Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1999
Early outpatient preoperative anesthesia assessment: does it help to reduce operating room cancellations?
Increased understanding of the high cost associated with operating room (OR) cancellations has led to efforts by healthcare providers to decrease case cancellations on the day of surgery. To investigate whether preoperative evaluations within 24 h of surgery were associated with more frequent OR cancellations than those completed 2-30 days before surgery, we prospectively studied OR cancellations for 3 mo. Of the 529 patients in the study, 166 were seen within 24 h of surgery (standard group), and the remaining 363 patients were seen 2-30 days before surgery (early group). There were 70 OR cancellations on the day of surgery, and the largest single group of cancellations was related to administrative problems. The standard group and the early group were similar in terms of gender, age, ASA physical status, and percentage of patients undergoing major surgery. The OR cancellation rates were also comparable between groups: 13.3% for the standard group and 13.2% for the early group. These data suggest that patients can be evaluated in an outpatient preoperative evaluation clinic in a timeframe that is convenient for the patient without adversely affecting the cancellation rate on the day of surgery. ⋯ The operating room cancellation rate for outpatients evaluated 2-30 days before surgery was compared with the cancellation rate for outpatients who received their anesthesia evaluation within 24 h of surgery. Because both groups had similar rates, outpatients may be seen at a convenient time without adversely affecting operating room cancellations.
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Anticipated technical difficulty is one factor that can influence the anesthesiologist's decision to perform neuraxial (spinal or epidural) blockade. Problems during the procedure may be associated with patient dissatisfaction, neurologic sequelae, or hematoma. We designed this study of 595 neuraxial blocks to determine whether any patient characteristics would be useful in predicting a difficult neuraxial block. Before the procedure, the following data were noted: demographic data, body habitus (normal, thin, muscular, obese), spinal landmarks (good = easily palpable spinous processes, poor = difficult to palpate spinous processes, none = unable to positively identify spinous processes), and spinal anatomy (assessed by inspection and examination as normal or deformed). We noted the technique, approach, needle type, needle gauge, etc. We also recorded whether the procedure was completed at the first (first-level success) or second spinal level and the total number of new skin punctures (attempts) necessary to complete the procedure. Of all the factors considered, the quality of landmarks best correlated with technical difficulty as measured by both first-level success and number of attempts. Abnormal spinal anatomy correlated with difficulty as measured by number of attempts. Body habitus also correlated with difficulty, but only as measured by number of attempts. There was no association between either measure of difficulty and any of the following: age, sex, spinal versus epidural, approach, needle type, needle gauge, or training level of the provider. Thoracic epidurals were less difficult than lumbar epidurals by both measures of difficulty. We conclude that body habitus does not seem to be the best predictor of technical difficulty. An examination of the patient's back for the quality of landmarks and obvious anatomical deformity better predicts the ease or difficulty of neuraxial block. Other factors seem to have little or no influence on the difficulty of neuraxial block procedures. ⋯ We studied a number of factors, including equipment, technique, and patient characteristics, that may indicate the ease or difficulty of performing neuraxial (spinal and epidural) blocks. Of these factors, only patient characteristics had significant predictive value. We found that an examination of the patient's back for the quality of landmarks and obvious anatomical deformity better predicts the ease or difficulty of neuraxial block than does body habitus.
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Anesthesia and analgesia · Aug 1999
Effects of one minimum alveolar anesthetic concentration sevoflurane on cerebral metabolism, blood flow, and CO2 reactivity in cardiac patients.
We investigated the cerebral hemodynamic effects of 1 minimum alveolar anesthetic concentration (MAC) sevoflurane anesthesia in nine male patients scheduled for elective coronary bypass grafting. For measurement of cerebral blood flow (CBF), a modified Kety-Schmidt saturation technique was used with argon as an inert tracer gas. Measurements of CBF were performed before the induction of anesthesia and 30 min after induction under normocapnic, hypocapnic, and hypercapnic conditions. Compared with the awake state under normocapnic conditions, sevoflurane reduced the mean cerebral metabolic rate of oxygen by 47% and the mean cerebral metabolic rate of glucose by 39%. Concomitantly, CBF was reduced by 38%, although mean arterial pressure was kept constant. Significant changes in jugular venous oxygen saturation were absent. Hypocapnia and hypercapnia caused a 51% decrease and a 58% increase in CBF, respectively. These changes in CBF caused by variation of Paco2 indicate that cerebrovascular CO2 reactivity persists during 1 MAC sevoflurane anesthesia. ⋯ We used a modified Kety-Schmidt saturation technique to investigate the effects of 1 minimum alveolar anesthetic concentration (MAC) sevoflurane on cerebral blood flow, metabolism, and CO2 reactivity in cardiac patients. We found that the global cerebral blood flow and global cerebral metabolic rate of oxygen remained coupled and that cerebrovascular CO2 reactivity is not impaired by the administration of 1 MAC sevoflurane.
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Anesthesia and analgesia · Aug 1999
Ventilatory response to CO2 in children with obstructive sleep apnea from adenotonsillar hypertrophy.
We measured the ventilatory response to CO2 as an indicator of respiratory control dysfunction in children with obstructive sleep apnea (OSA) scheduled for adenotonsillectomy. Measurements were performed in unpremedicated children via an endotracheal tube under 0.4%-0.5% end-tidal halothane anesthesia. Mean ventilatory CO2 response slopes for 11 children with OSA requiring adenotonsillectomy (Group I) were compared with those for 14 children without OSA requiring adenotonsillectomy (Group II) and 15 children without OSA requiring nonairway surgery (Group III). The mean ventilatory slope corrected for body surface area for Groups I, II, and III were 539 +/- 338, 828 +/- 234, and 850 +/- 380 mL.min-1.mm Hg ETCO2(-1).m-2, respectively (P < 0.05, Group I versus Groups II and III). Historical data--including snoring, apneic episodes > 10 s, daytime hypersomnolence, and nocturnal enuresis--defined those with OSA. Obesity occurred more frequently in patients with OSA and with depressed ventilatory responses (P < 0.001). Children with OSA from adenotonsillar hypertrophy have a diminished ventilatory response to CO2 stimulation, compared with those without OSA symptoms. The depressed response may account, in part, for the reported increased risk of perioperative respiratory complications in this population. ⋯ Children with obstructive sleep apnea undergoing adenotonsillar surgery are at risk of postoperative respiratory compromise. We found that patients with a clinical history suggesting obstructive sleep apnea have a diminished ventilatory response to CO2 rebreathing, compared with controls.
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Anesthesia and analgesia · Aug 1999
Assessing the relative quality of anesthesiology and critical care medicine Internet mailing lists.
We studied the relative quality of a subset of anesthesiology and critical care medicine Internet mailing lists regarding the publishing capacity of their members to compare them with the major journals and conferences regarding these specialties. Using systematic searches on MEDLINE and according to the Science Citation Index 1995, we investigated the impact factor of mailing list subscribers, of the first authors of the selected articles, and of the first authors of published abstracts from conferences. We studied six mailing lists, seven journals, and four conferences. Journals and conferences showed a higher percentage of published authors and higher average impact factor among their first authors than the mailing lists did per subscriber. However, when only the subset of publishing authors from the three media was considered, no significant differences were found. We conclude that qualified authors may be found among the subscribers of Internet medical mailing lists on anesthesiology and critical care medicine. These professional discussion groups could complement peer-reviewed publications and conferences in professional information exchange and continuing medical education. ⋯ Internet publishing is not governed by rules that assure certain basic quality standards. Methods for assessing these standards are needed. We compared discussion groups with medical journals and conferences on anesthesiology and critical care medicine by calculating the impact factor of their members and first authors, respectively. Our study shows that qualified authors may be found in all three media.