Anesthesia and analgesia
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Anesthesia and analgesia · May 2004
Clinical TrialFiberoptic endotracheal intubation after topicalization with in-circuit nebulized lidocaine in a child with a difficult airway.
This case report describes the successful fiberoptic intubation of an uncooperative child with a difficult airway due to gross burn scarring in the facial and neck region by administering 4% end-tidal sevoflurane and simultaneously delivering 4% nebulized lidocaine via a small-volume nebulizer that was connected to the inspiratory limb of the circle system via a T-piece adapter. This case suggests that simultaneously administering a volatile anesthetic with nebulized lidocaine might be an alternative way to deliver lidocaine and might provide better topical anesthesia for uncooperative patients. ⋯ An in-circuit nebulization system to deliver topical lidocaine may facilitate fiberoptic-assisted intubation in anesthetized, spontaneously breathing children with compromised airways.
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Anesthesia and analgesia · May 2004
Clinical TrialIs bilateral monitoring of cerebral oxygen saturation necessary during neonatal aortic arch reconstruction?
In this study, we measured cerebral oxygenation in both cerebral hemispheres by using near-infrared spectroscopy before, during, and after regional low-flow cerebral perfusion (RLFP) to determine whether bilateral monitoring was necessary. Neonates undergoing aortic arch reconstruction with RLFP were studied. The bilateral regional cerebral oxygenation index was measured and recorded at 1-min intervals during the following periods: 1) before bypass, 2) during bypass before RLFP, 3) during RLFP, 4) on bypass after RLFP, and 5) post-bypass. Before bypass and on bypass before RLFP, the correlation (r = 0.979 and 0.852) and agreement (mean bias, right versus left, 0 and +2) between hemispheres were excellent. During RLFP, however, correlation (r = 0.35) and agreement (mean bias of the right versus left side, +6.3) worsened and only partially returned to baseline values after RLFP. Nine of 19 patients had sustained differences in cerebral oxygen saturation of >10%, always with the left side values less than the right. Bilateral monitoring detects desaturation in the left cerebral hemisphere during RLFP. The long-term consequences of lower saturations on the left side of the brain are unclear. ⋯ Left-sided cerebral hemisphere oxygen saturation, measured with near-infrared spectroscopy, was less than right-sided cerebral oxygen saturation during regional low-flow cerebral perfusion used for neonatal aortic arch reconstruction.
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Anesthesia and analgesia · May 2004
The failure of retrograde autologous priming of the cardiopulmonary bypass circuit to reduce blood use after cardiac surgical procedures.
Hemodilution during cardiopulmonary bypass (CPB) is a primary risk factor for blood transfusion in cardiac surgical patients. Priming of the CPB circuit with the patients' own blood (retrograde autologous priming, RAP) is a technique used to limit hemodilution and reduce transfusion requirements. We designed this study to examine the impact of RAP on perioperative blood product use. Using a retrospective cohort study design, the medical records of all patients undergoing CPB (excluding circulatory arrest cases) by a single surgeon were examined. Data were collected over a 24-mo period when RAP was routinely used as a blood conservation strategy (RAP group, n = 257). This group was compared with a cohort of patients during the 24 mo immediately preceding the introduction of RAP into clinical practice (no RAP group, n = 288). A small, statistically insignificant reduction in the percentage of patients receiving packed red blood cells was observed in the RAP group (44% versus 51% no RAP, P = 0.083). No differences were found between the groups in the number of units of packed red blood cells, platelets, or fresh frozen plasma transfused throughout the perioperative period. These results suggest that overall, RAP does not offer a clinically important benefit as a blood conservation technique. ⋯ Priming of the cardiopulmonary bypass circuit with the patients' own blood (retrograde autologous priming) resulted in insignificant reductions in blood use in a large, unselected group of patients undergoing cardiac surgical procedures.
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Anesthesia and analgesia · May 2004
A survey of orthopedic surgeons' attitudes and knowledge regarding regional anesthesia.
We conducted a survey to explore the surgical attitudes and preferences regarding regional anesthesia among Canadian orthopedic surgeons. Surveys were returned by 468 (61%) of 768 surgeons. Forty-eight percent of respondents directed their patients' choice of anesthetic. Forty percent of surgeons directed their patients to choose regional anesthesia. The principal reasons for favoring regional anesthesia were less postoperative pain (32%), decreased nausea and vomiting (12%), and safety (14%). Reasons for not favoring regional anesthesia were delays in the induction of anesthesia (43%) and an unpredictable success rate (12%). This survey suggests that orthopedic surgeons are supportive of regional anesthesia. Barriers to increased popularity include perceived delays and unreliability. ⋯ Orthopedic surgeons understand the benefits of and are supportive of the use of regional anesthesia in their practices. Barriers to increased popularity include perceived operating room delays and lack of reliability.
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Tissue plasminogen activator (tPA) has a prominent role in physiological fibrinolysis in vivo. Thrombosis has been associated with clinical scenarios (e.g., atherosclerotic disease) known to involve local decreases in tPA activity with concomitant formation of reactive nitrogen species such as peroxynitrite (OONO(-)), a molecule formed from nitric oxide and superoxide. We hypothesized that exposure of tPA to OONO(-) would result in a decrease in tPA activity. OONO(-) was generated with 3-morpholinosydnonimine (SIN-1), a molecule that produces both nitric oxide and superoxide. Recombinant tPA was incubated at 37 degrees C for 60 min with 0 microM SIN-1; 100 microM SIN-1; 100 microM SIN-1 and 4000 U/mL recombinant human superoxide dismutase; or 4000 U/mL recombinant human superoxide dismutase (n = 8 separate reactions per condition). Changes in tPA activity were assessed by addition of tPA samples to tissue factor-exposed human plasma and measuring clot fibrinolysis with a thrombelastograph. Exposure to SIN-1 resulted in a decrease in tPA-mediated fibrinolysis (<1% activity of tPA not exposed to SIN-1) that was significantly (P < 0.001) different from the other three conditions. There were no significant differences between the other conditions. We conclude that tPA is inhibited by OONO(-), and that OONO(-) may have a role in clinical thrombotic scenarios. ⋯ Tissue plasminogen activator (tPA) has a prominent role in fibrinolysis in vivo. Thrombosis has been associated with clinical scenarios involving decreases in tPA activity with concomitant formation of the oxidant peroxynitrite. We determined that peroxynitrite decreased tPA activity via thrombelastography. Peroxynitrite-mediated tPA inactivation may have a role in thrombotic states.