高通气综合征的认知行为治疗

目的：探讨高通气综合征的有效疗法。方法：选择经Nijmegen问卷累积分诊断为高通气综合征患者计37例，给予抗焦虑药及一般治疗的同时采用认知行为治疗，将能坚持认知行为治疗的21例患者分为（A组）；未能按要求治疗及末采用认知行为治疗的患者16例分为（B组），对两组患者的治疗效果进行其疗效对比观察。结果：治疗30天后，A组显效率52．3％，总有效率90．5％，而B组显效率和总有效率分别为18．8％，50．0％。A组疗效明显高于B组，显效率（P＜0．05）及总有效率（P＜0．05）均有显著性差异，结论：认知行为治疗高通气综合征有良好的疗效。     

脑出血术后的机械通气治疗

目的 探讨脑出血术后患者机械通气治疗的策略及其疗效。方法 脑出血术后患者中，符合上机指征的有53例，在常规治疗的基础上，予以机械通气。分析治疗前后呼吸指标的变化。结果 脑出血术后，给予机械通气治疗2h后，与机械通气前比较，各项指标包括呼吸频率RR、氧分压脚晚、二氧化碳分压PaCO2、血氧饱和度SpO2均有改善，并有统计学意义（P〈0．05）。经过综合治疗后，好转出院18例（33．96％），自动出院16例（30．19％），死亡19例（35．85％）。结论 脑出血术后患者，合理机械通气治疗（包括过度通气等）可明显改善患者的呼吸功能、减少死亡率。     

Whole-brain vascular reactivity measured by fMRI using hyperventilation and breath-holding tasks: efficacy of 3D prospective acquisition correction (3D-PACE) for head motion

Functional MR imaging (fMRI) study using hyperventilation and breath-holding task has been reported to be one of the non-invasive methods to examine whole-brain vascular reactivity. The purpose of this study was to evaluate the efficacy of a method for 3D prospective detection and correction of head motion (3D-PACE) in a study of whole-brain vascular reactivity using hyperventilation and breath-holding tasks. Eight healthy volunteers were scanned using an fMRI protocol of hyperventilation and breath-holding task blocks at 3 T in separate runs with and without 3D-PACE. In two subjects, two more runs with and without 3D-PACE were repeated. The mean total number of activated voxels ± standard deviation was 26,405.3±1,822.2 in the run with 3D-PACE and 17,329.9±2,766.3 in the run without 3D-PACE (P<0.05), although there is some intersubject variation regarding the effect of 3D-PACE. In the two subjects whose performed two more runs, the number of activated voxels were smaller in the run without 3D-PACE than even in the run with 3D-PACE performed later. We conclude that 3D-PACE is beneficial for fMRI studies of whole-brain vascular reactivity induced by hyperventilation and breath-holding.     

Hyperventilation in asthma: A validation study of the Nijmegen Questionnaire – NQ

Introduction: The Nijmegen questionnaire (NQ) has previously been used for screening the hyperventilation syndrome (HVS) in asthmatics. However, no validity study has been reported so far. Objective: To examine the validity and reliability of the NQ in asthma patients and identify the prevalence of HVS. Methods: The NQ (n?=?162) was examined for translation, construct, cross-sectional and discriminant validity as well as for internal consistency and test–retest reliability. Results: Principal component analysis and exploratory factor analysis revealed a single factor solution with 11 items and 58.6% of explained variability. These 11 NQ items showed high internal consistency (Cronbach's alpha?=?0.92) and test–retest reliability (IR?=?0.98). Higher NQ scores were found in the following subgroups: women versus men (p?p?p?p?2 (ETCO₂) ≤35 versus >35?mmHg (p?17 discriminated the participants with regard to the presence of HVS. The NQ showed 92.73% sensitivity and 91.59% specificity. The total NQ score was found significantly correlated with ETCO₂ (r?=??0.68), RR (r?=?0.66) and BHT (r?=??0.65). The prevalence of HVS was found 34%. Conclusion: The NQ is a valid and reliable questionnaire for screening HVS in patients with stable mild-to-moderate asthma.     

过度通气正常二氧化碳分压的方式对促进异氟醚麻醉苏醒的有效性和安全性

目的过度通气正常二氧化碳分压的方式对促进异氟醚麻醉苏醒的有效性和安全性。方法择期甲状腺手术患者32例。采用1 MAC异氟醚吸入复合瑞芬太尼持续静脉输注维持麻醉。进入苏醒期后随机分为两组:过度通气正常二氧化碳分压组(I组),在苏醒期采用正常二氧化碳(新鲜气流内加入适量CO2)过度通气策略,维持PETCO2为42~45mm Hg。对照组(C组)按传统方法增加新鲜气体流量(无CO2)加速麻醉药洗出。记录并比较两组关闭挥发器至BIS值75时间、睁眼时间和拔管时间。并观察不良反应发生情况。结果与C组比较,恢复期I组PETCO2、气道峰压明显升高(P0.01),I组BIS至75时间、BIS至95时间、睁眼时间、张口时间和拔管时间明显缩短(P0.01)。两组患者均未发生恶心、呕吐或寒战不良反应,仅I组2例患者出现术后烦躁,与C组比较差异无统计学意义。结论过度通气正常二氧化碳分压方式能够安全有效地加速异氟醚麻醉苏醒。     

Tissue pulsatility imaging of cerebral vasoreactivity during hyperventilation

Tissue pulsatility imaging (TPI) is an ultrasonic technique that is being developed at the University of Washington to measure tissue displacement or strain as a result of blood flow over the cardiac and respiratory cycles. This technique is based in principle on plethysmography, an older nonultrasound technology for measuring expansion of a whole limb or body part due to perfusion. TPI adapts tissue Doppler signal processing methods to measure the "plethysmographic" signal from hundreds or thousands of sample volumes in an ultrasound image plane. This paper presents a feasibility study to determine if TPI can be used to assess cerebral vasoreactivity. Ultrasound data were collected transcranially through the temporal acoustic window from four subjects before, during and after voluntary hyperventilation. In each subject, decreases in tissue pulsatility during hyperventilation were observed that were statistically correlated with the subject's end-tidal CO2 measurements. (     

Respiratory Mechanisms and Clinical Syndromes

A review of respiratory mechanisms is outlined and the links between sympathetic and parasympathetic discharge are described. The links between respiratory rhythms, autonomic modulation and the clinical syndromes of hyperventilation and obstructive sleep apnoea are delineated.     

Interoceptive threat leads to defensive mobilization in highly anxiety sensitive persons

To study defensive mobilization elicited by the exposure to interoceptive arousal sensations, we exposed highly anxiety sensitive students to a symptom provocation task. Symptom reports, autonomic arousal, and the startle eyeblink response were monitored during guided hyperventilation and a recovery period in 26 highly anxiety sensitive persons and 22 controls. Normoventilation was used as a non-provocative comparison condition. Hyperventilation led to autonomic arousal and a marked increase in somatic symptoms. While high and low anxiety sensitive persons did not differ in their defensive activation during hyperventilation, group differences were detected during early recovery. Highly anxiety sensitive students exhibited a potentiation of startle response magnitudes and increased autonomic arousal after hyper- as compared to after normoventilation, indicating defensive mobilization evoked by the prolonged presence of feared somatic sensations.     

Hyperventilation revisited: physiological effects and efficacy on focal seizure activation in the era of video-EEG monitoring

PURPOSE: Hyperventilation is an activation method that provokes physiological slowing of brain rhythms, interictal discharges, and seizures, especially in generalized idiopathic epilepsies. In this study we assessed its effectiveness in inducing focal seizures during video-EEG monitoring. METHODS: We analyzed the effects of hyperventilation (HV) during video-EEG monitoring (video-EEG) of patients with medically intractable focal epilepsies. We excluded children younger than 10 years, mentally retarded patients, and individuals with frequent seizures. RESULTS: We analyzed 97 patients; 24 had positive seizure activation (PSA), and 73 had negative seizure activation (NSA). No differences were found between groups regarding sex, age, age at epilepsy onset, duration of epilepsy, frequency of seizures, and etiology. Temporal lobe epilepsies were significantly more activated than frontal lobe epilepsies. Spontaneous and activated seizures did not differ in terms of their clinical characteristics, and the activation did not affect the performance of ictal single-photon emission computed tomography (SPECT). CONCLUSIONS: HV is a safe and effective method of seizure activation during monitoring. It does not modify any of the characteristics of the seizures and allows the obtaining of valuable ictal SPECTs. This observation is clinically relevant and suggests the effectiveness and the potential of HV in shortening the presurgical evaluation, especially of temporal lobe epilepsy patients, consequently reducing its costs and increasing the number of candidates for epilepsy surgery.     

Doppler continuous-wave analysis of grafted mammary artery as a non-invasive technique for static and dynamic assessment of coronary flow in man

Summary In this paper, Doppler continuous-wave analysis of blood velocity in the internal mammary artery, anastomosed to the left coronary vascular bed in humans who have undergone myocardial revascularization, is proposed as a non-invasive technique to study coronary blood flow during physiological procedures which cause it to change. Blood velocity curves obtained in normal and anastomosed internal mammary arteries were compared during hyperventilation and the Valsalva manoeuvre. During hyperventilation, blood velocity increased in the normal mammary but not in the anastomosed artery. During the expiratory effort of the Valsalva manoeuvre, the mean blood velocity decreased in the normal mammary artery but it did not change significantly in the anastomosed artery. Variations in the mean velocity were largely prevented by simultaneous and well-balanced increases and decreases in the diastolic and systolic velocities, respectively.