Artículos Anestesia
Dr. Mauricio Oyuela Pavón
de trauma nivel 1.
Prehospital Intubations and Mortality: A Level 1 Trauma Center Perspective
Miguel A. Cobas, MD*, Maria Alejandra De la Peña, MD*, Ronald Manning,
RN, MSPH, Keith Candiotti, MD*, and Albert J. Varon, MD*
Anesthesia Analgesia 2009; 109:489-493
From the *Department of Anesthesiology, Perioperative Medicine, and
Pain Management, and DeWitt Daughtry Family Department of Surgery,
Miller School of Medicine, University of Miami, Miami, Florida.
Address correspondence and reprint requests to Miguel Cobas, MD,
Department of Anesthesiology, University of Miami, 1400 NW 12th Ave.,
Suite 3155, Miami, FL 33136. Address e-mail to mco...@med.miami.edu.
BACKGROUND: Ryder Trauma Center is a Level 1 trauma center with
approximately 3800 emergency admissions per year. In this study, we
sought to determine the incidence of failed prehospital intubations
(PHI), its correlation with hospital mortality, and possible risk
factors associated with PHI.
METHODS: A prospective observational study was conducted evaluating
trauma patients who had emergency prehospital airway management and
were admitted during the period between August 2003 and June 2006. The
PHI was considered a failure if the initial assessment determined
improper placement of the endotracheal tube or if alternative airway
management devices were used as a rescue measure after intubation was
attempted.
RESULTS: One-thousand-three-hundred-twenty patients had emergency
airway interventions performed by an anesthesiologist upon arrival at
the trauma center. Of those, 203 had been initially intubated in the
field by emergency medical services personnel, with 74 of 203 (36%)
surviving to discharge. When evaluating the success of the intubation,
63 of 203 (31%) met the criteria for failed PHI, all of them requiring
intubation, with only 18 of 63 (29%) surviving to discharge. These
patients had rescue airway management provided either via Combitube®
(n = 28), Laryngeal Mask Airway® (n = 6), or a cricothyroidotomy (n =
4). An additional 25 of 63 patients (12%) had unrecognized esophageal
intubations discovered upon the initial airway assessment performed on
arrival. We found no difference in mortality between those patients
who were properly intubated and those who were not. Several other
variables, including age, gender, weight, mechanism of injury,
presence of facial injuries, and emergency medical services were not
correlated with an increased incidence of failed intubations.
CONCLUSION: This prospective study showed a 31% incidence of failed
PHI in a large metropolitan trauma center. We found no difference in
mortality between patients who were properly intubated and those who
were not, supporting the use of bag-valve-mask as an adequate method
of airway management for critically ill trauma patients in whom
intubation cannot be achieved promptly in the prehospital setting.
Valoración de hipotensión y cambios hemodinámicos en la presión
arterial medidos con un mango en el brazo.
Tracking Hypotension and Dynamic Changes in Arterial Blood Pressure
with Brachial Cuff Measurements
Karim Lakhal, MD*, Stephan Ehrmann, MD, Isabelle Runge, MD, Annick
Legras, MD, Pierre-François Dequin, MD, PhD, Emmanuelle Mercier, MD,
Michel Wolff, MD, PhD*, Bernard Régnier, MD, PhD*, and Thierry
Boulain, MD.
Anesthesia Analgesia 2009; 109:494-501
From the *Service de réanimation médicale et maladies infectieuses,
Hôpital Bichat-Claude Bernard, Assistance Publique des Hôpitaux de
Paris, 16 rue Henri Huchard, Paris; Service de réanimation médicale
polyvalente, Hôpital Bretonneau, CHRU de Tours, 2 Bd Tonnellé, Tours;
and Service de réanimation médicale, Hôpital de La Source, Centre
Hospitalier Régional, avenue de l'Hôpital, Orléans, France.
Address correspondence and reprint requests to Thierry Boulain, MD,
Service de réanimation médicale, Hôpital de La Source, Centre
Hospitalier Régional, avenue de l'Hôpital, F45067 Orléans cedex 1,
France. Address e-mail to thierry...@chr-orleans.fr
BACKGROUND: Arterial cannulation is strongly recommended during shock.
Nevertheless, this procedure is associated with significant risks and
may delay other emergent procedures. We assessed the discriminative
power of brachial cuff oscillometric noninvasive blood pressure (NIBP)
for identifying patients with an invasive mean arterial blood pressure
(MAP) below 65 mm Hg or increasing their invasive MAP after
cardiovascular interventions.
METHODS: This prospective study, conducted in three intensive care
units, included adults in circulatory failure who underwent 45°
passive leg raising, 300 mL fluid loading, and additional 200 mL fluid
loading. The collected data were four invasive and noninvasive MAP
measurements at each study phase.
RESULTS: Among 111 patients (50 septic, 15 cardiogenic, and 46 other
source of shock), when averaging measurements of each study phase,
NIBP measurements accurately predicted an invasive MAP lower than 65
mm Hg: area under the receiver operating characteristic curve 0.90
(95% CI: 0.71-1), positive and negative likelihood ratios 7.7 (95% CI:
5.4-11) and 0.31 (95% CI: 0.22-0.44) (cutoff 65 mm Hg).
For identifying patients increasing their invasive MAP by more than
10%, the area under the receiver operating characteristic curve was
0.95 (95% CI: 0.92-0.96); positive and negative likelihood ratios
(cutoff 10%) were 25.7 (95% CI: 10.8-61.4) and 0.26 (95% CI:
0.2-0.34).
CONCLUSIONS: NIBP measurements have a good discriminative power for
identifying hypotensive patients and performed even better in tracking
MAP changes, provided that one averages four NIBP measurements.
--
Dr. Mauricio Oyuela Pavón
Tegucigalpa, Honduras
MSN: dr....@live.com
Skype: mauricio_oyuela
Tigo: +50499013462
Dr. Mauricio Oyuela Pavón
trastorno común
de sangrado.
Neuroaxial techniques in Obstetric and Non-Obstetric Patients with
Common Bleeding
Diatheses
Stephen Choi, MD*, and Richard Brull, MD, FRCPC*
Anesthesia Analgesia 2009; 109:648-660
From the *Department of Anesthesia, University of Toronto; and
Department of Anesthesia
and Pain Management, Toronto Western Hospital, University Health
Network, Toronto,
Ontario, Canada.
Address correspondence and reprint requests to Dr. Richard Brull, Department of
Anesthesia and Pain Management, Toronto Western Hospital, University
Health Network,
399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8. Address e-mail
to richar...@uhn.on.ca.
Abstract
BACKGROUND: There are few data in the literature regarding the safety
of neuraxial
techniques in patients with the most common bleeding diatheses,
including hemophilia,
von Willebrand's disease (vWD), and idiopathic thrombocytopenic
purpura (ITP). Neuraxial
techniques are not widely used in these populations because of
concerns of potential
hemorrhagic and/or subsequent neurologic complications. In this
article, we review
the available literature describing neuraxial techniques in patients
with hemophilia,
vWD, or ITP with the aim to assist anesthesiologists considering
neuraxial techniques
in these populations.
METHODS: After a systematic Pubmed, MEDLINE, and EMBASE search, we
reviewed 30 articles
published between January 1, 1975 and October 1, 2008 in which
neuraxial techniques
were performed in patients with hemophilia, vWD, or ITP to determine
the perioperative
management and evaluate the frequency of hemorrhagic complications.
RESULTS: We identified 507 neuraxial techniques (482 patients)
performed in patients
with hemophilia (107 neuraxial techniques, 85 patients), vWD (74
neuraxial techniques,
72 patients), or ITP (326 neuraxial techniques, 325 patients). Among
the 507 neuraxial
techniques performed, there were 371 lumbar epidural anesthetics, 78
spinal anesthetics,
53 lumbar punctures, 2 combined spinal epidural analgesia, 2
paravertebral blocks,
and 1 thoracic epidural anesthetic. Four hundred six neuraxial
techniques were placed
in the obstetric population, 53 were performed in the emergency room
for diagnostic
lumbar puncture, 46 were performed for lower limb orthopedic surgery,
1 was performed
for postoperative analgesia, and 1 was performed for an obstetric
patient undergoing
non-obstetric surgery. Factor replacement to normal levels (>0.5 IU
mL-1) was initiated
before block performance, though treatment was not standardized, in
105 of 107 patients
with hemophilia and 10 of 74 with vWD. Sixty-four of the 74 patients
with vWD had
spontaneous normalization of factor levels before block performance.
No hemorrhagic
complications were reported when the diagnosis of hemophilia or vWD
was known before
the neuraxial technique. A single case of spinal hematoma (resulting
in permanent
paraplegia) was identified when the presence of hemophilia was not known before
needle insertion and factor replacement had not been given. In all 326 cases of
ITP, with or without systemic treatment of platelet transfusion, there
were no reports
of hemorrhagic complications associated with neuraxial techniques. Among the 326
neuraxial techniques placed in the setting of ITP, 9 patients had
platelet counts
of <50 x 109 L-1, 19 had a platelet counts of 50-75 x 109 L-1, 204
had a platelet
counts of 75-100 x 109 L-1, and 94 had a platelet count more than 100 x 109 L-1
before needle insertion.
CONCLUSIONS: There is a paucity of published data regarding the
provision and safety
of neuraxial techniques in patients with common bleeding diatheses. The minimum
"safe" factor levels and platelet count for neuraxial techniques
remain undefined
in both the obstetric and general populations, and evidence-based
recommendations
in the setting of hemophilia, vWD, or ITP cannot be offered.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bupivacaina se une a liposomas Pegylatados.
Bupivacaine Binding to Pegylated Liposomes
Brett A. Howell, BS, and Anuj Chauhan, PhD.
Anesthesia Analgesia 2009; 109:678-682
From the Department of Chemical Engineering, University of Florida, Gainesville,
Florida.
Address correspondence and reprint requests to Dr. Anuj Chauhan,
Department of Chemical
Engineering, University of Florida, Gainesville, FL 32611. Address
e-mail to cha...@che.ufl.edu.
Abstract
BACKGROUND: Local anesthetic drugs, such as bupivacaine, can cause
severe toxicity.
Lipid emulsions have been proposed and used clinically for treating such cases.
Liposomes may be an alternative for overdose treatment because of
their unique structures
and surface charges, which allows them to act as high affinity drug "sinks" and
remove bupivacaine from solution.
METHODS: We conducted in vitro experiments with unilamellar and
multilamellar anionic,
polymer-coated liposomes to determine the amount of bupivacaine bound
to liposomes
in buffer solutions as a means of assessing the liposome-drug affinity. Binding
experiments were also done in human serum to determine the liposomes' ability to
compete with serum proteins for binding drug molecules.
RESULTS: Unilamellar liposomes sequestered 60%-65% and 77%-85% of
bupivacaine from
buffer at 1.45 and 2.9 mg lipid/mL, respectively. The increased lipid
loading increased
the drug uptake at all drug concentrations measured (P = 0.001, 0.002,
<0.001,
and 0.003 for 5, 20, 35, and 50 µM, respectively). Multilamellar liposomes bound
more drug per unit mass, with 71%-90% of the total bupivacaine bound
at a phospholipid
concentration of 1.45 mg lipid/mL. When comparing unilamellar and multilamellar
liposomes at 1.45 mg lipid/mL, the multilamellar liposomes were
significantly better
at 3 of the 4 drug concentrations measured (P = 0.002, 0.001, 0.001,
and 0.08 for
5, 20, 35, and 50 µM, respectively). In human serum samples,
unilamellar liposomes
(2.9 mg lipid/mL) reduced the unbound (free) drug by 36% (P = 0.037),
56% (P = 0.022),
47% (P = 0.042), and 50% (P = 0.018) for bupivacaine concentrations of
5, 20, 35,
and 50 µM, respectively.
CONCLUSIONS: The anionic, pegylated liposomes exhibit high binding for
bupivacaine,
both in buffer and in human serum. These results suggest that an IV injection of
liposomes could be useful for the treatment of bupivacaine toxicity
through drug
redistribution.
Dr. Mauricio Oyuela Pavón
platelet counts of <50 x 109 L-1, 19 had a platelet counts of 50-75 x 109
L-1, 204 had a platelet counts of 75-100 x 109 L-1, and 94 had a platelet
count more than 100 x 109 L-1 before needle insertion.
CONCLUSIONS: There is a paucity of published data regarding the provision
and safety of neuraxial techniques in patients with common bleeding
diatheses. The minimum "safe" factor levels and platelet count for neuraxial
techniques remain undefined in both the obstetric and general populations,
and evidence-based recommendations in the setting of hemophilia, vWD, or ITP
cannot be offered.
Bupivacaina se une a liposomas Pegylatados.
Bupivacaine Binding to Pegylated Liposomes
Brett A. Howell, BS, and Anuj Chauhan, PhD.
Anesthesia Analgesia 2009; 109:678-682
From the Department of Chemical Engineering, University of Florida,
Gainesville, Florida.
Address correspondence and reprint requests to Dr. Anuj Chauhan, Department
of Chemical Engineering, University of Florida, Gainesville, FL 32611.
Address e-mail to cha...@che.ufl.edu.
Abstract
BACKGROUND: Local anesthetic drugs, such as bupivacaine, can cause severe
toxicity. Lipid emulsions have been proposed and used clinically for
treating such cases. Liposomes may be an alternative for overdose treatment
because of their unique structures and surface charges, which allows them to
act as high affinity drug "sinks" and remove bupivacaine from solution.
METHODS: We conducted in vitro experiments with unilamellar and
multilamellar anionic, polymer-coated liposomes to determine the amount of
bupivacaine bound to liposomes in buffer solutions as a means of assessing
the liposome-drug affinity. Binding experiments were also done in human
serum to determine the liposomes' ability to compete with serum proteins for
binding drug molecules.
RESULTS: Unilamellar liposomes sequestered 60%-65% and 77%-85% of
bupivacaine from buffer at 1.45 and 2.9 mg lipid/mL, respectively. The
increased lipid loading increased the drug uptake at all drug concentrations
measured (P = 0.001, 0.002, <0.001, and 0.003 for 5, 20, 35, and 50 µM,