Abstract:
BACKGROUND:Blood conservation strategies and transfusion guidelines remain a heavily debated clinical topic. Previous investigational trials have shown that acute isovolemic hemodilution does not limit adequate oxygen delivery; however, a true critical hemoglobin level has never been investigated or defined due to safety concerns for human volunteers. Validated physiologic modeling may be useful to investigate hemodilution at critical hemoglobin levels without the ethical or safety hazards of clinical trials. Our hypothesis is that HumMod, an integrative physiological model, can replicate the cardiovascular and metabolic findings of previous clinical studies of acute isovolemic hemodilution and use coronary blood flow and coronary oxygen delivery in extreme hemodilution to predict a safety threshold. METHODS:By varying cardiovascular and sizing parameters, unique individuals were generated to simulate a population using HumMod, an integrative mathematical model of human physiology. Hemodilution was performed by simultaneously hemorrhaging 500 mL aliquots of blood while infusing equal volumes of hetastarch, 5% albumin balanced salt solution, or triple volumes of lactated Ringer's solution over 10 minutes. Five hemodilution protocols reported over 3 studies were directly replicated with HumMod to compare and validate essential cardiovascular and metabolic responses to hemodilution in moderately healthy, awake adults. Cardiovascular parameters, mental status, arterial and mixed venous oxygen content, and oxyhemoglobin saturation were recorded after the removal of each aliquot. The outputs of this simulation were considered independent variables and were stratified by hemoglobin concentration at the time of measurement to assess hemoglobin as an independent predictor of hemodynamic and metabolic behavior. RESULTS:The published reports exhibited discrepancies: Weiskopf saw increased heart rate and cardiac index, while Jones and Ickx saw no change in these variables. In HumMod, arterial pressure was maintained during moderate hemodilution due to decreases in peripheral resistance opposing increases in cardiac index. HumMod showed preserved ventilation through moderate hemodilution, compensated for by an increased oxygen extraction similar to the studies of Jones and Ickx. The simulation results qualitatively followed the clinical studies, but there were statistical differences. In more extreme hemodilution, HumMod had a lesser increase in cardiac index, which led to deficiencies in oxygen delivery and low venous saturation. In the simulations, coronary blood flow and oxygen delivery increase up to a critical hemoglobin threshold of 55-75 g/L in HumMod. In this range, coronary blood flow and oxygen delivery fell, leading to cardiac injury. The allowable amount of hemodilution before reaching the critical point is most closely correlated with nonmuscle mass (r = 0.69) and resting cardiac output (r = 0.67). CONCLUSIONS:There were significant statistical differences in the model population and the clinical populations, but overall, the model responses lay within the clinical findings. This suggests our model is an effective replication of hemodilution in conscious, healthy adults. A critical hemoglobin range of 5.5-7.5 g/L was predicted and found to be highly correlated with nonmuscle mass and resting cardiac output.
journal_name
Anesth Analgjournal_title
Anesthesia and analgesiaauthors
Sims CR 3rd,Delima LR,Calimaran A,Hester R,Pruett WAdoi
10.1213/ANE.0000000000002430subject
Has Abstractpub_date
2018-01-01 00:00:00pages
93-101issue
1eissn
0003-2999issn
1526-7598journal_volume
126pub_type
杂志文章abstract:BACKGROUND:Cerebral cholinergic transmission plays a key role in cognitive function, and anticholinergic drugs administered during the perioperative phase are a hypothetical cause of postoperative cognitive dysfunction (POCD). We hypothesized that a perioperative increase in serum anticholinergic activity (SAA) is asso...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章
doi:10.1213/ANE.0000000000000390
更新日期:2014-10-01 00:00:00
abstract:UNLABELLED:Recent investigations have sought to improve intrathecal analgesia by combining opioids with other classes of analgesics. In this study we assessed the ability of intrathecal midazolam to increase the potency and duration of the analgesic effects of intrathecal fentanyl without causing adverse effects. Thirt...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1213/01.ane.0000112434.68702.e4
更新日期:2004-06-01 00:00:00
abstract:UNLABELLED:General anesthesia promotes atelectasis formation, which is augmented by administration of large oxygen concentrations. We studied the efficacy of positive end-expiratory pressure (PEEP) application during the induction of general anesthesia (fraction of inspired oxygen [FIO(2)] 1.0) to prevent atelectasis. ...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/01.ane.0000087042.02266.f6
更新日期:2003-12-01 00:00:00
abstract:BACKGROUND:Hypothermia (HT) reduces neuronal injury after perinatal asphyxia. The anesthetic gas xenon (XE) may enhance this effect. We investigated the sedative and respiratory effects of variable XE concentrations at 37 degrees C normothermia (NT) or 32 degrees C HT after a hypoxic-ischemic (HI) insult to determine t...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/ane.0b013e3181618669
更新日期:2008-03-01 00:00:00
abstract:UNLABELLED:We evaluated the blood-sparing effects of intraoperative moderate acute normovolemic hemodilution (ANH) combined with intraoperative tranexamic acid treatment and shed blood reinfusion in patients undergoing off-pump coronary artery bypass (OPCAB). One-hundred consecutive OPCAB patients (baseline hematocrit ...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1213/01.ane.0000113238.35409.fe
更新日期:2004-05-01 00:00:00
abstract:BACKGROUND:Percutaneous cricothyroidotomy may be a life-saving procedure in cannot intubate-cannot ventilate situations. In this study we compared the insertion times of a new indicator-guided cricothyroidotomy device and a wire-guided device in mannequins. METHODS:This study was a crossover trial comparing the insert...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/01.ane.0000266439.43797.9e
更新日期:2007-07-01 00:00:00
abstract::The potency of conventional inhaled anesthetics increases with increasing age: the 50% effective dose (minimum alveolar anesthetic concentration [MAC]) for anesthesia in the neonatal animal or human exceeds MAC in the young adult by approximately 30% to 60%. We tested whether this relationship also applies to the alka...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1097/00000539-199704000-00028
更新日期:1997-04-01 00:00:00
abstract::Including positive end-expiratory pressure (PEEP) in the manual resuscitation bag (MRB) may render manual hyperinflation (MHI) ineffective as a secretion maneuver technique in mechanically ventilated patients. In this study we aimed to determine the effect of increased PEEP or decreased compliance on peak expiratory f...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1213/01.ANE.0000147505.98565.AC
更新日期:2005-04-01 00:00:00
abstract::The management of severe pain may require "balanced analgesia," involving the use of analgesics with different modes of action. Clonidine, an alpha(2)-adrenoreceptor agonist produces analgesia by itself as well as when given with morphine and local anesthetics. Ketorolac is indicated for the management of moderately s...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1097/00000539-200005000-00028
更新日期:2000-05-01 00:00:00
abstract:BACKGROUND:Cigarette smoking by surgical patients is associated with increased complications, particularly perioperative respiratory problems and poor wound healing. In this study, we sought to determine whether a pragmatic perioperative smoking cessation intervention designed for a busy preadmission clinic would be su...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章,随机对照试验
doi:10.1213/ANE.0b013e318298a6b0
更新日期:2013-09-01 00:00:00
abstract:BACKGROUND:Detection of ongoing spontaneous pain behaviors in laboratory animals remains a research challenge. Most preclinical pain studies measure elicited behavioral responses to an external noxious stimulus; however, ongoing spontaneous pain in humans and animals may be unrelated to hypersensitivity, and likely dim...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/ANE.0000000000000119
更新日期:2014-04-01 00:00:00
abstract::We describe the treatment of two patients with hemorrhagic shock unresponsive to volume replacement and catecholamines. Both patients responded to a small-dose infusion of vasopressin, which allowed tapering off of the catecholamines. The possible role of small-dose infusions of vasopressin in fluid- and catecholamine...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/01.ANE.0000175209.61051.7F
更新日期:2005-09-01 00:00:00
abstract::We tested whether anesthesia that includes nitrous oxide (N2O) results in the development of intraoperative and postoperative pulmonary complications, including hypoxemia. We also tested whether aging contributes to the development of such complications, particularly when anesthesia includes N2O. We randomly allocated...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:1990-12-01 00:00:00
abstract::The fatal/anesthetic ratio (FAR) in 44 swine weighing 32.6 +/- 0.7 kg (SEM) was determined. Fatal anesthetic concentration (the numerator for FAR) was defined as the end-tidal concentration at which the pig lived at least 10 min, during experiments that involved step increments in anesthetic concentrations. Previously...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:
更新日期:1987-06-01 00:00:00
abstract:UNLABELLED:We used a double-blind design to study urodynamic changes induced by mu-agonists (fentanyl, morphine), a partial mu-agonist antagonist (buprenorphine), a putative mu-antagonist, kappa-agonist (nalbuphine), and ketoprofen, an injectable nonsteroidal antiinflammatory drug. Men (20-55 yr old) were randomly assi...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/00000539-199808000-00042
更新日期:1998-08-01 00:00:00
abstract:UNLABELLED:In the present study, we investigated the effect of remifentanil on cerebral blood flow velocity (CBFV). We investigated 20 patients (ASA physical status III) scheduled for elective coronary artery bypass graft surgery. Anesthesia was induced with remifentanil 5 microg/kg IV (Group 1, n = 10) or 2 microg/kg ...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章
doi:10.1097/00000539-199809000-00013
更新日期:1998-09-01 00:00:00
abstract::Cytokine release during surgery can produce a long-lasting hyperalgesia. Thus, preoperatively-administered cytokine inhibitors might reduce the production of cytokines, decreasing central nervous system sensitization and improving the quality of postoperative pain relief. We investigated the hypothesis that preincisio...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1213/01.ANE.0000132974.32249.C8
更新日期:2004-11-01 00:00:00
abstract::We studied 60 children undergoing elective surgery to evaluate the effect of interactions between vecuronium and isoflurane or halothane on the potency and duration of neuromuscular blockade, as measured by electromyography. Vecuronium was first administered by a logarithm-based cumulative method (14, 22, 35, 56, 89 m...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1213/00000539-199003000-00003
更新日期:1990-03-01 00:00:00
abstract::Morphine anesthesia is often recommended in patients with reduced cardiac reserve. As the effect of morphine on the balance between myocardial oxygen supply and demand is not well understood, the effect of large doses of morphine (3 mg/kg, subcutaneously) on experimental myocardial infarction size in the rat was evalu...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:
更新日期:1982-10-01 00:00:00
abstract::Quantitative electroencephalogram (qEEG) monitors are often used to estimate depth of anesthesia and intraoperative recall during general anesthesia. As with any monitor, the processed numerical output is often misleading and has to be interpreted within a clinical context. For the safe clinical use of these monitors,...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章,评审
doi:10.1213/ane.0b013e3181a9fc38
更新日期:2009-08-01 00:00:00
abstract:PURPOSE:Some severe complications during percutaneous dilatational tracheostomy (PDT) may be related to poor visualization of tracheal structures. Subjectively, the bronchoscopical view obtained via a laryngeal mask airway (LMA) seems to be better than that obtained with an endotracheal tube (ETT). In this prospective,...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章,随机对照试验
doi:10.1213/ANE.0b013e3181d27fb4
更新日期:2010-04-01 00:00:00
abstract::The hemodynamic effects of esmolol were studied in 40 patients scheduled for elective coronary artery surgery to determine whether the administration of esmolol in chronically beta-blocked patients would result in additional attenuation of sympathetically mediated hemodynamic stress responses to noxious stimuli. Patie...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:1987-02-01 00:00:00
abstract::Cimetidine blunts the increase in cerebral blood flow (CBF) normally observed during hypoxia. It is important, therefore, to know whether other H2-blockers also affect the cerebral circulation adaptation to hypoxia. Cerebral blood flow was measured in 24 awake dogs after an intravenous injection of either saline (cont...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/00000539-199104000-00020
更新日期:1991-04-01 00:00:00
abstract:UNLABELLED:Heart transplantation in patients with increased pulmonary vascular resistance is often associated with postbypass right heart failure. We therefore compared the abilities of prostaglandin E(1) (PGE(1)) and inhaled nitric oxide to reduce pulmonary vascular resistance during heart transplantation. Patients un...
journal_title:Anesthesia and analgesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/00000539-200003000-00005
更新日期:2000-03-01 00:00:00
abstract:BACKGROUND:Mitochondrial injury is a major cause of sepsis-induced organ failure. Polydatin (PD), a natural polyphenol, demonstrates protective mitochondrial effects in neurons and arteriolar smooth muscle cells during severe shock. In this study, we investigated the effects of PD on renal tubular epithelial cell (RTEC...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/ANE.0000000000000977
更新日期:2015-11-01 00:00:00
abstract::Successful procedural sedation represents a spectrum of patient- and clinician-related goals. The absence of a gold-standard measure of the efficacy of procedural sedation has led to a variety of outcomes being used in clinical trials, with the consequent lack of consistency among measures, making comparisons among tr...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章,评审
doi:10.1213/ANE.0000000000000934
更新日期:2016-01-01 00:00:00
abstract::We compared the systemic toxicity of bupivacaine, levobupivacaine, and ropivacaine in anesthetized rats. We also compared the ability to resuscitate rats after lethal doses of these local anesthetics. Bupivacaine, levobupivacaine, or ropivacaine was infused at a rate of 2 mg. kg(-1). min(-1) while electrocardiogram, e...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1097/00000539-200109000-00039
更新日期:2001-09-01 00:00:00
abstract:BACKGROUND:In the present study, we examined the effects and mechanisms of the Chinese herb resveratrol on attenuation of morphine tolerance in rats. METHODS:Male Wistar rats were implanted with 2 intrathecal catheters; one catheter was connected to a mini-osmotic pump, used for either morphine (15 μg/h) or saline (1 ...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/ANE.0b013e31825da0fb
更新日期:2012-10-01 00:00:00
abstract:BACKGROUND:The purpose of this study was to determine whether mechanically ventilated trauma patients with a positive urine drug screen (UDS) for cocaine and/or amphetamines have different opioid analgesic and sedative requirements compared with similar patients with a negative drug screen for these stimulants. METHOD...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/ANE.0000000000001740
更新日期:2017-03-01 00:00:00
abstract::The effects of halothane and enflurane anesthesia under conditions of normo-, hyper-, and hypocarbia on the autoregulation of cerebral blood flow (CBF) in the goat were evaluated. The goat was selected because of its unique arterial blood supply to the head and the development of a method by which CBF may be continuou...
journal_title:Anesthesia and analgesia
pub_type: 杂志文章
doi:10.1213/00000539-197601000-00024
更新日期:1976-01-01 00:00:00