Effect of the rate of rise of carotid body Pco2, on the time course of ventilation

Dutton, Robert E.; Hodson, W. Alan; Davies, D. G.; Fenner, A

doi:10.1016/0034-5687(67)90065-5

Cited by 26 publications

(7 citation statements)

References 16 publications

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“…Step COµ functions, for example, cause an 'overshoot' in ventilation, whilst progressive functions do not (Dutton, Hodson, Davies & Fenner, 1967). The importance of the 'time derivative' in the response to a chemical stimulus (Lahiri, 1983) may partly explain why ýé peaked earlier (within 60 s) when the rate of desaturation was greatest (Fig.…”

Section: Immediate Response To Hypoxaemiamentioning

confidence: 99%

A Comparison of the Ventilatory Response of Sleeping Newborn Lambs to Step and Progressive Hypoxaemia

Cohen

Malcolm

Henderson‐Smart

1997

The Journal of Physiology

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Slight variations in the rate at which hypoxaemia develops may significantly alter the ventilatory response (VR) elicited. Here we have developed a technique to compare the VRs elicited from sleeping newborn lambs by specific (step versus progressive), short‐duration (≥ 5 min) episodes of hypoxaemia. The results may help us understand the limitations of using tests which deliver poorly defined stimuli to evaluate the postnatal development of the oxygen chemoreflex. The VRs of five lambs elicited by a 5 min step or progressive reduction in the arterial oxygen saturation (Sa,O2) during quiet sleep were compared. Minute ventilation (V̇i, face mask) and Sa,O2 (pulse oximeter) were measured continuously. Alternate step (Sa,O2 reduced to 80–85 % within 60 s and maintained for a further 4 min) and progressive tests (progressive reduction in Sa,O2 to 80 % over 5 min) were administered daily between postnatal days 2–14. There was a significant difference between the mean VR to step versus progressive hypoxaemia. The VR to a step challenge was biphasic (ΔV̇i=+32 ± 5% at 1 min and −1 ± 4% at 5 min; mean ±s.e.m.). Progressive hypoxaemia elicited a more subdued but sustained hyperpnoea (ΔV̇i=+11 ± 2% at 1 min and +11 ± 4% at 5 min). The difference between these two response profiles was statistically significant (P < 0.001). Mean responses of lambs aged ≤ 5 days (4 ± 0.2 days) and ≥ 9 days (10 ± 0.3 days) were also compared. There was an upward shift in the position of step and progressive response curves of older lambs, reflecting primarily the increased vigour of the initial hyperpnoea elicited by step (ΔV̇i at 1 min =+20 ± 4% at 4 days vs.+40 ± 11 % at 10 days) as well as progressive (ΔV̇i at 1 min =+6 ± 2% at 4 days vs.+17 ± 5%at 10 days) hypoxaemia. Qualitatively different VRs may be elicited from the newborn, depending upon the specific hypoxaemic profile administered. Therefore, to evaluate the significance of VRs elicited in response to classical, steady‐state hypoxia at different postnatal ages properly, the stimulus must be accurately described.

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Section: Immediate Response To Hypoxaemiamentioning

confidence: 99%

A Comparison of the Ventilatory Response of Sleeping Newborn Lambs to Step and Progressive Hypoxaemia

Cohen

Malcolm

Henderson‐Smart

1997

The Journal of Physiology

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“…Since peripheral chemoreceptors respond very rapidly, on a breath‐by‐breath basis, chemical stimuli that are rapidly administered and brief would best take advantage of their specific time response characteristics to avoid involving the slower responding central chemoreflexes (Dutton et al. ; Gelfand and Lambertsen ).…”

Section: Introductionmentioning

confidence: 99%

“…The majority of studies have reported blunted hypercapnic ventilatory response (HCVR) (Kelling et al 1985;Manning et al 1992), which is a measure of peripheral and central chemosensitivity while other investigators have found no significant difference in sensitivity to steady-state hypoxia and hypercapnia compared with able-bodied controls (Ben-Dov et al 2009). Since peripheral chemoreceptors respond very rapidly, on a breath-by-breath basis, chemical stimuli that are rapidly administered and brief would best take advantage of their specific time response characteristics to avoid involving the slower responding central chemoreflexes (Dutton et al 1967;Gelfand and Lambertsen 1973).…”

Section: Introductionmentioning

confidence: 99%

Spinal cord injury is associated with enhanced peripheral chemoreflex sensitivity

2016

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Sleep‐disordered breathing (SDB) is prevalent in individuals with chronic spinal cord injury (SCI), but the exact mechanism is unknown. The aim of this study was to investigate whether peripheral chemoreceptors activity is enhanced in individuals with chronic SCI compared to abled‐bodied control subjects using CO 2 and O2 chemical tests. In protocol (1) 30 subjects (8 cervical [cSCI], 7 thoracic [tSCI] and 15 able‐bodied [AB]) were studied to determine the ventilatory response to hyperoxia during wakefulness in the supine position. In protocol (2) 24 subjects (6 cSCI, 6 tSCI, and 12 AB subjects) were studied to determine the ventilatory response to a single breath of CO 2 (SBCO 2). The chemoreflex response to SBCO 2 was calculated as ∆VE/∆CO 2 (L/min/mmHg). The ventilatory response to hyperoxia was defined as the % change in VT following acute hyperoxia compared to preceding baseline. During hyperoxia SCI subjects had a significant decrease in VT and VE (63.4 ± 21.7% and 63.1 ± 23.0% baseline, respectively, P < 0.05) compared to AB (VT: 87.1 ± 14.3% and VE: 91.38 ± 15.1% baseline, respectively, P < 0.05). There was no significant difference between cSCI and tSCI in the VT or VE during hyperoxia (P = NS). There was no significant correlation between AHI and VE% baseline (r = −0.28) in SCI and AB (n = 30). SCI participants had a greater ventilatory response to an SBCO 2 than AB (0.78 ± 0.42 L/min/mmHg vs. 0.26 ± 0.10 L/min/mmHg, respectively, P < 0.05). Peripheral ventilatory chemoresponsiveness is elevated in individuals with chronic SCI compared to able‐bodied individuals.

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“…Another suggestion has been that the rate of rise of the carotid arterial CO2 stimulus acting either directly via the carotid bodies or during processing of the neural information in the medulla is an important factor (Dutton, Hodson, Davies & Fenner, 1967). Recently, however, several studies have suggested that the timing of the stimulation and neural discharge of the carotid body with relationship to the respiratory cycle is a significant variable.…”

Section: Introductionmentioning

confidence: 99%

“…It has been suggested that the increased effect of oscillating signals might originate at the level of the carotid body itself; that the arterial Pco, crosses a threshold for CO2 stimulation leading to rectification of the signal (Bhattacharyya et al 1970). Another suggestion has been that the rate of rise of the carotid arterial CO2 stimulus acting either directly via the carotid bodies or during processing of the neural information in the medulla is an important factor (Dutton, Hodson, Davies & Fenner, 1967). Recently, however, several studies have suggested that the timing of the stimulation and neural discharge of the carotid body with relationship to the respiratory cycle is a significant variable.…”

Section: Introductionmentioning

confidence: 99%

The importance of timing on the respiratory effects of intermittent carotid sinus nerve stimulation

Eldridge¹

1972

The Journal of Physiology

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Effect of the rate of rise of carotid body Pco2, on the time course of ventilation

Cited by 26 publications

References 16 publications

A Comparison of the Ventilatory Response of Sleeping Newborn Lambs to Step and Progressive Hypoxaemia

A Comparison of the Ventilatory Response of Sleeping Newborn Lambs to Step and Progressive Hypoxaemia

Spinal cord injury is associated with enhanced peripheral chemoreflex sensitivity

The importance of timing on the respiratory effects of intermittent carotid sinus nerve stimulation

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