Postanesthesia Day Research Articles

Persistent Complete Atrioventricular Block after Induction of General Anesthesia in a Healthy Patient

<p>A 38-year-old female patient had bradycardia in the preoperative electrocardiogram (ECG), and she showed severe bradycardia, with the heart rate (HR) under 40 beats per minute (bpm) even after arrival in the operating room. Immediately after endotracheal intubation, ventricular tachycardia with HR over 200 bpm occurred, but it disappeared voluntarily. The surgery was postponed for additional cardiac evaluation because of the persistent severe bradycardia. On postanesthesia day 2, complete atrioventricular (AV) block appeared. We expected spontaneous recovery over 2 weeks, but the complete AV block persisted. A permanent pacemaker was eventually inserted, and the patient was discharged without other complications on day 4 after insertion of the pacemaker. We report this case because complete AV block has commonly occurred in patients with risk factors such as first AV block, secondary AV block, or bundle branch block, but complete AV block has occurred despite the absence of arrhythmia in this patient.</p>

Correlation between olfactory and post-operative cognitive dysfunction of the elderly orthopedic surgery patients in the perianesthesia

Objective To investigate the change of olfactory and cognitive function at the perianesthesia of elderly orthopedic surgery patients, and analyze the correlation between them. Methods Thirty elderly orthopedic surgery patients in the anesthesia group who were scheduled for orthopaedic surgery. They were also tested with the Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory assessment in the day before anesthesia, 3nd and 7th day post-anesthesia. The cognitive function of each case was assessed using a battery of neuropsychological tests including Mini-Mental State Examination(MMSE), Hopkins Verbal Learning Test-Revised (HVLT-R), Trail Making Test (TMT), Stroop Color Word Test (SCWT), Digit-Symbol Coding Test (DSCT) and Verbal Fluency Test(VFT). A total of 30 healthy volunteers were recruited under the same inclusion and exclusion criteria, as the control group. Neuropsychological tests were performed to the control group at the same time period as in patients group. Results Compared with the control group, the olfactory identification score was lower in the anesthesia group on 3rd and 7th post-anesthesia day respectively, the difference is statistically significant(P<0.05). On 3rd post-anesthesia day, the scores of MMSE, short-term retention, delayed retention were lower, the scores of the TMT, SCWT were higher(P<0.05). On 7th post-anesthesia day, the scores of short-term retention were lower and the TMT were higher(P<0.05). Linear correlation analysis showed that the different values of olfactory identification score were correlated positively with the different values of short-term retention and delayed retention on 3rd and 7th post-anesthesia day. Conclusions The olfactory dysfunction mainly presented with the decrease of the olfactory identification score of elderly orthopedic surgery patients in the peri-anesthesia. The cognitive dysfunction mainly presented with the decrease of short-term retention, delayed retention and the ability of concentrating. The olfactory dysfunction was positively correlated with the post-anesthesia cognitive dysfunction. Key words: Aged; Orthopedics surgery; Perianesthesia; Olfactory function; Post-operative cognitive dysfunction

Does exposure to inhalation anesthesia gases change the ratio of X-bearing sperms and Y-bearing Sperms? A worth exploring project into an uncharted domain

According to recent surveys performed in United States and India, anesthesia care providers were observed to have sired female offspring in a higher proportion than male offspring as their firstborn progeny; however, the reasons for the skew are not clear. Our hypothesis is that the underlying biological evidence may be elucidated by unraveling differences (if any) between the concentrations of X-bearing sperms and Y-bearing sperms in the semen samples obtained from males exposed to varied levels of anesthetics in their lifetimes. Therefore, the objectives of the envisaged study would be to conduct a three-stage investigative study on in-vitro human semen samples to determine (a) X-bearing sperms and Y-bearing sperms concentrations’ ratio in male pediatric anesthesia care providers’ semen samples, (b) changes in X-bearing sperms and Y-bearing sperms concentrations’ ratios between the pre-rotation and post-rotation semen samples of male medical student volunteers/observers, and (c) changes in X-bearing sperms and Y-bearing sperms concentrations’ ratios between the pre-operative and post-operative day-3 semen samples of male patients presenting for outpatient procedures under inhalational anesthesia. The expected outcomes would be (a) linear and positive correlation of the anesthetic gas usage (exposure) with increased X-bearing sperms/Y-bearing sperms ratio in post-anesthesia day 3 sample as compared to the baseline preoperative sample, (b) linear and positive correlation of the anesthetic gas usage (exposure) with increased X-bearing sperms/Y-bearing sperms ratio in post-rotation sample as compared to the baseline sample, and (c) observation of high X-bearing sperms/Y-bearing sperms ratio in the pediatric anesthesia care providers. In summary, effects (if any) of occupational or personal exposure to inhalational anesthetic gases on the X-bearing sperms and Y-bearing sperms ratio is a worthy project wherein lots of questions that have arisen over decades could find the path to their definitive answers, based on envisaged laboratory investigations into this uncharted domain.

Ketamine and propofol have opposite effects on postanesthetic sleep architecture in rats: relevance to the endogenous sleep-wakefulness substances orexin and melanin-concentrating hormone.

Anesthesia and surgery disturb sleep. Disturbed sleep adversely affects postoperative complications involving the cardiovascular system, diabetes, and infection. General anesthetics share neuronal mechanisms involving endogenous sleep-wakefulness-related substances, such as orexin (OX) and melanin-concentrating hormone (MCH). We evaluated changes in sleep architecture and the concentration of OX and MCH during the peri-anesthetic period. To examine sleep architecture, male Sprague-Dawley rats weighing 350-450g received ketamine 100mg/kg (n=9) or propofol 80mg/kg (n=6) by intraperitoneal injection. Electroencephalography was recorded from 2days pre- to 5days postanesthesia. To quantify levels of OX and MCH, 144 similar rats received the same doses of ketamine (n=80) or propofol (n=64). Brain concentrations of these substances were determined at 0, 20, 60, and 120min after anesthetic administration. Ketamine decreased OX content in the hypothalamus during the anesthesia period. OX content was restored to pre-anesthesia levels in the hypothalamus and pons. Both anesthetics increased brain MCH content in the postanesthetic period, with the degree of increase being greater with propofol. Ketamine enhanced wakefulness and inhibited non-rapid eye movement sleep (NREMS) immediately after anesthesia. Conversely, propofol inhibited wakefulness and enhanced NREMS in that period. Ketamine inhibited wakefulness and enhanced NREMS during the dark phase on the first postanesthesia day. Anesthetics affect various endogenous sleep-wakefulness-related substances; however, the modulation pattern may depend on the type of anesthetic. The process of postanesthetic sleep disturbance was agent specific. Our results provide fundamental evidence to treat anesthetic-related sleep disturbance.

Spatial Memory Using Active Allothetic Place Avoidance in Adult Rats After Isoflurane Anesthesia

We described a paradigm of active allothetic place avoidance (AAPA) as a measure of spatial memory in adult rats. We hypothesized that, pending successful AAPA training, treatment with isoflurane would trigger spatial memory deficits. Fifteen of 20 adult rats were successfully trained and randomly allocated to control and isoflurane treatment groups. An additional 7 animals were used to demonstrate hemodynamic stability during general anesthesia. After training, experimental animals received a 2-hour isoflurane anesthetic. General endotracheal anesthesia was maintained at an isoflurane concentration of 1.8% to 2%. After intervention, retention of training was tested on postanesthesia days 1, 3, and 7. Animals treated with isoflurane displayed selected spatial memory changes up to postanesthesia day 7. There were 2 findings of decreased active avoidance behavior in rats receiving isoflurane: a significant (P=0.029) reduction in maximum path of avoidance in the isoflurane-treated rats compared with controls, and a significant (P=0.038) increase in total path length in the controls. No other measured AAPA parameters achieved statistical significance. Control animals demonstrated increased active avoidance behavior in the AAPA task compared with isoflurane-treated animals. Animals exposed to 2-hour isoflurane general anesthetic had a reduction in the maximum path of avoidance measure up to 7 days postanesthesia, whereas gross spatial parameters such as number of entrances into the shock zone were not significantly different between groups. The AAPA model may prove useful in ascertaining the learning and memory deficits of postoperative cognitive dysfunction.

Assessment of Renal Effects of Sevoflurane in Elderly Patients Using Urinary Markers

To the Editor: Although sevoflurane anesthesia has been shown not to cause nephrotoxicity in adults with normal renal function, its effect in patients with impaired renal function or in the elderly has not been thoroughly investigated. Recently, urinary albumin has gained attention as a marker of postanesthetic renal injury in surgical patients [1], but there is no agreement on how the results of studies should be interpreted. At our institution, we have investigated the effects of inhaled anesthetics on renal function in elderly patients. We present the data of our study, in which urinary albumin, alpha1 microglobulin (MG), beta2 MG, and N-acetyl- beta-D-glucosaminidase (NAG) were used as markers of renal injury in elderly patients anesthetized with sevoflurane. Thirteen patients aged >or=to70 yr undergoing gastrectomy were randomly assigned to receive either sevoflurane anesthesia (n = 7; mean age 77.6 yr) or isoflurane anesthesia (n = 6; mean age 78.5 yr). We used routine anesthetic techniques for our institution in this study, i.e., local epidural anesthesia combined with inhaled anesthesia (3 L/min air, 2 L/min oxygen, and either sevoflurane or isoflurane). A urine sample was collected via a catheter before anesthesia, and cumulative urine samples were then collected during and after anesthesia (immediately before surgery; 2 h after the start of surgery; at the end of surgery; and 3 h and Days 1, 3, and 7 after anesthesia). There were no significant differences in patient demographics. The mean minimum alveolar anesthetic concentration-hour was 5.1 for the sevoflurane group and 3.7 for the isoflurane group. The mean urinary albumin excretion was 65.0 mg/g creatinine (gCr) and 44.4 mg/gCr before anesthesia, which significantly increased to 147.9 mg/gCr and 196.9 mg/gCr 2 h after the start of surgery, sustained similar values 3 h after anesthesia, and returned to close to the preanesthetic values on Postanesthesia Day 1 in the sevoflurane group and the isoflurane group, respectively. No significant difference was found between the two groups, and the increase in urinary albumin excretion indicated that transient glomerular injury occurred with both anesthetics. The mean urinary alpha1 and beta2 MG levels were 9.3 mg/gCr and 0.81 mg/gCr in the sevoflurane group and 7.4 mg/gCr and 0.70 mg/gCr in the isoflurane group before anesthesia, showed a gradual but significant increase in both groups during anesthesia, and reached 31.4 mg/gCr and 6.20 mg/gCr in the sevoflurane group and 44.1 mg/gCr and 10.9 mg/gCr in the isoflurane group by 3 h after anesthesia. The values of alpha (1) and beta2 MG then temporally dropped on Postanesthesia Day 1, but they increased again on Day 3 in both groups and decreased again on Day 7 (cause unknown). The mean urinary NAG also began to increase during anesthesia to significantly higher levels than the preanesthetic values (18.9 mg/gCr in the sevoflurane group and 16.9 mg/gCr in the isoflurane group), reached a peak 3 h after anesthesia (40.6 mg/gCr in the sevoflurane group and 35.7 mg/gCr in the isoflurane group), but returned to almost the preanesthetic values on Postanesthesia Day 1. The changes in the urinary enzyme levels indicated the presence of transient renal tubular injury in both groups. In conclusion, using urinary markers, we found that sevoflurane and isoflurane anesthesia in combination with epidural anesthesia resulted in similar degrees of mild, transient, glomerular, and tubular functional impairment in elderly surgical patients undergoing gastrectomy. Kokichi Hase, MD Kazuko Meguro, MD Takako Nakamura, MD Department of Anesthesiology; Tokyo Metropolitan Geriatric Hospital; Tokyo 173-0015, Japan

Nephrotoxicity of Sevoflurane Versus Desflurane Anesthesia in Volunteers

Present package labeling for sevoflurane recommends the use of fresh gas flow rates of 2 L/min or more when delivering anesthesia with sevoflurane.This recommendation resulted from a concern about the potential nephrotoxicity of a degradation product of sevoflurane, "Compound A," produced by the action of carbon dioxide absorbents on sevoflurane. To assess the adequacy of this recommendation, we compared the nephrotoxicity of 8 h of 1.25 minimum alveolar anesthetic concentration (MAC) sevoflurane (n = 10) versus desflurane (n = 9) in fluid-restricted (i.e., nothing by mouth overnight) volunteers when the anesthetic was given in a standard circle absorber anesthetic system at 2 L/min. Subjects were tested for markers of renal injury (urinary albumin, glucose, alpha-glutathione-S-transferase [GST], and pi-GST; and serum creatinine and blood urea nitrogen [BUN]) before and 1, 2, 3, and/or 5-7 days after anesthesia. Desflurane did not produce renal injury. Rebreathing of sevoflurane produced average inspired concentrations of Compound A of 41 +/- 3 ppm (mean +/- SD). Sevoflurane was associated with transient injury to: 1) the glomerulus, as revealed by postanesthetic albuminuria; 2) the proximal tubule, as revealed by postanesthetic glucosuria and increased urinary alpha-GST; and 3) the distal tubule, as revealed by postanesthetic increased urinary pi-GST. These effects varied greatly (e.g., on postanesthesia Day 3, the 24-h albumin excretion was <0.03 g (normal) for one volunteer; 0.03-1 g for five others; 1-2 g for two others; 2.1 g for one volunteer; and 4.4 g for another volunteer). Neither anesthetic affected serum creatinine or BUN, nor changed the ability of the kidney to concentrate urine in response to vasopressin, 5 U/70 kg subcutaneously (i.e., these measures failed to reveal the injury produced). In addition, sevoflurane, but not desflurane, caused small postanesthetic increases in serum alanine aminotransferase (ALT), suggesting mild, transient hepatic injury. (Anesth Analg 1997;84:160-8)