Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “RESUSCITATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources

Resuscitation with Hextend decreases endogenous circulating heparin activity and accelerates clot initiation after hemorrhage in the rabbit.

UNLABELLED: Hemorrhagic shock can result in a hypercoagulable state and has been associated with both hemorrhagic and thrombotic complications in the perioperative period. The author hypothesized that hemorrhage and resuscitation could result in a hypercoagulable state via changes in the heparin-antithrombin III anticoagulant mechanism in rabbits. Rabbits sedated with ketamine underwent sham operation (n = 8) or hemorrhage (25 mL/kg blood shed) for 60 min, followed by resuscitation with an equal volume of 5% human albumin (n = 8) or Hextend (n = 8). Coagulation analysis with the Thrombelastograph analyzer and determination of endogenous heparin and antithrombin III activity were performed on arterial blood samples obtained before hemorrhage and 30 min after resuscitation. The reaction time significantly decreased by 34% after hemorrhage and resuscitation with Hextend, whereas no other significant changes in Thrombelastograph variables were noted. Antithrombin III activity was significantly less in the Albumin (83% +/- 8% of control, mean +/- SD) and Hextend (88% +/- 8%) Resuscitated groups compared with the Sham-Operated animals. Of interest, only the Hextend-Resuscitated animals demonstrated a significant decrease in heparin activity (53.4 +/- 13.6 mU/mL before hemorrhage, 42.3 +/- 5.6 mU/mL after resuscitation). A Hextend)-mediated decrease of both heparin and antithrombin III activity may explain the acceleration of clot initiation compared with albumin administration after hemorrhage in the rabbit. IMPLICATIONS: Hemorrhage may result in a hypercoagulable state after resuscitation. Decreases in both endogenous heparin and antithrombin III activity after hemorrhage and Hextend resuscitation in rabbits resulted in a significantly decreased time to clot coagulation analysis initiation without a significant change in the rate of clot formation or final clot strength.

Animals↗

Stress hormone response during and after cardiopulmonary resuscitation.

The purpose of this study was to assess whether plasma adrenocorticotropin, cortisol, vasopressin, and renin concentrations are higher in resuscitated than in nonresuscitated patients during cardiopulmonary resuscitation, and whether there are possible correlations between these hormones and blood pressure or heart rate in the immediate postresuscitation phase. Of 34 consecutive patients (36-85 yr of age) with out-of-hospital cardiac arrest, 20 could be successfully resuscitated and admitted to hospital, whereas in the remaining 14 patients restoration of spontaneous circulation could not be achieved. During cardiopulmonary resuscitation, median adrenocorticotropin, cortisol, vasopressin, and renin concentrations in the external jugular vein were 237 pg/ml, 32.6 micrograms/dl, 122 pg/ml, and 46.5 ng/l, respectively, in resuscitated patients, and 45 pg/ml (P = 0.018), 18.4 micrograms/dl (P = 0.481), 88 pg/ml (P = 0.049), and 11 ng/l (P = 0.017), respectively, in nonresuscitated patients. Median adrenocorticotropin, cortisol, vasopressin, and renin concentrations were 101 pg/ml, 34.6 micrograms/dl, 22 pg/ml, and 25 ng/l, respectively, 60 min after successful resuscitation. No significant correlations were found between hormone levels and blood pressure or heart rate, but there was a significant negative correlation between the interval from collapse to the start of cardiopulmonary resuscitation and plasma cortisol concentrations during cardiopulmonary resuscitation (Spearman rank correlation coefficient = -0.967, P less than 0.001), indicating an impaired cortisol release from the adrenal cortex. The lower hormone concentrations of the nonresuscitated patients measured during cardiopulmonary resuscitation might indicate an impairment in neuroendocrine response.

Adrenocorticotropic Hormone↗

An evaluation of the physical and functional characteristics of resuscitators for use in pediatrics.

OBJECTIVE: To evaluate the physical and functional characteristics of pediatric self-inflating resuscitators. DESIGN: Tested under simulated clinical conditions. Results were analyzed by descriptive analysis. SETTING: A pulmonary laboratory in a university hospital. METHODS: Eight new pediatric self-inflating resuscitators were obtained from the manufacturers and evaluated for functional characteristics including: a) fraction of delivered oxygen at 10 L/min and a tidal volume of 300 mL; b) maximum stroke volume against no resistance; and c) maximum cycling frequency at -5 degrees C, 20 degrees C, and 48 degrees C. The resuscitators were also evaluated for physical characteristics, including potential for misassembly, pressure relief valves, expiratory valve leak, and inspiratory resistance. RESULTS: All resuscitators met the minimum standards of the Canadian Standards Association and American Standards for Testing of Materials. However, one bag cycled at only 32 breaths/min at -5 degrees C, marginally within accepted standards. Only five self-inflating resuscitators had pop-off valves. These valves malfunctioned, with valve activation occurring well above the accepted standards. Three of the self-inflating resuscitators could be misassembled for use. Four of the resuscitators were unable to deliver tidal volumes required for preoxygenation in a 20-kg child. CONCLUSIONS: While these self-inflating resuscitators met the minimum standards, they are all unable to deliver 100% oxygen. One unit is probably not appropriate in the out-of-hospital setting when ambient temperatures are less than 0 degrees C. Those resuscitators that can be misassembled are dangerous in unskilled hands. In addition, reliance on pop-off valve activation to limit airway pressure is dangerous.

Child↗

Improvements in rheologic properties of blood by fluid resuscitation after burn injury in rats.

Severe burn injury impairs tissue perfusion both by adversely altering the rheologic properties of blood and by decreasing circulating blood volume. Although resuscitation is known to improve perfusion by increasing whole blood volume, it is possible that it may also improve blood flow. To assess these latter effects of resuscitation after burn injury, we studied several determinants of blood flow. Burned animals were resuscitated with 20 ml of lactated Ringer's solution given intraperitoneally. This fluid resuscitation significantly improved the hemoconcentration that was produced by burn injury (p less than 0.05). Burn injury caused an increase in free plasma hemoglobin (p less than 0.05). Fluid resuscitation after injury reduced free plasma hemoglobin compared with that of the burned animals (p less than 0.05), although it still remained higher than free plasma hemoglobin in unburned controls (p less than 0.05). Increased whole blood viscosity and increased osmotic fragility, which were caused by burn injury, were also corrected by fluid resuscitation. Finally, the decrease in red blood cell membrane deformability that is associated with burn injury was improved by resuscitation, although it never completely returned to normal. These results demonstrate beneficial effects of fluid resuscitation on rheologic properties of blood after burn injury. Restoration of blood flow to tissue by resuscitation after burn injury may be due to improved blood rheology as well as to intravascular volume loading.

Animals↗

Should normothermia be restored and maintained during resuscitation after trauma and hemorrhage?

BACKGROUND: Although hypothermia often occurs after trauma and has protective effects during ischemia and organ preservation, it remains unknown whether maintenance of hypothermia or restoring the body temperature to normothermia during resuscitation has any deleterious or beneficial effects on heart performance and organ blood flow after trauma-hemorrhage. METHODS: Male rats underwent laparotomy (i.e., induced trauma) and were exsanguinated to and maintained at a mean arterial pressure of 40 mm Hg until 40% of the maximum shed volume was returned in the form of Ringer's lactate. Body temperature decreased from approximately 36.5 degrees C to below 32 degrees C. The animals were then resuscitated with four times the volume of maximal bleedout with Ringer's lactate. In one group, body temperature was rewarmed to 37 degrees C during resuscitation. In another group, body temperature was maintained at hypothermia (32 degrees C) for 4 hours after resuscitation. In an additional group, the body temperature was kept at 37 degrees C during hemorrhage as well as during resuscitation. Left ventricle performance parameters such as maximal rate of left ventricular pressure increase and decrease (+/-dP/dt(max)) were measured up to 4 hours. Cardiac output and regional blood flow were determined by radioactive microspheres at 4 hours after the completion of resuscitation. RESULTS: The maintenance of normothermia during hemor. rhage or prolonged hypothermia after resuscitation depressed the left ventricular performance parameters, cardiac output, and regional blood flow in various organs. Rewarming the body to normothermia during resuscitation, however, significantly increased heart performance, cardiac output (from hypothermia 16.2 +/- 1.4 to 22.3 +/- 1.4 mL/min per 100 g body weight,p < 0.05) and total hepatic blood flow (from hypothermia 117.5 +/- 5.3 to 166.0 +/- 9.3 mL/min per 100 g tissue, p < .05). CONCLUSION: Our data indicate that restoration of normothermia during resuscitation improves cardiac function and hepatic blood flow compared with hypothermia.

Animals↗

Tissue hemoglobin O2 saturation during resuscitation of traumatic shock monitored using near infrared spectrometry.

BACKGROUND: Near infrared (NIR) spectrometry offers a noninvasive monitor of tissue hemoglobin O2 saturation and has been developed to report a quantitative clinical variable, StO2 [= HbO2/(HbO2 + Hb)]. In this study, a prototype NIR oximeter was used to investigate the hypothesis that changes in systemic O2 delivery index (D(O2)I) would be reflected by changes in StO2 in skeletal muscle, subcutaneous tissue, or both, as reperfusion occurs during shock resuscitation. StO2 was also compared with other indices of severity of shock or adequacy of resuscitation, including arterial base deficit, lactate, gastric mucosal P(CO2) (PgCO2), and mixed venous hemoglobin O2 saturation (S(VO2)). METHODS: Skeletal muscle and subcutaneous tissue StO2 were monitored simultaneously in eight severely injured trauma patients (88% blunt mechanism; age, 42 +/- 6 years; Injury Severity Score, 27 +/- 3) during standardized shock resuscitation in the intensive care unit with the primary goal of D(O2)I > or = 600 mL O2/min/m2 for 24 hours, and for an additional 12 hours during transition from resuscitation to standard intensive care unit care. RESULTS: Skeletal muscle StO2 increased significantly from 15 +/- 2% (mean +/- SEM) at the start of resuscitation to 49 +/- 14% at 24 hours, and to approximately 55% from 25 to 36 hours. Subcutaneous tissue StO2 approximately 82% and was significantly greater than skeletal muscle StO2 throughout. D(O2)I increased significantly from 372 +/- 54 to 718 +/- 47 mL O2/min/m2 during resuscitation. Over 36 hours, mean D(O2)I and skeletal muscle StO2 were highly correlated (r = 0.95). Neither D(O2)I-PgCO2 nor D(O2)I-S(VO2) were significantly correlated; neither S(VO2) nor subcutaneous tissue StO2 changed significantly. CONCLUSION: Hemoglobin O2 saturation was monitored noninvasively and simultaneously in skeletal muscle and subcutaneous tissues as StO2 (%) by using a prototype NIR oximeter. Skeletal muscle StO2 tracked systemic O2 delivery during and after resuscitation. As a rapidly deployable, noninvasive monitor of peripheral tissue oxygenation and O2 delivery, skeletal muscle StO2 obtained using NIR spectrometry would be useful to guide resuscitation in the intensive care unit, to monitor resuscitation status in the operating room, and, potentially, in combination with indicators such as base deficit and lactate, to detect shock during initial assessment of the severe trauma patient in the emergency department.

Adult↗

Normal versus supranormal oxygen delivery goals in shock resuscitation: the response is the same.

BACKGROUND: Shock resuscitation is integral to early management of severely injured patients. Our standardized shock resuscitation protocol, developed in 1997 and implemented as a computerized intensive care unit (ICU) bedside decision support tool in 2000, used oxygen delivery index (Do I) > or = 600 mL/min/m as the intervention endpoint. In a recent publication, Shoemaker et al. refuted positive outcome effect of early supranormal Do (i.e., Do I > or = 600) resuscitation. In response to and because of ongoing concern for excessive volume loading, we decreased our Do I endpoint from 600 to 500. Our hypothesis was that by decreasing the Do I endpoint, less crystalloid would be administered. We compare resuscitation responses to the protocol with goals of Do I > or = 600 versus 500 in two patient cohorts. METHODS: A standardized protocol was used to direct bedside decisions for resuscitation of patients with major injury (Injury Severity Score > 15), blood loss (> or = 6 units of packed red blood cells), metabolic stress (base deficit > or = 6 mEq/L), and no severe brain injury. The protocol logic is to attain and maintain Do I > or = a specified goal for the first 24 ICU hours using primarily blood and volume loading. Two cohorts were compared: Do I > or = 500 (18 patients admitted February-August 2001) versus Do I > or = 600 (18 patients admitted during 2000 age and gender matched with the Do I > or = 500 group). Data were analyzed using analysis of variance, chi, and t tests (p < 0.05). RESULTS: Both groups had similar demographics (age 30 +/- 3 years; 78% men; Injury Severity Score 27 +/- 3), hemodynamics, and severity of shock at start of resuscitation in the ICU. Resuscitation response was Do I increase to > or = 600 for both cohorts within approximately 12 hours. Throughout the 24-hour ICU process, the Do I > or = 500 cohort received less lactated Ringer's volume than the Do I > or = 600 cohort (total of 8 +/- 1 vs. 12 +/- 2 L; p < 0.05) and tended to receive less blood transfusion (total of 3 +/- 1 vs. 5 +/- 1 units of packed red blood cells). CONCLUSION: Shock resuscitation using Do I > or = 500 was indistinguishable from Do I > or = 600 mL/min/m. Less volume loading was required to attain and maintain Do I > or = 500 than 600 using computerized protocol technology to standardize resuscitation during the first 24 ICU hours.

Adult↗

Cytosolic Ca2+ concentration and contraction-relaxation properties of ventricular myocytes from Escherichia coli endotoxemic guinea pigs: effect of fluid resuscitation.

Hearts isolated from a guinea pig model of Escherichia coli endotoxemia exhibit decreased systolic contractile function and reduced diastolic compliance of the left ventricle within 4 h after injection of endotoxin. Fluid resuscitation prevented the endotoxin-induced decrease in diastolic compliance without affecting systolic contractile depression. Because intrinsic myocardial dysfunction after endotoxemia may result from alterations in intracellular Ca2+ handling, we tested the hypothesis that in vivo fluid resuscitation improved diastolic function by altering Ca2+ handling of the myocardium. We tested this hypothesis by measuring cell shortening and intracellular Ca2+ of ventricular myocytes isolated from endotoxemic guinea pigs. E. coli endotoxin (LPS, 1 mg/kg)-injected guinea pigs were divided into resuscitated and nonresuscitated groups. Fluid resuscitated animals received a Ringer's infusion (8 mL.kg-1.h-1) intravenously (i.v.) beginning immediately after endotoxin injection. Four hours later, ventricular myocytes were isolated enzymatically and loaded with fura-2/AM. When myocytes were field stimulated at .8 Hz, peak systolic Ca2+ transients of LPS-resuscitated (619 +/- 75 nM) and LPS-nonresuscitated (599 +/- 60 nM) myocytes were not significantly different from each other, but both were significantly less than values from control myocytes (1187 +/- 118 nM, p < .05). The percentage of cell shortening of LPS-resuscitated (6.2 +/- .9%) and LPS-nonresuscitated (6.2 +/- .3%) myocytes were also less than control (11.8 +/- .5%, p < .05). In contrast to improved diastolic compliance of fluid-resuscitated hearts, diastolic [Ca2+]i of myocytes (at .8 Hz) from LPS-resuscitated animals (138 +/- 47 nM) was not statistically different from LPS-nonresuscitated animals (129 +/- 19 nM). Diastolic values of both LPS groups were consistently lower than control value (251 +/- 38 nM, p < .05). These data suggest that improved diastolic compliance of LPS hearts following fluid resuscitation is not associated with improved myocyte contractility or myoplasmic Ca2+ handling.

Animals↗

Phagocytic reticuloendothelial function after hemorrhage and resuscitation: modulation by different fluids.

Although the efficacy of colloid resuscitation fluids in restoring cardiovascular status in hemorrhagic shock is accepted, the effect they have on the activity of the reticuloendothelial system (RES) is less clear. As interaction with the RES may be important in determining susceptibility to infections after resuscitation the effects of three such fluids, hydroxyethyl starch, Haemaccel, and fresh autologous blood on RES function after a 40% hemorrhage have been investigated in BALB/C mice. The mice, anesthetized with isoflurane, were bled over a 10 min period, left hypovolemic for 30 min, and then resuscitated with their shed blood or the same volume of asanguineous fluid. Normothermia was maintained throughout the experiments. Whole body phagocytic activity was assessed at 1, 6, 24, 48, and 72 h after the end of hemorrhage by measuring the clearance rate (K) of intravenously injected 51Cr-labeled sheep red blood cells. No significant change in K was found at any time in animals resuscitated with shed blood. However, significant increases in K were found 48 h after resuscitation with Haemaccel. Hepatic uptake of sheep red blood cells was significantly increased at 48 and 72 h in Haemaccel-resuscitated animals compared with hydroxyethyl starch or shed blood resuscitation, whereas spleen uptake decreased at 72 h. Lung uptake was not affected at any time with any fluid. The same volume of Haemaccel had no significant effect either on K or on organ uptake when given to normovolemic animals. The changes in organ uptake after hemorrhage and resuscitation with Haemaccel were partially prevented if animals were resuscitated with Haemaccel plus autologous red cells.

Animals↗

Beta1-adrenergic blockade during cardiopulmonary resuscitation improves survival.

OBJECTIVE: The short-acting beta1-selective adrenergic blocking agent, esmolol, was administrated during cardiopulmonary resuscitation with the hypothesis that initial resuscitation and postresuscitation survival would be improved. DESIGN: Prospective, randomized, controlled study. SETTING: Animal research laboratory. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Ventricular fibrillation was induced in 18 male Sprague-Dawley rats, which were then left untreated for 6 mins before attempted resuscitation with precordial compression, mechanical ventilation, and electrical defibrillation. Animals were randomized to receive 300 microg/kg esmolol in a volume of 200 microL or an equivalent volume of saline placebo during cardiopulmonary resuscitation. Electrical defibrillation was attempted after 12 mins of ventricular fibrillation. MEASUREMENTS AND MAIN RESULTS: Esmolol-treated animals required a significantly smaller number of electrical shocks before resuscitation. Each of the esmolol-treated but only five of nine placebo-treated animals were successfully resuscitated. Postresuscitation contractile and left ventricular diastolic functions of resuscitated animals were significantly better after esmolol administration and duration of survival was significantly increased. CONCLUSIONS: A short-acting beta1-selective adrenergic blocking agent, when administered during cardiopulmonary resuscitation, significantly improved initial cardiac resuscitation, minimized postresuscitation myocardial dysfunction, and increased the duration of postresuscitation survival.

Adrenergic beta-Antagonists↗

Normotensive and hypotensive closed-loop resuscitation using 3.0% NaCl to treat multiple hemorrhages in sheep.

OBJECTIVE: NaCl solutions (7.5%) have been reported to be effective for resuscitation in animals and trauma patients, but these solutions are not approved for use in the United States. We hypothesized that infusion of Food and Drug Administration-approved 3% NaCl provides superior cardiovascular and metabolic function while reducing the overall fluid requirement for resuscitation of hemorrhage. Our objective was to compare four groups, hypotensive and normotensive resuscitation of hemorrhage using 3% NaCl (HS) or lactated Ringer's (LR). DESIGN: Sheep were hemorrhaged in three separate bleeds, 25 mL/kg at T0 mins and 5 mL/kg at both T50 and T70 mins. SETTING: University laboratory. SUBJECTS: Instrumented conscious sheep. INTERVENTIONS: Resuscitation was started at T30 mins and continued until T180. Normotensive and hypotensive resuscitation to mean arterial pressures of 90 mm Hg and 65 mm Hg, respectively, was performed with LR or HS using a closed-loop resuscitation system. MEASUREMENTS AND MAIN RESULTS: All four groups were successfully resuscitated to near target levels. Two animals in the hypotensive treatment protocols died during the second and third bleeding, one with the LR65 group and one with the HS65 group. Mean infused volumes were 59.9 +/- 7.0 and 18.0 +/- 5.9 in the LR90 and LR65 groups, respectively, and were 19.6 +/- 2.2 mL/kg and 13.3 +/- 5.7 mL/kg in the HS90 and HS65 treatments (p < .05; LR90 vs. each of the groups). Cardiac indexes were significantly higher with normotensive vs. hypotensive treatment. However, there was no hemodynamic advantage apparent with HS vs. LR when compared with the normotensive or hypotensive treatments. Some animals had high lactate levels (>10 mmol) with both of the hypotensive treatments and also with the HS90 treatment, while not one of the 11 LR90 treatment animals had lactate levels >8 mmol. CONCLUSIONS: Volume sparing was apparent with HS, but no hemodynamic or metabolic advantage was apparent when used for either normotensive or hypotensive resuscitation. Trends toward lower base excess values and higher occurrences of deaths only in the hypotensive treatment protocols suggest that resuscitation to a target mean arterial pressure of 65 mm Hg may be too low.

Animals↗

Hyperosmotic-hyperoncotic versus hyperosmotic-hyperviscous: small volume resuscitation in hemorrhagic shock.

The aim of this study was to test the effects of using a high-viscosity fluid after small-volume hyperosmotic resuscitation from hemorrhagic shock and to compare this to hyperosmotic followed by hyperoncotic resuscitation. Studies were made in the awake hamster window chamber preparation with the animals subjected to hemorrhage of 50% of blood volume and resuscitated with a small volume of a 7.5% NaCl solution, which was followed within minutes by infusion of 25% of withdrawn volume of either 0.7% or 0.8% alginate solutions (A0.7%, 7.6 cp; and A0.8%, 10.2 cp) or 5% hydroxyethyl starch (HES 5%, 2.1 cp). All modalities of resuscitation returned blood pressure to near baseline values in 5 min, which remained elevated after 90 min with A0.7% and A0.8% but returned to near shock values in 15 min with HES 5%. Microvascular flow and functional capillary density (FCD) followed the same pattern, being significantly higher for the alginate solutions than HES 5% after 90 min. Plasma viscosity 90 min after resuscitation was 2.1 and 2.6 cp for A0.7% and A0.8%, respectively, and 1.1 cP for HES 5%. There was an apparent directly proportional relationship between the concentration of alginate and blood pressure recovery, with blood pressure near normal with A0.8%, and approximately 20 mmHg lower with A0.7%. The recovery of microvascular flow and FCD, although showing a trend toward being more effective with A0.8%, was not significantly different from A0.7% but statistically different and improved relative to HES 5%. The high-viscosity fluids provide a novel small-volume method of resuscitation that maximizes microvascular perfusion for extended periods until surgical control of bleeding is possible. Results show that high-plasma-viscosity resuscitation provides a more consistent and prolonged resuscitation than hyperoncotic treatment. The increase in viscosity presents a gradual recovery in blood pressure and may be used as an alternative for small-volume hypotensive resuscitation, increasing tissue perfusion while potentially limiting hemorrhage in vascular injuries of the major blood vessels.

Animals↗

Choice of fluid influences outcome in prolonged hypotensive resuscitation after hemorrhage in awake rats.

Hypotensive resuscitation (Hypo) has been considered an alternate resuscitation strategy in clinical settings that prevent the application of standard Advanced Trauma Life Support care. However, validation of this approach when used for prolonged periods of time remains to be demonstrated. The purpose of this study was to evaluate prolonged Hypo as an alternative to standard resuscitation using various currently available resuscitative fluids. Unanesthetized, male Sprague-Dawley rats underwent computer-controlled hemorrhagic shock and resuscitation. There were six experimental groups; nonhemorrhage (NH), nonresuscitated control (C), Hypo with lactated Ringer's (HypoLR), Hypo with Hextend, 6% hydroxyethyl starch in a balanced salt solution (HEX), Hypo with PolyHeme, a polymerized hemoglobin solution (HBOC), or standard resuscitation with LR (StandLR). Animals were bled over 15 min to a mean arterial blood pressure (MAP) of 40 mmHg where the blood pressure (BP) was held for 30 min. Hypo groups were resuscitated to 60 mmHg for 4 h followed by further resuscitation to 80 mmHg. StandLR rats were resuscitated to 80 mmHg immediately after the hemorrhage period. Animals were monitored until death or they were sacrifice at 24 h. Prolonged Hypo with HEX or LR resulted in a trend toward improved 24-h survival compared with C (71%, 65%, and 48%, respectively), and performed at least as well as StandLR (58% survival). HEX required significantly less intravenous fluid (0.7x total estimated blood volume [EBV]) compared with HypoLR (1.9x EBV) and StandLR (3.2x EBV) (P < 0.05). Although HBOC required the smallest fluid volume (0.4x EBV), survival was no better than C and it resulted in the most significant acidosis. These results support the decision to use Hextend for Hypo, a strategy currently being applied on the battlefield.

Acidosis↗

Effect of different resuscitation fluids on cytokine response in a rat model of hemorrhagic shock.

This study was designed to determine the effects of different resuscitation fluids on the production of proinflammatory and anti-inflammatory cytokines in an animal model of hemorrhagic shock. Wistar male rats (n = 24; 8/group) were subjected to a volume-controlled hemorrhagic shock for 30 minutes and resuscitated as follows: (1) sham group without resuscitation, (2) lactated Ringer solution (LR), 3:1; (3) 4% hydroxyethyl starch (HES) solution, 1:1; and (4) 4% modified fluid gelatin (GEL), 1:1. Hemodynamic parameters were recorded, and blood samples were collected at 0 min and 30, 90, 150, 210, 270, and 330 min after hemorrhage for plasma levels of IL-6, IL-10, and TNFalpha. The circulating concentrations of IL-6 at 90, 150, 210, 270, and 330 min and TNFalpha levels at 150, 210, and 270 min after hemorrhage were significantly elevated in animals resuscitated with GEL compared with HES or LR (P < 0.05). At 210, 270, and 330 min, IL-10 concentration was decreased significantly in GEL-resuscitated rats compared with rats resuscitated with LR or HES (P < 0.05). Mean blood pressure and serum levels of lactate after resuscitation were not different among three kinds of fluids. LR, HES, and GEL are comparable in volume efficacy for resuscitation of hemorrhagic shock but are associated with different postresuscitation immune responses. Resuscitation with GEL may be associated with cytokine production favoring a proinflammatory response. The marked elevation of IL-6 observed in the GEL-treated animals may play a role in the relatively high frequency of anaphylactoid reaction in clinical use of GEL.

Animals↗

Effects of crystalloid and colloid resuscitation on hemorrhage-induced vascular hyporesponsiveness to norepinephrine in the rat.

BACKGROUND: We have shown previously that hemorrhagic hypotension is associated with a progressive development of vascular hyporeactivity to norepinephrine (NE). The present study investigated whether select crystalloid or colloid resuscitation fluids would ameliorate this effect. METHOD: Anesthetized male rats were hemorrhaged to and maintained at a mean arterial pressure (MAP) of 50 mm Hg for 60 minutes. Rats (n = 7 per group) were then resuscitated with lactated Ringer's (LR), 7.5% hypertonic saline (HS) for 1 hour followed by LR (HS-LR), Hespan, or Hextend to restore and maintain MAP to 70 mm Hg over 4 hours. Additional hemorrhaged groups were resuscitated with LR to the baseline MAP (LR-BL) or received no resuscitation. A sham hemorrhage group served as controls. The responses of MAP and the blood flow of the superior mesenteric, celiac, left renal, and left femoral arteries to NE (3 microg/kg administered intravenously) were measured at BL (prehemorrhage); at the end of the hypotensive period; and at 1, 2, and 4 hours after resuscitation. RESULTS: Hemorrhagic hypotension significantly (p < 0.01) reduced the NE-induced pressor response in MAP and significantly reduced the contractile responses (reflected by the reduction of blood flow after NE administration) of the four arteries to NE. Hespan and Hextend infusion improved the NE response of MAP and the contractile responses of the observed arteries to NE significantly better than LR, HS-LR, or LR-BL. The colloids improved the vascular contractile responses to NE in the superior mesenteric and left femoral arteries and the pressor response of MAP to NE, to 80% to 90% of their basal response level compared with 40% to 60% with the crystalloid fluids (p < 0.05). LR-BL infusion resulted in hemodilution, with no added benefit to vascular responsiveness. CONCLUSION: These data suggest that hypotensive resuscitation to 70 mm Hg with colloids was better than crystalloids in improving vascular responsiveness to the pressor effects of NE and required smaller volumes. Normotensive resuscitation with LR was not better than hypotensive resuscitation. Not all vasculatures improved equally after fluid resuscitation.

Animals↗

Direct peritoneal resuscitation from hemorrhagic shock: effect of time delay in therapy initiation.

BACKGROUND: After conventional resuscitation from hemorrhagic shock, splanchnic microvessels progressively constrict, leading to impairment of blood flow. This occurs despite restoration and maintenance of central hemodynamics. The authors' recent studies have demonstrated that topical and continuous ex vivo exposure of the gut microvasculature to a glucose-based clinical peritoneal dialysis solution (Delflex), as a technique of direct peritoneal resuscitation (DPR), can prevent these postresuscitation events when initiated simultaneously with conventional resuscitation. This study aimed to determine whether DPR applied after conventional resuscitation reverses the established postresuscitation intestinal vasoconstriction and hypoperfusion. METHODS: Male Sprague-Dawley rats were bled to 50% of baseline mean arterial pressure and resuscitated intravenously over 30 minutes with the shed blood returned plus two times the shed blood volume of saline. Initiation of ex vivo, topical DPR was delayed to 2 hours (group 1, n = 8), or to 4 hours (group 2, n = 8), respectively, after conventional resuscitation. Intravital microscopy and Doppler velocimetry were used to measure terminal ileal microvascular diameters of inflow A1 and premucosal A3 (proximal pA3, distal dA3) arterioles and blood flow in the A1 arteriole, respectively. Maximum arteriolar dilation capacity was obtained from the topical application, in the tissue bath, of the endothelium-independent nitric oxide-donor sodium nitroprusside (10M). RESULTS: Hemorrhagic shock caused a selective vasoconstriction of A1 (-24.1% +/- 2.15%) arterioles from baseline, which was not seen in A3 vessels. This caused A1 blood flow to drop by -68.6% of the prehemorrhage value. Conventional resuscitation restored and maintained hemodynamics in all the animals without additional fluid therapy. In contrast, there was a generalized and progressive postresuscitation vasoconstriction of A1 (-21.7%), pA3 (-18.5%), and dA3 (-18.7%) vessels. The average postresuscitation A1 blood flow was -49.5% of the prehemorrhage value, indicating a persistent postresuscitation hypoperfusion. Direct peritoneal resuscitation reversed the postresuscitation vasoconstriction by 40.9% and enhanced A1 blood flow by 112.9% of the respective postresuscitation values. CONCLUSIONS: Delayed DPR reverses the gut postresuscitation vasoconstriction and hypoperfusion regardless of the initiation time. This occurs without adverse effects on hemodynamics. Direct peritoneal resuscitation-mediated enhancement of tissue perfusion results from the local effects from the vasoactive components of the Delflex solution, which are hyperosmolality, lactate buffer anion, and, to a lesser extent, low pH. The molecular mechanism of this vasodilation effect needs further investigation.

Analysis of Variance↗

A survey of opinion amongst trained nurses and junior medical staff on current practices in resuscitation.

An anonymously-completed questionnaire was used to examine the opinions of trained nurses and their junior medical colleagues regarding the resuscitation of a patient following cardiac arrest. Nurses were less satisfied with their pre-qualification training and recorded lower scores on a subjective assessment of performance than did the doctors. Those nurses who had attended some post-qualification training in resuscitation were significantly more confident of their resuscitation skills. Both doctors and nurses agreed on some frequently-encountered problems such as the presence of too many people and the uncertainty of those present of the role they should assume. Doctors recorded poor initial resuscitation and the absence of equipment as common problems significantly more often than did the nurses. Nurses showed a lack of knowledge of the drugs used during a resuscitation: 30% were unsure of the function of more than half of the drugs. Nearly 20% of nurses showed a similar lack of knowledge with regard to the equipment used. Those having post-qualification training in resuscitation recorded significantly greater knowledge in these areas. Widespread support was shown for the proposed initiation of compulsory resuscitation lectures, the presence on each ward of resuscitation equipment and more clearly defined roles for those taking part in the procedure. A requirement for a full-time resuscitation officer is clearly indicated.

Attitude of Health Personnel↗

As seen on TV: observational study of cardiopulmonary resuscitation in British television medical dramas.

OBJECTIVE: To determine the frequency and accuracy with which cardiopulmonary resuscitation is portrayed in British television medical dramas. DESIGN: Observational study. SUBJECTS: 64 episodes of three major British television medical dramas: Casualty, Cardiac Arrest, and Medics. MAIN OUTCOME MEASURES: Frequency of cardiopulmonary resuscitation shown on television; age, sex, and diagnosis of the patients undergoing resuscitation; rate of survival through resuscitation. RESULTS: Overall 52 patients had a cardiorespiratory arrest on screen and 3 had a respiratory arrest alone, all the arrests occurring in 40 of the 64 episodes. Of the 52 patients having cardiorespiratory arrest, 32 (62%) underwent an attempt at cardiopulmonary resuscitation; 8 attempts were successful. All 3 of the patients having respiratory arrests alone received ventilatory support and survived. On 48% of occasions, victims of cardiac arrest seemed to be less than 35 years old. CONCLUSIONS: Cardiorespiratory resuscitation is often depicted in British television medical dramas. Patients portrayed receiving resuscitation are likely to be in a younger age group than in real life. Though the reasons for resuscitation are more varied and more often associated with trauma than in reality, the overall success rate is nevertheless realistic. Widespread overoptimism of patients for survival after resuscitation cannot necessarily be blamed on British television medical dramas.

Cardiopulmonary Resuscitation↗