Anesthesia and analgesia
-
Anesthesia and analgesia · May 2001
Comparative StudyThe disposition of the cervical spine and deformation of available cord space with conventional- and balloon laryngoscopy-guided laryngeal intubation: a comparative study.
Orotracheal intubation causes cervical spine (C-spine) extension and potential (hypothetical) space available for the cord (SAC)-deformation. In the present study, we determined and compared the changes induced by conventional- and balloon laryngoscopy-guided orolaryngeal intubation in the upper C-spine's osseous unit-orientation, segmental angulation, segmental SAC-sagittal surface areas (SSAs), segmental/total posterior SAC-aspect, and segmental SAC-width. Eight healthy volunteers were enrolled. A set of neutral head position (baseline)- and two sets of intubation-lateral C-spine radiographs were obtained. Relative to baseline, both intubation techniques induced significant changes in the occiput (OCC)-, third cervical vertebra (C3)-, C4-, and C5-orientation, the OCC-C1-segmental angulation, all the segmental SAC-SSAs, and the OCC-C1-, and C1-2-posterior SAC-aspect (P < 0.05 to < 0.001); conventional intubation caused additional significant changes in C2-orientation, total (OCC through C5)-posterior SAC-aspect, and OCC-C1-SAC-width (P < 0.05 to < 0.001). Relative to conventional intubation, balloon-assisted intubation caused less change in C3-orientation and C2-3-SAC-width (P < 0.05), and less reduction in OCC-C1-, C1-2-, and C4-5-SAC-SSAs (P < 0.05 to < 0.01). Orotracheal intubation should be cautiously performed in patients with space-occupying upper-C-spine-SAC lesions, even if there is no concomitant osseous/ligamentous pathology. In such cases, balloon laryngoscopy may be chosen over the conventional technique, because it causes less SAC deformation. ⋯ This study shows that direct laryngoscopy-guided orotracheal intubation causes deformation of the upper cervical space available for the cord, even in the absence of cervical spine instability. These effects are attenuated with balloon laryngoscopy, and thus, its use is recommended in patients with space-occupying lesions within the spinal canal.
-
Anesthesia and analgesia · May 2001
Comparative StudyThe detection of interatrial flow patency in awake and anesthetized patients: a comparative study using transnasal transesophageal echocardiography.
The Valsalva maneuver in the awake patient and the ventilation maneuver in the tracheally intubated anesthetized patient are two provocation methods to detect a patent foramen ovale (PFO) by means of contrast transesophageal echocardiography. In 60 patients undergoing posterior fossa surgery, a contrast agent was administered via a peripheral vein during a Valsalva maneuver immediately before anesthesia induction, followed by central venous administration during a ventilation maneuver in the same patients when anesthetized and endotracheally intubated. We evaluated both maneuvers with a 32-element monoplane transnasal transesophageal echocardiography probe to trace the atrial flow of the contrast agent in a 90 degrees bicaval view. A maneuver was rated positive when more than four bubbles appeared in the left atrium during the first three cardiac cycles after intrathoracic pressure release. The right atrial cross-sectional area before pressure release, and the peak septal excursion during atrial contrast opacification, were measured. McNemar's test was used to assess a paired dichotomous response on the two maneuvers for a significant difference. In 56 patients, the ventilation maneuver was significantly (P < 0.037) more often positive for PFO (n = 14) than the Valsalva maneuver (n = 7). Although there was no difference in the methods regarding the peak septal excursion, the mean right atrial area before pressure release was significantly smaller during the ventilation maneuver than during the Valsalva maneuver (11.2 +/- 3.1 cm(2) vs 14.4 +/- 3.3 cm(2), n = 42, P < 0.05). In the patients with a positive ventilation, but a negative Valsalva maneuver, the discrepancy was even larger (10.9 +/- 4.4 cm(2) vs 16.3 +/- 4.2 cm(2), n = 7, P < 0.001). We conclude that the ventilation maneuver is superior to the Valsalva maneuver in detecting PFO. Our data suggest that a peak pressure of 30 cm H(2)O during the ventilation maneuver achieves a more pronounced reduction in right atrial load and allows right atrial pressure to exceed left atrial pressure when intrathoracic pressure is released. ⋯ A controlled ventilation maneuver in anesthetized patients immediately before posterior fossa surgery may be superior to the preoperative Valsalva maneuver in detecting a patent foramen ovale by contrast transesophageal echocardiography. This approach identifies patients at high risk for paradoxic embolism, but it is not practical for preoperative identification of patients who might benefit from patent foramen ovale closure before surgery.
-
Anesthesia and analgesia · May 2001
Case ReportsPerioperative care of a patient with acute fatty liver of pregnancy.
Acute fatty liver of pregnancy (AFLP) is a late gestational complication with biochemical similarities to the inherited disorders of mitochondrial fatty acid oxidation and clinical similarities to fulminant hepatic failure. The following case illustrates our perioperative management of this rarely encountered disorder.
-
Anesthesia and analgesia · May 2001
Inhibition of synovial plasma extravasation by preemptive administration of an antiinflammatory irrigation solution in the rat knee.
Inflammation and hyperalgesia during surgical procedures are caused by the local release of multiple inflammatory mediators. We used a rat knee joint model of acute inflammation (synovial plasma extravasation) to determine whether preemptive intraarticular irrigation of the antiinflammatory drugs ketoprofen, amitriptyline, or oxymetazoline, alone or in combination, can reduce inflammatory soup-induced plasma extravasation. These three drugs were selected because of their abilities to collectively inhibit the inflammatory effects of biogenic amines, eicosanoid production, and the release of neuropeptides from C-fiber terminals. Synovial perfusion of each one of the three drugs 10 min before, and then in combination with, the inflammatory soup (bradykinin, 5-hydroxytryptamine, and mustard oil) did not reduce plasma extravasation. Similarly, two-drug combinations did not significantly reduce inflammatory soup-induced plasma extravasation. The combination of all three drugs (amitriptyline, ketoprofen, and oxymetazoline) produced a dramatic inhibition of plasma extravasation and was more effective than any of the two-drug combinations. A comparison between the preemptive (10 min before inflammatory soup perfusion) and postinflammatory administration (10 min after inflammatory soup perfusion) showed that the postinflammatory administration of the three-drug solution lost all ability to inhibit inflammatory soup-induced plasma extravasation. We conclude that acute synovial inflammation, which is induced and maintained by multiple mediators, can be substantially inhibited only by the preemptive administration of a drug combination that targets multiple inflammatory mediators. ⋯ Preemptive, intraarticular irrigation of a combination of multiple antiinflammatory drugs is a novel and potentially effective method for reducing the synovial inflammatory response, such as that during arthroscopy. In this study, a three-drug combination infusion was statistically superior to one- or two-drug infusions in a rat model.
-
Anesthesia and analgesia · May 2001
Case ReportsArytenoid dislocation while using a McCoy laryngoscope.
Arytenoid dislocation (AD) involves either a complete disruption of the cricoarytenoid joint or a malpositioning of the arytenoid cartilages (AC) with reference to other laryngeal cartilages. In this report, we present a case of AD while using a McCoy laryngoscope. Although McCoy laryngoscope is recognized as a useful option for the cases of difficult endotracheal intubation, we are concerned that AD is likely with this device.