FEVEREIRO DE 2012: Destaques dos principais periódicos em Anestesiologia
Autor: Marcio Augusto Lacerda | Publicado: 2012-02-02T21:42:00-02:00







Perioperative Single Dose Ketorolac to Prevent
Postoperative Pain: A Meta-Analysis of Randomized Trials

http://www.anesthesia-analgesia.org/content/114/2/424

Gildasio S. De Oliveira Jr., MD, MSCI, Deepti Agarwal, MD
and Honorio T. Benzon, MD

Abstract

BACKGROUND:
Preventive analgesia using non-opioid analgesic strategies is recognized as a
pathway to improve postoperative pain control while minimizing opioid-related
side effects. Ketorolac is a nonsteroidal antiinflammatory drug frequently used
to treat postoperative pain. However, the optimal dose and route of
administration for systemic single dose ketorolac to prevent postoperative pain
is not well defined. We performed a quantitative systematic review to evaluate
the efficacy of a single dose of perioperative ketorolac on postoperative
analgesia.

METHODS: We
followed the PRISMA statement guidelines. A wide search was performed to
identify randomized controlled trials that evaluated the effects of a single
dose of systemic ketorolac on postoperative pain and opioid consumption.
Meta-analysis was performed using a random-effects model. Effects of ketorolac
dose were evaluated by pooling studies into 30- and 60-mg dosage groups.
Asymmetry of funnel plots was examined using Egger regression. The presence of
heterogeneity was assessed by subgroup analysis according to the route of
systemic administration (IV versus IM) and the time of drug administration
(preincision versus postincision).

RESULTS:
Thirteen randomized clinical trials with 782 subjects were included. The
weighted mean difference (95% confidence interval [CI]) of combined effects
showed a difference for ketorolac over placebo for early pain at rest of −0.64
(−1.11 to −0.18) but not at late pain at rest, −0.29 (−0.88 to 0.29) summary
point (0–10 scale). Opioid consumption was decreased by the 60-mg dose, with a
mean (95% CI) IV morphine equivalent consumption of −1.64 mg (−2.90 to −0.37
mg). The opioid-sparing effects of ketorolac compared with placebo were greater
when the drug was administered IM compared with when the drug was administered
IV, with a mean difference (95% CI) IV morphine equivalent consumption of −2.13
mg (−4.1 to −0.21 mg). Postoperative nausea and vomiting were reduced by the
60-mg dose, with an odds ratio (95% CI) of 0.49 (0.29–0.81).

CONCLUSIONS: Single dose systemic ketorolac is an
effective adjunct in multimodal regimens to reduce postoperative pain.
Improved postoperative analgesia achieved with ketorolac was also accompanied
by a reduction in postoperative nausea and vomiting. The 60-mg dose
offers significant benefits but there is a lack of current evidence that the
30-mg dose offers significant benefits on postoperative pain outcomes.

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A Review of the Impact of Phenylephrine
Administration on Maternal Hemodynamics and Maternal and Neonatal Outcomes in
Women Undergoing Cesarean Delivery Under Spinal Anesthesia

http://www.anesthesia-analgesia.org/content/114/2/377

Ashraf S.
Habib, MBBCh, MSc, MHS, FRCA

Abstract

Phenylephrine
is effective for the management of spinal anesthesia-induced hypotension in
parturients undergoing cesarean delivery under spinal anesthesia. While
ephedrine was previously considered the vasopressor of choice in obstetric
patients, phenylephrine is increasingly being used. This is largely due to
studies suggesting improved fetal acid-base status with the use of
phenylephrine as well as the low incidence of hypotension and its related side
effects with prophylactic phenylephrine regimens. This review highlights the
effects of phenylephrine compared with ephedrine on maternal hemodynamics
(arterial blood pressure, heart rate, and cardiac output), and occurrence of intraoperative
nausea and vomiting. The impact of the administration of phenylephrine as a
bolus for the treatment of established hypotension compared with its
administration as a prophylactic infusion is discussed. This article also
reviews the impact of phenylephrine compared with ephedrine on uteroplacental
perfusion, and fetal outcomes such as neonatal acid-base status and Apgar
scores. The optimum dosing regimen for phenylephrine administration is also
discussed.

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Plasma methemoglobin as a potential biomarker
of anemic stress in humans

http://www.springerlink.com/content/h22h6594054j7w27/

Gregory M.
T. Hare, Alexander Mu, Alexander Romaschin, Albert K.-Y. Tsui, Nadine Shehata,
W. Scott Beattie and C. David Mazer

Abstract

Purpose&nbsp; 

Transfusion
of allogeneic red blood cells (RBCs) is one of the main treatments of acute
anemia secondary to blood loss and fluid resuscitation within the operating
room. Decisions to transfuse blood are based largely on intermediate biological
markers (hemoglobin, arterial oxygen saturation, blood pressure, heart rate)
which may not accurately reflect inadequacy of tissue oxygen delivery. Based on
experimental studies, we hypothesized that anemia-induced tissue hypoxia
activates adaptive mechanisms which promote local vascular nitric oxide (NO)
production to improve tissue perfusion and survival during acute anemia. Hemoglobin
(Hb) oxidation to methemoglobin (MetHb) may be a byproduct of such local NO
production. Therefore, we tested the hypothesis that MetHb is a biomarker of
hypoxic-anemic stress during acute hemodilution associated with cardiopulmonary
bypass.

Methods&nbsp; 

With
institutional ethics approval, routine laboratory arterial blood gas and
co-oximetry values were obtained from 295 patients undergoing heart surgery
during February 1 to September 30, 2010, and the values were assessed
retrospectively. All samples with an arterial oxygen saturation value ≥90% were
included (n = 1,421). The maximal change in Hb associated with hemodilution on
cardiopulmonary bypass was determined within 48 hr of surgery (n = 180). A
chart review was performed to determine the incidence of RBC transfusion and
exogenous nitrate administration. All anonymous data were analyzed by linear
regression to determine the relationship between Hb and MetHb. A Wilcoxon
Signed Rank Test and Student’s t test were used to determine changes in Hb, MetHb,
and carboxyhemoglobin (CarboxHb) levels. All data are presented as mean and
significance was assigned at P &lt; 0.05.

Results&nbsp; 

A
significant decrease in Hb [118 (20) g·L−1 vs 94 (18) g·L−1] was associated
with an increase in MetHb [0.88 (0.22)% vs 0.95 (0.24)%] (P &lt; 0.001 for
both), but not CarboxHb [1.08 (0.47)% vs 1.08 (0.49)%]. Regression analysis
revealed a significant relationship between the change in Hb and MetHb (F =
40.3; P &lt; 0.001) but not between the change in Hb and CarboxyHb (F = 0.2; P
= 0.694). This correlation was not influenced by RBC transfusion or exogenous
nitrate use.

Conclusions&nbsp; 

A negative
correlation was observed between the change in Hb and MetHb in patients
undergoing cardiac surgery and cardiopulmonary bypass. These data support the
previously unreported hypothesis that MetHb may be a marker of anemic stress
associated with reduced tissue perfusion during acute hemodilution in humans.
Further prospective studies are needed to determine if these changes in MetHb
are linked to adverse outcomes in patients undergoing cardiac surgery.



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Short-term
preoperative smoking cessation and postoperative complications: a systematic review
and meta-analysis

http://www.springerlink.com/content/28103111g1644560/

Jean Wong,
David Paul Lam, Amir Abrishami, Matthew T. V. Chan and Frances Chung

Abstract

Purpose&nbsp; 

The
literature was reviewed to determine the risks or benefits of short-term (less
than four weeks) smoking cessation on postoperative complications and to derive
the minimum duration of preoperative abstinence from smoking required to reduce
such complications in adult surgical patients.

Source&nbsp; 

We searched
MEDLINE, EMBASE, Cochrane, and other relevant databases for cohort studies and
randomized controlled trials that reported postoperative complications (i.e.,
respiratory, cardiovascular, wound-healing) and mortality in patients who quit
smoking within six months of surgery. Using a random effects model,
meta-analyses were conducted to compare the relative risks of complications in
ex-smokers with varying intervals of smoking cessation vs the risks in current
smokers.

Principal
findings&nbsp; 

We included
25 studies. Compared with current smokers, the risk of respiratory
complications was similar in smokers who quit less than two or two to four
weeks before surgery (risk ratio [RR] 1.20; 95% confidence interval [CI] 0.96
to 1.50 vs RR 1.14; CI 0.90 to 1.45, respectively). Smokers who quit more than
four and more than eight weeks before surgery had lower risks of respiratory
complications than current smokers (RR 0.77; 95% CI 0.61 to 0.96 and RR 0.53;
95% CI 0.37 to 0.76, respectively). For wound-healing complications, the risk
was less in smokers who quit more than three to four weeks before surgery than
in current smokers (RR 0.69; 95% CI 0.56 to 0.84). Few studies reported
cardiovascular complications and there were few deaths.

Conclusion&nbsp; 

At least
four weeks of abstinence from smoking reduces respiratory complications, and
abstinence of at least three to four weeks reduces wound-healing complications.
Short-term (less than four weeks) smoking cessation does not appear to increase
or reduce the risk of postoperative respiratory complications.

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Postoperative intravenous morphine titration

http://bja.oxfordjournals.org/content/108/2/193.full

F.
Aubrun1,*, J.-X. Mazoit2 and B. Riou3

Summary

Relief of
acute pain during the immediate postoperative period is an important task for
anaesthetists. Morphine is widely used to control moderate-to-severe
postoperative pain and the use of small i.v. boluses of morphine in the
post-anaesthesia care unit allows a rapid titration of the dose needed for
adequate pain relief. The essential principle of a titration regimen must be to
adapt the morphine dose to the pain level. Although morphine would not appear
to be the most appropriate choice for achieving rapid pain relief, this is the
sole opioid assessed in many studies of immediate postoperative pain management
using titration. More than 90% of the patients have pain relief using a
protocol of morphine titration and the mean dose required to obtain pain relief
is 12 (7) mg, after a median of four boluses. Sedation is frequent during i.v.
morphine titration and should be considered as a morphine-related adverse event
and not evidence of pain relief. The incidence of ventilatory depression is
very low when the criteria to limit the dose of i.v. morphine are enforced.
Morphine titration can be used with caution in elderly patients, in children, or
in obese patients. In practice, i.v. morphine titration allows the physician to
meet the needs of individual patients rapidly and limits the risk of overdose
making this method the first step in postoperative pain management.

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Case Scenario: Perianesthetic Management of
Laryngospasm in Children

Orliaguet,
Gilles A. M.D., Ph.D.*; Gall, Olivier M.D., Ph.D.†; Savoldelli, Georges L.
M.D., M.Ed.‡; Couloigner, Vincent M.D., Ph.D.§

http://journals.lww.com/anesthesiology/Fulltext/2012/02000/Case_Scenario___Perianesthetic_Management_of.31.aspx

Summary

PERIOPERATIVE
laryngospasm is an anesthetic emergency that is still responsible for
significant morbidity and mortality in pediatric patients.1 It is a relatively
frequent complication that occurs with varying frequency dependent on multiple
factors.2–5 Once the diagnosis has been made, the main goals are identifying
and removing the offending stimulus, applying airway maneuvers to open the airway,
and administering anesthetic agents if the obstruction is not relieved. The
purpose of this case scenario is to highlight key points essential for the
prevention, diagnosis, and treatment of laryngospasm occurring during
anesthesia.

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Practice Guidelines for Acute Pain Management
in the Perioperative Setting: An Updated Report by the American Society of
Anesthesiologists Task Force on Acute Pain Management

http://journals.lww.com/anesthesiology/Fulltext/2012/02000/Practice_Guidelines_for_Acute_Pain_Management_in.10.aspx

Summary

PRACTICE
Guidelines are systematically developed recommendations that assist the
practitioner and patient in making decisions about health care. These
recommendations may be adopted, modified, or rejected according to clinical
needs and constraints and are not intended to replace local institutional policies.
In addition, Practice Guidelines developed by the American Society of
Anesthesiologists (ASA) are not intended as standards or absolute requirements,
and their use cannot guarantee any specific outcome. Practice Guidelines are
subject to revision as warranted by the evolution of medical knowledge,
technology, and practice. They provide basic recommendations that are supported
by a synthesis and analysis of the current literature, expert and practitioner
opinion, open forum commentary, and clinical feasibility data.

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Anesthetic Management and Outcome in Patients
during Endovascular Therapy for Acute Stroke

http://journals.lww.com/anesthesiology/Fulltext/2012/02000/Anesthetic_Management_and_Outcome_in_Patients.22.aspx

Davis,
Melinda J. B. Med., F.A.N.Z.C.A.*; Menon, Bijoy K. M.D.†; Baghirzada, Leyla B.
M.D.‡; Campos-Herrera, Cynthia R. M.D.†; Goyal, Mayank M.D.§; Hill, Michael D. M.D.#;
Archer, David P. M.D.‖; 

Abstract

Background:
Studies of endovascular treatment for acute ischemic stroke have identified
general anesthesia as a predictor for poor outcome in comparison with local
anesthesia/sedation. This retrospective study attempts to identify modifiable
factors associated with poor outcome, while adjusting for baseline stroke
severity, in patients receiving general anesthesia.

Methods: We
reviewed charts of 129 patients treated between January 2003 and September
2009. The primary outcome was the modified Rankin Score of 0–2 for 3 months
poststroke. Predictors of neurologic outcome included baseline National
Institutes of Health Stroke Scale score, blood glucose concentration, and age.
Additional risk factors evaluated were prolonged stroke onset-treatment
interval and systolic blood pressure less than 140 mmHg. Choice of local
anesthesia or general anesthesia was recorded.

Results:
The study group was 96 out of 129 patients for whom modified Rankin Scale
scores were available; 48 patients received general anesthesia and 48 local
anesthesia. The proportion of patients with “good” outcomes were 15% and 60% in
the general anesthesia group and local anesthesia group, respectively (P &lt;
0.001). Lowest systolic blood pressure and general anesthesia were correlated
(r = −0.7, P &lt; 0.001). Independent predictors for good neurologic outcome
were local anesthesia, systolic blood pressure greater than 140 mmHg, and low
baseline stroke scores.

Conclusions:
Adjusted for stroke severity, patients who received general anesthesia for
treatment are less likely to have a good outcome than those managed with local
anesthesia. This may be due to preintervention risk not included in the stroke
severity measures. Hypotension, more frequent in the general anesthesia
patients, may also contribute.