Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2004
Clinical TrialThe intubating laryngeal mask airway facilitates tracheal intubation in the lateral position.
Although the difficulty of tracheal intubation in the lateral position has not been systematically evaluated, airway loss during surgery in a laterally positioned patient may have hazardous consequences. We explored whether the intubating laryngeal mask airway (ILMA) facilitates tracheal intubation in patients with normal airway anatomy, i.e., Mallampati grade
or=5 cm, positioned in the lateral position. We evaluated whether this technique can be used as a rescue when the airway is lost during the middle of surgery in laterally positioned patients with respect to success rate and intubation time. Anesthesia was induced with propofol, fentanyl, and vecuronium in 50 patients undergoing spine surgery for lumbar disk herniation (Lateral) and 50 undergoing other surgical procedures (Supine). Patients having disk surgery (Lateral) were positioned on their right or left sides before induction of general anesthesia, and intubation was performed in that position. Patients in the control group (Supine) were anesthetized in supine position, and intubation was performed in that position. Intubation was performed blindly via an ILMA in both groups. The time required for intubation and number and types of adjusting maneuvers used were recorded. Data were compared by the Mann-Whitney U test, Fisher's exact test, chi(2) test, or unpaired Student's t-test, as appropriate. Data presented as mean (SD). Demographic and airway measures were similar in the two groups, except for mouth opening, which was slightly wider in patients in the lateral position: 5.1 (0.9) versus 4.6 (0.7) cm. The time required for intubation was similar in each group ( approximately 25 s), as was intubation success (96%). We conclude that blind intubation via an ILMA offers a frequent success rate and a clinically acceptable intubation time (<1 min) even in the lateral position. ⋯ Blind intubation via the intubating laryngeal mask airway (ILMA) offers frequent success and a clinically acceptable intubation time even in patients in the lateral position. -
Anesthesia and analgesia · Mar 2004
The incidence and prediction of automatically detected intraoperative cardiovascular events in noncardiac surgery.
The objective of this study was to evaluate prognostic models for quality assurance purposes in predicting automatically detected intraoperative cardiovascular events (CVE) in 58458 patients undergoing noncardiac surgery. To this end, we assessed the performance of two established models for risk assessment in anesthesia, the Revised Cardiac Risk Index (RCRI) and the ASA physical status classification. We then developed two new models. CVEs were detected from the database of an electronic anesthesia record-keeping system. Logistic regression was used to build a complex and a simple predictive model. Performance of the prognostic models was assessed using analysis of discrimination and calibration. In 5249 patients (17.8%) of the evaluation (n = 29437) and 5031 patients (17.3%) of the validation cohorts (n = 29021), a minimum of one CVE was detected. CVEs were associated with significantly more frequent hospital mortality (2.1% versus 1.0%; P < 0.01). The new models demonstrated good discriminative power, with an area under the receiver operating characteristic curve (AUC) of 0.709 and 0.707 respectively. Discrimination of the ASA classification (AUC 0.647) and the RCRI (AUC 0.620) were less. Neither the two new models nor ASA classification nor the RCRI showed acceptable calibration. ASA classification and the RCRI alone both proved unsuitable for the prediction of intraoperative CVEs. ⋯ The objective of this study was to evaluate prognostic models for quality assurance purposes to predict the occurrence of automatically detected intraoperative cardiovascular events in 58,458 patients undergoing noncardiac surgery. Two newly developed models showed good discrimination but, because of reduced calibration, their clinical use is limited. The ASA physical status classification and the Revised Cardiac Risk Index are unsuitable for the prediction of intraoperative cardiovascular events.
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Anesthesia and analgesia · Mar 2004
Clinical TrialContinuous psoas compartment blocks after major orthopedic surgery in children: a prospective computed tomographic scan and clinical studies.
Femoral shaft or hip surgeries are very painful for children. We conducted both computed tomographic (CT) and clinical prospective studies to define new landmarks in children and to evaluate the effectiveness of continuous psoas compartment blocks (CPCBs) using disposable elastomeric pumps. In a preliminary CT scan study of 20 patients, the plexus depth was correlated to patient age and the optimal point of puncture for CPCB was three-quarters of the distance from the spinous process of L4 to a line parallel to the spinal column passing through the posterior superior iliac spine. In a subsequent prospective series, a CPCB was administered before surgery to 15 children for pain relief after femoral and hip osteotomies. After general anesthesia, a 0.5 mL/kg bolus of a mixture of 1% lidocaine with epinephrine (1/200.000) and 0.5% ropivacaine was injected through the CPCB catheter. After contrast media assessment of the catheter location, a disposable pump (Infusor LV); Baxter, Paris, France) with 0.2% ropivacaine was connected and pump flow was adjusted to the patient's weight (0.2 mg x kg(-1) x h(-1)). Postoperative pain was evaluated using a visual analog scale or the Children and Infants Postoperative Pain Score at hour H1, H6, H12, H18, H24, H36, and H48, and in terms of rescue analgesia, adverse events, and motor blocks. All blocks were effective during surgery. Postoperative analgesia was excellent. The median pain scores were 1 for H1 and 0 beginning H6. The motor blockade was minimal before 24 h and absent thereafter. No major adverse event was noted. Parents of 93% of the children were satisfied. We conclude that postoperative analgesia with CPCB is a very effective technique in children after major proximal lower limb orthopedic surgery. The CT scan landmarks described in this study were more medial than the conventional landmarks used in the literature. ⋯ Continuous psoas compartment blocks provide optimal pain relief in children after major orthopedic surgery without major adverse events. The landmarks used, defined in a preliminary computed tomographic scan study, were more medial than conventional landmarks.
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Anesthesia and analgesia · Mar 2004
Clinical TrialAssessing residual neuromuscular blockade using acceleromyography can be deceptive in postoperative awake patients.
Postoperative awake patients may have significant residual neuromuscular block. In awake patients, the results of accelerometry are affected by extra movements to which the thumb may be subject. In this study, we evaluated the repeatability of train-of-four (TOF) ratio using acceleromyography in 253 patients recovering from anesthesia. Immediately after arrival in the postanesthesia care unit, the ulnar nerve was stimulated with TOF stimulation. The evoked response at the thumb was measured by the TOF-Watch apparatus. The current intensity was 30 mA. Two TOF stimulations were applied and recorded at 30-s intervals. A Bland-Altman test was used. The Kappa (kappa) test for clinical agreement between the two measurements was also calculated according to the presence or absence of a residual neuromuscular blockade, defined as a TOF ratio <0.9. According to the presence of a residual neuromuscular blockade, the paired TOF ratios were discordant in 61 patients (24%; 95% confidence interval, 21%-27%). The kappa test indicated a moderate agreement (k = 0.47). We demonstrated that accelerometry as used in this study is not always accurate. Two isolated acceleromyograph TOF ratios are not an accurate representation of the neuromuscular status of the patient recovering from anesthesia. ⋯ Clinicians should be aware that acceleromyography as used in this study does not always provide precise train-of-four ratio measurements. Two isolated acceleromyograph train-of-four ratios are not an accurate representation of the neuromuscular status of the patient recovering from anesthesia.
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Anesthesia and analgesia · Mar 2004
Case ReportsPersistent cerebrospinal fluid leak: a complication of the combined spinal-epidural technique.
Persistent cerebrospinal fluid (CSF) leak is an apparently rare complication of dural puncture from spinal or epidural anesthesia. Combined spinal-epidural techniques are increasingly popular but persistent CSF leak has not been reported. We describe three parturients with persistent fluid leak from the insertion site after epidural catheter removal following combined spinal-epidural anesthesia. Uncertainties related to the diagnosis, treatment, and the implications of this complication are discussed, including beta(2)-transferrin immunofixation assay as a diagnostic test for the presence of CSF in this situation. ⋯ Combined spinal-epidural block can be complicated by persistent fluid leak from the skin insertion site. Testing for the presence of cerebrospinal fluid may be a useful aid to management.