Coronary artery spasm with ventricular tachycardia after administration of methoxamine during cervical epidural anesthesia--a case report

Coronary artery spasm occurred during thoracotomy under cervical epidural anesthesia in a 60-year-old male patient who had no prior history of myocardial ischemia. It is most likely that the administration of methoxamine induced the spasm. Hypotension and venodilatation induced by the epidural anesthesia and increased vagal tone might also contribute to the spasm.

Age-related increase in systolic fraction of pulmonary vein flow velocity-time integral from transesophageal Doppler echocardiography in subjects without cardiac disease

The pulmonary vein flow velocity-time profile would be equivalent to the pulmonary vein flow volume-time profile, provided that the cross-sectional area of the pulmonary vein remains unchanged during 1 cardiac cycle. The systolic fraction of the pulmonary vein flow velocity-time integral, a ratio of velocity-time integral of the S wave to the sum of velocity-time integrals of the S and D waves, represents the ratio of left atrial storage volume to left ventricular stroke volume. This systolic fraction may help early filling of the left ventricle through an appropriate storage of blood and generation of driving pressure in the left atrium. Because early filling of the left ventricle is progressively impaired with age, it was hypothesized that this systolic fraction is increased with age. Forty-four noncardiac surgical patients (age range 17 to 70 years) who underwent transesophageal Doppler echocardiography under general anesthesia were studied, and left upper pulmonary vein flow and mitral inflow velocities were recorded. The ratio of peak velocity of the E wave to that of the A wave of mitral inflow velocity-time profile (y) decreased with age (y = -0.0245 x age + 2.41; r = -0.672, p < 0.01). Systolic fraction (y) increased with age (y = 0.00373 x age + 0.514; r = 0.656, p < 0.01). The age-related increase in the systolic fraction of pulmonary vein flow velocity-time integral may account for the compensation for impaired early filling of the left ventricle in elderly patients.

Haemodynamic changes associated with thermodilution cardiac output determination during myocardial ischaemia or pulmonary oedema in dogs

Since the technique of thermodilution (TD) cardiac output measurements per se causes haemodynamic alterations, the authors examined whether the alterations elicited by iced injectate are augmented in the presence of myocardial ischaemia (MI) or pulmonary oedema (PE), compromised conditions frequently associated with critically ill patients. MI (N = 7) or PE (N = 7) was induced by clamping the anterior descending coronary artery or by a slow infusion of oleic acid into the right atrium, respectively, in anaesthetized dogs. Injection of iced injectate, 3 ml, caused similar changes in heart rate, mean systemic and pulmonary arterial pressures, pulmonary blood flow, right ventricular dP/dt, and right atrial pressure in dogs with and without MI or PE. Cardiac output estimated by TD correlated closely with pulmonary blood flow measured by electromagnetic flowmeter in both MI and PE (r > 0.9). No profound alterations in haemodynamics were observed at any injection during TD cardiac output measurements under MI or PE. These results indicate that TD cardiac output determination does not cause serious haemodynamic alterations, and can estimate right ventricular output accurately under MI and PE.

[Anaphylactoid reactions to contrast media which occurred during cholecystectomy and subsequent disseminated intravascular coagulation--a case report]

A 67-year-old woman without any history of allergic episode developed severe hypotension (40 mmHg) without skin rash one minute after the administration of amidotrizoic acid for intraoperative cholangiography during thoracic epidural and light general anesthesia. Although ephedrine, methoxamine, dopamine and norepinephrine were administered, severe hypotension persisted for three hours and epinephrine was only effective. Marked elevations of serum levels of histamine, leukotriene D4 and leukotriene E4 were noted after the episode, suggesting the occurrence of the anaphylactoid reaction to amidotrizoic acid and the activation of the immunological complement system. After the recovery from the anaphylactoid reaction, the patient developed disseminated intravascular coagulation (DIC) and severe bleeding around the wound for which reoperation was needed. It is necessary to consider some prophylactic treatments against DIC when severe anaphylactoid reaction occurred.

Distribution patterns and frequency of proliferating cells in cutaneous keratinocytic neoplasms. Immunohistochemical study with a monoclonal antibody (TOB7) used against proliferating cell nuclear antigen

BACKGROUND

Almost all markers for proliferating cells need freshly frozen tissues for evaluation; therefore retrospective study is impossible.

OBJECTIVE

In the present study, a murine monoclonal antibody (TOB7) against the proliferating cell nuclear antigen (PCNA) was used for the analysis of cell kinetics of cutaneous keratinocytic neoplasms. The antibody is applicable to formalin-fixed, paraffin-embedded tissues.

METHODS

The frequency of PCNA-positive cells and their distribution patterns were immunohistochemically investigated in various cutaneous keratinocytic neoplasms.

RESULTS

Squamous cell carcinoma and Bowen's disease showed significantly increased numbers of PCNA-positive cells when compared with other keratinocytic neoplasms. A characteristic marginal or random distribution pattern of PCNA-positive cells was observed in the lesions of each disease category.

CONCLUSION

Important information on the growth dynamics of keratinocytic neoplasms was obtained in this retrospective immunohistochemical study.

[Anaphylactic shock with ventricular fibrillation induced by chlorhexidine]

We experienced a case in which a 66 year-old male patient developed anaphylactic shock followed by ventricular fibrillation, possibly due to intravenous aspiration of chlorhexidine used for topical application when right internal jugular vein was punctured. He was successfully resuscitated without any sequelae. Although lymphocyte transformation test failed to identify the specific allergen, IgE antibodies against chlorhexidine in the patient's serum were detected by radioallergosorbent technique. Chlorhexidine is an extensively used antiseptic, but there have been many reports regarding severe adverse reactions associated with its use. Chlorhexidine does not seem to be a safe antiseptic.

[The relation between upper respiratory tract infection and mild hypoxemia during general anesthesia in children]

Anesthesiologists often face the problem of a child with symptoms of an acute upper respiratory infection (URI) presenting for surgery. Anesthesia in the presence of uncomplicated URI may not be contraindicated. However, we experienced three cases of such children in which lung atelectasis developed after the induction of general anesthesia. Because continuous monitoring of arterial oxygen saturation by pulse oximetry (SpO2) was useful for detecting mild hypoxemia in these patients, we retrospectively examined the possible association between URI symptoms and SpO2 in 63 children. Patients with symptoms of URI showed a significantly high incidence of decreased SpO2 to below 95% for 5 minutes. Our results suggest that, with URI symptoms even uncomplicated, symptomatic patients have increased risks for the development of mild hypoxemia during anesthesia.

[Subendocardial infarction on recovery from anesthesia]

A 57-year-old man without any history of coronary artery disease underwent total hip replacement for which a continuous lumbar epidural analgesia combined with general anesthesia was used. During the recovery from anesthesia, the patient developed sudden hypotension and ventricular fibrillation (Vf), followed by ST elevation (I, II, III, aVF and V2-V6) on ECG. A coronary angiography, which was performed 30 min after the onset of Vf, revealed both the total occlusion of proximal left anterior descending artery (LAD) and 25% stenosis of proximal right coronary artery. It seemed that coronary artery spasm had occurred during the emergence from anesthesia, and then the coronary spasm ceased in a minute or two, while thrombus was produced in proximal LAD. The patient recovered from the episode of myocardial ischemia after percutaneous transluminal coronary recanalization and intraaortic balloon pumping. This patient was operated again on 4th and 8th postoperative days uneventfully under general anesthesia (enflurane and nitrous oxide in oxygen).

[Midazolam as a premedicant for trigeminal nerve blocks]

Although patients with trigeminal neuralgia can be treated satisfactorily with nerve blocks, the block procedure is sometimes very painful and uncomfortable for them. To investigate the efficacy and adverse effects of midazolam as a premedicant for trigeminal nerve blocks, 19 patients were randomly assigned to receive either midazolam (0.05 mg.kg-1, n = 6), midazolam (0.1 mg.kg-1, n = 7), or saline/placebo (n = 6) before the block. The patients given midazolam (0.1 mg.kg-1) had a significantly lower incidence of recalling the block procedure and had complained of less discomfort when interviewed the following day. No serious adverse effects were observed in any patient given midazolam. Midazolam can be used safely as an effective premedicant for potentially uncomfortable procedures such as trigeminal nerve blocks.

Oral clonidine blunts the heart rate response to intravenous atropine in humans

Clonidine, recently introduced into anesthesia practice, may cause bradycardia. Whether this bradycardia is reversible with atropine is not known. Accordingly, we studied heart rate (HR) responses to intravenous atropine in 80 patients assigned randomly to either a control group, who received no medication (n = 20), or a clonidine group, who received oral clonidine of approximately 1.2 micrograms.kg-1 (n = 20), 2.5 micrograms.kg-1 (n = 20), or 5 micrograms.kg-1 (n = 20). All patients received incremental doses of atropine, 2.5, 2.5, and 5 micrograms.kg-1, at 2-min intervals (total dose 10 micrograms.kg-1). Positive chronotropic response to the cumulative atropine dose of 10 micrograms.kg-1 was attenuated significantly only in patients given clonidine 5 micrograms.kg-1 (7 +/- 1 beats per min, mean +/- standard error) when compared with those given smaller doses of clonidine (15 +/- 2, 16 +/- 2 beats per min) or no clonidine (19 +/- 2 beats per min) (P less than 0.05). To determine whether HR hyporesponsiveness to atropine induced by clonidine can be overcome by a larger dose of atropine, the authors studied 30 additional patients given clonidine 5 micrograms.kg-1 or no medication. In all patients not receiving clonidine (n = 15), HR increased by more than 20 beats per min when atropine of 15 micrograms.kg-1 was administered, whereas in only 5 patients (33%) receiving clonidine did the HR increase by 20 beats per min after atropine 15 micrograms.kg-1 (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary oedema after airway obstruction due to bilateral vocal cord paralysis

We report a case of pulmonary oedema which developed after airway obstruction due to bilateral vocal cord paralysis. The patient was a 52-yr-old woman undergoing craniotomy for an acoustic neuroma. Anaesthesia was uneventful. Spontaneous ventilation resumed after reversal of neuromuscular blockade. Following extubation she showed signs of airway obstruction and dyspnoea. The trachea was reintubated but she became hypoxic, PaO2-36 mmHg, produced pink frothy secretions and the x-ray was typical of pulmonary oedema. The oedema cleared within 24 hr. Tracheostomy was performed one week later as the cords were still fixed, but the latter had recovered by three months and the tracheostomy was closed. The cause of the cord paralysis is unknown but probably was a result of surgical trauma to the brain stem.

[Effects of enflurane on the elastic properties of frog skinned skeletal muscle fiber under relaxed and rigor conditions]

We studied the effects of enflurane on the elastic property of the mechanical skinned fiber prepared from M. Semitendinosus of bullfrog. Longitudinal and lateral elastic properties of the skinned fibers were measured under relaxed and rigor conditions to clarify the effects of enflurane on actomyosin complex. Under the rigor condition, enflurane did not change the lateral elasticity of the fibers, but enflurane decreased the longitudinal elasticity. On the other hand, under the relaxed condition, enflurane did not change the elasticity. The results suggest that enflurane probably decreases the force of binding of cross-bridges to actin, which is one of the factors to reduce the maximal force.

Detection of heat-stable enterotoxin in a cholera toxin gene-positive strain of Vibrio cholerae O1

DNA colony hybridization with a polynucleotide clonal DNA probe for heat-stable enterotoxin of Vibrio cholerae non-O1 (NAG-ST) was used to screen 197 isolates of V. cholerae O1. Under stringent hybridizing and washing conditions, one strain (GP156) reacted with the probe. The concentrated supernatant from V. cholerae O1 GP156, heated at 100 degrees C for 5 min, elicited fluid accumulation in the suckling mice and that could be completely neutralized by an anti-NAG-ST monoclonal antibody (mAb2F). The preparation from V. cholerae O1 GP156 also inhibited the binding of mAb2F to NAG-ST in a competitive ELISA. V. cholerae O1 GP156 was confirmed to possess a gene encoding cholera toxin (CT). These results indicate that a heat-stable enterotoxin is produced by certain strains of CT-producing V. cholerae O1.

Oral clonidine preanesthetic medication augments the pressor responses to intravenous ephedrine in awake or anesthetized patients

To evaluate the possible interaction between clonidine and ephedrine, the authors studied hemodynamic responses to intravenous ephedrine in 80 patients who received either clonidine pre-anesthetic medication of approximately 5 micrograms.kg-1 orally (n = 40) or no medication (n = 40). The patients were studied while they were either awake (n = 40) or anesthetized with enflurane and nitrous oxide in oxygen (n = 40). Hemodynamic measurements were made at 1-min intervals for 10 min after ephedrine 0.1 mg.kg-1 was injected as a bolus. Although the responses to ephedrine were always greater in anesthetized patients, the magnitudes of mean blood pressure increases in patients who received clonidine (10 +/- 8% for awake and 27 +/- 11% for anesthetized subjects, mean +/- standard deviation [SD]) were significantly greater (P less than 0.05) than in patients not receiving clonidine (4 +/- 5% for awake and 17 +/- 11% for anesthetized subjects). The enhanced pressor responses to ephedrine observed in both awake and anesthetized patients in the presence of clonidine may be attributed to increased catecholamine storage at sympathetic nerve endings due to clonidine, enhanced sensitivity of tissue receptors to which ephedrine binds, potentiation of alpha-adrenoceptor mediated vasoconstriction of both agents, or all of these. It is concluded that oral clonidine preanesthetic medication of 5 micrograms.kg-1 does augment rather than attenuate the pressor responses to intravenous ephedrine in patients both prior to and during general anesthesia.

Haemodynamic and cerebral blood flow alterations after reduction of increased cerebrospinal fluid pressure in dogs

To clarify some of the mechanisms for the hypotension that may occur after cranial decompression, the authors examined alterations in cerebral blood flow (CBF) and systemic and pulmonary haemodynamic variables when cerebrospinal fluid (CSF) pressure was increased and then suddenly reduced in eight anaesthetized dogs. After CSF pressure was elevated to 50-85 mmHg for two hours, CBF decreased from 46.3 +/- 4.4 to 31.6 +/- 8.5 ml.100 g-1.min-1 (mean +/- SD, P less than 0.01). Mean systemic arterial pressure (MAP), mean pulmonary artery pressure (MPAP), pulmonary artery wedge pressure (PAWP), and systemic vascular resistance index (SVRI) increased by 20 +/- 11 mmHg, 3.9 +/- 2.5 mmHg, 5.2 +/- 3.3 mmHg, and 1448 +/- 1377 dynes.sec.cm-5.m2 from baseline values, respectively (P less than 0.01). Rapid reduction of increased CSF pressure caused CBF to increase to 61.5 +/- 19.1 ml.100 g-1.min-1, whereas MAP, MPAP, PAWP, and SVRI decreased by 22 +/- 11 mmHg, 2.4 +/- 0.9 mmHg, 2.3 +/- 2.0 mmHg, and 1289 +/- 1237 dynes.sec.cm-5.m2 from previous values (P less than 0.01) at 30 min following the decompression. However, cardiac index and pulmonary vascular resistance index remained unchanged during the study period. The present animal data indicate that the decrease in MAP after decompression is mainly a result of a reduction in systemic vascular resistance.

[Venous air embolism following repositioning from sitting to supine]

We have experienced a patient in whom venous air embolism reoccurred, when the patient's position was changed from sitting to supine. A 40 year old male with Arnold-Chiari malformation underwent suboccipital decompression and cervical laminectomy under the sitting position. During surgery, three episodes of venous air embolism were detected by high pitched sound through precordial ultrasound Doppler stethoscope, an abrupt increase in pulmonary arterial pressure, a decrease in end-tidal carbon dioxide concentration; and a small amount of bubbled air was removed from the central venous catheter. At the end of surgery when the patient was turned to supine position, the signs of venous air embolism reappeared and 3 ml of bubbled air was also removed. This case suggests that there is some remaining air in the large veins of the upper part of the body once the air embolism has occurred during sitting position and thus we need to confirm that no air is left in the large veins before repositioning. We should be cautious of reoccurrence of venous air embolism whenever patient's position is changed.

[Hemodynamic effects of lung inflation during bilateral and single lung ventilation--a clinical investigation]

Hemodynamic changes during positive airway pressure ventilation is well known. To compare changes of hemodynamic variables during one-lung inflation with those during two-lung inflation, we studied the effects of lung inflation on hemodynamic changes in 15 anesthetized patients who were intubated endobronchially. When the airway pressure was increased from 0 cmH2O to 10, 20, 30 cmH2O, systolic pressure decreased gradually and central venous pressure increased during both two-lung and one-lung inflations (P less than 0.05). During one-lung inflation, the decrease in arterial pressure relative to apneic arterial pressure was significantly less than those during two-lung inflation at each level of airway pressure (P less than 0.05). During one-lung inflation, central venous pressure which was higher relative to apneic central venous pressure, and was less than that during two-lung inflation at 30 cmH2O (P less than 0.05). Heart rate was unchanged during both two and one-lung inflations compared with apneic heart rate. We conclude that during one-lung inflation, systolic pressure and central venous pressure are influenced less by the increased airway pressure than during two-lung inflation. The results indicate that during one lung ventilation, lungs inflated with clinically accepted levels of airway pressure do not depress the systemic circulation, but when the airway pressure during one-lung inflation (like a leak test) exceeded over 30 cmH2O, a significant depression of the systemic circulation occurs.

Effects of cocaine on pial arterioles in cats

We used the closed cranial window technique to observe the responses of pial arterioles to topical application of cocaine in 29 anesthetized cats. Alterations in arteriolar diameter were dependent on the concentration of cocaine applied. Cocaine dissolved in artificial cerebrospinal fluid at concentrations of 10(-8) or 10(-7) M was without effect. Concentrations of 10(-6) and 10(-5) M produced dilation (4.9 +/- 1.5% [mean +/- SEM] and 5.9 +/- 2.0%, respectively) in large arterioles (greater than 100 microns) but no significant change in the diameter of small arterioles (less than 100 microns). A concentration of 10(-4) M dilated both large and small arterioles (20.3 +/- 3.1% and 12.0 +/- 7.1%, respectively). Pretreatment with 1 mg/kg i.v. propranolol blocked the increase in pial arteriolar diameter after application of 10(-4) M cocaine and produced significant vasoconstriction in small arterioles (-8.3 +/- 3.1%). Cocaine produces vasodilation of cat cerebral arterioles. This effect appears to be mediated, at least in part, by mechanisms that depend on stimulation of beta-adrenergic receptors.

Clinical evaluation of clonidine added to lidocaine solution for epidural anesthesia

The effects of clonidine added to lidocaine solution used for epidural anesthesia were assessed in 92 women scheduled for surgery and premedicated with diazepam 10 mg po. Patients received 18 ml 2% lidocaine with clonidine 5 micrograms.ml-1 (group C-5, n = 26), with clonidine 10 micrograms.ml-1 (group C-10, n = 20), with epinephrine 5 micrograms.ml-1 (group E, n = 26), or plain (group P, n = 20). No significant difference in the number of segments of analgesia was found at any observation period among the four groups of patients. The decreases in mean blood pressure (BP) observed 20 min after epidural injection in those given clonidine (5 +/- 8% for C-5, 10 +/- 11% for C-10, mean +/- SD) were similar to those given plain lidocaine (7 +/- 12%) but significantly less than those given epinephrine (18 +/- 12%, P less than 0.01 vs. C-5 or P). The response of BP to ephedrine given for restoring BP during anesthesia was not attenuated in patients who received epidural clonidine. Heart rate (HR) decreased significantly in patients given clonidine 10 micrograms.ml-1 (7 +/- 8%, P less than 0.01), but not in those given clonidine 5 micrograms.ml-1, whereas HR increased significantly in those given lidocaine plain or with epinephrine (10 +/- 8% and 28 +/- 14%, respectively, P less than 0.01). The incidence of sinus bradycardia was similar among the four groups of patients. Significant differences were also observed in sedation score between clonidine groups and groups P or E; sedation appeared approximately 10-20 min after epidural injection in both clonidine groups.(ABSTRACT TRUNCATED AT 250 WORDS)

End-tidal carbon dioxide monitoring during awake blind nasotracheal intubation

STUDY OBJECTIVE

To test the usefulness of the end-tidal carbon dioxide monitor in facilitating awake blind nasotracheal intubation in patients with potentially difficult airways.

DESIGN

Randomized, controlled comparison of regimen.

SETTING

Inpatient surgery clinic at a university hospital.

PATIENTS

Sixty-one consecutive patients with potentially difficult airways.

INTERVENTIONS

After airway anesthesia with 4% lidocaine was administered to all patients, either fentanyl and diazepam (n = 30) or fentanyl alone (n = 31) was given intravenously before the awake blind nasotracheal intubation procedure.

MEASUREMENTS AND MAIN RESULTS

End-tidal carbon dioxide concentration, arterial blood pressure, heart rate, and arterial oxygen saturation (by pulse oximeter) were measured in each patient during the awake blind nasotracheal intubation procedure. The day after anesthesia and surgery, each patient was asked to assess the degree of discomfort experienced during the procedure. In 54 of 61 patients, the end-tidal carbon dioxide monitor facilitated awake blind nasotracheal intubation. End-tidal carbon dioxide was significantly higher in patients given both fentanyl and diazepam than in those given fentanyl alone (7.4% +/- 1.4% vs 5.9% +/- 0.9%, respectively; p less than 0.05), but no patient in either group recalled the awake intubation as extremely uncomfortable.

CONCLUSIONS

Monitoring of end-tidal carbon dioxide is useful and valuable in both facilitating blind nasotracheal intubation and avoiding profound hypoventilation.