Autonomic cardiovascular responses in parkinsonism: effect of levodopa with dopa-decarboxylase inhibition

ABSTRACT – Autonomically mediated cardiovascular responses to certain manoeuvres were studied in 20 parkinson patients, 24 h off levodopa-decarboxylase inhibitor medication and again one h after medication. Results were compared with 15 healthy control subjects. The heart rate at rest was higher in parkinson, the respiratory sinus arrhythmia was lower, while the Valsalva ratio, the heart rate and blood pressure responses during an orthostatic test and the heart rate response to a dive reflex test were normal. These findings indicate a normal function of peripheral autonomic nerves and a possible central parasympathetic dysfunction.
There were significantly attenuated responses of heart rate, blood pressure and contralateral forearm blood flow to an isometric handgrip. Since the peripheral autonomic nerves seemed to be normal, these results could be related to a reduced central command and/or diminished stimulation of postulated peripheral ergoreceptors in parkinsonism.
There was no major effect on the cardiovascular responses by the acutely administered medication.     

Autonomic cardiovascular responses in distal myopathy (Welander)

Autonomically mediated cardiovascular responses were evaluated in 9 patients with Welander distal myopathy and compared to data from an age- and sex-matched control group. The myopathy patients had a normal respiratory sinus arrhythmia and a normal heart rate response to the Valsalva menoeuvre, indicating a normal vagal function. They had a normal initial heart rate response to the orthostatic position, indicating a normal function of the sympathetic nerves. The main difference between the groups was found in the orthostatic position. The myopathy patients reacted with a greater increase in systolic blood pressure and a smaller heart rate increase than the controls. This suggests an altered peripheral vasomotor function, possibly with a more predominant activation of alfa than beta adrenergic receptors leading to vasoconstriction. In addition, a low forearm blood flow at rest and a les pronounced blood flow increase during the isometric handgrip were found in the myopathy patients. This finding could also be explained by proneness to vasoconstriction. It is concluded that patients with Welander distal myopathy have no signs of dysfunction of the peripheral autonomic nerves.     

Cluster headache: interictal asymmetric increment in intraocular pressure elicited by Valsalva manoeuvre

Changes in intraocular pressure (IOP) elicited by a Valsalva manoeuvre were studied in 11 male patients (mean age 39.8 years) suffering from episodic cluster headache (CH), and 12 healthy male controls (mean age 39.9 years). The tests were performed at rest and while exhaling hard through a mouthpiece connected to a mercury manometer. In the CH group, during symptomatic periods, between attacks, Valsalva manoeuvre elicited an asymmetric increase in IOP with significantly higher values on the symptomatic side (P = 0011), whereas no asymmetric increments in IOP were found during asymptomatic periods. Outside the cluster period the IOP values both baseline and with Valsalva manoeuvre did not differ from controls. The increment in IOP took place within a few seconds, as in spontaneous CH attacks, thus pointing to a rapid increase in intraocular blood volume or vasodilatation. These findings may reflect a latent increased vascular reactivity of the symptomatic orbit during CH period.     

Effects of Pringle manoeuvre and ischaemic preconditioning on haemodynamic stability in patients undergoing elective hepatectomy: a randomized trial

Background. The Pringle manoeuvre and ischaemic preconditioningare applied to prevent blood loss and ischaemia-reperfusioninjury, respectively, during liver surgery. In this prospectiveclinical trial we report on the intraoperative haemodynamiceffects of the Pringle manoeuvre alone or in combination withischaemic preconditioning. Methods. Patients (n=68) were assigned randomly to three groups:(i) resection with the Pringle manoeuvre; (ii) with ischaemicpreconditioning before the Pringle manoeuvre for resection;(iii) without pedicle clamping. Results. Following the Pringle manoeuvre the mean arterial pressureincreased transiently, but significantly decreased after unclampingas a result of peripheral vasodilation. Ischaemic preconditioningimproved cardiovascular stability by lowering the need for catecholaminesafter liver reperfusion without affecting the blood sparingbenefits of the Pringle manoeuvre. In addition, ischaemic preconditioningprotected against reperfusion-induced tissue injury. Conclusions. Ischaemic preconditioning provides both betterintraoperative haemodynamic stability and anti-ischaemic effectsthereby allowing us to take full advantage of blood loss reductionby the Pringle manoeuvre.     

Effects of molsidomine and lexipafant in hepatic ischaemia--reperfusion injury

PURPOSE: The purpose of this study was to evaluate the effects of nitric oxide donor molsidomine and platelet-activating factor (PAF) antagonist lexipafant on the hepatic IR injury in rats. METHODS: Fifty male Sprague-Dawley rats (200-225 g) were divided into five groups each containing 10 rats; group SO: Sham operation group; group I: hepatic ischaemia group; group IR: ischaemia-reperfusion (IR); group M: IR plus pretreatment with molsidomine; group L: IR plus pretreatment with lexipafant. Hepatic ischaemia and reperfusion, each were applied for 45 min. Hepatic specimens were obtained to determine the tissue levels of malondialdehyde (MDA) and histological changes. Blood samples were obtained by cardiac puncture for determination of alanine transaminase (ALT), aspartate transaminase (AST) and lactic dehydrogenase (LDH). RESULTS: The liver damage scores of groups I, IR, M and L were significantly higher than that of group SO (P < 0.001). The liver damage scores of groups IR and M were significantly higher than that of group I (P = 0.009 and 0.0035, respectively). The liver damage scores of groups M and L were significantly lower than that of group IR (P < 0.001 for both M and L). Mean MDA levels of groups I and IR were significantly higher than those of group SO (P < 0.001). Administrations of molsidomine and lexipafant prior to ischaemia-reperfusion (IR) resulted in significant reduction of the MDA values (P < 0.001). A statistically significant (P < 0.001) decrease in the levels of AST, ALT and LDH was observed in groups M and L compared with group IR. CONCLUSION: In conclusion, these observations suggest that pre-treatment with nitric oxide donor molsidomine and PAF antagonist lexipafant before the reperfusion period may be useful in preventing hepatic reperfusion injury.     

The Epley manoeuvre for benign paroxysmal positional vertigo – a systematic review

Benign paroxysmal positional vertigo (BPPV) is a syndrome characterized by short‐lived episodes of vertigo in association with rapid changes in head position. Current treatment approaches include rehabilitative exercises and physical manoeuvres including the Epley manouevre. Randomized clinical trials of the Epley manoeuvre were identified. Outcome measures that were considered include: frequency and severity of attacks of vertigo; proportion of patients improved by each intervention; and conversion of a ‘positive’ Dix–Hallpike test to a ‘negative’ Dix–Hallpike test. Patients who received the Epley manoeuvre were more likely to have complete resolution of their symptoms [odds ratio 4.92 (95% C.I. 1.84–13.16)], and more likely to convert from a positive to negative Dix–Hallpike test [odds ratio 5.67 (95% C.I. 2.21–14.56)]. There were no serious adverse effects of treatment. There is some evidence that the Epley manouevre is a safe effective treatment for posterior canal BPPV.     

Impedance cardiographic measurement of the physiological response to the Valsalva manoeuvre

The Valsalva manoeuvre was performed, with airway pressures of 10, 20, 30, 40 and 50 mmHg, on 11 healthy male subjects in both the standing and supine positions, and was evaluated with impedance cardiography using the Minnesota impedance cardiograph. Along with the impedance waveform, the output of a finger photoplethysmograph was recorded. The ratios of the amplitude of the finger and impedance pulses at the end of a 10s strain phase during the Valsalva manoeuvre were compared with those of the control period. The results in the standing position showed the impedance ratio changed from 0.81 to 0.61 as the airway pressure increased from 10 to 50 mmHg, whereas, over the same pressure range, the finger pulse ratio changed from 0.44 to 0.21. In the supine position, the response was similar to that for standing for most pressures. Upon release of the pressure, the impedance showed an immediate, large decrease, which suggests a significant rightheart and vena cava component in the impedance cardiographic signal. The results show that the impedance signals responded similarly to those of previous studies of central arterial pressure during the Valsalva manoeuvre, whereas the finger pulse decrease was approximately twice as much.     

A new method of predicting pulmonary capillary wedge pressure: the arterial pressure ratio

The response of arterial blood pressure to an increase in intrathoracic pressure has been shown to be predictive of pulmonary capillary wedge pressure. We devised a new method, which we termed the arterial pressure ratio. We defined arterial pressure ratio as the ratio of systolic blood pressure of the final beat during the strain phase of the Valsalva manoeuvre to that during apnoea before the manoeuvre, and tested the accuracy of arterial pressure ratio in predicting pulmonary capillary wedge pressure. In 30 patients scheduled for elective abdominal aortic reconstruction, following induction of general anaesthesia and tracheal intubation, a 20-G catheter and pulmonary artery catheter were inserted through the radial artery and right internal jugular vein, respectively. Pulmonary capillary wedge pressure was then measured during a brief period of apnoea and the Valsalva manoeuvre was performed by application of pressure to the reservoir bag. Airway pressure was maintained at 30 cmH2O for 10 s and then released. Radial arterial pressure and airway pressure were recorded simultaneously, and arterial pressure ratio was calculated. There was a close linear correlation between arterial pressure ratio and pulmonary capillary wedge pressure (r = 0.88, p < 0.0001).     

Saline contrast and colour Doppler transoesophageal echocardiography in detecting a patent foramen ovale and right-to-left shunts in stroke patients

Summary. A paradoxical embolism due to right-to-left shunt through a patent foramen ovale (PFO) can be responsible for stroke and other ischaemic cerebral events. We studied the usefulness of saline contrast transoesophageal echocardiography after the Valsalva manoeuvre in detecting PFO and right-to-left shunts in 28 adult patients without known reason for a recent stroke. The results were compared with conventional transthoracic colour Doppler and with transoesophageal colour Doppler techniques. A PFO was found in 24 patients (86%) of our selected study population, whereas in four patients no PFO was found. A PFO with left-to-right shunt could be diagnosed by transthoracic colour Doppler echocardiography in only one case. A PFO with left-to-right shunt was found by transoesophageal colour Doppler echocardiography in 17 patients (61%), but in only three of them was a right-to-left shunt detected, even after the Valsalva manoeuvre. In contrast, a PFO with right-to-left shunt could be detected in 21 patients (75%) by using saline contrast transoesophageal echocardiography with the Valsalva manoeuvre. However, the method was unable to detect three cases of PFO with only left-to-right shunt, which were detected by colour Doppler transoesophageal echocardiography. In conclusion, our results show that saline contrast transoesophageal echocardiography with the Valsalva manoeuvre greatly improves the echocardiographic detection of PFO with right-to-left shunts in stroke patients.     

肺超声在老年患者腹腔镜结直肠癌手术中的应用

目的 通过肺超声评估老年患者腹腔镜手术术后肺不张的发生率及严重程度,并评估肺超声在肺复张过程中的指导作用,为肺超声在围术期的应用提供依据。方法 选取2018年9月～2019年9月在我院拟行腹腔镜结直肠癌手术的42例老年患者为研究对象,年龄60～80岁,美国麻醉师协会（ASA）Ⅱ或Ⅲ级。采用随机对照法分为两组：对照组（C组,n=21）和复张组(RM组,n=21)。两组分别在麻醉前（T1）、手术结束时（T2）、拔管后30 min（T3）3个时间点进行肺部超声十二分区法扫查,手术结束时（T2）RM组的肺不张患者在超声监测下行肺复张,C组不行肺复张。用肺超声分数评估肺不张严重程度以及发生率,记录T1、T2、T3时的肺超声分数,记录PaO2、SpO、手术时间、术中失血量、输液量及尿量。术中采取相同的麻醉方法和机械通气策略。结果 ① T2时C组肺不张发生率95%,RM组肺不张发生率100%;两组比较,差异无统计学意义（P＞0.05）。T3时 C组肺不张发生率95%,RM组肺不张发生率50%;两组比较,差异有统计学意义（P＜0.05）。② T3时RM组肺超声总分低于C组（P＜0.001）;左侧5区和6区、右侧5区和6区,RM组的肺超声分数小于C组（P＜0.05）;在RM组,T3时肺超声总分小于T2时（P＜0.001）。③ 两组PaO2、SpO2、手术时间、失血量、输液量、尿量比较,差异无统计学意义（P＞0.05）。结论 老年患者腹腔镜结直肠癌手术术后肺不张的发生率极高,为 100%。超声监测下肺复张能有效降低术后肺不张发生率,降低肺超声分数、肺不张严重程度及改善肺通气,肺超声可在围术期推广使用。