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Cardiac arrest (CA) remains a major cause of death despite advancements in cardiopulmonary resuscitation (CPR), post-resuscitation care, and international efforts to develop evidence-based guidelines. Effectively managing ventilation and oxygenation during and after CPR is vital for patient survival and neurological outcomes, yet it remains a challenging task. This review examines current strategies for ventilation and oxygenation during and after CPR, focusing on evidence-based guidelines, the balance between ventilation effectiveness and risks, and proposed methods for monitoring ventilation quality. It emphasizes the need to provide adequate ventilation and oxygenation during and after CPR while avoiding hyperventilation and hypoventilation, which can negatively impact resuscitation and post-CA outcomes. The review also explores mechanical ventilation as an alternative to manual methods and the use of feedback devices. The impact of post-CA ventilation and oxygenation on patient outcomes and recommended management strategies are discussed. Finally, the review highlights current gaps in the literature and the need for more well-designed large clinical studies, such as the impact of different ventilation variables (tidal volume and breathing frequency) on the return of spontaneous circulation and long-term outcomes., Competing Interests: Dr Scott discloses relationships with the American Association for Respiratory Care (AARC) and Relias Media. Dr Li discloses relationships with AARC, Fisher & Paykel Healthcare, Aerogen, MEKICS Co, Vincent, the Rice Foundation, and Heyer. Dr Li is a section editor for Respiratory Care. Drs Scott and Li disclose patent applications on a device to monitor and alarm manual ventilation parameters during cardiopulmonary resuscitation (WO2021167870A1; US20230131417A1). Mr Algahtani has disclosed no conflicts of interest., (Copyright © 2024 by Daedalus Enterprises.)

Hyperventilation (HV) therapy uses vasoconstriction to reduce intracranial pressure (ICP) by reducing cerebral blood volume. However, as HV also lowers cerebral blood flow (CBF), it may provoke misery perfusion (MP), in which the decrease in CBF is coupled with increased oxygen extraction fraction (OEF). MP may rapidly lead to the exhaustion of brain energy metabolites, making the brain vulnerable to ischemia. MP is difficult to detect at the bedside, which is where transcranial hybrid, near-infrared spectroscopies are promising because they non-invasively measure OEF and CBF. We have tested this technology during HV (∼30 min) with bilateral, frontal lobe monitoring to assess MP in 27 sessions in 18 patients with traumatic brain injury. In this study, HV did not lead to MP at a group level ( p > 0.05). However, a statistical approach yielded 89 events with a high probability of MP in 19 sessions. We have characterized each statistically significant event in detail and its possible relationship to clinical and radiological status (decompressive craniectomy and presence of a cerebral lesion), without detecting any statistically significant difference ( p > 0.05). However, MP detection stresses the need for personalized, real-time assessment in future clinical trials with HV, in order to provide an optimal evaluation of the risk-benefit balance of HV. Our study provides pilot data demonstrating that bedside transcranial hybrid near-infrared spectroscopies could be utilized to assess potential MP.

A head-space gas chromatographic method for the determination of carbon tetrachloride in human blood is described. Standard samples with 0.5 ml whole blood containing different concentrations of CCl4 were analyzed at column temperatures ranging from 50 degrees to 90 degrees C. Advantages of this method include high sensitivity, simplicity in handling, rapid achievement of reliable results, accuracy and low costs. The practicability of this analytical method was studied in a patient following suicidal oral ingestion of a lethal dose of carbon tetrachloride. [ABSTRACT FROM AUTHOR]

To study under standardized experimental conditions the effect of a CO2-induced hyperventilation therapy on carbon tetrachloride (CCl4) levels following acute CCl4 poisoning, rats received 2.5 ml CCl4/kg BW by gastric intubation and were subsequently either treated by CO2-induced hyperventilation or kept in an atmosphere containing air. Peak levels of CCl4 were observed in the fat, liver and blood 3-6 h after the intoxication and were found to be considerably lower in animals treated by CO2-induced hyperventilation compared to their respective controls. These data therefore strongly support the efficacy of the CO2-induced hyperventilation therapy for CCl4 intoxication. [ABSTRACT FROM AUTHOR]

Background: The hyperventilation syndrome (HVS) is characterized by somatic/ psychological symptoms due to sustained hypocapnia and respiratory alkalosis without any organic disease., Objective: The purpose of this study was to compare ventilatory parameters and symptoms reproducibility during the hyperventilation provocation test (HVPT) and cardiopulmonary exercise test (CPET) as diagnostic tools in patients with HVS, and to identify the most frequent etiologies of the HVS by a systematic assessment., Methods: After exclusion of organic causes, 59 patients with HVS according to Nijmegen's questionnaire (NQ) score ≥23 with associated hypocapnia (PaCO 2 /PET CO2 <35 mm Hg) were studied., Results: The most frequent comorbidities of HVS were anxiety and asthma (respectively 95% and 73% of patients). All patients described ≥3 symptoms of NQ during the HVPT vs 14% of patients during the CPET (p<0.01). For similar maximal ventilation (61 L/min during HVPT vs 60 L/min during CPET), the median level of PET CO2  decreased from 30 mmHg at baseline to 15 mmHg during hyperventilation and increased from 31 mmHg at baseline to 34 mmHg at peak exercise (all p<0.01). No significant difference for the ventilatory parameters was found between patients with HVS (n = 16) and patients with HVS + asthma (n = 43)., Conclusions: In term of symptoms reproducibility, HVPT is a better diagnostic tool than CPET for HVS. An important proportion of patients with HVS has an atypical asthma previously misdiagnosed. The exercise-induced hyperventilation did not induce abnormal reduction in PET CO2 , suggesting that the exercise could be a therapeutic tool in HVS., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Psychophysiological theories postulate respiratory dysregulation as a mechanism contributing to panic disorder (PD). Additionally, symptomatic and respiratory recovery from voluntary hyperventilation (HVT-recovery) have been shown to lag in PD and it is unclear if HVT-recovery normalizes with treatment. Thirty-seven panic disorder patients were randomized to hypoventilation therapy (TX, n = 20) or waitlist control (WL, n = 17) (Meuret et al., 2008). In a secondary analysis, their HVT-recovery was analyzed at pre- and post-TX/WL, compared to 29 healthy controls (HC). HVT included three phases: 5-min baseline, 3-min hyperventilation, and 8-min recovery. HVT-elicited symptom severity and anxiety were rated following each phase, and end-tidal PCO 2 and respiratory rate (RR) were recorded throughout. Treatment, compared to WL, was highly effective in reducing PD pathology (d=2.21, Meuret et al., 2008). At pre-TX/WL, PD demonstrated delayed HVT-recovery PCO 2 and higher RR. Treated patients demonstrated normalization of HVT-recovery for PCO 2 and RR; however, improvements of HVT-recovery for symptom severity and anxiety did not differ between TX and WL. Results replicate pretreatment HVT respiratory recovery abnormalities in PD and further demonstrate normalization, comparable to HC, following successful treatment. The results provide support for respiratory dysregulation as a feature of PD and demonstrate the utility of HVT respiratory recovery as treatment outcome measure for respiration-based PD therapy., (Copyright © 2020. Published by Elsevier Ltd.)

Postural orthostatic tachycardia syndrome (POTS) is a chronic, multifactorial syndrome with complex symptoms of orthostatic intolerance. Breathlessness is a prevalent symptom, however little is known about the aetiology. Anecdotal evidence suggests that breathless POTS patients commonly demonstrate dysfunctional breathing/hyperventilation syndrome (DB/HVS). There are, however, no published data regarding DB/HVS in POTS, and whether physiotherapy/breathing retraining may improve patients' breathing pattern and symptoms. The aim of this study was to explore the potential impact of a physiotherapy intervention involving education and breathing control on DB/HVS in POTS. A retrospective observational cohort study of all patients with POTS referred to respiratory physiotherapy for treatment of DB/HVS over a 20-month period was undertaken. 100 patients (99 female, mean (standard deviation) age 31 (12) years) with a clinical diagnosis of DB/HV were referred, of which data was available for 66 patients pre - post intervention. Significant improvements in Nijmegen score, respiratory rate and breath hold time (seconds) were observed following treatment. These data provide a testable hypothesis that breathing retraining may provide breathless POTS patients with some symptomatic relief, thus improving their health-related quality of life. The intervention can be easily protocolised to ensure treatment fidelity. Our preliminary findings provide a platform for a subsequent randomised controlled trial of breathing retraining in POTS., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: To determine whether acupuncture at GB34 affects cerebral blood flow (CBF) via the anterior cerebral arteries (ACAs) and middle cerebral arteries (MCAs)., Methods: This study included 10 healthy young male volunteers. CBF velocity and cerebrovascular reactivity (CVR) were measured using transcranial Doppler sonography (TCD). The changes in hyperventilation-induced carbon dioxide (CO 2 ) reactivity and modified blood flow velocity at 40 mm Hg (CV40) were observed for both ACAs and MCAs before and after GB34 acupuncture treatment. Blood pressure and heart rate were also measured before and after GB34 acupuncture treatment., Results: The CO 2 reactivity of the ipsilateral MCA significantly increased after GB34 acupuncture treatment, compared with that at baseline (P=0.007). In contrast, the CO 2 reactivity of both ACAs and the contralateral MCA remained unchanged. The CV40 of both ACAs and MCAs did not change after GB34 acupuncture treatment and neither did the mean arterial blood pressure and heart rate., Conclusions: GB34 acupuncture treatment increased CO 2 reactivity specifically in the ipsilateral MCA, but had no effect on either the ACAs or the contralateral MCA. These data suggest that GB34 acupuncture treatment improves the vasodilatory potential of the cerebral vasculature to compensate for fluctuations caused by changes in external conditions and could potentially be useful for the treatment of disorders of the ipsilateral MCA circulation.

Poor distress tolerance (DT) is considered an underlying facet of anxiety, depression, and a number of other psychological disorders. Mindfulness may help to increase DT by fostering an attitude of acceptance or nonjudgment toward distressing experiences. Accordingly, the present study examined the effects of a brief mindfulness training on tolerance of different types of distress, and tested whether trait mindfulness moderates the effect of such training. Undergraduates (n = 107) naïve to mindfulness completed a measure of trait mindfulness and underwent a series of stress tasks (cold pressor, hyperventilation challenge, neutralization task) before and after completing a 15-minute mindfulness training or a no-instruction control in which participants listened to relaxing music. Participants in the mindfulness condition demonstrated greater task persistence on the hyperventilation task compared to the control group, as well as a decreased urge to neutralize the effects of writing an upsetting sentence. No effect on distress ratings during the tasks were found. Overall trait mindfulness did not significantly moderate task persistence, but those with lower scores on the act with awareness facet of mindfulness demonstrated greater relative benefit of mindfulness training on the hyperventilation challenge. Mediation analyses revealed significant indirect effects of mindfulness training on cold pressor task persistence and urges to neutralize through the use of the nonjudge and nonreact facets of mindfulness. These results suggest that a brief mindfulness training can increase DT without affecting the subjective experience of distress., (Copyright © 2018. Published by Elsevier Ltd.)

Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder characterized by intellectual disability, specific facial features, and marked autonomic nervous system dysfunction, especially with disturbances of regulating respiration and intestinal mobility. It is caused by variants in the transcription factor TCF4. Heterogeneity in the clinical and molecular diagnostic criteria and care practices has prompted a group of international experts to establish guidelines for diagnostics and care. For issues, for which there was limited information available in international literature, we collaborated with national support groups and the participants of a syndrome specific international conference to obtain further information. Here, we discuss the resultant consensus, including the clinical definition of PTHS and a molecular diagnostic pathway. Recommendations for managing particular health problems such as dysregulated respiration are provided. We emphasize the need for integration of care for physical and behavioral issues. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimization of diagnostics and care., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Previous research has shown that hypoventilation therapy reduces panic symptoms in part by increasing basal partial pressure of carbon dioxide (PCO 2 ) levels. We tested an additional pathway by which hypoventilation therapy could exert its therapeutic effects: through repeated interoceptive exposure to sensations of dyspnea., Methods: A total of 35 patients with panic disorder were trained to perform exercises to raise their end-tidal PCO 2 levels using a portable capnometry device. Anxiety, dyspnea, end-tidal PCO 2 , and respiratory rate were assessed during each exercise across 4 weeks of training. Mixed-model analysis examined whether within-exercise levels of dyspnea were predictive of reduction of panicogenic cognitions., Results: As expected, within-exercise anxiety and respiratory rate decreased over time. Unexpectedly, PCO 2 dropped significantly from the beginning to the end of exercise, with these drops becoming progressively smaller across weeks. Dyspnea increased and remained consistently above basal levels across weeks. As hypothesized, greater dyspnea was related to significantly lower panicogenic cognitions over time even after controlling for anxiety and PCO 2 . Additional exploratory analyses showed that within-exercise increases in dyspnea were related to within-exercise increases in anxiety but were not related to within-exercise increases in PCO 2 ., Conclusions: In support of the interoceptive exposure model, we found that greater dyspnea during hypoventilation exercises resulted in lower panicogenic cognitions even after the effect of PCO 2 was taken into account. The findings offer an additional important target in panic treatment., (Copyright © 2018 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Pitt-Hopkins syndrome (PTHS) is a rare, genetic disorder caused by a molecular variant of TCF4 which is involved in embryologic neuronal differentiation. PTHS is characterized by syndromic facies, psychomotor delay, and intellectual disability. Other associated features include early-onset myopia, seizures, constipation, and hyperventilation-apneic spells. Many also meet criteria for autism spectrum disorder. Here the authors present a series of 23 PTHS patients with molecularly confirmed TCF4 variants and describe 3 unique individuals. The first carries a small deletion but does not exhibit the typical facial features nor the typical pattern of developmental delay. The second exhibits typical facial features, but has attained more advanced motor and verbal skills than other reported cases to date. The third displays typical features of PTHS, however inherited a large chromosomal duplication involving TCF4 from his unaffected father with somatic mosaicism. To the authors' knowledge, this is the first chromosomal duplication case reported to date.

Objective: The objective of this study was to investigate if a breathing technique could counteract the effects of hyperventilation due to a sustained attention task on shoulder muscle activity., Background: The trend towards higher levels of automation in industry is increasing. Consequently, manufacturing operators often monitor automated process for long periods of their work shift. Prolonged monitoring work requires sustained attention, which is a cognitive process that humans are typically poor at and find stressful. As sustained attention becomes an increasing requirement of manufacturing operators' job content, the resulting stress experienced could contribute to the onset of many health problems, including work related musculoskeletal disorders (WRMSDs)., Methods: The SART attention test was completed by a group of participants before and after a breathing intervention exercise. The effects of the abdominal breathing intervention on breathing rate, upper trapezius muscle activity and end-tidal CO₂ were evaluated., Results: The breathing intervention reduced the moderation effect of end-tidal CO₂ on upper trapezius muscle activity., Conclusions: Abdominal breathing could be a useful technique in reducing the effects of sustained attention work on muscular activity., Application: This research can be applied to highly-automated manufacturing industries, where prolonged monitoring of work is widespread and could, in its role as a stressor, be a potential contributor to WRMSDs., Competing Interests: The authors declare no conflict of interest.

Introduction: HIV infection is often preceded or accompanied by psychiatric comorbidities. These disorders improve with complementary therapies. The aim of this study was to measure the effect of massage therapy on anxiety, depression, hyperventilation and quality of life in HIV infected patients., Method: Adult HIV-infected patients were randomized (n=29) in massage therapy group (one hour a week during four weeks) and control group. Anxiety and depression (HADS-A and HADS-D), hyperventilation (Nijmegen questionnaire) and quality of life (WHOQOL-HIV) were evaluated at inclusion and after 4 weeks., Results: At inclusion, 51% and 17% of the patients had a positive HADS-A and HADS-D score respectively. Two facets from WHOQOL-HIV ("Home environment" and "Death and dying" (p=0.04)) were different between groups. After the four week massage therapy, a significant improvement was observed only for Nijmegen questionnaire (p=0.01) and HADS-A (p=0.04) contrarily to WHOQOL-HIV and HADS-D. Domains of the WHOQOL-HIV did not improve following the massage therapy. Only "Pain and discomfort" facet improved after massage therapy (p=0.04)., Conclusion: This study highlights the positive impact of a four week massage therapy on anxiety and hyperventilation in HIV infected patients. However, neither benefit of this program was observed on depression and quality of life., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The hyperventilation syndrome is a complex entity whose management is poorly codified. We report a synthesis about the management of adult patients diagnosed with hyperventilation syndrome. A systematic literature review has identified fifteen articles dealing, among them three studies about drug treatment and the others about non-pharmacological approaches. Among the last ones, a re-educational approach based on abdominal ventilation and regulation of the ventilatory rate seems and an educative approach seems to be the most effective. Methodological biases did not permit a conclusion on the efficacy of these treatments. Practically, teaching abdominal ventilation and respiratory rate regulation, associated with a personalized therapeutic education, seems to be a pertinent management approach. Other clinical studies should explore this issue., (Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.)

A 56-year-old white woman was referred to the pulmonary clinic for evaluation of unexplained shortness of breath. She enjoyed good health until 3 months prior to this visit when she reported experiencing recurrent episodes of shortness of breath and oppressive retrosternal chest discomfort with radiation to the neck. Episodes lasting 5 to 10 min often occurred at rest and were inconsistently related to physical activity. These symptoms became progressively worse and were often associated with light-headedness and presyncope. Her past medical history was uneventful apart from a prior diagnosis of breast cysts and suspected prolactinoma. Her symptoms escalated to such a level that she was forced to seek urgent medical attention at our institutional ED on two separate occasions in the preceding weeks. These visits precipitated a number of investigations and, eventually, a referral to the pulmonary clinic., (Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Objective: Meeting the complex needs of patients with chronic common mental health disorders (CMHDs) may be the greatest challenge facing organized medical practice. On the basis of a well-established and proven theoretical foundation for controlled respiration as a behavioral intervention for CMHDs, as well as preliminary evidence that gamification can improve health outcomes through increasing patient engagement, this randomized controlled pilot study evaluated the feasibility and clinical efficacy of a mobile health game called "Flowy" ( www.flowygame.com ) that digitally delivered breathing retraining exercises for anxiety, panic, and hyperventilation symptom management., Materials and Methods: We designed an unblinded, Web-based, parallel-group randomized controlled trial focusing on feasibility, clinical efficacy, and design proof of concept. In the intervention condition (n = 31), participants received free access to "Flowy" for 4 weeks. In the control condition (n = 32), participants were placed on a waitlist for 4 weeks before being offered free access to "Flowy." Online measurements using psychological self-report questionnaires were made at 2 and 4 weeks post-baseline., Results: At trial conclusion, participants found "Flowy" acceptable as an anxiety management intervention. "Flowy" engaged participants sufficiently to endorse proactive gameplay. Intent-to-treat analysis revealed a reduction in anxiety, panic, and self-report hyperventilation scores in both trial arms, with the intervention arm experiencing greater quality of life. Participants perceived "Flowy" as a fun and useful intervention, proactively used "Flowy" as part of their care, and would recommend "Flowy" to family and friends., Conclusions: Our results suggest that a digital delivery of breathing retraining exercises through a mobile health game can manage anxiety, panic, and hyperventilation symptoms associated with CMHDs.

Heat-induced hyperventilation may reduce PaCO2 and thereby cerebral perfusion and oxygenation and in turn exercise performance. To test this hypothesis, eight volunteers completed three incremental exercise tests to exhaustion: (a) 18 °C ambient temperature (CON); (b) 38 °C (HEAT); and (c) 38 °C with addition of CO2 to inspiration to prevent the hyperventilation-induced reduction in PaCO2 (HEAT + CO2 ). In HEAT and HEAT + CO2 , rectal temperature was elevated prior to the exercise tests by means of hot water submersion and was higher (P < 0.05) than in CON. Compared with CON, ventilation was elevated (P < 0.01), and hence, PaCO2 reduced in HEAT. This caused a reduction (P < 0.05) in mean cerebral artery velocity (MCAvmean ) from 68.6 ± 15.5 to 53.9 ± 10.0 cm/s, which was completely restored in HEAT + CO2 (68.8 ± 5.8 cm/s). Cerebral oxygenation followed a similar pattern. V ˙ O 2   m a x was 4.6 ± 0.1 L/min in CON and decreased (P < 0.05) to 4.1 ± 0.2 L/min in HEAT and remained reduced in HEAT + CO2 (4.1 ± 0.2 L/min). Despite normalization of MCAvmean and cerebral oxygenation in HEAT + CO2 , this did not improve exercise performance, and thus, the reduced MCAvmean in HEAT does not seem to limit exercise performance., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Aims: More than 18,000 patients need medical emergencies management in dental offices in Iran annually. The present study investigates medical emergencies management among Iranian dentists., Materials and Methods: From the list of the cell phone numbers of the dentists practicing in the city of Tehran, 210 dentists were selected randomly. A self-administered questionnaire was used as the data collection instrument. The questionnaire requested information on personal and professional characteristics of the dentists, as well as their knowledge and self-reported practice in the field of medical emergency management, and availability of required drugs and equipments to manage medical emergencies in their offices., Results: Totally, 177 dentists (84%) completed the questionnaire. Less than 60% of the participants were knowledgeable about characteristics of hypoglycemic patient, chest pain with cardiac origin, and true cardiopulmonary resuscitation (CPR) practice. Regarding practice, less than one quarter of the respondents acquired acceptable scores. In regression models, higher practice scores were significantly associated with higher knowledge scores (p < 0.001)., Conclusion: The results call for a need to further education on the subject for dentists. Continuing education and changing dental curriculum in the various forms seems to be useful in enhancement of the self-reported knowledge and practice of dentists., Clinical Significance: To successful control of medical emergencies in the dental office, dentists must be prepared to recognize and manage a variety of such conditions. In addition to dentist's knowledge and skill, availability of necessary equipments and trained staff is also of critical importance.

In this paper, the actions needed to manage specific medical emergencies are discussed. Each emergency requires a correct diagnosis to be made for effective and safe management. Contemporary management in dental practice avoids the intravenous route when drugs are required to treat the emergency.

Traumatic brain injury (TBI) exacts a great toll on society. Fortunately, there is growing evidence that the management of TBI in the early minutes after injury may significantly reduce morbidity and mortality. In response, evidence-based prehospital and in-hospital TBI treatment guidelines have been established by authoritative bodies. However, no large studies have yet evaluated the effectiveness of implementing these guidelines in the prehospital setting. This article describes the background, design, implementation, emergency medical services (EMS) treatment protocols, and statistical analysis of a prospective, controlled (before/after), statewide study designed to evaluate the effect of implementing the EMS TBI guidelines-the Excellence in Prehospital Injury Care (EPIC) study (NIH/NINDS R01NS071049, "EPIC"; and 3R01NS071049-S1, "EPIC4Kids"). The specific aim of the study is to test the hypothesis that statewide implementation of the international adult and pediatric EMS TBI guidelines will significantly reduce mortality and improve nonmortality outcomes in patients with moderate or severe TBI. Furthermore, it will specifically evaluate the effect of guideline implementation on outcomes in the subgroup of patients who are intubated in the field. Over the course of the entire study (~9 years), it is estimated that approximately 25,000 patients will be enrolled., (© 2014 by the Society for Academic Emergency Medicine.)

Background: Lactic acidosis is associated with cardiovascular failure. Buffering with sodium bicarbonate is proposed in severe lactic acidosis. Bicarbonate induces carbon dioxide generation and hypocalcemia, both cardiovascular depressant factors. The authors thus investigated the cardiovascular and metabolic effects of an adapted sodium bicarbonate therapy, including prevention of carbon dioxide increase with hyperventilation and ionized calcium decrease with calcium administration., Methods: Lactic acidosis was induced by hemorrhagic shock. Twenty animals were randomized into five groups: (1) standard resuscitation with blood retransfusion and norepinephrine (2) adapted sodium bicarbonate therapy (3) nonadapted sodium bicarbonate therapy (4) standard resuscitation plus calcium administration (5) hyperventilation. Evaluation was focused in vivo on extracellular pH, on intracellular pH estimated by P nuclear magnetic resonance and on myocardial contractility by conductance catheter. Aortic rings and mesenteric arteries were isolated and mounted in a myograph, after which arterial contractility was measured., Results: All animals in the hyperventilation group died prematurely and were not included in the statistical analysis. When compared with sham rats, shock induced extracellular (median, 7.13; interquartile range, [0.10] vs. 7.30 [0.01]; P = 0.0007) and intracellular acidosis (7.26 [0.18] vs. 7.05 [0.13]; P = 0.0001), hyperlactatemia (7.30 [0.01] vs. 7.13 [0.10]; P = 0.0008), depressed myocardial elastance (2.87 [1.31] vs. 0.5 [0.53] mmHg/μl; P = 0.0001), and vascular hyporesponsiveness to vasoconstrictors. Compared with nonadapted therapy, adapted bicarbonate therapy normalized extracellular pH (7.03 [0.12] vs. 7.36 [0.04]; P < 0.05), increased intracellular pH to supraphysiological values, improved myocardial elastance (1.68 [0.41] vs. 0.72 [0.44] mmHg/μl; P < 0.05), and improved aortic and mesenteric vasoreactivity., Conclusions: A therapeutic strategy based on alkalinization with sodium bicarbonate along with hyperventilation and calcium administration increases pH and improves cardiovascular function.

Background: Dysfunctional breathing is described as chronic or recurrent changes in breathing pattern causing respiratory and non-respiratory symptoms. It is an umbrella term that encompasses hyperventilation syndrome and vocal cord dysfunction. Dysfunctional breathing affects 10% of the general population. Symptoms include dyspnoea, chest tightness, sighing and chest pain which arise secondary to alterations in respiratory pattern and rate. Little is known about dysfunctional breathing in children. Preliminary data suggest 5.3% or more of children with asthma have dysfunctional breathing and that, unlike in adults, it is associated with poorer asthma control. It is not known what proportion of the general paediatric population is affected. Breathing training is recommended as a first-line treatment for adults with dysfunctional breathing (with or without asthma) but no similar recommendations are available for the management of children. As such, breathing retraining is adapted from adult regimens based on the age and ability of the child., Objectives: To determine whether breathing retraining in children with dysfunctional breathing has beneficial effects as measured by quality of life indices.To determine whether there are any adverse effects of breathing retraining in young people with dysfunctional breathing., Search Methods: We identified trials for consideration using both electronic and manual search strategies. We searched CENTRAL, MEDLINE and EMBASE. We searched the National Research Register (NRR) Archive, Health Services Research Projects in Progress (HSRProj), Current Controlled Trials register (incorporating the metaRegister of Controlled Trials and the International Standard Randomised Controlled Trial Number (ISRCTN) to identify research in progress and unpublished research. The latest search was undertaken in October 2013., Selection Criteria: We planned to include randomised, quasi-randomised or cluster-randomised controlled trials. We excluded observational studies, case studies and studies utilising a cross-over design. The cross-over design was considered inappropriate due to the purported long-lasting effects of breathing retraining. Children up to the age of 18 years with a clinical diagnosis of dysfunctional breathing were eligible for inclusion. We planned to include children with a primary diagnosis of asthma with the intention of undertaking a subgroup analysis. Children with symptoms secondary to cardiac or metabolic disease were excluded.We considered any type of breathing retraining exercise for inclusion in this review, such as breathing control, diaphragmatic breathing, yoga breathing, Buteyko breathing, biofeedback-guided breathing modification and yawn/sigh suppression. We considered programmes where exercises were either supervised (by parents or a health professional, or both) or unsupervised. We also considered relaxation techniques and acute episode management as long as it was clear that breathing exercises were a component of the intervention.Any intervention without breathing exercises or where breathing exercises were not key to the intervention were excluded., Data Collection and Analysis: We planned that two authors (NJB and MJ) would extract data independently using a standardised form. Any discrepancies would be resolved by consensus. Where agreement could not be reached a third review author (MLE) would have considered the paper., Main Results: We identified 264 potential trials and reviews from the search. Following removal of duplicates, we screened 224 papers based on title and abstract. We retrieved six full-text papers and further evaluated them but they did not meet the inclusion criteria. There were, therefore, no studies suitable for inclusion in this review., Authors' Conclusions: The results of this systematic review cannot inform clinical practice as no suitable trials were identified for inclusion. Therefore, it is currently unknown whether these interventions offer any added value in this patient group or whether specific types of breathing exercise demonstrate superiority over others. Given that breathing exercises are frequently used to treat dysfunctional breathing/hyperventilation syndrome, there is an urgent need for well-designed clinical trials in this area. Future trials should conform to the CONSORT statement for standards of reporting and use validated outcome measures. Trial reports should also ensure full disclosure of data for all important clinical outcomes.

Introduction: Chronic idiopathic hyperventilation (CIH) is a form of dysfunctional breathing that has proven hard to treat effectively., Objectives: To perform a preliminary test of the hypothesis that by periodically inducing normocapnia over several weeks, it would be possible to raise the normal resting level of CO2 and achieve a reduction of symptoms., Methods: Six CIH patients were treated 2 h a day for 4 weeks with a novel breathing mask. The mask was used to induce normocapnia in these chronically hypocapnic patients. Capillary blood gases and acid/base parameters [capillary CO2 tension (PcapCO2 ), pH, and standard base excess (SBE)] were measured at baseline and once each week at least 3 h after mask use, as well as spirometric values, breath-holding tolerance and hyperventilation symptoms as per the Nijmegen Questionnaire (NQ)., Results: The mask treatment resulted in a significant increase of resting PcapCO2 (+0.45 kPa, P = 0.028), a moderate increase in SBE (+1.4 mEq/L, P = 0.035) and a small reduction in daily symptoms (-3.8 NQ units, P = 0.046). The effect was most pronounced in the first 2 weeks of treatment., Conclusion: By inducing normocapnia with the breathing mask 2 h a day for 4 weeks, the normal resting CO2 and acid/base levels in chronically hyperventilating patients were partially corrected, and symptoms were reduced., (© 2013 John Wiley & Sons Ltd.)

Background: Dysfunctional breathing/hyperventilation syndrome (DB/HVS) is a respiratory disorder, psychologically or physiologically based, involving breathing too deeply and/or too rapidly (hyperventilation) or erratic breathing interspersed with breath-holding or sighing (DB). DB/HVS can result in significant patient morbidity and an array of symptoms including breathlessness, chest tightness, dizziness, tremor and paraesthesia. DB/HVS has an estimated prevalence of 9.5% in the general adult population, however, there is little consensus regarding the most effective management of this patient group., Objectives: (1) To determine whether breathing exercises in patients with DB/HVS have beneficial effects as measured by quality of life indices (2) To determine whether there are any adverse effects of breathing exercises in patients with DB/HVS SEARCH METHODS: We identified trials for consideration using both electronic and manual search strategies. We searched CENTRAL, MEDLINE, EMBASE, and four other databases. The latest search was in February 2013., Selection Criteria: We planned to include randomised, quasi-randomised or cluster randomised controlled trials (RCTs) in which breathing exercises, or a combined intervention including breathing exercises as a key component, were compared with either no treatment or another therapy that did not include breathing exercises in patients with DB/HVS. Observational studies, case studies and studies utilising a cross-over design were not eligible for inclusion.We considered any type of breathing exercise for inclusion in this review, such as breathing control, diaphragmatic breathing, yoga breathing, Buteyko breathing, biofeedback-guided breathing modification, yawn/sigh suppression. Programs where exercises were either supervised or unsupervised were eligible as were relaxation techniques and acute-episode management, as long as it was clear that breathing exercises were a key component of the intervention.We excluded any intervention without breathing exercises or where breathing exercises were not key to the intervention., Data Collection and Analysis: Two review authors independently checked search results for eligible studies, assessed all studies that appeared to meet the selection criteria and extracted data. We used standard procedures recommended by The Cochrane Collaboration., Main Results: We included a single RCT assessed at unclear risk of bias, which compared relaxation therapy (n = 15) versus relaxation therapy and breathing exercises (n = 15) and a no therapy control group (n = 15).Quality of life was not an outcome measure in this RCT, and no numerical data or statistical analysis were presented in this paper. A significant reduction in the frequency and severity of hyperventilation attacks in the breathing exercise group compared with the control group was reported. In addition, a significant difference in frequency and severity of hyperventilation attacks between the breathing and relaxation group was reported. However, no information could be extracted from the paper regarding the size of the treatment effects., Authors' Conclusions: The results of this systematic review are unable to inform clinical practice, based on the inclusion of only one small, poorly reported RCT. There is no credible evidence regarding the effectiveness of breathing exercises for the clinical symptoms of DB/HVS. It is currently unknown whether these interventions offer any added value in this patient group or whether specific types of breathing exercise demonstrate superiority over others. Given that breathing exercises are frequently used to treat DB/HVS, there is an urgent need for further well designed clinical trials in this area. Future trials should conform to the CONSORT statement for standards of reporting and use appropriate, validated outcome measures. Trial reports should also ensure full disclosure of data for all important clinical outcomes.

It remains unclear if diminished high frequency heart rate variability (HF-HRV) can be found across anxiety disorders. HF-HRV and heart rate (HR) were examined in panic (PD), generalized anxiety (GAD), social anxiety (SAD), and obsessive-compulsive disorder (OCD) relative to healthy controls at baseline and during anxiety stressors. All disorders evidenced diminished baseline HF-HRV relative to controls. Baseline HRV differences were maintained throughout relaxation. For hyperventilation, PD and GAD demonstrated greater HR than controls. Psychotropic medication did not account for HF-HRV differences except in OCD. Age and sex evidenced multiple main effects. Findings suggest that low baseline HF-HRV represents a common index for inhibitory deficits across PD, GAD, and SAD, which is consistent with the notion of autonomic inflexibility in anxiety disorders. Elevated HR responses to hyperventilation, however, are specific to PD and GAD., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Head injury is a common condition with a high morbidity and mortality. Serious intracranial haematomas require early recognition and evacuation to maximise chances of independent outcomes. Recent organisational changes have promoted the development of trauma units and major trauma centres where patients can go through triage and be managed in an appropriate environment, and the development of management pathways in intensive treatment units has resulted in improvements in the outcome of traumatic brain injuries. Evidence for the treatment of cerebral perfusion pressure, and management of hyperventilation, osmotherapy, tracheostomy, and leakage of cerebrospinal fluid (CSF) has accumulated during the last decade and is important in the management of patients in all clinical settings. Since head injury is commonly associated with maxillofacial injuries, this review will be relevant to all who deal with this aspect of trauma., (Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)