Perioperative management of severe anorexia nervosa.

As the prevalence of anorexia nervosa (AN) increased, surgery in severe AN patients also increased in the 2000s. We experienced a surgical case of a patient with severe AN, showing an extremely low BMI of 8.6 kg m(-2). We investigated the problems associated with this case and propose criteria to manage severe AN. We endeavour to report on the perioperative management of rare and severe symptoms and surgical indications of severely malnourished patients. All published reports were identified through comprehensive searches using PubMed, BioMedLib, and the Japan Medical Abstracts Society with the following terms and keywords: 'anorexia nervosa', 'eating disorder', 'hypoglycaemia', 'leucocytopaenia', 'gelatinous bone marrow', 'surgery', and 'operation'. In cases of AN with a BMI under 13 kg m(-2), marked hypoglycaemia, leucocytopaenia <3.0×10(9) litre(-1), or both, potentially fatal complications frequently occur. Accordingly, patients need strict nutritional support to avoid re-feeding syndrome until surgery. During the course of anaesthesia, careless loading of glucose or catecholamine may lead to disturbance of electrolytes or fatal arrhythmia. Intensive care and early feeding as soon as possible after surgery are important to prevent surgical site infection. Although not many perioperative cases of AN have been reported, clinicians must be aware of the danger and the causes of mortality in critical cases. Thus, the decision to undertake surgery must be taken carefully and close perioperative coordination among physicians, surgeons, psychiatrists, anaesthesiologists, and intensivists is essential.

Anaesthesia for a patient with paraneoplastic limbic encephalitis with ovarian teratoma: relationship to anti-N-methyl-D-aspartate receptor antibodies.

Paraneoplastic limbic encephalitis associated with ovarian teratoma has recently been related to the development of antibodies to specific heteromers of the N-methyl-d-aspartate receptor and exhibits various manifestations including psychiatric symptoms, hypoventilation, seizures and derangement of autonomic nervous system function. Although recovery can sometimes occur spontaneously, early tumour resection with immunotherapy facilitates earlier recovery. Herein, we describe anaesthetic management of a 20-year-old woman who developed general convulsions and decreased level of consciousness, whom we suspected of having paraneoplastic limbic encephalitis and was scheduled for left ovarian tumour resection. Anaesthetic management was successful with no complications but the case acts as focus of discussion for the potential interaction of N-methyl-D-aspartate receptors and anaesthetic sensitivity.

Role of left atrial appendage in left atrial reservoir function as evaluated by left atrial appendage clamping during cardiac surgery.

We evaluated the role of left atrial appendage (LAA) in the left atrial (LA) reservoir function by assessing the changes in LA flow dynamics after LAA clamping during cardiac surgery. The subjects were 8 patients who had undergone coronary artery bypass grafting (CABG) and 7 who had undergone mitral valvular surgery due to mitral regurgitation. We recorded transmitral, pulmonary venous and LAA flow velocity patterns by intraoperative transesophageal pulsed Doppler echocardiography, monitoring LA pressure before and 5 minutes after LAA clamping. The maximal LAA area was significantly greater, and the peak late diastolic LAA emptying flow velocity was significantly lower before LAA clamping in the mitral regurgitation group than in the CABG group. In both groups, the peak early and late diastolic transmitral and pulmonary venous flow velocities significantly increased, and the peak second systolic pulmonary flow velocity significantly decreased during LAA clamping. There were no significant changes in heart rate and systemic systolic blood pressure during LAA clamping, whereas mean LA pressure and maximal LA dimension significantly increased in both the groups. The LA pressure-volume relation during ventricular systole shifted upward and to the left during LAA clamping, and the slope was steeper in the MR group than in the CABG group. We conclude that the LAA is more compliant than the LA main chamber, and plays an important role in LA reservoir function in the presence of LA pressure and/or volume overload.

The antinociceptive effects of intrathecally administered SCH32615, an enkephalinase inhibitor in the rat.

The presence of opioid receptors and enkephalin-releasing neurons in the spinal dorsal horn prompted us to examine whether an enkephalinase inhibitor, SCH32615, given intrathecally would alter the response of the rat on several nociceptive endpoints: 49 degrees C hot plate (HP), 52 degrees C HP; tail flick (TF) and the paw pressure (PP) test. SCH (16-320 nmol, i.t.) resulted in a submaximal dose-dependent increase in the 49 degrees C HP, 52 degrees C HP, TF, and PP measures with the respective ED50 values being 40, 74, 68 and 83 nmol, respectively. AT 320 nmol, no additional increment in effect was observed. Concurrent examination of the effects of 0.1-10 nmol morphine on the 49 degrees C HP, 52 degrees C HP, TF and PP measures revealed i.t. ED50 values of 0.2, 0.8, 0.9 and 0.6 nmol, respectively, with the maximum dose leading to a complete block on all measures. The effects of SCH were totally reversed by naloxone (1 mg/kg, i.p.), a dose which had no detectable effect upon baseline nociceptive response measures. The effects of SCH, even at the highest dose were not accompanied by motor dysfunction or catalepsy. These results are consistent with the hypothesis that high-threshold thermal and mechanical stimuli will evoke the release of an opioid in the spinal space, the metabolism of which is significantly influenced by enkephalinase inhibition.

Effects of tocainide and lidocaine on the transmembrane action potentials as related to external potassium and calcium concentrations in guinea-pig papillary muscles.

Effects of lidocaine and tocainide on transmembrane potentials were studied in isolated guinea-pig papillary muscles, superfused with modified Tyrode's solution containing either 5.4, 2.7, 10.0 or 8.1 mmol/l potassium concentration, [K]0. The last solution applied contained either 1.8 (normal [Ca]0) or 7.2 mmol/l [Ca]0 (high [Ca]0. The concentrations of lidocaine and tocainide used were 18.5, 36.9 and 73.9 mumol/l and 43.7, 87.5 and 174.9 mumol/l in 5.4 mmol/l [K]0 solution and 36.9 and 87.5 mumol/l in the other solutions, respectively. At the driving rate of 1 Hz in 5.4 mmol/l "K]0 solution, both drugs produced dose-dependently a reduction of maximum rate of rise of action potential (Vmax), together with a prolongation of the relative refractory period. Vmax decreased progressively as the driving rate was increased from 1 Hz (for lidocaine) and from 0.25 Hz (for tocainide) to 5 Hz. This action was accentuated dose-dependently. A slow component (time constant tau = 232 ms for lidocaine, 281--303 ms for tocainide) and slower component (tau = 2.1--3.8 s for tocainide) of the recovery (reactivation) of Vmax were observed in premature responses at 0.25 Hz and in the first response after interruption of the basic driving rate at 1 Hz. All these effects were accentuated with rising [K]0 and attenuated in the high [Ca]0 solution. Both drugs abbreviated the action potential duration at 50% (APD50) and 90% (APD90) levels at 5.4, 8.1 and 10.0 mmol/l [K]0 but not at 2.7 mmol/l [K]0 nor a high [Ca]0 at 1 Hz. These [K]0-dependent effects of lidocaine on Vmax were successfully simulated by the model proposed by Hondeghem and Katzung (1977), with a slight change in parameter values. The mode of interaction of lidocaine with sodium channels in the open, closed and rested states was deduced from these results.

Molecular evolution of a host-range gene in geminiviruses infecting asexual populations of Eupatorium makinoi.

Asexual plants of Eupatorium makinoi is frequently infected with tobacco leaf curl geminivirus (TLCV). The host range of TLCV is narrow, and ORF C4 is considered to function as a host range determinant. Using this TLCV-Eupatorium system, we tested the expectation that the rate of amino acid replacements will be accelerated in ORF C4 if resistant genes of the host plants drive molecular evolution in ORF C4. ORF C4 is entirely contained within a longer ORF C1 encoding a replication protein. We analyzed 21 sequences containing ORF C4 and a part of ORF C1. While per-site number of synonymous substitutions exceeded that of replacements in ORF C1, per-site number of replacements exceeded that of synonymous substitutions in ORF C4. However, this excess of per-site replacement in ORF C4 was mostly explained by the overlap gene nature, because most synonymous substitutions in ORF C1 change amino acid of ORF C4. In conclusion, not positive but negative selection is a predominant mode characterizing molecular evolution of ORF C4.

Effect of endothelin-1(1-31) on intracellular free calcium in cultured human mesangial cells.

We found that human chymase selectively produces 31-amino-acid length endothelins (1-31) (ETs(1-31)). We investigated the effect of synthetic ET-1(1-31) on intracellular free Ca2+ concentration ([Ca2+]i) in cultured human mesangial cells. ET-1(1-31) increased [Ca2+]i in a concentration-dependent manner to a similar extent as ET-1. The ET-1 (1-31)-induced [Ca2+]i increase was not influenced by removal of extracellular Ca2+ but was inhibited by thapsigargin. ET-1(1-31)-induced [Ca2+]i increase was not affected by phosphoramidon. It was inhibited by BQ123, but not by BQ788. These results suggest that ET-1(1-31) by itself exhibits bioactive properties probably through endothelin ET(A) or ET(A)-like receptors. Since human chymase has been reported to exist in the kidney, ET-1(1-31) may be a candidate substance for mesangium-relevant diseases.

Ehlers-Danlos syndrome with soft-tissue contractures.

We report four patients with a form of Ehlers-Danlos syndrome associated with soft-tissue contractures from birth and skin hyperalgesia. In early infancy, these cases were thought to be forms of arthrogryposis multiplex congenita, Larsen's syndrome or Marfan's syndrome. The characteristic triad of signs of Ehlers-Danlos disease gradually appeared from four to six years of age, allowing us to establish the correct diagnosis. We discuss the differential diagnosis of these connective-tissue disorders and the problems of the orthopaedic treatment of the associated joint deformities. Ehlers-Danlos syndrome is a heterogeneous group of metabolic diseases of collagen and our cases constitute a group which is distinct from the conventional types.

The lumbar spine in spastic diplegia. A radiographic study.

Some radiological features of the lumbar spine of 84 patients with spastic diplegia were compared with 50 control subjects. The average age of the patients was 20.1 years (3 to 39). Spondylolysis of the fifth lumbar vertebra was found in 21%, four times more frequently than in normal subjects. No patient under nine years of age had spondylolysis and the frequency increased with age. The average angle of lumbar lordosis in spastic patients in the standing position was greater than in normal subjects, and increased with age. The patients had a decreased sacrofemoral angle which caused an increase in Ferguson's angle and explained the increased angle of lumbar lordosis.

Bronchospasm induced by cardiopulmonary bypass.

Severe bronchospasm during cardiopulmonary bypass (CPB) is an unusual event. A 16-year-old girl with pulmonary stenosis who underwent reconstruction of the right ventricle outflow tract experienced severe bronchospasm following CPB. Just after the initiation of the partial CPB, high inspiratory airway pressure was suddenly recognized. The lung had become too stiff for the anesthetic circuit bag to be squeezed by hand. Tracheobronchial obstruction was ruled out by investigation with a fiberoptic bronchoscope. A presumptive diagnosis of severe bronchospasm was made, and aggressive bronchodilator therapy was instituted. The attack was successfully treated with aggressive bronchodilator therapy. Although the exact causes for bronchospasm in our case are not clear, CPB factors, such as the release of complements and allergic reactions might have induced the attack under relatively light anesthetic state.

Transesophageal echocardiographic assessment of pulmonary arterial and venous flow during high-frequency jet ventilation.

STUDY OBJECTIVE: To evaluate high-frequency jet ventilation (HFJV) effects on pulmonary arterial and venous flow compared to those of intermittent positive-pressure ventilation (IPPV) by using pulsed Doppler transesophageal echocardiography. DESIGN: Prospective clinical study. SETTING: University-affiliated hospital operating room. PATIENTS: 13 ASA physical status I and II patients undergoing lower abdominal or lower extremity surgery. INTERVENTIONS: PATIENTS had total IV anesthesia with propofol and fentanyl. After anesthesia induction, a transesophageal echocardiography probe was inserted into the esophagus. IPPV (TV, 8-10 mL/kg; respiratory rate, 10-12 cycles/min; I/E ratio, 1:2; FIO(2), 1.0) and HFJV (driving pressure, 0.5-0.6 kgf/cm(2); frequency,3 Hz; I/E ratio, 1:1; FIO(2), 1.0) were performed under hemodynamically stable conditions. MEASUREMENTS: Pulmonary-arterial-flow velocity, pulmonary-venous-flow velocity, left ventricular short-axis view, and airway-pressure curve were recorded simultaneously. Parameters measured were: hemodynamic variables, arterial blood gases, inspiratory airway pressure; [from pulmonary-arterial-flow velocity] pre-ejection period (PEP), acceleration time (AT), right ventricular ejection time (RVET), and their ratios (PEP/AT, AT/RVET); [from pulmonary-venous-flow velocity] time-velocity integral of the first systolic wave (S1), second systolic wave (S2), and diastolic wave (D), and systolic fraction (integral S1 + S2/S1+ S2 + D); [from M-mode] left-ventricular-end systolic volume, left-ventricular-end diastolic volume (LVEDV), stroke volume, cardiac output, and ejection fraction, using Teichholz's method. MAIN RESULTS: Peak inspiratory airway pressure during HFJV was significantly lower than that during IPPV. HFJV significantly decreased PEP/AT, correlating positively with pulmonary arterial pressure, and significantly increased AT and AT/RVET, correlating negatively with pulmonary arterial pressure. Systolic fraction, correlating negatively with left atrial pressure, increased significantly during HFJV, as did LVEDV, stroke volume, cardiac output, and ejection fraction. CONCLUSIONS: Our results suggest that, in comparison to IPPV, HFJV significantly decreases pulmonary arterial pressure and left atrial pressure, resulting in significant increases in cardiac output and ejection fraction in healthy anesthetized adults.

[Effects of lidocaine and its metabolite, monoethylglycine xylidide (MEGX), on transmembrane action potentials in guinea-pig papillary muscles].

Effects of lidocaine 5, 10, 20 micrograms.ml-1 and its metabolite, MEGX 5, 10, 20 micrograms.ml-1, on transmembrane action potentials were studied in isolated guinea-pig papillary muscles, perfused with modified Tyrode's solution. The basic driving rate was 1 Hz and the rate was changed from 1 Hz to 0.25, 0.5, 2, 3 and 4 Hz in a stepwise manner. Both lidocaine and MEGX produced dose- and rate-dependent depression of maximum rate of rise of action potential (Vmax) without significant changes in resting membrane potentials. The recovery kinetics of Vmax was studied by either applying premature stimuli at basic driving rate of 0.25 Hz or by stopping the basic driving of 1 Hz for 1s to 60s. A slow component (time constant: 176-206 ms for lidocaine, 300-340 ms for MEGX) was observed in premature response. And a slower component (time constant: 3-4s for MEGX) was observed in the first response after stopping stimulation. Both drugs shortened the action potential duration. These results suggest that MEGX has a lidocaine-like class I antiarrhythmic actions and that it might modify the actions of lidocaine especially in patients with elevated plasma MEGX concentration.

[Effects of volatile anesthetics on force interval relationships in guinea-pig atrial preparations].

Depressant effects of halothane, enflurane and isoflurane on isolated guinea-pig left atrial muscles bathed in Tyrode's solution at 30 degrees C were examined. Contractions were elicited by stimulation through external field electrodes while tension was recorded continuously. Frequency-force relationships at stimulation rates of 0.1, 0.2, 0.5 and 1 Hz were studied. The pD2 values of these volatile anesthetics at each stimulation rates were not different significantly, suggesting the frequency-independent depressions of these anesthetics. Interval-strength relationships at time intervals of 0.3-20 sec during 1 Hz-stimulation were also studied. Mechanical restitution curves after converting to logistic function reached a peak at 8-20 sec and were fitted well to double exponential functions with time constants of 200-600 msec (k1) and 2-6 sec (k2). All volatile anesthetics depressed the magnitude constants for fast response in a dose dependent manner. Accordingly, at high concentrations, mechanical resuscitation curves tended to fit single exponential function. Halothane and enflurane did not alter time constant k1, k2 significantly, while isoflurane increased k2 significantly. These results suggest that the mechanisms of myocardial depressant effects are different between these anesthetics.

[Voltage-dependent effects of lidocaine and its metabolite, monoethylglycine xylidide (MEGX), on maximum rate of rise (Vmax) of action potential upstroke in guinea-pig papillary muscles].

We studied the effects of lidocaine and MEGX on the sodium current, using Vmax as an indicator, at an extracellular potassium concentration ([K]o) of 10 mmol.l-1, and compared the present results with those obtained at 5.4 mmol.l-1 [K]o in our previous study. At 10 mmol.l-1 [K]o, both lidocaine (10 micrograms.ml-1) and MEGX (10 micrograms.ml-1) significantly decreased the Vmax at the steady-state of 1 Hz, caused a significant rate-dependent decrease in Vmax, and slowed the recovery kinetics of Vmax. These effects of both agents were more prominent than those obtained at 5.4 mmol.l-1 [K]o, suggesting that MEGX as well as lidocaine produce voltage-or [K]o-dependent blocking effects on Vmax.

[Changes of arterial blood pressure and heart rate during induction of anesthesia with propofol--efficacy of propofol titration using bispectral index as an indicator].

Bispectral index (BIS) is a processed EEG parameter that measures the hypnotic effects of anesthetic and sedative agents on the brain. We studied whether propofol titration using BIS allows us to prevent hemodynamic changes during induction of anesthesia and endotracheal intubation. Thirty patients without hypertension and obesity were studied. In the titration group (n = 15), BIS was maintained at 40 during induction of anesthesia with propofol. In the bolus group, anesthesia was induced with a bolus infusion of propofol 2 mg.kg-1 (n = 15). Arterial blood pressure and heart rate were recorded before induction of anesthesia, during induction of anesthesia, immediately after, and 1 min, 2 min, and 3 min after intubation. Diastolic blood pressure and heart rate increased significantly after endotracheal intubation in both groups. Systolic blood pressure significantly increased immediately after intubation in the bolus group, but was unchanged in the titration group. These results suggest that BIS is useful to prevent significant increases in systolic blood pressure associated with endotracheal intubation during induction of anesthesia with propofol.

[Evaluation of pulmonary capillary wedge pressure tracing for the detection of intraoperative myocardial ischemia].

We studied the usefulness of the pulmonary capillary wedge pressure (PCWP) tracing for the detection of intraoperative myocardial ischemia. Both PCWP wave forms and 7-lead electrocardiogram were monitored in 109 patients undergoing coronary artery bypass graft surgery. Measurements were made six times in each patient. Myocardial ischemia was identified in 99 (27%) of the 366 measurements, and among them, 68 (69%) developed abnormal PCWP wave forms (AC wave greater than 15 mmHg, or V wave greater than 20 mmHg). Although these results were consistent with those of Kaplan et al (1981), we could not agree with their conclusion that PCWP tracing can be helpful in the early diagnosis of subendocardial ischemia. It was not possible to record PCWP continuously because of the risk of pulmonary infarction, and PCWP was influenced by noncardiac factors such as sympathetic reaction to surgical stimuli. We think that PCWP tracing would be of benefit in detecting intraoperative serious ischemia; serious myocardial ischemia was likely to have occurred when abnormalities in both PCWP tracing and ST segment changes were identified. The incidence of both PCWP changes and ECG ischemia was highest in the postbypass period, suggesting that the risk of serious myocardial ischemia is highest in the post-bypass period.

[Assessment of left ventricular contractility (Emax) and arterial load (Ea) in humans by transesophageal echocardiography and radial artery pressure tracing].

We determined both the slope of the left ventricular end-systolic pressure-volume relation (Emax), which is a measure of contractility independent of loading conditions, and the slope of the arterial end-systolic pressure-stroke volume relation (Ea), which is a measure of arterial load independent of ventricular function, in 10 patients undergoing elective noncardiac surgery. Left ventricular end-systolic volume (Ves) was measured by transesophageal echocardiography and instantaneous left ventricular end-systolic pressure (Pes) was estimated from the dicrotic notch pressure in the radial artery. Emax was calculated during afterload reduction (nicardipine 30 micrograms.kg-1 iv), and the correlation of Emax to either Pes/Ves ratio or MAP (mean arterial blood pressure)/Ves ratio was accomplished in order to investigate whether these indices were clinically useful measurements of ventricular function or not. Ea was also calculated from the data obtained before and 2-3 min after nicardipine iv. The averaged Emax and x-axis intercept (Vo) were 3.11 mmHg.ml-1 and -3.8 ml, respectively. The correlation coefficient obtained between Emax and Pes/Ves was 0.96, and that obtained between Emax and MAP/Ves was 0.97. Ea decreased significantly (P < 0.05) following intravenous nicardipine, demonstrating a decreased arterial load. The direction of changes in Ea was similar to that reported previously in systemic vascular resistance. From these results, we conclude that measurement of Emax (or Pes/Ves, MAP/Ves) and Ea using transesophageal echocardiography and radial artery pressure tracing is feasible and these are a useful tool to estimate left ventricular performance and arterial load during surgery.

[Application of the concept of fuzzy logistic controller for treatment of hypertension during anesthesia].

The concept of Zadeh's fuzzy logistic controller was applied to control hypertension during anesthesia, and its clinical usefulness was examined in patients undergoing elective surgery. Arterial blood pressure was determined by use of an automatic blood pressure device. Nicardipine was used as hypotensive drug. Based on the fuzzy control rules, we developed state-action diagram so as to maintain systolic blood pressure at around 130 mmHg. Nicardipine was infused by using a digitally controlled infusion pump, and its infusion rate was changed according to this diagram. Although acute hypertension associated with endotracheal intubation was not significantly attenuated, hypertension associated with either skin incision or endotracheal extubation, where blood pressure increased slowly, was successfully controlled with our system. These results suggest that the application of the concept of fuzzy logistic controller is useful for treatment of hypertension during anesthesia, especially when blood pressure increases slowly.

[Assessment of ventriculoarterial coupling in humans by transesophageal echocardiography and radial artery pressure tracing].

To investigate coupling between the heart and arterial system in patients undergoing elective non-cardiac surgery, we determined both the ventricular elastance and the effective arterial elastance in two groups of subjects: normal group, 68 subjects without heart disease; and cardiac group, 33 subjects with heart disease. Left ventricular end-systolic (Ves) and end-diastolic (Ved) volumes were determined by transesophageal echocardiography. By assuming that left ventricular end-systolic pressure (Pes) is close to mean arterial blood pressure (MAP) and that x-axis intercept (Vo) is zero, the ventricular elastance (E'max) was approximated as MAP/Ves, and the effective arterial elastance (Ea) as MAP/(Ved-Ves). In 222 (74%) of the 299 measurements obtained in normal group, Ea/E'max was nearly 0.5, which is a condition for a maximal mechanical efficiency, while in 61 measurements (20%) Ea was almost equal to E'max (Ea/E'max = 1), which is a condition for maximal stroke work from a given end-diastolic volume. In contrast, in cardiac group, Ea/E'max was nearly 0.5 in 56 (41%) of the 137 measurements, while in 42 measurements (31%) Ea/E'max was nearly 1. In addition, although the value of Ea/E'max over 2, which represents severe heart failure, was not observed in normal group, Ea/E'max was over 2 in 10 measurements (7%) in cardiac group. Thus, the present results suggest that, as reported previously in awake patients, ventriculoarterial coupling is set toward higher left ventricular work efficiency in surgical patients without heart disease, whereas in patients with heart disease, ventricular and arterial properties are so matched as to maximize stroke work at the expense of the work efficiency.

[Effects of nitric oxide synthase inhibitor on skin blood flow responses to acute isovolemic hemodilution during halothane and isoflurane anesthesia].

Eighteen dogs under halothane or isoflurane anesthesia were subjected for a study in skin blood flow of the forearm under acute isovolemic hemodilution. Hematocrit was intentionally reduced to about 50% of baseline in ten minutes and hematocrit changes were induced by exchange of blood with hydroxyethyl starch. The skin blood flow increase response, measured by laser Doppler flowmetry, to hemodilution was abolished after inhibition of endogenous nitric oxide synthesis by N omega-nitro-L-arginine methyl ester. Skin blood flow responses to hemodilution and N omega-nitro-L-arginine methyl ester were different between halothane group and isoflurane group. Nitric oxide may have an important part to play in vasodilation during acute isovolemic hemodilution, and it may be affected differently by halothane and isoflurane.