Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2003
Comparative StudyDifficult tracheal intubation is more common in obese than in lean patients.
Whether tracheal intubation is more difficult in obese patients is debatable. We compared the incidence of difficult tracheal intubation in obese and lean patients by using a recently validated objective scale, the intubation difficulty scale (IDS). We studied 134 lean (body mass index, <30 kg/m2) and 129 obese (body mass index, >or=35 kg/m2) consecutive patients. The IDS scores, categorized as difficult intubation (IDS >or=>5) or not (IDS <5), and the patient data, including oxygen saturation (SpO2) while breathing oxygen, were compared between lean and obese patients. In addition, risk factors for difficult intubation were determined in obese patients. The IDS score was >or=5 in 3 lean and 20 obese patients (P = 0.0001). A Mallampati score of III-IV was the only independent risk factor for difficult intubation in obese patients (odds ratio, 12.51; 95% confidence interval, 2.01-77.81), but its specificity and positive predictive value were 62% and 29%, respectively. SpO2 values noted during intubation were (mean +/- SD) 99% +/- 1% (range, 91%-100%) and 95% +/- 8% (range, 50%-100%) in lean and obese patients, respectively (P < 0.0001). We conclude that difficult intubation is more common among obese than nonobese patients. None of the classic risk factors for difficult intubation was satisfactory in obese patients. The high risk of desaturation warrants studies to identify new predictors of difficult intubation in the obese. ⋯ We report a difficult intubation rate of 15.5% in obese patients and 2.2% in lean patients. None of the risk factors for difficult intubation described in the lean population was satisfactory in the obese patients. We also report a high risk of desaturation in obese patients with difficult intubation.
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Anesthesia and analgesia · Aug 2003
Adverse events after protamine administration following cardiopulmonary bypass in infants and children.
We performed this study to determine the incidence of and risk factors for adverse events (AEs) in infants and children after the IV administration of protamine after cardiopulmonary bypass. In a retrospective cohort study, all relevant anesthesia records from a 3-yr period were examined to identify AEs after protamine. The AEs were then grouped into three categories by applying increasingly strict criteria. Among 1249 anesthesia records, there were no documented episodes of isolated or hypotension-associated right-sided cardiac failure or acute pulmonary dysfunction. The incidence of systemic hypotension after protamine was between 1.76% (95% confidence interval [CI], 1.11%-2.65%) and 2.88% (95% CI, 2.03%-3.97%), depending on the strictness of case definition. To identify risk factors, we performed a nested case-control study in which unmatched controls were randomly selected from the parent cohort at a 4:1 ratio to cases. Cases of hypotension after protamine were more likely during operations on girls (odds ratio [OR], 6.47; 95% CI, 1.66-32.8), after larger doses of protamine (OR, 1.88; 95% CI, 1.03-3.63), or after smaller doses of heparin (OR, 0.49; 95% CI, 0.17-0.67). ⋯ Systemic hypotension after protamine administration occurred in 1.76%-2.88% of pediatric patients having cardiac surgery. Female sex, larger protamine dose, and smaller heparin dose were each associated with increased risk. The development of protamine alternatives or prophylactic therapies may be useful for reducing the frequency of these events.
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Anesthesia and analgesia · Aug 2003
Comparative StudyA comparison of the neurotoxic effects on the spinal cord of tetracaine, lidocaine, bupivacaine, and ropivacaine administered intrathecally in rabbits.
We have reported that increased glutamate concentrations in microdialysate of the cerebrospinal fluid (CSF) may be clue phenomena to elucidate mechanisms of neurotoxicity of intrathecal tetracaine. However, little is known about whether this is true for other local anesthetics. In this study, we compared the effects of local anesthetics on glutamate concentrations in CSF microdialysate and neurologic and histopathologic outcome. Rabbits were assigned into 5 groups (n = 6 in each) and intrathecally received 0.3 mL of NaCl solution (control), 2% tetracaine, 10% lidocaine, 2% bupivacaine, or 2% ropivacaine. Neurologic and histopathologic assessments were performed 1 wk after the administration. Intrathecal local anesthetics significantly increased glutamate concentrations with no significant differences among the four local anesthetics. The sensory and motor functions in the lidocaine group were significantly worse than in the other groups. Characteristic histopathologic changes were vacuolation in the dorsal funiculus and chromatolytic damage of motor neurons. The extent of vacuolation of the dorsal funiculus was in the order of lidocaine = tetracaine > bupivacaine > ropivacaine. Although the differences among the local anesthetics cannot be explained by glutamate concentrations, the results suggest that the margin of safety may be smallest with lidocaine. ⋯ Large concentrations of local anesthetics administered intrathecally increased glutamate concentrations in the cerebrospinal fluid. The margin of safety may be smallest with lidocaine.
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Anesthesia and analgesia · Aug 2003
Postoperative pain experience: results from a national survey suggest postoperative pain continues to be undermanaged.
Postoperative pain can have a significant effect on patient recovery. An understanding of patient attitudes and concerns about postoperative pain is important for identifying ways health care professionals can improve postoperative care. To assess patients' postoperative pain experience and the status of acute pain management, we conducted a national study by using telephone questionnaires. A random sample of 250 adults who had undergone surgical procedures recently in the United States was obtained from National Family Opinion. Patients were asked about the severity of postsurgical pain, treatment, satisfaction with pain medication, patient education, and perceptions about postoperative pain and pain medications. Approximately 80% of patients experienced acute pain after surgery. Of these patients, 86% had moderate, severe, or extreme pain, with more patients experiencing pain after discharge than before discharge. Experiencing postoperative pain was the most common concern (59%) of patients. Almost 25% of patients who received pain medications experienced adverse effects; however, almost 90% of them were satisfied with their pain medications. Approximately two thirds of patients reported that a health care professional talked with them about their pain. Despite an increased focus on pain management programs and the development of new standards for pain management, many patients continue to experience intense pain after surgery. Additional efforts are required to improve patients' postoperative pain experience. ⋯ A survey of 250 US adults who had undergone a recent surgical procedure asked about their postoperative pain experience. Approximately 80% of patients experienced pain after surgery. Of these patients, 86% had moderate, severe, or extreme pain. Additional efforts are required to improve patients' postoperative pain experience.