Reflex Nature of the Cardiorespiratory Response to Primary Thoracic Blast Injury in the Anaesthetised Rat

Ohnishi, Mitsuo; Kirkman, Emrys; Guy, Richard; Watkins, P. E.

doi:10.1113/eph8602145

Cited by 44 publications

(22 citation statements)

References 19 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The change in arterial blood gases after blast and subsequent haemorrhage are consistent with previous studies (Ohnishi et al 2001). Animals subjected to thoracic blast displayed a lower P a, J and arterial pH and higher P a,CO 2 when compared to those subjected to sham blast.…”

Section: Figuresupporting

confidence: 81%

“…Prolonged hypotension induced by thoracic blast per se is accompanied by a bradycardia rather than a tachycardia (Ohnishi et al 2001), as might be expected if the reflex was functioning normally. To date, there are no reported studies of the effects of thoracic blast on the function of the baroreflex.…”

Section: Discussionmentioning

confidence: 84%

“…Animals subjected to thoracic blast displayed a lower P a, J and arterial pH and higher P a,CO 2 when compared to those subjected to sham blast. This alteration in blood gas is unlikely to be because of respiratory depression at this time since previous studies have shown that after a brief blast-induced apnoea respiratory activity returns to normal levels within 5 min (Ohnishi et al 2001). However, the hypoxia and hypercarbia could be consistent with impaired pulmonary gas transport after blast (Damon et al 1971).…”

Section: Figurementioning

confidence: 93%

See 2 more Smart Citations

The Effects of Primary Thoracic Blast Injury and Morphine on the Response to Haemorrhage in the Anaesthetised Rat

Sawdon

Ohnishi

Watkins

et al. 2002

Experimental Physiology

Self Cite

View full text Add to dashboard Cite

Primary thoracic blast injury causes a triad of bradycardia, hypotension and apnoea mediated in part via a vagal reflex. Blast casualties may also suffer blood loss, and the response to progressive simple haemorrhage is biphasic: an initial tachycardia followed by a vagally mediated reflex bradycardia which can be attenuated by μ opioid agonists. The aims of this study were to determine the effects of thoracic blast injury on the response to subsequent haemorrhage, and the effects of morphine, administered after blast, on the response to blood loss. Male Wistar rats, terminally anaesthetised with alphadolone‐alphaxolone (19‐21 mg kg−1 h−1 I.V.), were allocated randomly to one of three groups: Group I, sham blast; Group II, thoracic blast; Group III, thoracic blast plus morphine (0.5 mg kg−1 I.V. given 5 min after blast). Blast (Groups II and III) resulted in significant (P < 0.05, ANOVA) bradycardia, hypotension and apnoea. Sham blast (Group I) had no effect. Ten minutes later, haemorrhage (40% of the estimated total blood volume (BV)) in Group I produced a biphasic response comprising a tachycardia followed by a peak bradycardia after the loss of 33% BV. Arterial blood pressure did not fall significantly until the loss of 13.3% BV. In Group II the haemorrhage‐induced tachycardia was absent and the bradycardia was augmented: peak bradycardia was seen after the loss of 23% BV. Mean arterial blood pressure (MBP) began to fall as soon as haemorrhage commenced and was significant after the loss of 10% BV. Morphine (Group III) prevented the haemorrhage‐induced bradycardia and delayed the significant fall in MBP until the loss of 30% BV. It is concluded that the response to thoracic blast injury augments the depressor response to haemorrhage while morphine attenuates this response.

show abstract

Section: Figuresupporting

confidence: 81%

Section: Discussionmentioning

confidence: 84%

Section: Figurementioning

confidence: 93%

See 1 more Smart Citation

The Effects of Primary Thoracic Blast Injury and Morphine on the Response to Haemorrhage in the Anaesthetised Rat

Sawdon

Ohnishi

Watkins

et al. 2002

Experimental Physiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Studies investigating the subsequent immune response have been reported most commonly in rats [5][6][7][8][9][10] , mice [11][12][13][14][15] and swine 16,17 . These studies have offered overwhelming evidence of the neutrophil response to PBLI in animal models, with increases in circulating and broncho-alveolar lavage fluid (BALF) neutrophils, increases in Myeloperoxidase (MPO) activity in the lung, and neutrophil staining by histology [9][10][11][12]14,18,19 .…”

Section: Introductionmentioning

confidence: 99%

CD43Lo classical monocytes participate in the cellular immune response to isolated primary blast lung injury

Barnett-Vanes

Sharrock

Eftaxiopoulou

et al. 2016

Journal of Trauma and Acute Care Surgery

View full text Add to dashboard Cite

BackgroundExplosive blast trauma occurs by four mechanisms: primary injuries are due to the isolated effect of the blast wave on the human body, secondary injuries are due to damage from fragments energised from the explosion, tertiary injuries result from acceleration of the body against an object or through the explosion energising hard materials in a solid form (not fragments) and encroaching upon the person, and quaternary injuries describe other physical insults, including burns and smoke inhalation 1 .Gas-containing organs such as the lungs are particularly susceptible to barotrauma, and 'Primary Blast Lung Injury' (PBLI) is a commonly reported injury amongst blast casualties. A review of terrorist bombings worldwide found the incidence of PBLI in immediate fatalities to be as high as 47% 2 ; whilst in a review of military blast casualties that survived to emergency admission, PBLI was found in 11.2% of 648 blast casualties. In this series, 16.2% of mounted and 17.1% of dismounted injuries developed PBLI, which was significantly associated with increased mortality 3,4 .Laboratory investigations of PBLI have sought to recapitulate the injury under experimental conditions. Studies investigating the subsequent immune response have been reported most commonly in rats 5-10 , mice [11][12][13][14][15] and swine 16,17 . These studies have offered overwhelming evidence of the neutrophil response to PBLI in animal models, with increases in circulating and broncho-alveolar lavage fluid (BALF) neutrophils, increases in Myeloperoxidase (MPO) activity in the lung, and neutrophil staining by histology [9][10][11][12]14,18,19 . However, the immune response to tissue damage differs depending on the type of organ injured and their local physiology; it remains unclear what specific contribution blast injuries to different parts of the body make to the inflammatory response that ensues. Whilst most clinically blast injured patients are polytraumatised, discerning these interacting immune responses experimentally is necessary for translational studies seeking to better understand, monitor or attenuate the immune response in blast trauma.Further, knowledge of the role played by other immune cells to PBLI is limited -no study has characterised the full repertoire of immune cells in PBLI; specifically, the involvement of monocytes in PBLI remains unclear. These cells are frequently recruited to sites of inflammation; in humans they are characterised by differential CD14 and CD16 expression 20 , in mice by CCR2, CX3CR1 and Ly6C 21,22 and in rats by CD43 alone or in conjunction with His48 23 . In rats, CD43 Hi and Lo monocytes are considered to be analogous to the Ly6C Lo (Non-classical) and Ly6C Hi (Classical) murine monocytes respectively. Classical Ly6C Hi monocytes are recruited to tissues in sterile 24 and infectious 25 models of inflammation. There, they can differentiate into inflammatory macrophages and dendritic cells, amplifying or resolving inflammation. In rats, circulating monocyte subsets are activated by inflammator...

show abstract

“…The bradycardia and apnoea seen after blast are both mediated by a vagal reflex [33][34][35][36]. The aetiology of the hypotension seen after primary blast injury is complex.…”

Section: Physiological Response To Primary Blast Injurymentioning

confidence: 99%

Characterization of the response to primary blast injury

Kirkman

Watts

2011

Phil. Trans. R. Soc. B

Self Cite

View full text Add to dashboard Cite

Lung injuries, predominantly arising from blast exposure, are a clinical problem in a significant minority of current military casualties. This special feature consists of a series of articles on lung injury. This first article examines the mechanism of the response to blast lung (primary blast injury to the lung). Subsequent articles examine the incidence of blast lung, clinical consequences and current concepts of treatment, computer (in silico) modelling of lung injury and finally chemical injuries to the lungs. Blast lung is caused by a shock wave generated by an explosion causing widespread damage in the lungs, leading to intrapulmonary haemorrhage. This, and the ensuing inflammatory response in the lung, leads to a compromise in pulmonary gas exchange and hypoxia that can worsen over several hours. There is also a characteristic cardio-respiratory effect mediated via an autonomic reflex causing apnoea (or rapid shallow breathing), bradycardia and hypotension (the latter possibly also due to the release of nitric oxide). An understanding of this response, and the way it modifies other reflexes, can help the development of new treatment strategies for this condition and for the way it influences the patient's response to concomitant injuries.

show abstract

Reflex Nature of the Cardiorespiratory Response to Primary Thoracic Blast Injury in the Anaesthetised Rat

Cited by 44 publications

References 19 publications

The Effects of Primary Thoracic Blast Injury and Morphine on the Response to Haemorrhage in the Anaesthetised Rat

The Effects of Primary Thoracic Blast Injury and Morphine on the Response to Haemorrhage in the Anaesthetised Rat

CD43Lo classical monocytes participate in the cellular immune response to isolated primary blast lung injury

Characterization of the response to primary blast injury

Contact Info

Product

Resources

About