No renal protection from volatile-anesthetic preconditioning in open heart surgery.

PURPOSE: Acute kidney injury (AKI) is a common complication of open heart surgery (OHS). Preconditioning with volatile anesthetics is well proven to provide myocardial protection. Renal protection provided by volatile-anesthetic preconditioning has also been investigated; however, it is still controversial at the clinical level. This study aimed to investigate whether preconditioning with volatile anesthetics could mediate renal protection in OHS. METHODS: A retrospective analytic study was designed. Medical records of patients (age ≥20 years) who had undergone OHS were reviewed. Types of anesthesia were classified as 'opioid-based anesthesia' (O group) and 'volatile-anesthetic-based anesthesia' (V group) according to the definitions given in the main text. Some medical records that had incomplete or ambiguous data were excluded. Renal protection was considered to be present if there was no clinical renal dysfunction as defined by the criteria given in the main text. AKI was considered to be present when there was a decrease of the postoperative estimated glomerular filtration rate (eGFR) that was >25 % of the preoperative eGFR. Also, postoperative 24-h oliguria (post-oliguria) and the provision of postoperative 48-h dialysis (post-dialysis) were considered. Differences between the O and V groups were tested by the appropriate statistics. A p value of <0.05 indicated significance. RESULTS: A total of 1,122 patients (702 males) were included in this study. The O and V groups included 704 and 418 patients, respectively. AKI was present in 9.52 and 8.37 % of the patients in the O and V groups, respectively (p = 0.532). Post-oliguria was found in 36.08 and 37.79 % of the patients in the O and V groups; and post-dialysis was provided in 3.98 and 4.31 %, respectively, of these patients; these two parameters showed no significant differences between the groups. CONCLUSIONS: This study could not demonstrate volatile-anesthetic-mediated renal protection in OHS. Therefore, in practice, pharmacological preconditioning with volatile anesthetics did not seem to be beneficial.

Effectiveness of mouthpiece nebulization and nasal swab stick packing for topical anesthesia in awake fiberoptic nasotracheal intubation.

OBJECTIVE: To evaluate the effectiveness of using mouthpiece nebulization and nasal swab stick packing for topical anesthesia in awake fiberoptic nasotracheal intubation. MATERIAL AND METHOD: This was a prospective descriptive study of 30 patients with ASA I-II who underwent elective surgery and suspected of difficult intubation between March 2004 and June 2006. After 2% lidocaine 5 ml was nebulizated in a micronebulizer using oxygen 10 L/min as a driving gas through a standard mouthpiece and 10% cocaine 1 ml on cotton swab-stick was applied to the selected nostril for 15 min, fiberoptic nasotracheal intubation was done while the patient was awake. If the patient had severe gag or cough reflex, 1% lidocaine 5 ml per each time could be injected through the working channel of the fiberoptic bronchoscope. The descriptive statistics were calculated by using SPSS version 11.0. RESULTS: The success rate of awake fiberoptic nasotracheal was 100%. The mean duration of awake fiberoptic nasotracheal intubation was 119.0 +/- 76.8 sec. The responses of the patient to instrumentation during 4 periods, i.e.: passing the endotracheal tube into the nose, passing the bronchoscope into the pharynx-larynx, passing the bronchoscope into the trachea-carina and passing the endotracheal tube into the trachea were, as follows: no response in about 53.3%, 63.3%, 23.3%,and 13.3%; mild pain or reflex in about 46.7%, 10%, 70%, and 86.7%; moderate pain or reflex in about 0%, 3.3%, 6.7%, and 0%; and severe pain or reflex requiring more local anesthetic in about 0%, 23.3%, 0%, and 0%, respectively. Despite complete topical anesthesia in the majority of the patients, two patients required 5 ml more 1% lidocaine and five patients required 10 mL more of the drug through the fiberoptic bronchoscope. There was no serious complication such as hypoxemia, arrhythmia. Twenty-four patients (80%) were satisfied with mouthpiece nebulization and nasal swab packing because they felt safe, did not have pain, and were comfortable; only three patients (10%) were dissatisfied because of numbness of the tongue and difficulty in swallowing; two patients (6.7%) had no comment; and one patient (3.3%) was unable to evaluate due to unplanned tracheostomy. CONCLUSION: In the present study technique of topical anesthesia using 2% lidocaine 5 mL mouthpiece nebulization and 10% cocaine 1 mL soaked nasal swab stick packing is useful and safe for awake fiberoptic nasotracheal intubation in patients with suspected difficult intubation. 76.7% of the patient did not require more local anesthesia and 80% were satisfied with this technique.