Postanesthetic malignant hyperthermia with convulsions

Journal of Anesthesia -     

EFFECT OF NITROGLYCERNE-INDUCED HYPOTENSION ON CANINE SPINAL CORD BLOOD FLOW

Twenty-four mongrel dogs were anaesthetized with pentobarbitoneand morphine sulphate. Neuromuscular blockade was achieved usingpancuronium. Spinal cord blood flow was measured using the radionuclidemicrosphere and hydrogen washout methods before, during, andfollowing nitroglycerine-induced hypotension. Heart rate, meanarterial pressure, cardiac output, pulmonary capillary wedgepressure, and acid-base balance were determined with each measurement.Mean arterial pressure was reduced by 50%. Spinal cord bloodflow, as measured by the microsphere method, increased duringthe period of hypotension, whereas values obtained using thehydrogen washout method were not significantly different fromthose at normotension. No significant change in spinal cordblood flow was detected by either method after the applicationof spinal distraction. Nitroglycerine acts predominantly onvenous capacitance vessels and it is postulated that perfusionpressure, and therefore flow, is maintained despite a reductionin arterial pressure. Presented in part at the Anual Meeting of the American Societyof Anesthesiologists, October 1985, San Francisco, California. ^*Shackleton Department of Anaesthetics, Southampton GeneralHospital, Shirley, Southampton, Hants SO9 4XY. Section of Orthopedic Surgery, Madison, Wisconsin.     

PULMONARY VENTILATION AND GAS EXCHANGE BEFORE AND AFTER CORRECTION OF CONGENITAL CARDIAC MALFORMATIONS

Sixteen children with congenital cardiac malformations weredivided into cyanotic (n = 9) and acyanotic (n = 7) groups,and pulmonary ventilation and gas exchange were assessed beforesurgery, after sternotomy, just after the completion of cardiopulmonarybypass (CPB), 30 min after CPB and after closure of sternostomybefore transfer to ICU. Most patients in the cyanotic grouphad oligaemic, while all in the acyanotic group had overperfused,lungs before surgery. Total compliance was similar in the twogroups. Alveolar ventilation was higher and the physiologicaldeadspace to tidal volume ratio (Vd/Vt) lower in the acyanoticgroup compared with the cyanotic group (P < 0.05) beforesurgery. In the cyanotic group the preoperative large differencebetween arterial (Pa_CO2) and end-tidal (PE'_CO2) carbon dioxidetension was smaller immediately after CPB and remained so afterclosure of the sternum. In the acyanotic children the smallarterial to end-tidal carbon dioxide difference before CPB hadincreased Just after and 30 min after CPB, and Vo/Vr was significantlyincreased (P < 0.05) just after CPB. After closure of thesternum the arterial to end-tidal carbon dioxide differenceand the Vo/Vr ratio had returned to baseline. The arterial toend-tidal carbon dioxide difference is a good indicator of ventilatoryefficiency after open heart surgery.     

Pharmacodynamic modeling of the EEG effects of ketamine and its enantiomers in man

The pharmacodynamics of a racemic mixture of ketamine R,S (±)-ketamine and of each enantiomer, S(+)-ketamine and R(–)-ketamine, were studied in five volunteers. The median frequency of the electroencephalogram (EEG) power spectrum, a continuous noninvasive measure of the degree of central nervous system (CNS) depression (pharmacodynamics), was related to measured serum concentrations of drug (pharmacokinetics). The concentration-effect relationship was described by an inhibitory sigmoid E_max pharmacodynamic model, yielding estimates of both maximal effect (E_max) and sensitivity (IC₅₀) to the racemic and enantiomeric forms of ketamine. R(–)-ketamine was not as effective as R,S(±)-ketamine or S(+)-ketamine in causing EEG slowing. The maximal decrease (mean±SD) of the median frequency (E_max)for R(–)-ketamine was 4.4±0.5 Hz and was significantly different fromR,S (±)-ketamine (7.6 ±1.7 Hz) and S(+)-ketamine (8.3±1.9Hz). The ketamine serum concentration that caused one-half of the maximal median frequency decrease (IC₅₀) was 1.8±0.5g/mL for R(–)-ketamine; 2.0±0.5 g/mL for R,S(±)-ketamine; and 0.8±0.4 g/mL for S(+)-ketamine. Because the maximal effect (E_max) of the R(–)-ketamine was different from that of S(+)-ketamine and R,S(±)-ketamine, it was not possible to directly compare the potency (i.e., IC₅₀) of these compounds. Accordingly, a classical agonist/partial-agonist interaction model was examined, using the separate enantiomer results to predict racemate results. Although the model did not predict racemate results well, its failure was not so great as to provide clear evidence of synergism (or excess antagonism) of the enantiomers.This work was supported in part by a Starter Grant from the American Society of Anesthesiologists, the Biomedical Research Support Grant NIH 2S07RR5353-20, 1981, (P.F.W.); and NIH and NIA Research Grants NS-17956 and AG03104 (D.R.S., A.J.T., L.B.S). The research fellowship of Dr. Schüttler was made possible by a NATO Foundation Grant (300-402-511-3), awarded by the German Academic Exchange Service. This study is part of Dr. Schüttler's Habilitation Thesis for the Faculty of Medicine at the University of Bonn, West Germany. Dr. Verotta is a fellow of the program of advanced training established by EEC and Regione Lombardia on leave of absence from Mario Negri Institute of Pharmacological Research, Milan, Italy.     

Exchange of free fatty acids and glucose in leg tissues before and immediately after surgery

The present study was undertaken to investigate whether there is an augmented uptake of free fatty acids (FFA) in the leg tissues immediately after surgery when the energy expenditure of the leg is increased considerably. Eight patients were studied before and after cholecystectomy. Blood and plasma flow were determined in one leg, as well as arterio-venous concentration differences for oxygen, glycose, lactate and the total fraction of FFA. To determine uptake and release of FFA, 1-(14C)-oleic acid was infused intravenously and the arterio-venous differences for (14C)-FFA were determined. The mean oxygen uptake in the leg increased from 0.72+/-0.06 mmol/min to 1.78+/-0.41 mmol/min. The uptake of free fatty acids in the leg did not increase significantly after cholecystectomy when compared to before operation in spite of the marked increase in oxygen uptake. Postoperatively there was, however, a positive linear relationship between the uptake of FFA and that of oxygen in the leg. The glucose uptake, after correction for released lactate, corresponded to 7% of the oxygen uptake before surgery and 13% after surgery. The arterial FFA concentration did not change. This study indicates that the combined possible contribution of glucose and free fatty acids to the oxidative energy metabolism of the leg tissues exceeded the oxygen uptake before, but not after surgery. In the postoperative state there was a positive correlation between oxygen uptake and FFA uptake in the leg.     

Intracellular mechanism of quinidine action on muscle contraction

Summary The mechanism of quinidine action on rabbit cardiac and skeletal muscle was examined with functionally skinned muscle-fiber preparations. By using these preparations we could correlate measurements of muscle tension with the effect of quinidine on the Ca²⁺ activation of the contractile proteins and on the Ca²⁺ uptake and release from the sarcoplasmic reticulum (SR). Effect of quinidine on the contractile proteins. Quinidine concentrations above 0.5 mmol/l increased the maximal Ca²⁺-activated tension development 12% for papillary muscle and 5% for soleus (slow-twitch). Adductor magnus (fast-twitch) showed no significant change. Quinidine (0.1–1.0 mmol/l) also increased the submaximal Ca²⁺-activated tension development for the three muscle types (papillary muscle=soleus>adductor magnus) and shifted the [Ca²⁺]-tension curves to the left in a dose-dependent fashion. Effects of quinidine on the Ca ²⁺ uptake and release from the SR. Sarcoplasmic reticulum of skinned fibers was loaded with Ca²⁺ (uptake phase), then Ca²⁺ was released by 25 mmol/l caffeine (release phase) giving a tension transient. The area under the tension transient was used to estimate the amount of Ca²⁺ released. Quinidine (>0.5 mmol/l) decreased the Ca²⁺ uptake (soleus>adductor magnus>papillary muscle) and increased the Ca²⁺ release [papillary muscle=soleus adductor magnus (only at 1.5 mmol/l, the highest concentration tested)] from the SR of all three muscles in a dose-dependent manner. Quinidine at low concentration (0.1 and 0.5 mmol/l) increased the caffeine-induced tension transient of papillary muscle and higher quinidine concentrations (1.0 and 1.5 mmol/l) decreased the caffeine-induced tension transient of soleus and adductor magnus during both the uptake and release phases. The decreased Ca²⁺ uptake of papillary muscle in 1.5 mmol/l quinidine was antagonized by increasing the free Mg²⁺ from 0.032 to 0.32 mmol/l.In summary, quinidine has similar mechanisms of action in all three muscles: increased Ca²⁺ activation of the contractile proteins, decreased Ca²⁺ uptake and increased Ca²⁺ release from the SR in functionally skinned muscle fibers. We conclude that quinidine-induced decreases in Ca²⁺ uptake by the SR could be responsible for quinidine-induced myocardial depression and that quinidine-induced increases in Ca²⁺ activation of the contractile proteins and Ca²⁺ release from the SR could be responsible for the increases in skeletal muscle contraction caused by quinidine.     

Impact of postanesthesia care unit delirium on self-reported cognitive function and perceived health status: a prospective observational cohort study

Quality of Life Research - The objective of this study was to determine the influence of postanesthesia care unit (PACU)&nbsp;delirium on self-reported cognitive function and perceived health...     

腰硬联合麻醉与全麻对老年腹部手术患者术后短期认知功能的影响

目的 探讨腰硬联合麻醉(CSEA)与全麻对老年腹部手术患者术后认知功能的影响。方法 选取本院2018年5月—2019年5月收治的82例老年腹部手术患者,按随机数表法分为观察组和对照组,各41例。观察组应用CSEA,对照组则采用全身麻醉。比较两组的麻醉相关指标,术后6 h、12 h、24 h的精神功能状态以及患者术后短期认知功能障碍的发生率。结果 观察组麻醉起效时间(min)、完全清醒时间(min)分别为(8.19±1.04)、(28.67±5.60)与对照组的(10.17±2.12)、(37.25±6.12)比较差异有统计学意义(P<0.05);观察组视觉模拟评分(VAS)(3.51±1.12)与对照组的(4.27±1.15)比较差异有统计学意义(P<0.05);观察组患者术后6 h、12 h、24 h时的MMSE评分分别为(22.27±1.46)、(26.23±1.26)、(28.19±1.24),均高于对照组的(21.46±1.35)、(24.68±1.23)、(26.37±1.19)(P<0.05);观察组短期内POCD的发生率为4.88%,低于对照组的24.39%,差异有统计学意义(P<0.05)。结论 对老年腹部手术患者采用CSEA,不仅能缩短麻醉起效时间和完全清醒的时间,减轻疼痛,而且对患者精神功能的影响小,可有效减少短期内认知功能障碍发生率。     

Comparison of the PROMIS Preference Score (PROPr) and EQ-5D-5L Index Value in General Population Samples in the United Kingdom,France, and Germany

ObjectivesThe Patient-Reported Outcome Measurement Information System (PROMIS) Preference score (PROPr) can be used to assess health state utility (HSU) and estimate quality-adjusted life-years in cost-effectiveness analyses. It is based on item response theory and promises to overcome limitations of existing HSU scores such as ceiling effects. The PROPr contains 7 PROMIS domains: cognitive abilities, depression, fatigue, pain, physical function, sleep disturbance, and ability to participate in social roles and activities. We aimed to compare the PROPr with the 5-level EQ-5D (EQ-5D-5L) in terms of psychometric properties using data from 3 countries.MethodsWe collected PROMIS-29 profile and EQ-5D-5L data from 3 general population samples (United Kingdom = 1509, France = 1501, Germany = 1502). Given that cognition is not assessed by the PROMIS-29, it was predicted by the recommended linear regression model. We compared the convergent validity, known-groups construct validity, and ceiling and floor effects of the PROPr and EQ-5D-5L.ResultsThe mean PROPr (0.48, 0.53, 0.48; P<.01) and EQ-5D-5L scores (0.82, 0.85, 0.83; P<.01) showed significant differences of similar magnitudes (d = 0.34; d = 0.32; d = 0.35; P<.01) across all samples. The differences were invariant to sex, income, occupation, education, and most conditions but not for age. The Pearson correlation coefficients between both scores were r = 0.74, r = 0.69, and r = 0.72. PROPr’s ceiling and floor effects both were minor to moderate. The EQ-5D-5L’s ceiling (floor) effects were major (negligible).ConclusionsBoth the EQ-5D-5L and the PROPr assessed by the PROMIS-29 show high validity. The PROPr yields considerably lower HSU values than the EQ-5D-5L. Consequences for quality-adjusted life-year measurements should be investigated in future research.