Exposure to and consumption of brackish water are associated with an elevated risk of infection, hypernatremia, and hypothermia. Minimal data exist to support the diagnosis and treatment of patients with long-term brackish water exposure. We present a case of a patient who spent 5 to 10 d semisubmerged in the Elizabeth River in coastal Virginia. A 55-y-old male presented via ambulance after 5 to 10 d of being "stuck in the mud." He was hypernatremic, with a sodium of 176 mEq·L-1, hypothermic to 34.5°C (94.1°F), and hypotensive at 88/50 mm Hg, with a sodium concentration of 176 mEq·L-1 and an osmolality of 412 mosm·kg-1. He developed pneumonia, with respiratory cultures growing Vibrio parahemolyticus, Klebsiella oxytoca, and Shewanella algae. He had pustules, which grew Aeromonas hydrophilia and Aeromonas caviae. A nasogastric tube was placed. Using suction, 500 mL of coarse sand and gravel was removed from his stomach. Antibiotics and intravenous fluids were given. The patient fully recovered after 3 wk and was discharged to rehabilitation. Exposure to brackish water can present a unique set of infectious and metabolic complications. Initial care should include treatment of metabolic derangements, such as hypovolemia, hypernatremia, and hypothermia, and treatment of infections with antibiotics based on knowledge of the most likely causative organisms.

The Association Between Borderline Dysnatremia and Perioperative Morbidity and Mortality: Retrospective Cohort Study of the American College of Surgeons National Surgical Quality Improvement Program Database.

BACKGROUND: Hyponatremia and hypernatremia, as conventionally defined (<135 mEq/L and >145 mEq/L, respectively), are associated with increased perioperative morbidity and mortality. However, the effects of subtle deviations in serum sodium concentration within the normal range are not well-characterized. OBJECTIVE: The purpose of this analysis is to determine the association between borderline hyponatremia (135-137 mEq/L) and hypernatremia (143-145 mEq/L) on perioperative morbidity and mortality. METHODS: A retrospective cohort study was performed using data from the American College of Surgeons National Surgical Quality Improvement Program database. This database is a repository of surgical outcome data collected from over 600 hospitals across the United States. The National Surgical Quality Improvement Program database was queried to extract all patients undergoing elective, noncardiac surgery from 2015 to 2019. The primary predictor variable was preoperative serum sodium concentration, measured less than 5 days before the index surgery. The 2 primary outcomes were the odds of morbidity and mortality occurring within 30 days of surgery. The risk of both outcomes in relation to preoperative serum sodium concentration was modeled using weighted generalized additive models to minimize the effect of selection bias while controlling for covariates. RESULTS: In the overall cohort, 1,003,956 of 4,551,726 available patients had a serum sodium concentration drawn within 5 days of their index surgery. The odds of morbidity and mortality across sodium levels of 130-150 mEq/L relative to a sodium level of 140 mEq/L followed a nonnormally distributed U-shaped curve. The mean serum sodium concentration in the study population was 139 mEq/L. All continuous covariates were significantly associated with both morbidity and mortality (P<.001). Preoperative serum sodium concentrations of less than 139 mEq/L and those greater than 144 mEq/L were independently associated with increased morbidity probabilities. Serum sodium concentrations of less than 138 mEq/L and those greater than 142 mEq/L were associated with increased mortality probabilities. Hypernatremia was associated with higher odds of both morbidity and mortality than corresponding degrees of hyponatremia. CONCLUSIONS: Among patients undergoing elective, noncardiac surgery, this retrospective analysis found that preoperative serum sodium levels less than 138 mEq/L and those greater than 142 mEq/L are associated with increased morbidity and mortality, even within currently accepted "normal" ranges. The retrospective nature of this investigation limits the ability to make causal determinations for these findings. Given the U-shaped distribution of risk, past investigations that assume a linear relationship between serum sodium concentration and surgical outcomes may need to be revisited. Likewise, these results question the current definition of perioperative eunatremia, which may require future prospective investigations.

Hemodynamic Effects of Cardiovascular Medications in a Normovolemic and Hemorrhaged Yorkshire-cross Swine Model.

The Yorkshire-cross swine model is a valuable translational model commonly used to study cardiovascular physiology and response to insult. Although the effects of vasoactive medications have been well described in healthy swine, the effects of these medications during hemorrhagic shock are less studied. In this study, we sought to expand the utility of the swine model by characterizing the hemodynamic changes that occurred after the administration of commonly available vasoactive medications during euvolemic and hypovolemic states. To this end, we anesthetized and established femoral arterial, central venous, and pulmonary arterial access in 15 juvenile Yorkshire-cross pigs. The pigs then received a series of rapidly metabolized but highly vasoactive medications in a standard dosing sequence. After completion of this sequence, each pig underwent a 30-mL/kg hemorrhage over 10 min, and the standard dosing sequence was repeated. We then used standard sta- tistical techniques to compare the effects of these vasoactive medications on a variety of hemodynamic parameters between the euvolemic and hemorrhagic states. All subjects completed the study protocol. The responses in the hemorrhagic state were often attenuated or even opposite of those in the euvolemic state. For example, phenylephrine decreased the mean arterial blood pressure during the euvolemic state but increased it in the hemorrhagic state. These results clarify previously poorly defined responses to commonly used vasoactive agents during the hemorrhagic state in swine. Our findings also demonstrate the need to consider the complex and dynamic physiologic state of hemorrhage when anticipating the effects of vasoactive drugs and planning study protocols.

Impact of a Multidisciplinary Long-Term Opioid Therapy Safety Program at a Military Tertiary Academic Medical Center.

OBJECTIVE: In light of the ongoing opioid crisis, Naval Medical Center Portsmouth (NMCP) created the Long-Term Opioid Therapy Safety (LOTS) program to reduce risks and improve long-term opioid therapy outcomes. Our primary outcome was change in compliance with the recommended safety metrics. DESIGN: This is a retrospective cohort study performed at NMCP, a large military academic medical center providing comprehensive medical care to DoD beneficiaries. The NMCP LOTS program provides both patient and provider narcotic education as well as medical record auditing. The NMCP LOTS program promotes adherence to published CDC, the DVA, and DoD guidelines. METHODS: Anonymized data were compiled each fiscal quarter and were analyzed retrospectively. Adult patients prescribed opioids for at least 90 days without a gap of 30 days between prescriptions were included in this study. The investigators recorded and reported provider compliance with LOTS metrics over the same period. RESULTS: Compliance with the recommended safety metrics improved. We noted a decrease in the number of long-term opioid patients, concurrent benzodiazepine prescriptions, and patients prescribed greater than 90 morphine equivalents per day during the observation period. The number of naloxone prescriptions for LOTS patients also increased, reflecting improved guideline adherence. CONCLUSION: Systematic education and feedback to providers are effective in creating a system and culture of opioid reduction, safe opioid prescribing, and system accountability. This article presents a comprehensive approach to modifying prescribing patterns of long-term opioids in a large healthcare system.

A Novel Low-Cost Ventilator for Use in a Worldwide Pandemic: The Portsmouth Ventilator.

The ongoing severe acute respiratory syndrome coronavirus 2 or coronavirus disease 2019 pandemic has demonstrated the potential need for a low-cost, rapidly deployable ventilator. Based on this premise, we sought to design a ventilator with the following criteria: 1) standard components that are accessible to the public, 2) "open-source" compatibility to allow anyone to easily recreate the system, 3) ability to ventilate in acute respiratory distress syndrome, and 4) lowest possible cost to provide adequate oxygenation and ventilation. DESIGN: We pursued development of a pneumatic-type ventilator. The basic design involves three electrically controlled solenoid valves, a pressure chamber, the patient breathing circuit, a positive end-expiratory pressure valve, and an electronics control system. Multiple safety elements were built into the design. The user-friendly interface allows simple control of ventilator settings. The ventilator delivers a hybrid form of pneumatic, assist-control ventilation, with predicted tidal volumes of 300-800 mL, positive end-expiratory pressure 0-20 cm H2O, and Fio2 21-100%. MAIN RESULTS: The ventilator was extensively tested with two separate high-fidelity lung simulators and a porcine in vivo model. Both lung simulators were able to simulate a variety of pathologic states, including obstructive lung disease and acute respiratory distress syndrome. The ventilator performed well across all simulated scenarios. Similarly, a porcine in vivo model was used to assess performance in live tissue, with a specific emphasis on gas exchange. The ventilator performed well in vivo and demonstrated noninferior ventilation and oxygenation when compared with the standard ventilator. CONCLUSIONS: The Portsmouth Ventilator was able to perform well across all simulated pathologies and in vivo. All components may be acquired by the public for a cost of approximately $250 U.S.D. Although this ventilator has limited functionality compared with modern ventilators, the simple design appears to be safe and would allow for rapid mass production if ventilator surge demand exceeded supply.

Cadaveric Porcine Spines as a Model for the Human Epidural Space.

Most patients who undergo epidural anesthesia are pregnant and thus a protected population, which has limited investigations of the human epidural space. Among the several species studied as models for the human spine, the porcine spine has been used as a model for spine instrumentation. Although the spread of colored dye within the porcine epidural space has been investigated, no model has demonstrated in situ spread by using radiopaque contrast dye. To this end, we here used 10 Yorkshire swine cadavers through an approved tissue sharing agreement. Epidural catheters were placed by using a landmark-based loss-of-resistance technique; placement was confirmed through radiography. The catheters were connected to epidural infusion pumps to ensure consistent dosing, 2-mL boluses of contrast dye were injected into the space, and radiographs were taken and recorded after each bolus. The total spread of the contrast dye was analyzed. We demonstrated consistent and reliable spread of fluid in the epidural space among the animals used, with low variability between animals of different weights. Our results support the use of the epidural space of cadaveric swine as a model for the human epidural space. Furthermore, the technique for epidural administration by using the landmark-based loss-of-resistance demonstrated in this model was validated, thus supporting future investigations of medication delivery into the epidural space.

Hiatal Hernia as the Cause of G-Induced Abdominal Pain.

Sliding hiatal hernias are common and affect approximately 10% to 80% of the general population. The condition typically presents with reflux-type symptoms and is diagnosed either with imaging or endoscopy. In this case, the hernia presented as G-induced abdominal pain. The patient was an F-18 pilot who experienced worsening epigastric abdominal pain proportionate to the amount of accelerative force experienced. The pain would occur at approximately 3 Gs and increase beyond that. The patient was asymptomatic at rest and denied any dysphagia or reflux symptoms. The only other symptom was the occurrence of a similar pain with diaphragmatic spasm, i.e., "hiccup." The patient underwent multiple imaging modalities and procedures and was eventually found to have a sliding hiatal hernia. He underwent a Nissen fundoplication to repair it. Approximately 3 months postoperatively, the patient was able to withstand significant acceleration without pain. He has no lasting sequelae from the hernia or surgery and continues to fly.