Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2003
Case ReportsTransnasal placement of biplane transesophageal echocardiography probe intraoperatively in an adolescent with congenital heart disease.
Intraoperative transesophageal echocardiography (TEE) is frequently used in children with congenital heart disease (CHD). Although transnasal TEE is being used in various settings in the adult population, there are no descriptions of its use intraoperatively in patients with CHD. This report describes the successful use of transnasal TEE after multiple unsuccessful transoral attempts in an adolescent male undergoing subaortic stenosis repair. ⋯ Transnasal transesophageal echocardiography (TEE) is being used in various settings in the adult population. The author describes its use intraoperatively in an adolescent undergoing surgery for congenital heart disease after unsuccessful transoral attempts.
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Anesthesia and analgesia · Dec 2003
Estimating alveolar dead space from the arterial to end-tidal CO(2) gradient: a modeling analysis.
Using an original, validated, high-fidelity model of pulmonary physiology, we compared the arterial to end-tidal CO(2) gradient divided by the arterial CO(2) tension (Pa-E'CO(2)/PaCO(2)) with alveolar dead space expressed as a fraction of alveolar tidal volume, calculated in the conventional manner using Fowler's technique and the Bohr equation: (VDalv/VTalv)(Bohr-Fowler). We examined the variability of Pa-E'CO(2)/PaCO(2) and of (VDalv/VTalv)(Bohr-Fowler) in the presence of three ventilation-perfusion defects while varying CO(2) production (Vdot;CO(2)), venous admixture, and anatomical dead space fraction (VDanat). Pa-E'CO(2)/PaCO(2) was approximately 59.5% of (VDalv/VTalv)(Bohr-Fowler). During constant alveolar configuration, the factors examined (Vdot;CO(2), pulmonary shunt fraction, and VDanat) each caused variation in (VDalv/VTalv)(Bohr-Fowler) and in Pa-E'CO(2)/PaCO(2). Induced variation was slightly larger for Pa-E'CO(2)/PaCO(2) during changes in VDanat, but was similar during variation of venous admixture and Vdot;CO(2). Pa-E'CO(2)/PaCO(2) may be a useful serial measurement in the critically ill patient because all the necessary data are easily obtained and calculation is significantly simpler than for (VDalv/VTalv)(Bohr-Fowler). ⋯ Using an original, validated, high-fidelity model of pulmonary physiology, we have demonstrated that the arterial to end-tidal carbon dioxide pressure gradient may be used to robustly and accurately quantify alveolar dead space. After clinical validation, its use could replace that of conventionally calculated alveolar dead space fraction, particularly in the critically ill.
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Anesthesia and analgesia · Dec 2003
Clinical TrialThe effect of right versus left lateral decubitus positions on induction of spinal anesthesia for cesarean delivery.
Induction of spinal anesthesia for cesarean delivery in the left lateral (LL) decubitus position combined with intraoperative left uterine displacement may result in pooling of local anesthetic onto one side of the body. We studied the effect of the right lateral (RL) and LL decubitus positions during placement of spinal anesthesia on the intrathecal spread of 0.5% hyperbaric bupivacaine plus fentanyl in 60 term parturients. Though all parturients acquired a loss of cold sensation at T4 15 min after intrathecal injection, more parturients in the LL group than in the RL group did so at 5 min (P < 0.05). The maximum levels of sensory blockades, amounts of fluid, vasopressor, and supplementary analgesia used, and the incidence of postoperative complications were similar. We conclude that the two positions can be used equally well when hyperbaric bupivacaine and fentanyl are used in cesarean delivery under spinal anesthesia. ⋯ We conducted a double-blinded randomized trial comparing the spread of spinal anesthesia placed with a parturient in either the right or left lateral position. There was a faster onset in the left lateral group; however, the maximum block heights and the time taken to achieve them were similar in both groups.
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Anesthesia and analgesia · Dec 2003
Case ReportsThe use of the LMA-ProSeal in airway resuscitation.
Insufflation of the stomach with air can be a complication of face mask ventilation in the case of airway obstruction. Although the laryngeal mask airway has proven value in airway resuscitation, it has two major failings: a relatively low seal pressure and lack of access to the alimentary tract. ⋯ The patient was resuscitated with a LMA-ProSeal, which permitted ventilation with high airway pressures. Return of oxyhemoglobin saturation occurred after decompression of the stomach with a gastric tube inserted via the LMA-ProSeal's gastric drain.
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Anesthesia and analgesia · Dec 2003
Case ReportsHyperbaric therapy for a postpartum patient with prolonged epidural blockade and tomographic evidence of epidural air.
We used the epidural technique "loss of resistance to air" to provide labor analgesia in a healthy parturient. Inadequate analgesia required epidural catheter replacement using the same technique. Delayed recovery of sensory and motor blockade postpartum necessitated computed tomography and magnetic resonance imaging studies. These revealed 4-6 mL of air in the epidural space with no evidence of thecal compression. On the advice of the neurologist, this patient underwent hyperbaric therapy 14 h after the discontinuation of the epidural infusion. The patient made a complete recovery and was discharged without neurologic sequelae. It is possible that epidural air delayed the absorption of local anesthetics as a result of a reduction in the vascular surface area. Although a cause and effect relationship between epidural air and prolonged neurological block cannot be categorically established, the use of "loss of resistance to air" technique complicated the differential diagnosis. ⋯ We report a case of prolonged motor and sensory block after labor analgesia using "loss of resistance to air" technique. The presence of epidural air on tomography resulted in the patient undergoing hyperbaric therapy. The use of loss of resistance to air technique complicated the differential diagnosis of prolonged sensory and motor block.