Total lung denervation

Eleven open-chest piglets were studied to examine the effects of vascular engorgement on partitioned airway and lung tissue mechanics, and to investigate the role of vagal denervation on lung function during engorgement. Alveolar pressure was measured using alveolar capsules. Pulmonary elastance (EL) and resistance (RL), airway (Raw), and tissue (Vti) resistance were calculated during mechanical ventilation. Acute fluid administration with polygeline (10 mL/kg boluses up to a total of 30 mL/kg) resulted in an increase of RL with increases in both Raw and Vti...

Bilateral interruption of the upper dorsal sympathetic chain at the D2 and D3 level represents the only permanent cure for essential hyperhidrosis. Following surgical sympathectomy, significant and symptomatic changes in pulmonary function have been observed. Since functional effects of the surgical intervention cannot be excluded, we wondered whether such alterations also occurred after thoracoscopic sympathicolysis; these should then be attributable to the surgical denervation itself. Pulmonary function tests (PFTs), including spirometry and body plethysmographic measurement of lung volumes and airway resistance and conductance, were compared before and 6 weeks after thoracoscopic sympathicolysis in 47 patients...

The inhibitory effects of CO2 on slowly adapting pulmonary stretch receptors (SARs) were studied before and after administration of acetazolamide, a carbonic anhydrase inhibitor, or nifedipine, a calcium channel blocker, in anesthetized, artificially ventilated rabbits after vagus nerve section. CO2 inhalation (maximal tracheal CO2 concentration ranging from 7.2% to 9.5%) for approximately 60 sec decreased the receptor activity during both inflation and deflation. The magnitude of decreased receptor activity during deflation became more pronounced than that seen during inflation...

Breathing was monitored during normocarbia, hypercarbia (6% CO2 in air), and the period immediately after the return to normocarbic conditions in intact, olfactory-denervated, and vagotomized bullfrogs. In intact frogs, ventilation increased during hypercarbia, but the breathing pattern remained episodic. Immediately upon return to air, there was a further paradoxical increase in breathing frequency, and breathing became continuous in most frogs. Results obtained from animals after olfactory receptor denervation indicate that tonic stimulation of olfactory receptors by airway CO2 inhibited breathing during hypercarbia...

The present study aimed to compare the reflex bronchoconstrictor effects of upper airway applications of dry airstreams with equivalent cooling produced by cold isotonic and hypertonic saline solutions in anaesthetized rabbits. A method of on-line, breath by breath analysis of lung mechanics was used. The changes in total lung resistance (RL) and dynamic lung compliance (Cdyn) produced by dry airstreams and by cold hypertonic saline were greater than those induced by cold isotonic saline. Warm isotonic saline and supersaturated airstreams were ineffective...

One hypothesis to explain the rapid neural component of exercise hyperpnea contends that afferent stimuli originating in the ventricles of the heart act reflexly on the respiratory center at the onset of exercise, ie, "cardiodynamic hyperpnea." Orthotopic cardiac transplantation (Tx) results in the loss of afferent information from the ventricles. Thus, Tx possibly results in transient hypercapnia and hypoxemia in deafferented heart transplant recipients (HTR) at the onset of exercise due to hypoventilation...

The increase of non specific surgeries in transplanted patients may be related to the better survival achieved by the efficacy of immunosuppressive therapy and improved surgical and intensive care conditions. Therefore, the anaesthetist may be mandated to give anaesthesia in such patients, treated in hospitals which are not involved in transplantation procedures. The ignorance of the main physiologic and pharmacological changes in the new grafted organ as well as the knowledge of high risks of rejection or infection contribute to the anxiety often encountered in front of these patients...

Success in neonatal lung transplantation depends on the growth of the transplanted lung. To study the effects of transplantation and denervation on primate lung growth without rejection or immunosuppression, an autotransplant model was chosen. Eight-week-old baboons underwent left lung autotransplantation (n = 5) or sham operation (n = 1). At age 13 weeks and 9 months, single lung volumes were calculated by nitrogen washout and computed tomography. Results were compared with those of 4 unoperated weight-matched controls (2 per age group)...

We have studied the effects on FEV1 of inhaled capsaicin in concentrations of 3 x 10(-6) to 3 x 10(-1) mg/ml and methacholine (1 to 16 mg/ml) in 15 heart-lung transplant (HLT) patients who had undergone recent transbronchial lung biopsy to determine the relationships in chronically denervated lungs between these different forms of airway hyperreactivity and inflammation. A total of 10 normal subjects and 17 asthmatic subjects were included for comparison. Capsaicin caused bronchodilation in eight HLT patients (FEV1 rising by 6...

Pulmonary hypertension and hyperperfusion were experimentally induced in conscious toads (Bufo marinus) to test whether excessive transcapillary filtration might result in pulmonary edema. Elimination of pulmocutaneous baroreceptor afferent input by bilateral sectioning of recurrent laryngeal nerves caused mean pulmonary arterial pressure to increase by nearly 25 mmHg and pulmonary blood flow to increase fourfold. Left lungs of control (normotensive) and hypertensive toads were isolated by snares at the hilus and excised for compartmental lung fluid analysis...

To compare the contribution of nitric oxide (NO) to the buffering of short-term and circadian fluctuations of arterial blood pressure with that of the baroreceptor reflex, conscious foxhounds were subjected to continuous 24-h blood pressure recordings. A pressure transducer was placed into the lumen of the abdominal aorta. Telemetry recordings were done under control conditions, following blockade of NO formation by intravenous bolus injection of NG-nitro-L-arginine (L-NNA; 16.5 +/- 2 mg/kg body wt) and after total sinoaortic and cardiopulmonary denervation in five dogs each...

To evaluate the contribution of the respiratory pattern to the ventilatory response after lung transplantation, we studied the changes in minute ventilation, tidal volume, and respiratory rate during CO2 rebreathing in 14 patients with severe obstructive pulmonary disease, and compared them with 10 normal subjects. Seven patients underwent a bilateral lung transplantation and 7 patients had single-lung transplantation. Single-lung transplant recipients increased their respiratory rate by the last postoperative test compared with either preoperative or initial test periods (0...

BACKGROUND: The functional relevance of an intact pulmonary sympathetic innervation for airway resistance is unknown. We therefore evaluated whether or not pulmonary sympathetic denervation by thoracic epidural anesthesia decreases the threshold of an inhalational provocation with acetylcholine in 20 patients with documented bronchial hyperreactivity scheduled for elective upper abdominal or thoracic surgery. METHODS: Baseline inhalational provocation with acetylcholine was performed 2-4 days before surgery...

BACKGROUND: Cardiac transplantation and chronic myocardial infarction interrupt vagal afferent nerve fibers, which originate mainly from the ventricles. Marked abnormalities of reflexes mediated by cardiopulmonary receptors with vagal afferent fibers have been demonstrated after both cardiac transplantation and chronic myocardial infarction. The relation between these reflex abnormalities and ventricular deafferentation is not known. METHODS AND RESULTS: To further assess this relation, we investigated the effects of left ventricular (LV) deafferentation on the control of renal sympathetic nerve activity (RSNA) by the vagal cardiopulmonary reflex in chloralose-anesthetized, mechanically ventilated dogs with sinoaortic denervation...

Whether or not neural blockade of pulmonary sympathetic innervation is of relevance for airway resistance in patients with chronic obstructive pulmonary disease (COPD) is unknown. Accordingly we evaluated airway resistance during sympathetic blockade by high thoracic epidural anaesthesia in patients with COPD. Before and 45 min after thoracic epidural injection of bupivacaine 0.75% (6-8 ml; n = 10) total respiratory resistance (oscillometry, ROS), vital capacity (VC), forced expiratory vital capacity in 1 s (FEV1, [%VC]), functional residual capacity (FRC; helium dilution method), and arterial blood gases were measured...

To assess whether pulmonary vagal afferents affect the duration of breathholding, the associated respiratory distress and their dependence on lung volume, we studied seven heart-lung transplant (HLT) patients with chronic pulmonary denervation and seven matched control subjects. Voluntary breathholds were performed at 20% and 80% vital capacity (VC) after rebreathing a 7% CO2-93% O2 gas mixture. Time to breakpoint, oxygen saturation, and end-tidal PCO2 were measured. All subjects were questioned on their sensations during breathholding; in addition, quantitative assessment of the sensations was obtained using a visual analog scale (VAS) in the seven control subjects and four HLT subjects...

We performed single-breath tests in closed-chest, paralyzed, and anesthetized dogs (6 with bilateral vagotomy and 6 with intact vagi) with the heart beating and during cardiac arrest. Repeated cardiac arrest was achieved by ventricular fibrillation and subsequent defibrillation. Twenty-four single-breath tests per dog were performed in combinations of three inspiratory volumes (VI; 0.2, 0.5, and 0.8 liter) and four postinspiratory pauses (0, 5, 10, and 30 s), either with or without cardiac arrest. The test gas contained four inert relatively insoluble gases (He, Ne, Ar, and SF6) with a sixfold range in diffusivity...

The technique of bilateral total splanchnicectomy performed through a posterior thoracoscopic approach is described. The advantages of this route include excellent visual exposure of the neural anatomy of the sympathetic and avoidance of single lung anaesthesia. The procedure was performed for the relief of intractable pain in patients with advanced pancreatic cancer (n = 3) and patients suffering from chronic pancreatitis (n = 5). Persistent relief of pain until death was obtained in the patients with pancreatic cancer (2, 4, 6 months)...

The relationships between mean arterial blood pressure (MAP) and the activity of putative pain modulatory neurons of the rostroventral medulla (ON and OFF cells) were determined in intact and cardiopulmonary deafferented rats. A total of 173 neurons were recorded from 97 rats as follows: 32 ON cells and 25 OFF cells from 39 intact rats; 32 ON cells and 20 OFF cells from 24 rats with bilateral sino-aortic deafferentation (SAD); 12 ON cells and 20 OFF cells from 19 rats with bilateral cervical vagotomy (CVAG); and 20 ON cells and 12 OFF cells from 15 rats with both SAD and CVAG...

Modification of carotid baroreflex heart and vascular responses during increased lung positive end-expiratory pressure (PEEP) were measured anesthetized aortic-denervated rabbits. Static carotid intrasinus pressure (ISP) was varied in increments of 12.5 mmHg over 25-140 mmHg during lung inflation conditions ranging from spontaneous breathing (SB) to positive-pressure respiration at 0.0-7.5 cmH2O PEEP. To distinguish cardiopulmonary vagally and nonvagally mediated influences, heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), and total peripheral resistance (TPR) were measured and compared before and after sequential vagotomy and beta- and alpha-receptor blockade...