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2.
Anesthesiology ; 132(3): 491-503, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31794512

RESUMO

BACKGROUND: Patients often use complementary and alternative herbal medicines, hence, potential exists for adverse herb-drug interactions. Fentanyl is metabolized by hepatic CYP3A4 and considered transported by blood-brain barrier P-glycoprotein. Both disposition processes could be upregulated by the herbal St. John's wort. This investigation evaluated effects of St. John's wort on fixed-dose and apparent steady-state IV fentanyl pharmacokinetics, pharmacodynamics, and clinical effects. METHODS: Healthy volunteers received a fentanyl fixed-dose infusion and an individually tailored target controlled infusion on separate days, before and after 30-day St. John's wort (300 mg thrice daily; n = 8) or placebo control (n = 8) in a randomized parallel-group design. Fentanyl plasma concentrations, pupil diameter, analgesic response to experimental pain (cold pressor), subjective side effects, and cognitive effects were measured. Plasma fentanyl concentrations and changes in pupil diameter were subjected to pharmacokinetic-pharmacodynamic modeling. RESULTS: St. John's wort did not alter fentanyl pharmacokinetics. Clearance (l/min) before and after St. John's wort (1.13 ± 0.29 and 1.24 ± 0.26, respectively) or placebo (0.96 ± 0.28 and 1.12 ± 0.27, respectively) were not different. St. John's wort also did not affect fentanyl pharmacodynamics as measured by pupil constriction after fixed-dose and tailored fentanyl infusions. EC50 (ng/ml) was 1.1 ± 0.7 and 1.4 ± 0.9 before and after St. John's wort versus 1.2 ± 0.8 and 1.4 ± 1.7 before and after placebo. Effect site equilibration time, T½,ke0 (min), was 12.8 ± 5.3 and 11.3 ± 6.4 before and after St. John's wort versus 11.4 ± 6.4 and 11.1 ± 5.6 before and after placebo. St. John's wort had no influence on analgesia, cognitive performance, or somatic cognitive-affective effects of fentanyl. CONCLUSIONS: St. John's wort did not alter fentanyl pharmacokinetics, pharmacodynamics or clinical effects, suggesting no effect on hepatic clearance or blood-brain barrier efflux. Patients taking St. John's wort will likely not respond differently to IV fentanyl for anesthesia or analgesia.


Assuntos
Analgésicos Opioides/farmacologia , Analgésicos Opioides/farmacocinética , Fentanila/farmacologia , Fentanila/farmacocinética , Interações Ervas-Drogas , Hypericum/efeitos adversos , Adulto , Analgésicos Opioides/administração & dosagem , Feminino , Fentanila/administração & dosagem , Humanos , Infusões Intravenosas , Masculino , Pupila/efeitos dos fármacos , Adulto Jovem
3.
J Surg Res ; 241: 72-77, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31009888

RESUMO

BACKGROUND: Microdermal implants are an increasingly popular form of body jewelry. The potential for electrical conduction burn at the site of metal jewelry left in situ during electrosurgery has prompted surgical societies to recommend routine removal before surgery. To date, however, there is a lack of evidence to support this practice. We assessed in vivo thermal effect and tissue damage around implants during and after electrocautery. MATERIALS AND METHODS: Stainless steel microdermal anchors were surgically implanted into four swine. After allowing for initial healing, negative controls were excised and evaluated. An electrocautery grounding pad was placed 2 cm caudal to the implant. Continuous electrocautery (coagulation/30 W) for 30 s was applied to the skin 2 cm cranial to the implant. Surface skin temperature was recorded during electrocautery using thermal imaging. Tissue damage was assessed by gross examination and histologic evaluation. The same procedure was then performed to the contralateral nonimplanted side as a sham control. RESULTS: Electrocoagulation raised skin temperature around the electrocautery tip 27.7°C (Tmax 64.8°C). Skin temperature around the dermal implant rose 1.58°C (Tmax 38.6°C) compared with 2.03°C (Tmax 39.2°C) in the nonimplanted control skin (P = 0.627). Skin temperatures at implanted and control sites showed no statistical difference at any recorded time interval. Histologic review of excised tissue samples showed no evidence of thermal injury. CONCLUSIONS: Metallic implants appear to have no effect on skin temperature during the use of electrocautery even when in close proximity to both the electrocautery pen and return pad. Aggressive steps to remove microdermal implants before surgery may be unnecessary.


Assuntos
Modificação Corporal não Terapêutica/efeitos adversos , Procedimentos Cirúrgicos Dermatológicos/efeitos adversos , Eletrocoagulação/efeitos adversos , Complicações Intraoperatórias/prevenção & controle , Animais , Modificação Corporal não Terapêutica/instrumentação , Complicações Intraoperatórias/etiologia , Modelos Animais , Sus scrofa , Suínos
4.
J Trauma Acute Care Surg ; 85(1S Suppl 2): S44-S48, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29953031

RESUMO

BACKGROUND: The early use of tranexamic acid (TXA) is strongly advocated in patients who are likely to require massive transfusion to decrease mortality. This study determines the influence of hemorrhage on the pharmacokinetics of TXA in a porcine model. METHODS: The investigation was a prospective experimental study in Yucatan minipigs. First, in vitro plasma-cell partitioning of TXA was evaluated by inoculating whole blood with known aliquots, centrifuging, and measuring the supernatant with high-performance liquid chromatography with mass spectrometry (HPLC-MS). Then, using in vivo modeling, normovolemic and hypovolemic (35% reduction in blood volume) swine (n = 4 per group) received 1 g of intravenous TXA and had blood sampled at 14 time points over 4 hours to determine baseline clearance via HPLC-MS. Additional swine (n = 4) were hemorrhaged 35% of their blood volume, and TXA was administered as a 15 mg/kg infusion over 10 minutes followed by infusion of 1.875 mg/kg per hour to simulate massive hemorrhage scenario. During the first hour of TXA administration, one total blood volume was hemorrhaged and simultaneously replaced with TXA free blood. Serial blood samples and the hemorrhaged blood were analyzed by HPLC-MS to determine the percentage of dose lost via hemorrhage. RESULTS: Clearance of TXA was diminished in the hypovolemic group compared with the normovolemic group (115 ± 4 vs 70 ± 7 mL/min). Percentage of dose lost via hemorrhage averaged 25%. The lowest measured plasma level during the exchange transfusion was 34 µg/mL. CONCLUSION: Mean 25% of the present 2017 Joint Trauma System Clinical Practice Guideline dosing of TXA can be lost to hemorrhage if a blood volume is transfused within an hour of initiating therapy. In the case of TXA, which has limited distribution and is administered during active hemorrhage and massive blood transfusions, replacement strategies should be developed and tested to find simple methods of adjusting the current dosing guidelines to maintain therapeutic plasma concentrations. LEVEL OF EVIDENCE: Therapeutic, level II.


Assuntos
Antifibrinolíticos/farmacocinética , Modelos Animais de Doenças , Exsanguinação/metabolismo , Ácido Tranexâmico/farmacocinética , Animais , Antifibrinolíticos/administração & dosagem , Antifibrinolíticos/sangue , Hipovolemia/metabolismo , Infusões Intravenosas , Masculino , Suínos , Porco Miniatura , Ácido Tranexâmico/administração & dosagem , Ácido Tranexâmico/sangue
5.
J Trauma Acute Care Surg ; 84(2): 379-385, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29194320

RESUMO

BACKGROUND: The acute coagulopathy of trauma is often accompanied by hyperfibrinolysis. Tranexamic acid (TXA) can reverse this phenomenon, and, when given early, decreases mortality from bleeding. Establishing intravenous (IV) access can be difficult in trauma and intraosseous (IO) access is often preferred for drug administration. Currently, there are no data on the efficacy of IO administered TXA. Our objectives were to compare serum concentrations of TXA when given IV and IO and to compare the efficacy of IO administered TXA to IV at reversing hyperfibrinolysis. METHODS: Using a porcine hemorrhage and ischemia-reperfusion model, 18 swine underwent hemorrhagic shock followed by a tissue plasminogen activator infusion to induce hyperfibrinolysis. Animals then received an IV or tibial IO infusion of TXA over 10 minutes. Blood was then analyzed using rotational thromboelastometry to monitor reversal of hyperfibrinolysis. Serum was analyzed for drug concentrations. RESULTS: After hemorrhage and ischemia-reperfusion, there were no significant differences in mean arterial pressure (48 vs. 49.5), lactate (11.1 vs. 10.8), and pH (7.20 vs. 7.22) between groups. Intraosseous TXA corrected the lysis index at 30 minutes in EX-TEM and IN-TEM, like IV infusion. Peak serum levels of TXA after IV and IO administration show concentrations of 160.9 µg/mL and 132.57 µg/mL respectively (p = 0.053). Peak levels occurred at the completion of infusion. Drug levels were tracked for four hours. At the end of monitoring, plasma concentrations of TXA were equivalent. CONCLUSION: Intraosseous administration of TXA is as effective as IV in reversing hyperfibrinolysis in a porcine model of hemorrhagic shock. Intraosseous administration was associated with a similar peak levels, pharmacokinetics, and clearance. Intraosseous administration of TXA can be considered in hemorrhagic shock when IV access cannot be established.


Assuntos
Choque Hemorrágico/tratamento farmacológico , Ácido Tranexâmico/administração & dosagem , Animais , Antifibrinolíticos/administração & dosagem , Antifibrinolíticos/farmacocinética , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Infusões Intraósseas , Injeções Intravenosas , Choque Hemorrágico/sangue , Suínos , Ácido Tranexâmico/farmacocinética , Resultado do Tratamento
6.
Prehosp Disaster Med ; 32(3): 305-310, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28270248

RESUMO

Introduction The American Heart Association (AHA; Dallas, Texas USA) and European Resuscitation Council (Niel, Belgium) cardiac arrest (CA) guidelines recommend the intraosseous (IO) route when intravenous (IV) access cannot be obtained. Vasopressin has been used as an alternative to epinephrine to treat ventricular fibrillation (VF). Hypothesis/Problem Limited data exist on the pharmacokinetics and resuscitative effects of vasopressin administered by the humeral IO (HIO) route for treatment of VF. The purpose of this study was to evaluate the effects of HIO and IV vasopressin, on the occurrence, odds, and time of return of spontaneous circulation (ROSC) and pharmacokinetic measures in a swine model of VF. METHODS: Twenty-seven Yorkshire-cross swine (60 to 80 kg) were assigned randomly to three groups: HIO (n=9), IV (n=9), and a control group (n=9). Ventricular fibrillation was induced and untreated for two minutes. Chest compressions began at two minutes post-arrest and vasopressin (40 U) administered at four minutes post-arrest. Serial blood specimens were collected for four minutes, then the swine were resuscitated until ROSC or 29 post-arrest minutes elapsed. RESULTS: Fisher's Exact test determined ROSC was significantly higher in the HIO 5/7 (71.5%) and IV 8/11 (72.7%) groups compared to the control 0/9 (0.0%; P=.001). Odds ratios of ROSC indicated no significant difference between the treatment groups (P=.68) but significant differences between the HIO and control, and the IV and control groups (P=.03 and .01, respectively). Analysis of Variance (ANOVA) indicated the mean time to ROSC for HIO and IV was 621.20 seconds (SD=204.21 seconds) and 554.50 seconds (SD=213.96 seconds), respectively, with no significant difference between the groups (U=11; P=.22). Multivariate Analysis of Variance (MANOVA) revealed the maximum plasma concentration (Cmax) and time to maximum concentration (Tmax) of vasopressin in the HIO and IV groups was 71753.9 pg/mL (SD=26744.58 pg/mL) and 61853.7 pg/mL (SD=22745.04 pg/mL); 111.42 seconds (SD=51.3 seconds) and 114.55 seconds (SD=55.02 seconds), respectively. Repeated measures ANOVA indicated no significant difference in plasma vasopressin concentrations between the treatment groups over four minutes (P=.48). CONCLUSIONS: The HIO route delivered vasopressin effectively in a swine model of VF. Occurrence, time, and odds of ROSC, as well as pharmacokinetic measurements of HIO vasopressin, were comparable to IV. Burgert JM , Johnson AD , Garcia-Blanco J , Fulton LV , Loughren MJ . The resuscitative and pharmacokinetic effects of humeral intraosseous vasopressin in a swine model of ventricular fibrillation. Prehosp Disaster Med. 2017;32(3):305-310.


Assuntos
Vasoconstritores/farmacocinética , Vasopressinas/farmacocinética , Fibrilação Ventricular/tratamento farmacológico , Animais , Reanimação Cardiopulmonar/métodos , Modelos Animais de Doenças , Esquema de Medicação , Infusões Intraósseas , Infusões Intravenosas , Masculino , Suínos , Resultado do Tratamento , Vasoconstritores/administração & dosagem , Vasopressinas/administração & dosagem , Fibrilação Ventricular/metabolismo
7.
Am J Disaster Med ; 11(4): 233-236, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28140437

RESUMO

OBJECTIVE: Characterize and compare the pharmacokinetics of atropine administered via the sternal intraosseous (IO) route in a normovolemic and hypovolemic swine model. DESIGN: Prospective, experimental study. SETTING: Vivarium. SUBJECTS: Yorkshire-cross swine (N = 12). INTERVENTION: Atropine was administered via the sternal IO route to normovolemic and hypovolemic swine. Blood samples were drawn at regular intervals after atropine administration and analyzed for plasma atropine concentration. Pharmacokinetic parameters were obtained from modeling the plasma concentrations. MAIN OUTCOME MEASUREMENTS: Pharmacokinetic parameters, maximum concentration (Cmax), and time to maximum concentration (Tmax). RESULTS: The normovolemic and hypovolemic models reached peak plasma concentration immediately and had a very rapid distribution phase with no apparent absorption phase for the IO groups. The hypovolemic group had slower clearance and longer half-life compared to the normovolemic group. CONCLUSION: The sternal IO route is an effective method of administering atropine and is comparable to the previously reported tibial IO and intravenous data even under conditions of significant hemorrhage.


Assuntos
Antídotos/administração & dosagem , Antídotos/farmacocinética , Atropina/administração & dosagem , Atropina/farmacocinética , Hipovolemia/tratamento farmacológico , Hipovolemia/fisiopatologia , Infusões Intraósseas , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/farmacocinética , Esterno , Animais , Guerra Química , Estudos Prospectivos , Suínos
8.
Am J Disaster Med ; 11(4): 237-242, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28140438

RESUMO

INTRODUCTION: The American Heart Association (AHA) recommends intravenous (IV) or intraosseous (IO) vasopressin in Advanced Cardiac Life Support (ACLS). Obtaining IV access in hypovolemic cardiac arrest patients can be difficult, and IO access is often obtained in these life threatening situations. No studies have been conducted to determine the effects of humeral IO (HIO) access with vasopressin in the return of spontaneous circulation (ROSC). Our study compared the kinetics of vasopressin and ROSC with HIO with IV access in the hypovolemic swine model. METHODS: Twenty-two Yorkshire swine were divided into three groups: HIO (n = 7), IV (n = 8), and a control group (n = 7). The IV and HIO group received vasopressin and cardiopulmonary resuscitation (CPR), while the control group received only CPR. All subjects were exsanguinated 31 percent of their blood volume, placed in cardiac arrest, and resuscitated per ACLS. Subjects that achieved ROSC were then monitored for 20 minutes. Blood samples (10 mL) collected at 0.5, 1, 1.5, 2, 2.5, 3, and 4 minutes after vasopressin injection and analyzed for maximum concentration (Cmax) and time to maximum concentration (Tmax). Data were analyzed using a multivariate analysis of variance (MANOVA) and a Fisher's Exact Test. RESULTS: ROSC was achieved in every subject that received vasopressin via the HIO route. Data analysis using a MANOVA pairwise comparison revealed no difference between mean Cmax (p = 0.601) and Tmax (p = 0.771) of vasopressin administered IV versus HIO routes. Analysis of the mean serum concentrations at time intervals using a repeated measures analysis of variance found no difference (p > 0.05). A Fisher's Exact Test revealed no difference in rate of ROSC between HIO and IV groups (p > 0.05). Odds ratio determined that there was a 33 times higher chance of survival among HIO subjects versus control (CPR and Defibrillation; p = 0.03) and no difference in the survivability of the HIO or IV groups (p = 0.52). CONCLUSION: The data from this study strongly suggest that there is no significant difference in ROSC, time to ROSC, hemodynamics, or pharmacokinetics between HIO vasopressin and IV vasopressin. This research reinforces current AHA guidelines recommending the use of HIO route early over delaying care awaiting IV access.


Assuntos
Reanimação Cardiopulmonar/métodos , Parada Cardíaca/tratamento farmacológico , Hipovolemia/tratamento farmacológico , Infusões Intraósseas/métodos , Vasoconstritores/administração & dosagem , Vasoconstritores/farmacocinética , Vasopressinas/administração & dosagem , Vasopressinas/farmacocinética , Animais , Modelos Animais de Doenças , Parada Cardíaca/fisiopatologia , Hipovolemia/fisiopatologia , Infusões Intravenosas , Masculino , Distribuição Aleatória , Suínos
9.
Am J Disaster Med ; 11(4): 279-282, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28140443

RESUMO

OBJECTIVE: Compare the onset and duration of rocuronium administered via the intravenous (IV), and intraosseous (IO) routes in a hypovolemic swine model. DESIGN: Prospective, between subjects, experimental study. SETTING: Vivarium. SUBJECTS: Yorkshire-cross swine (N = 8). INTERVENTION: Electromyography (EMG) amplitudes were recorded at baseline and for every 15 seconds after administering 1.2 mg/kg of rocuronium via IV or IO routes to hypovolemic swine. EMG amplitudes were measured until termination of EMG activity and then measured every 5 minutes until there was a return to baseline values. Individual data were transformed to percent baseline. MAIN OUTCOME MEASUREMENTS: The time from the end of injection to 90 percent reduction of baseline EMG activity (Onset90), the time to maximum reduction (Onsetpeak), and the maximum reduction of the neuromuscular response (peak effect), as well as, time from the end of injection to the return of 25, 50, 75, and 95 percent of baseline EMG activity was used to characterize onset and recovery of neuromuscular function. RESULTS: Maximum reduction, Onset 90 and Onset peak times were not statistically different between groups. The IV group's mean time to recovery of all benchmarks was faster than the IO group. The IO group took statistically longer than the IV group to return to 25, 50, 75, and 95 percent of baseline activity. CONCLUSION: The IO route is an effective method of administering rocuronium and is comparable to the IV route even under conditions of significant hemorrhage.


Assuntos
Androstanóis/administração & dosagem , Androstanóis/farmacocinética , Parada Cardíaca/tratamento farmacológico , Hipovolemia/tratamento farmacológico , Infusões Intraósseas , Animais , Reanimação Cardiopulmonar , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Eletromiografia , Infusões Intravenosas , Estudos Prospectivos , Distribuição Aleatória , Rocurônio , Suínos , Espectrometria de Massas em Tandem
10.
Am J Disaster Med ; 10(3): 217-22, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26663305

RESUMO

OBJECTIVE: Compare the pharmacokinetics of atropine administered via the intravenous (IV), intramuscular (IM), and intraosseous (IO) routes in a normovolemic and hypovolemic swine model. DESIGN: Prospective, between subjects, experimental study. SETTING: Vivarium. SUBJECTS: Yorkshire-cross swine (N = 36). INTERVENTION: Atropine was administered via IV, IM, or IO routes to normovolemic and hypovolemic swine. Blood samples were drawn at regular intervals after atropine administration and analyzed for plasma atropine concentration. Pharmacokinetic parameters were obtained from modeling the plasma concentrations. MAIN OUTCOME MEASUREMENTS: Pharmacokinetic parameters, maximum concentration (Cmax) and time to maximum concentration (Tmax). RESULTS: The IV and IO groups in both the normovolemic and hypovolemic models reached peak plasma concentration immediately and had a very rapid distribution phase with no apparent absorption phase for the IO groups. Peak plasma concentration and time to reach peak concentration were both significantly lower for the IM groups. There was a significant increase in absorption time with IM administration in the hypovolemic model compared to the normovolemic model. CONCLUSION: The IO route is an effective method of administering atropine and is comparable to the IV route even under conditions of significant hemorrhage. Therapeutic levels of atropine may be delayed and possibly difficult to obtain via IM injection in the presence of hypovolemic shock.


Assuntos
Atropina/administração & dosagem , Atropina/farmacocinética , Hipovolemia/tratamento farmacológico , Hipovolemia/fisiopatologia , Animais , Atropina/sangue , Atropina/uso terapêutico , Infusões Intraósseas , Infusões Intravenosas , Injeções Intramusculares , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/sangue , Antagonistas Muscarínicos/farmacocinética , Antagonistas Muscarínicos/uso terapêutico , Estudos Prospectivos , Suínos
11.
J Spec Oper Med ; 14(2): 35-37, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24952038

RESUMO

AIM: To compare the onset and duration of intravenous (IV) and intraosseous (IO) administration of succinylcholine in swine. METHODS: Electromyographic (EMG) amplitudes were used to characterize muscle paralysis following administration of succinylcholine via the IV or IO route in four Yorkshire-cross swine. RESULTS: The onset of action of succinylcholine was statistically longer after IO administration (0.97±0.40) compared with IV administration (0.55±0.26) (p=.048). Duration of action was unaffected by route of administration: IO, 11.4±4.2, and IV, 12.9±3.8 (p=.65). CONCLUSIONS: Succinylcholine can be effectively administered via the IO route. However, an increased dose may be necessary when administering succinylcholine via the IO route to achieve the same rapid onset as standard IV dosing.


Assuntos
Músculo Esquelético/efeitos dos fármacos , Bloqueio Neuromuscular/métodos , Fármacos Neuromusculares Despolarizantes/administração & dosagem , Succinilcolina/administração & dosagem , Administração Intravenosa , Animais , Estudos Cross-Over , Eletromiografia , Infusões Intraósseas , Fármacos Neuromusculares Despolarizantes/farmacologia , Paralisia , Succinilcolina/farmacologia , Sus scrofa , Suínos
12.
West J Emerg Med ; 15(2): 241-5, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24672619

RESUMO

INTRODUCTION: The intraosseous (IO) route has become a popular method to gain access to the peripheral circulation in emergency situations. Despite little supporting data, it is generally believed that IO absorption is immediate and equivalent to the intravenous (IV) route. It is important to determine if rocuronium can effectively be administered by the IO route. The aim of the study was to determine and compare the onset and duration of rocuronium when administered via the IO and IV routes in a normovolemic pig model. METHODS: We recorded electromyographic (EMG) data following tibial IO and peripheral IV administration of rocuronium (1.2 mg/kg) in 10 swine weighing between 56 and 71 Kg. We transformed data were transformed to percent of baseline, determined onset and recovery characteristics. RESULTS: The onset EMG-time profiles for IO and IV administration were very similar: tibial IO compared to IV administration did not statistically alter the onset of paralysis. The IO group took statistically longer than the IV group to return to 50 (p=0.042), 75 (p=0.034) and 95 (p=0.036) percent of baseline activity. CONCLUSION: The duration of effect is statistically longer after IO administration but is more of an academic interest than a clinical concern. The results of this study suggest that rocuronium can effectively be administered via the IO route without the need for dose adjustments.


Assuntos
Androstanóis/administração & dosagem , Fármacos Neuromusculares não Despolarizantes/administração & dosagem , Androstanóis/farmacologia , Animais , Eletromiografia/efeitos dos fármacos , Infusões Intraósseas , Infusões Intravenosas , Fármacos Neuromusculares não Despolarizantes/farmacologia , Rocurônio , Suínos/metabolismo
13.
AANA J ; 80(4 Suppl): S6-10, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23248824

RESUMO

The purpose of this study was to determine and compare the maximum concentration (C(max)) and time to maximum concentration (T(max)) of epinephrine administered via tibial intraosseous (IO), sternal IO, and intravenous (i.v.) routes in a porcine model of cardiac arrest during cardiopulmonary resuscitation. Five pigs each were randomly assigned to 3 groups: tibial IO, sternal IO, and i.v. Cardiac arrest was induced with i.v. potassium chloride. After 2 minutes, cardiopulmonary resuscitation was initiated. Epinephrine was administered to each animal, and serial blood samples were collected over the next 3 minutes. Enzyme-linked immunosorbent assay was used to determine the epinephrine concentration. Multivariate analysis of variance helped determine if there were statistically significant differences between groups. There were significant differences in Cmax between the sternal IO and i.v. (P = .009) and tibial IO and i.v. (P = .03) groups but no significant difference between tibial and sternal IO groups (P = .75). Significant differences existed in Tmax between the tibial IO and i.v. (P = .04) and between tibial IO and sternal IO (P = .02) groups but no difference between the sternal IO and i.v. groups (P = .56). Intravenous administration of 1 mg of epinephrine resulted in a serum concentration 5.87 and 2.86 times greater than for the tibial and sternal routes, respectively.


Assuntos
Epinefrina/farmacocinética , Parada Cardíaca/tratamento farmacológico , Infusões Intraósseas/métodos , Esterno , Tíbia , Animais , Reanimação Cardiopulmonar/métodos , Epinefrina/sangue , Parada Cardíaca/induzido quimicamente , Infusões Intravenosas/métodos , Projetos Piloto , Suínos , Simpatomiméticos/sangue , Simpatomiméticos/farmacocinética
14.
US Army Med Dep J ; : 31-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23007934

RESUMO

The purpose of this study was to examine the effectiveness of the hemostatic agent BleedArrest compared to control. This was a prospective, experimental design employing an established porcine model of uncontrolled hemorrhage. The minimum number of animals (n=10 per group) was used to obtain a statistically valid result. There were no statistically significant differences between the groups (P>.05) indicating that the groups were equivalent on the following parameters: activating clotting time, the subject weights, core body temperatures, amount of one minute hemorrhage, arterial blood pressures, and the amount and percentage of total blood volume. There were significant differences in the amount of hemorrhage (P=.033) between the BleedArrest (mean=72, SD±72 mL) and control (mean=317.30, SD±112.02 mL). BleedArrest is statistically and clinically superior at controlling hemorrhage compared to the standard pressure dressing control group. In conclusion, BleedArrest is an effective hemostatic agent for use in civilian and military trauma management.


Assuntos
Hemorragia/prevenção & controle , Hemostáticos/uso terapêutico , Animais , Modelos Animais de Doenças , Artéria Femoral/lesões , Veia Femoral/lesões , Masculino , Militares , Estudos Prospectivos , Suínos
15.
US Army Med Dep J ; : 36-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23007935

RESUMO

INTRODUCTION: Although hemostatic agents may be effective at stopping hemorrhage, they may fail because of hemodilution from intravenous fluids. The purpose of this study was to investigate the effects of QuikClot Combat Gauze (QCG) on rebleeding in a class II hemorrhage in the presence of hemodilution in a lethal femoral injury. METHODS: This was a prospective experimental, between swine subjects design. Pigs were assigned to one of two groups: QCG (n=15) or control (n=15). Thirty percent of the pig's blood was exsanguinated and then a 3:1 ratio of ringers lactate was administered. A groin injury was created by transecting the femoral artery and vein to simulate a battlefield injury and allowed to bleed for one minute. After one minute of hemorrhage, proximal pressure was applied to the injury, and QCG was placed into the wound followed by standard wound packing. The control group underwent the same procedures with the exception of the hemostatic agent. For both groups, 5 minutes of direct pressure was applied to the wound followed by a standard pressure dressing. Dressings were removed after 30 minutes, and the amount of hemorrhage was calculated in milliliters for each group for a period of 5 minutes. An activated clotting time was used to exclude any pigs with coagulation pathology. RESULTS: A multivariate analysis of variance indicated that there were no significant differences in the groups relative to weight, amount of one minute hemorrhage, fluid deficit replacement, blood volume, and the activated clotting time (P>.05) indicating that the groups were equivalent on these parameters. A t test indicated that there was significantly less bleeding (P=.002) in the QCG group (36 mL±112 mL) compared to the control group (340 mL±297 ml). CONCLUSION: QCG produces a robust clot that can more effectively tolerate hemodilution compared to a control group.


Assuntos
Bandagens , Hemodiluição , Hemorragia/prevenção & controle , Hemostáticos/uso terapêutico , Caulim/administração & dosagem , Animais , Plaquetas/efeitos dos fármacos , Artéria Femoral/lesões , Análise Multivariada , Estudos Prospectivos , Suínos
16.
Mil Med ; 177(3): 340-4, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22479924

RESUMO

Uncontrolled bleeding remains the leading cause of preventable death in trauma. Hemostatic agents are effective in hemorrhage control but often fail following high-volume crystalloid resuscitation. Aggressive fluid resuscitation increases the blood pressure which may dislodge the newly formed clot causing rebleeding. The purpose of this study was to determine the systolic blood pressure (SBP) and the mean arterial pressure (MAP) at which rebleeding occurs when a clot is formed by one of these hemostatic agents (BleedArrest, TraumaDex, or Celox) compared to a control group. This was a prospective, experimental study using male 5 Yorkshire swine per group (BleedArrest, TraumaDex, Celox, or control). The femoral artery and vein were transected to simulate a traumatic injury. Subjects were allowed to bleed for 60 seconds then one of the agents was poured into the wound. The control group underwent the same procedures but without the hemostatic agent. After 30 minutes, dressings were removed and the SBP was increased incrementally using intravenous phenylephrine until rebleeding occurred or until the arterial blood pressure reached 210 mm/Hg. The SBP and MAP were significantly higher in the BleedArrest, TraumaDex, and Celox groups compared to a control group (p < 0.05).


Assuntos
Biopolímeros/uso terapêutico , Pressão Sanguínea , Fêmur/lesões , Hemorragia/fisiopatologia , Hemorragia/terapia , Hemostáticos/uso terapêutico , Polissacarídeos/uso terapêutico , Animais , Coagulação Sanguínea , Modelos Animais de Doenças , Masculino , Suínos
17.
Mil Med ; 177(12): 1543-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23397703

RESUMO

The purpose of this study was twofold: (1) to examine the effectiveness of QuikClot Combat Gauze (QCG) compared to a control group and (2) investigate the effect of movement on hemorrhage control when QCG is employed. This was a prospective, experimental design employing an established porcine model of uncontrolled hemorrhage. The minimum number of animals (n = 11 per group) was used to obtain a statistically valid result. There were no statistically significant differences between the groups (p > 0.05) indicating that the groups were equivalent on the following parameters: activating clotting time, the subject weights, core body temperatures, amount of 1 minute hemorrhage, arterial blood pressures, and the amount and percentage of total blood volume. There were significant differences in the amount of hemorrhage (p = 0.018) and the number of movements (p = 0.000) between the QCG and control. QCG is statistically and clinically superior at controlling hemorrhage compared to the standard pressure dressing control group. Furthermore, it produces a more robust clot that can withstand significant movement. In conclusion, QCG is an effective hemostatic agent for use in civilian and military trauma management.


Assuntos
Hemorragia/terapia , Hemostáticos/administração & dosagem , Animais , Modelos Animais de Doenças , Artéria Femoral/lesões , Veia Femoral/lesões , Suínos
18.
J Surg Res ; 164(1): e125-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20863522

RESUMO

BACKGROUND: Hemorrhage is the second leading cause of death in civilian trauma and the leading cause of preventable death in military trauma. The purpose of this study was to examine the effectiveness of three hemostatic agents: BleedArrest, TraumaDex, and Celox. MATERIALS AND METHODS: This was a prospective, experimental study using male Yorkshire swine. The pigs (n = 5 per group) were randomly assigned to one of the following: BleedArrest, TraumaDex, Celox, or control. To simulate a trauma injury, the investigators generated a complex groin injury with transection of the femoral artery and vein in all pigs. After 1 min of uncontrolled hemorrhage, one of the hemostatic agents was poured into the wound, followed by standard wound packing. The control group underwent the same procedures with the exception of the hemostatic agents. In all groups, 5 min of direct manual pressure was applied to the wound followed by a standard pressure dressing. After 30 min, dressings were removed, and the amount of bleeding was determined. RESULTS: There were significant differences between the BleedArrest (mean = 21.2, SD ± 36.6 mL) TraumaDex (mean = 68, SD ± 103.5 mL) and Celox (mean = 18.l6, SD ± 41.6 mL) groups compared with Control group (mean = 230, SD ± 154 mL) (P < 0.05). However, there were no statistically significant difference between BleedArrest, TraumaDex, and Celox groups (P = 0.478). CONCLUSIONS: BleedArrest, Celox, and TraumaDex were statistically and clinically superior at controlling hemorrhage compared with the standard pressure dressing in the control group.


Assuntos
Biopolímeros/farmacologia , Hemorragia/tratamento farmacológico , Hemostáticos/farmacologia , Polissacarídeos/farmacologia , Animais , Bandagens , Modelos Animais de Doenças , Artéria Femoral/lesões , Veia Femoral/lesões , Masculino , Pressão , Sus scrofa
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