Fluorescence and Laser Photon Counting: Measurements of Epithelial [Ca2+]i or [Na+]i with Ciliary Beat Frequency

We describe a system we developed that enabled simultaneous measurements of either epithelial calcium ion concentration ([Ca²⁺]i) or sodium ion concentration [Na⁺]i with the ciliary beat frequency (CBF) in native ciliated epithelia using either Fura-2 (AM) or SBFI (AM) ratiometric fluorescence photon counting along with nonstationary laser light scattering. Studies were performed using native epithelial tissues obtained from ovine tracheae. The dynamic range of the laser light-scattering system was determined by a simulated light beating experiment. The nonstationary CBF was demonstrated by the time-frequency analysis of the raw photon count sequences of backscattered heterodyne photons from cultured and native epithelia. Calibrations of calcium and sodium ion concentrations were performed using the respective Fura-2 and SBFI impermanent salts as well as in native epithelia. The cumulative responses of 10^–6, 10^–5, and 10^–4} M nifedipine on [Ca²⁺]i together with the CBF as well as the cumulative responses of 10^–5, 10^–4, and 10^–3 M amiloride on [Na⁺]i together with the CBF were also determined. Nifedipine decreased [Ca²⁺]i but had no effect on CBF. Amiloride decreased [Na⁺]i and CBF. Stimulation of CBF corresponded with either an increase of [Na⁺]i or an increase of [Ca²⁺]i. Decreases of [Na⁺]i or substantial decreases of [Ca²⁺]i were associated with decreases in the CBF. These data demonstrate the utility of this system for investigating the regulatory mechanisms of intracellular ions dynamics and the CBF in native epithelia. © 1998 Biomedical Engineering Society. PAC98: 8780+s, 8722-q, 4262Be     

Bolus doses of esmolol for the prevention of perioperative hyper-tension and tachycardia

The effectiveness of esmolol, an ultra short-acting cardioselective beta blocker, in the prevention and treatment of post-intubation haemodynamic perturbations, was investigated. Forty-eight ASA physical status I and II patients undergoing hysterectomy were randomly assigned to receive a single intravenous bolus of placebo, esmolol 100 mg, or esmolol 200 mg in a double-blind fashion. This was administered over 15 sec, and immediately followed by thiopentone 3-5 mg.kg-1, succinylcholine 1.5 mg.kg-1, and tracheal intubation 90 sec later. The heart rate following induction of anaesthesia was lower in the esmolol 200 mg group (P less than 0.01); following intubation, the increase in heart rate in the placebo group was greater than in the esmolol groups (P less than 0.05). The systolic blood pressure post-induction was lower in the esmolol 200 mg group (P less than 0.05); following intubation, however, no significant differences were seen among groups in systolic, diastolic, or mean blood pressures. Following tracheal intubation, the incidence of ventricular arrhythmias was lower in the esmolol groups (P less than 0.05). In summary, esmolol in 100 mg and 200 mg doses was effective in mitigating the haemodynamic response following tracheal intubation.     

尼卡地平预防双腔支气管导管插管反应的观察

目的　观察应用尼卡地平预防双腔支气管导管插管心血管反应的效果。　方法　肺、食道择期手术病人 40例 ,随机分为 2组 ,每组 2 0例。咪唑安定 0 .0 4mg/kg、异丙酚 1.5mg/kg、芬太尼 4μg/kg、维库溴铵 0 .12mg/kg静脉诱导后 ,甲组给予尼卡地平 4μg/kg ,乙组给予生理盐水 3ml作为对照。分别于诱导前、后 ,插管后即刻及 1、3、5min监测收缩压 (SBP)、舒张压 (DBP)、心率 (HR) ,并计算心率收缩压乘积 (RPP)。　结果　A组插管后血压无明显升高 ,心率较诱导前无明显增快 ,B组插管后血压明显升高。　结论　尼卡地平可抑制双腔支气管导管插管时的心血管副反应。     

直视下行大鼠气管插管的改良方法

目的 提高大鼠气管插管的成功率;方法 对比传统闭式法与改良直视法的成功率;结果传统闭式法的成功率为50％,改良直视法的成功率为100％。结论 改良直视法优于传统闭式法,值得推广应用。     

Monitoring normal and aberrant electrocardiographic activity from an endotracheal tube: Comparison of the surface,esophageal, and tracheal electrocardiograms

Introduction. We designed an endotracheal (ET) tube with orthogonally spaced ECG cuff electrodes. This ET tube was evaluated in dogs and sheep to determine (1) whether ECGs recorded from our tube were sufficient to make accurate clinical decisions concerning heart rate and rhythm; and (2) whether metallic cuff electrodes in direct contact with the trachea could induce mucosal burn injury during episodes of defibrillation.Methods. Using experimental animals, we obtained ECGs from their tracheae and compared our findings with ECGs obtained from surface and esophageal electrodes. The electrical activity of the heart was modified by increasing the depth of anesthesia, occluding the left coronary artery, and administering beta-adrenergic drugs. Before the dogs were euthanized, they were subjected to episodes of transthoracic and intrathoracic defibrillation at energy levels of 200 to 400 J. A postmortem pathological examination of the trachea was performed to determine the incidence of mucosal burn injury.Results. Tracheal electrocardiography provided valid information on heart-rate monitoring and certain morphology profiles. The R-R, PR, QRS, and QT intervals measured from the trachea had a correlation of 1.0, 0.96, 0.83, and 0.98, respectively, when compared with the same intervals obtained from surface electrodes. Two tracheae subjected to intrathoracic defibrillation at >300 J revealed evidence of minor burn injury. Some localized epithelium loss was displayed in all tracheae; we attributed this to tracheal intubation.Conclusion. Tracheal electrocardiography may be useful in trauma patients who require intubation where injury precludes placement of chest ECG electrodes.     

Awake intubation of the adult trachea using the Bullard laryngo-scope

Awake intubation using the Bullard laryngoscope can be comfortably and easily performed in the adult. Five cases are presented in which tracheal intubation was performed under topical anaesthesia with light intravenous sedation. In each case, topical anaesthesia was performed by insertion of a Guedel oral airway, with lidocaine ointment applied to the inferior and posterior surfaces. In one case, Bullard intubation was successful where direct laryngoscopy and multiple attempts at bronchoscopic intubation by three different operators had failed. We conclude that the Bullard laryngoscope can be easily used in awake patients and may be a useful alternative where other methods for awake intubation have failed.     

侧柏叶乙酸乙酯提取物对豚鼠离体气管平滑肌的作用

用离体豚鼠气管条,探讨侧柏叶乙酸乙酯提取物对气管平滑肌作用。结果表明,侧柏叶乙酸乙酯提取物能抑制乙酰胆碱,氯化钾所致气管平滑肌收缩,而且能使乙酰胆碱收缩气管平没肌的量效曲线右移,并抑制最大效应,其作用为剂量依赖性心肌肥厚提示侧柏叶乙酸乙酯提取物松驰气管平滑肌作用机制可能与影响Ｃａ＾２＋的跨膜转运有关。     

艾司洛尔预防气管内插管心血管反应的临床观察

研究艾司洛尔静注预防气管插管时心血管反应的效果。将９０例ＡＳＡⅠ～Ⅱ级择期全麻下手术患者随机分为３组,Ａ组（ｎ＝３０）静注艾司洛尔１ｍｇ．ｋｇ－１,Ｂ组（ｎ＝３０）静注艾司洛尔２ｍｇ．ｋｇ－１,Ｃ组（ｎ＝３０）为对照组,静注同等容量的生理盐水。观察注药前、插管前及插管后１ｍｉｎ、２ｍｉｎ、３ｍｉｎ、５ｍｉｎ、１０ｍｉｎ时,心率、收缩压和舒张压的变化。结果显示：Ａ组和Ｂ组均能较好地缓解窥喉和气管插管时心率增快和血压升高的心血管反应,效果尤以Ｂ组为佳;３组中各有１例发生心动过缓和低血压,未见哮喘和过敏。研究提示：艾司洛尔能安全有效地减轻插管时的心血管反应。