Effects of hypercapnia and inspiratory flow-resistive loading on respiratory activity in chronic airways obstruction.

Altose, Murray D.; McCauley, W; Kelsen, Steven G.; Cherniack, Neil S.

doi:10.1172/jci108665

Cited by 132 publications

(63 citation statements)

References 25 publications

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“…Most investigators have reported that the slope of this response is depressed in hypercapnic patients [6], but some [18], like the present authors ( fig. 1), found slopes equivalent to those in normocapnic patients.…”

Section: Discussionmentioning

confidence: 46%

“…An inability to maintain a normal respiratory motor response during an exacerbation of COPD could lead to critical hypoventilation, respiratory failure, and death. Unfortunately, investigations have yielded inconsistent results, with reports of increased [4], decreased [5,6], and equivalent [7,8] respiratory motor output in hypercapnic and normocapnic patients. These conflicting findings stem, in part, from limitations of techniques used to measure respiratory motor output, such as the diaphragmatic electromyogram and airway occlusion pressure [9].…”

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confidence: 99%

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The voluntary drive to breathe is not decreased in hypercapnic patients with severe COPD

2001

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The voluntary drive to breathe is not decreased in hypercapnic patients with severe COPD. A. Topeli, F. Laghi, M.J. Tobin. #ERS Journals Ltd 2001. ABSTRACT: How do the respiratory centres of patients with chronic obstructive pulmonary disease (COPD) and hypercapnia respond to acute increases in inspiratory load? A depressed respiratory motor output has long been postulated, but studies on this issue have yielded inconsistent results, partly due to limitations of investigative techniques. Many of these limitations can be overcome by the twitch interpolation technique, which is capable of accurately quantifying the degree of diaphragmatic activation, termed the voluntary drive to breathe. The hypothesis that patients with COPD and hypercapnia compensate for an acute increase in mechanical load on the inspiratory muscles with a lower voluntary drive to breathe than is the case with normocapnic patients was tested.Measurements were obtained in 15 patients with COPD, six of whom displayed hypercapnia and nine normocapnia. The maximum degree of diaphragmatic activation, expressed as a voluntary activation index (mean¡SEM), was higher in hypercapnic than in normocapnic patients (98.7¡0.7 versus 94.5¡0.9% (p~0.006)), as was the mean value (94.5¡0.7 versus 88.5¡1.9% (p~0.01)). Within-patient values of the index were also less variable in the hypercapnic patients (coefficients of variation, 3.4¡0.3 versus 6.1¡0.9%, p~0.01). Multiple regression analysis revealed the ratio of dynamic elastance to maximum transdiaphragmatic pressure, an index of inspiratory muscle loading, and pH as the only variables that correlated with maximum voluntary activation index (r 2~0 .69, p~0.02 for each variable). Contrary to the hypothesis, it was concluded that voluntary activation of the diaphragm was greater and less variable in hypercapnic patients than normocapnic patients with severe chronic obstructive pulmonary disease during an acute increase in inspiratory mechanical load. Whether greater diaphragmatic recruitment during episodes of a severe exacerbation of chronic obstructive pulmonary disease provides a survival advantage for hypercapnic patients with chronic obstructive pulmonary disease remains to be determined.

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Section: Discussionmentioning

confidence: 46%

mentioning

confidence: 99%

The voluntary drive to breathe is not decreased in hypercapnic patients with severe COPD

2001

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“…The sensitivity can be reduced by genetic condition, observed in about 10% of the population, 14 or, in some patients, it can be acquired by chronic diseases such as chronic obstructive pulmonary disease 15 or diabetes 16 -conditions that were not present in our patients with SCI. In critically ill patients, sensitivity to CO 2 may also be reduced because of sedatives and opioids 17 used during mechanical ventilation, and because of the metabolic alkalosis 18 frequently observed with the use of diuretics and corticosteroids.…”

Section: Discussionmentioning

confidence: 85%

Respiratory CO2 response in acute cervical spinal cord injury (CO2 response in spinal cord injury)

et al. 2013

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Study design: Retrospective study. Objectives: The objective of this study was to compare the CO 2 response of acute tetraplegic cervical spinal cord injury (SCI) patients undergoing mechanical ventilation with a control group of critically ill patients ready for weaning of mechanical ventilation and successfully extubated. Setting: This study was conducted at the intensive care unit of a University Hospital in Mallorca, Spain. Methods: CO 2 response was studied in 12 acute tetraplegic cervical SCI patients at the C4 ÀC7 level and 22 control patients. The control group patients were consecutively selected from a database of patients with mechanical ventilation and who were successfully extubated after a CO 2 response test. To increase the CO 2 , we used the method of re-inhalation of expired air, and we evaluated the hypercapnic ventilatory response, the change in minute ventilation induced by the increase of partial pressure of arterial carbon dioxide (PaCO 2 ), which measures the whole respiratory system (metabolic control, neuromuscular or ventilatory apparatus), and the hypercapnic drive response, the change in the airway occlusion pressure at 100 ms induced by the increase in PaCO 2 , which measures the chemosensitivity of the respiratory center. Results: Cervical SCI patients were younger than the control group patients (26±7 and 62±12 years, respectively; Po0.001). Mean values of the hypercapnic ventilatory response in cervical SCI and control groups were 0.52±0.31 and 0.64±0.33 l min À1 per mm Hg (P ¼ 0.40), respectively, and the hypercapnic drive response was 0.24 ± 0.16 and 0.48 ± 0.23 cm H 2 O per mm Hg (P ¼ 0.001), respectively. Conclusion: Acute tetraplegic cervical SCI patients had reduced hypercapnic drive response that may contribute to the difficult weaning, without reduction in hypercapnic ventilatory response.

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“…Is after the onset of inspiration (P0O.). (Whitelaw, Derenne & MilicEmili, 1975;Derenne, Couture, Iscoe, Whitelaw & Milic-Emili, 1976;Altose, McCauley, Kelsen & Cherniack, 1977;Burki, Mitchell, Chaudhary & Zecbman, 1977; Gqlb, Klein, Schiffman, Lugliani & Aronstam, 1977;Lopata et al, 1977).…”

Section: Inputs To the Respiratory Centrementioning

confidence: 99%

Methods in the assessment of the control of breathing.

Sauders

1980

Brit J Clinical Pharma

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Effects of hypercapnia and inspiratory flow-resistive loading on respiratory activity in chronic airways obstruction.

Cited by 132 publications

References 25 publications

The voluntary drive to breathe is not decreased in hypercapnic patients with severe COPD

The voluntary drive to breathe is not decreased in hypercapnic patients with severe COPD

Respiratory CO2 response in acute cervical spinal cord injury (CO2 response in spinal cord injury)

Methods in the assessment of the control of breathing.

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