Respiratory Parameters In Patients Research Articles

Effect of Early ≤ 3 Mets (Metabolic Equivalent of Tasks) of Physical Activity on Patient's Outcome after Cardiac Surgery.

To determine the effect of <3 Mets (Metabolic Equivalent of Tasks) of physical activity on zero postoperative days for improving hemodynamic and respiratory parameters of patients after cardiac surgeries. Randomized control trial. BARMWTHospital, Rawalpindi, from March to August 2015. Arandomized controlled trial was conducted on 174 CABG and valvular heart disease patients undergoing cardiac surgical procedures. After selection of sample via non-probability purposive sampling, they were randomly allocated into interventional group (n=87) and control group (n=87). Treatment protocol for experimental group was ≤3 Mets of physical activity, i.e. chest physiotherapy, sitting over edge of bed, standing and sitting on chair at bedside, on zero postoperative day but the control group was treated with conventional treatment on first postoperative day. Pre- and post-treatment assessment was done in control and interventional groups on both zero and first postoperative days. Data was analyzed on SPSS version 21. The patients' mean age was 51.86 ±13.76 years. Male to female ratio was 132:42. Statistically significant differences in respiratory rate and SpO2 (p=0.000 and 0.000, respectively) were found between both groups. Among ABG's, PCO2 and pH showed significant differences with p values of 0.039 and <0.001, respectively. No significant differences were observed between both groups regarding electrolytes (Na+, K+, Cl-, p-values of 0.361, 0.575 and 0.120 respectively) and creatinine (p=0.783). Marked improvement in oxygen saturation, dyspnea and a fall in systolic BPwas seen in interventional group. There was also observed to be a reduction in the length of ICU stay among interventional group patients as frequency with percentage of total stay was compared to control group. Early physical activity (≤3 METS) post-cardiac surgeries prevent respiratory complications through improvement in dyspnea, respiratory rate, and oxygen saturation.

The Association Between Neck Pain and Pulmonary Function: A Systematic Review.

The aim of this study was to systematically review the evidence on respiratory function changes in patients with chronic neck pain. MEDLINE, Elsevier, ProQuest, PubMed, Scopus, Springer, and Google scholar electronic databases were explored thorough December 2015. English-language studies investigating cervical musculoskeletal and respiratory parameters in patients with chronic neck pain were included. Characteristics of the patients, sampling method and size, musculoskeletal and respiratory parameters studied, and appropriateness of the statistical tests were considered. Studies were rated based on study design and performance. Of the 68 studies reviewed, 9 observational studies met our inclusion criteria. Significant difference in maximum inspiratory and expiratory pressures were reported in patients with chronic neck pain compared to asymptomatic subjects. Some of the respiratory volumes were found to be lower in patients with chronic neck pain. Muscle strength and endurance, cervical range of motion, and psychological states were found to be significantly correlated with respiratory parameters. Lower Pco2 in patients and significant relationship between chest expansion and neck pain were also shown. Respiratory retraining was found to be effective in improving some cervical musculoskeletal and respiratory impairment. Functional pulmonary impairments accompany chronic neck pain. Based on the observed association, investigation of the effectiveness of management of CNP on respiratory function is strongly suggested.

Association between intracardiac hemodynamics and respiratory function in patients with coronary artery disease and respiratory comorbidity

The aim of this study was to investigate a relationship between the myocardial structure and function and respiratory parameters in patients with coronary artery disease (CAD) and respiratory disease.Methods. We performed spirometry, body plethysmography, lung diffusing capacity test and measured the left ventricle (LV) systolic and diastolic function in patients with CAD with or without respiratory diseases and ventilation disorders.Results. Patients with CAD (n = 662) participated in the study. The LV systolic dysfunction was found only in 60 patients (9.1%), while diastolic dysfunction was found in 387 patients with CAD (58.4%). Most patients with obstructive ventilation disorders had the systolic or diastolic LV dysfunction (40 patients (66.7%) and 197 patients (79.4%), respectively). Flow and volume lung function parameters and the lung diffusing capacity were associated with some echocardiographic and pulsed wave Doppler parameters.Conclusion. Comorbidity of CAD and lung obstructive disease was associated with more frequent systolic and diastolic LV dysfunction. The relationship between respiratory and cardiac parameters could indicate the cross impact that could deteriorate the course of both the diseases.

Chronic obstructive pulmonary disease and comorbid hypertension: assessment of systemic inflammation and endothelial dysfunction

This study was aimed at determination relationships between systemic inflammation and endothelial dysfunction biomarkers and different cardiovascular and respiratory parameters in patients with chronic obstructive pulmonary disease (COPD) and comorbid hypertension. Methods . Sixty five patients (50 males, 15 females) with stage 1–4 COPD and hypertension of different severity were involved in the study. Results. High levels of inflammation and endothelial dysfunction biomarkers (hsCRP, sICAM1, endothelin1, and sPselectin) were found in patients with COPD and hyper tension. Statistically significant relationships were found between inflammatory biomarkers and endothelial dysfunction biomarkers and between biomarkers and different cardiovascular and respiratory parameters in patients with COPD and comorbid hypertension. Conclusion . Inflammation and endothelial dysfunction biomarker levels change according to increasing in systemic arterial pressure and worsening of bronchial obstruction. This relationship should be considered while examining patients with COPD and comorbid hypertension.

Effect of Endotracheal Suctioning with and without Normal Saline on Hemodynamic and Respiratory Parameters in Patients Undergoing Mechanical Ventilation in ICU of Hospitals Supervised by Guilan University of Medical Sciences

Airway suction is one of the most popular methods for drainage airways in patients with artificial airway; thus, correct suction of airways is important. Hence, the purpose of this study is to determine the effects of suction methods with and without normal saline on hemodynamic and respiratory patients. This randomized crossover clinical trial was conducted on two groups consisting of 37 mechanically ventilated patients by suctioning with and without normal saline. After at least 2 hours, the second stage was conducted and the patients were displaced in groups A and B. respiratory and hemodynamic parameters were measured at different intervals. The average age of patients was 21.8 ± 51.2; in terms of consciousness, 70% of patients were Sedate. Systolic blood pressure (P = 0.20), diastolic blood pressure (P <0.0001), average arterial pressure (P <0.0001) and heart rate (P <0.0001) increased over time immediately after the suction and then declined; in approximately 5 minutes after suction, it approached its baseline. This difference was significant in other cases except for systolic blood pressure. The mean respiratory rate, mean airway pressure, mean oxygen-saturated haemoglobin, mean end-tidal carbon dioxide were similar in both suction groups with and without normal saline during different time steps and no significant differences were observed. As long as there is no sufficient evidence to use normal saline on endotracheal suctioning, this method is not recommended to be used routinely. It is recommended to substitute strategies such as airway hydration, adequate hydration of patients, early mobilization of patients and administration of mucolytic drugs.

Nasal high-flow oxygen therapy in patients with hypoxic respiratory failure: effect on functional and subjective respiratory parameters compared to conventional oxygen therapy and non-invasive ventilation (NIV).

BackgroundAim of the study was to compare the short-term effects of oxygen therapy via a high-flow nasal cannula (HFNC) on functional and subjective respiratory parameters in patients with acute hypoxic respiratory failure in comparison to non-invasive ventilation (NIV) and standard treatment via a Venturi mask.MethodsFourteen patients with acute hypoxic respiratory failure were treated with HFNC (FiO2 0.6, gas flow 55 l/min), NIV (FiO2 0.6, PEEP 5 cm H2O Hg, tidal volume 6–8 ml/kg ideal body weight,) and Venturi mask (FiO2 0.6, oxygen flow 15 l/min,) in a randomized order for 30 min each. Data collection included objective respiratory and circulatory parameters as well as a subjective rating of dyspnea and discomfort by the patients on a 10-point scale. In a final interview, all three methods were comparatively evaluated by each patient using a scale from 1 (=very good) to 6 (=failed) and the patients were asked to choose one method for further treatment.ResultsPaO2 was highest under NIV (129 ± 38 mmHg) compared to HFNC (101 ± 34 mmHg, p <0.01 vs. NIV) and VM (85 ± 21 mmHg, p <0.001 vs. NIV, p <0.01 vs. HFNC, ANOVA). All other functional parameters showed no relevant differences. In contrast, dyspnea was significantly better using a HFNC (2.9 ± 2.1, 10-point Borg scale) compared to NIV (5.0 ± 3.3, p <0.05), whereas dyspnea rating under HFNC and VM (3.3 ± 2.3) was not significantly different. A similar pattern was found when patients rated their overall discomfort on the 10 point scale: HFNC 2.7 ± 1.8, VM 3.1 ± 2.8 (ns vs. HFNC), NIV 5.4 ± 3.1 (p <0.05 vs. HFNC). In the final evaluation patients gave the best ratings to HFNC 2.3 ± 1.4, followed by VM 3.2 ± 1.7 (ns vs. HFNC) and NIV 4.5 ± 1.7 (p <0.01 vs. HFNC and p <0.05 vs. VM). For further treatment 10 patients chose HFNC, three VM and one NIV.ConclusionsIn hypoxic respiratory failure HFNC offers a good balance between oxygenation and comfort compared to NIV and Venturi mask and seems to be well tolerated by patients.Trial registrationGerman clinical trials register: DRKS00005132.

Treinamento muscular respiratório em pacientes em desmame da ventilação mecânica

Introdução: A fraqueza da musculatura respiratória é uma das principais causas da dificuldade e/ou insucesso no desmame. Para minimizar os efeitos da ventilação mecânica (VM) prolongada, os fisioterapeutas utilizam o treinamento muscular respiratório, sendo o Threshold IMT® o método mais utilizado. Objetivo: Avaliar a eficácia do treinamento muscular respiratório com o uso do aparelho Threshold IMT®, sobre parâmetros respiratórios de pacientes em desmame da VM. Métodos: Os pacientes foram distribuídos aleatoriamente em grupo controle e grupo experimental (GI e GII). Foram avaliados no primeiro dia do início do desmame quanto à força muscular respiratória: Pressão inspiratória máxima/Pressão Expiratória Máxima (PImáx/PEmáx), volume corrente (VC), frequência respiratória (FR) e cardíaca (FC). Diariamente, durante sete dias, o GI recebeu três sessões de fisioterapia convencional e o GII realizou, adicionalmente, treinamento muscular respiratório (TMR) com o Threshold IMT®, uma vez ao dia, no período da tarde, conectado à traqueostomia, sendo três séries de dez repetições com carga de 20% da PImáx. Os dados foram tratados estatisticamente, adotando-se o nível de significância α=0,05. Resultados: Observou-se aumento (p=0,02) na FR e redução da PImáx (p=0,04) no GI, demonstrando aumento do trabalho respiratório e perda de força muscular entre o primeiro e sétimo dia de desmame. No GII, as variáveis não sofreram alterações significativas, observando-se a manutenção da função respiratória. Conclusão: Sendo assim, o TMR foi benéfico, garantindo a manutenção dos parâmetros respiratórios, podendo ser um aliado para o desmame.

English

BACKGROUND: Pranayama is an art of controlling the life force of breath. It produces many systemic psycho-physical effects in the body, besides its specific effects on the respiratory functions. It is claimed that practice of 'pranayama' is one of the ways to achieve this goal of physical and mental health. 'Regular practice of pranayama has found to be helpful in developing a healthy body and a sound mind. Several studies have shown the beneficial effects of pranayama practice on respiratory parameters in patients with respiratory disorders, especially asthmatics. The present study was done to find out whether short-term practice of pranayama has any additive effects on respiratory parameters of normal healthy persons. METHODOLOGY: The present study was conducted in Department of Physiology, Vijayanagar Institute of Medical Sciences, Bellary on 200 medical and paramedical students comprising of both males and females, fulfilling the inclusion criteria. In the beginning they were given training in practice of pranayama, after which all the subjects practiced two types of pranayama for a total duration of 12 weeks. Lung parameters like Respiratory rate (R.R), Tidal volume (VT), Inspiratory reserve volume (I.R.V), Expiratory reserve volume (E.R.V), Vital capacity (VT), Forced expiratory volume in first second (FEV1) and Peak expiratory flow rate (P.E.F.R) were recorded at the beginning and at the end of the 12 weeks study period. RESULTS: The subjects showed improved ventilatory functions, in the form of decrease in respiratory rate (R.R) and increase in Vital capacity (VT). Lung volumes like Tidal volume (VT), Inspiratory reserve volume (I.R.V) and Expiratory reserve volume (E.R.V) also showed significant increase. CONCLUSION: There was a statistically significant increase in all the above lung parameters in the regular yoga practitioners.

Pulmonary function tests in type 2 diabetes mellitus and their association with glycemic control and duration of the disease.

Background:Pulmonary complications of diabetes mellitus (DM) have been poorly characterized. Some authors have reported normal pulmonary functions and even concluded that spirometry is not at all necessary in diabetic patients. Some studies have shown abnormal respiratory parameters in patients of DM. Moreover, the duration of DM and glycemic control have varied impact on the pulmonary functions.Aims and Objectives:The study was undertaken to analyze the pulmonary function parameters in diabetic patients and compare them with age and gender matched healthy subjects. We correlated forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) in diabetic patients with duration of the disease and glycosylated hemoglobin (HbA1c).Materials and Methods:Pulmonary function tests (PFTs) were recorded in 60 type 2 diabetic male patients and 60 normal healthy male controls aged 40-60 years by using Helios 702 spirometer. The PFTs recorded were - FVC, FEV1, FEV1/FVC, FEF25, FEF50, FEF75, FEF25–75, FEF0.2–1.2, and peak expiratory flow rate (PEFR). HbA1c of all the patients was estimated by ion exchange resin method, which is a very standard method of estimation. PFTs of diabetic patients and controls were compared by applying Student′s unpaired t test. Associations between FVC and FEV1 and HbA1c and duration of illness in diabetic patients were analyzed by applying Pearson′s coefficient.Results:The PFTs were significantly decreased in diabetic patients compared with the healthy controls except FEV1/FVC. There was no correlation found between FVC and FEV1 and duration of illness as well as HbA1c.Conclusion:DM being a systemic disease, which also affects lungs causing restrictive type of ventilatory changes probably because of glycosylation of connective tissues, reduced pulmonary elastic recoil and inflammatory changes in lungs. We found glycemic levels and duration of disease are probably not the major determinants of lung pathology, which requires further research.

Effects of Nasal High Flow on Ventilation in Volunteers, COPD and Idiopathic Pulmonary Fibrosis Patients

Background: A high flow of air applied by large bore nasal cannulae has been suggested to improve symptoms of chronic respiratory insufficiency. In pediatric patients, nasal high-flow (nHF) ventilation was similarly effective compared to noninvasive ventilation with a face mask. Objectives: The aim of this study was to describe changes in respiratory parameters. Methods: We measured pressure amplitudes during the respiratory cycle and mean pressures in patients with idiopathic pulmonary fibrosis (IPF) and COPD. In order to achieve tidal volume and minute volume measurements, we used a polysomnography device. Capillary blood was taken for blood gas analysis before and after nHF breathing (8 h). Results: nHF led to an increase in pressure amplitude and mean pressure in healthy volunteers and in patients with COPD and IPF in comparison with spontaneous breathing. In COPD, nHF increased tidal volume, while no difference in tidal volume was observed in patients with IPF. Interestingly, tidal volume decreased in healthy volunteers. Breathing rates and minute volumes were reduced in all groups. Capillary pCO₂ decreased in patients with IPF and COPD. Conclusions: nHF resulted in significant effects on respiratory parameters in patients with obstructive and restrictive pulmonary diseases. The rise in pressure amplitude and mean pressure and the decrease in breathing rate and minute volume will support inspiratory efforts, helps to increase effectiveness of ventilation and will contribute to a reduction in the work of breathing. A CO₂ wash-out effect in the upper airway part of the anatomical dead space may contribute to the beneficial effects of the nHF instrument.

P6. Leg movements during sleep in patients with obstructive sleep apnea

Introduction Leg movements (LMs) during sleep are frequent in patients with obstructive sleep apnea syndrome (OSAS). Current giudelines distinguish LMs associated with respiratory events from periodic leg movements (PLM), excluding the former when assessing PLM. The aim of the current study was to describe the time structure of global LMs, the relationship between PLM and respiratory related movements (RRM), and the relationship between RRMs and the main respiratory parameters in patients with OSAS. Methods Retrospective chart review of all patients visiting the sleep lab of the Sleep and Epilepsy Center of the Neurocenter of Southern Switzerland between January 2010 and July 2011, which (1) had undergone full polysomnographic recording, (2) were between 18 and 75 years, (3) had an apnea-hypopnea index >20 and oxygen desaturation index >10 with more than half of all apneas being obstructive and (4) had >15 LMs/h (leg movements index (LMI)). We excluded patients with (1) any medical condition, that could influence LMs or apnea (such as narcolepsy, parasomnias, neurological disorders, renal or heart failure), (2) medication known or suspected to affect LMs (e.g. dopaminergic, benzodiazepines, antidepressants, etc.) and (3) recordings with artefacts of tibialis anterior or flow for more than 20% of the total sleep time. All LMs were scored and classifed as RRM, PLM, or isolated LMs according to WASM-IRLSSG criteria (2006). Intermovement intervals of LMs were analysed with distribution mixture analysis and differences between subjects with and without respiratory-related LMs were explored with non-parameteric tests. Results Fifty six patients have been included (8F 48 M, 56 ± 12 years). Distribution mixture analysis of intermovement intervals (IMI) of all LMs identified 3 classes of LMs which could be distinguished based on their peak frequencies ( Fig. 1 ). These were around 5 s, 20 s, and 40 s. The latter class (IMIs ∼40 s) could be traced back to the respiratory-related LMs, while the 20 s peak corresponds to periodic LMs, also found in patients with restless legs syndrome (RLS). LMs with very short IMIs (∼5 s) are related to wakefullness and arousal. Within the total group, 10 patients had no respiratory LMs ( Conclusions Our preliminary results show that respiratory LMs can be distinguished from periodic LMs based on their time structure (IMI). Importantly, respiratory LMs are found predominantly in patients with periodic LMs suggesting a possible shared trait for increased motor activity during sleep. The time structure analysis of LMs may be able provide information on the pathogenesis and meaning of LMs in OSAS patients and might explain the different response of LMs to ventilatory treatment.

Nasal high-flow oxygen in patients with hypoxic respiratory failure: effect on functional and subjective respiratory parameters compared to conventional oxygen therapy and noninvasive ventilation

Background: Aim of the study was to compare the short-term effects of oxygen therapy via a high-flow nasal cannula (HFNC) on functional and subjective respiratory parameters in patients with acute hypoxic respiratory failure in comparison to non-invasive ventilation (NIV) and standard treatment via a Venturi mask. Methods: Fourteen patients with acute hypoxic respiratory failure were treated with HFNC (FiO2 0.6, gas flow 55 l/min), NIV (FiO2 0.6, PEEP 5 cm H2O Hg, tidal volume 6–8 ml/kg ideal body weight,) and Venturi mask (FiO2 0.6, oxygen flow 15 l/min,) in a randomized order for 30 min each. Data collection included objective respiratory and circulatory parameters as well as a subjective rating of dyspnea and discomfort by the patients on a 10-point scale. In a final interview, all three methods were comparatively evaluated by each patient using a scale from 1 (=very good) to 6 (=failed) and the patients were asked to choose one method for further treatment. Results: PaO2 was highest under NIV (129 ± 38 mmHg) compared to HFNC (101 ± 34 mmHg, p <0.01 vs. NIV) and VM (85 ± 21 mmHg, p <0.001 vs. NIV, p <0.01 vs. HFNC, ANOVA). All other functional parameters showed no relevant differences. In contrast, dyspnea was significantly better using a HFNC (2.9 ± 2.1, 10-point Borg scale) compared to NIV (5.0 ± 3.3, p <0.05), whereas dyspnea rating under HFNC and VM (3.3 ± 2.3) was not significantly different. A similar pattern was found when patients rated their overall discomfort on the 10 point scale: HFNC 2.7 ± 1.8, VM 3.1 ± 2.8 (ns vs. HFNC), NIV 5.4 ± 3.1 (p <0.05 vs. HFNC). In the final evaluation patients gave the best ratings to HFNC 2.3 ± 1.4, followed by VM 3.2 ± 1.7 (ns vs. HFNC) and NIV 4.5 ± 1.7 (p <0.01 vs. HFNC and p <0.05 vs. VM). For further treatment 10 patients chose HFNC, three VM and one NIV. Conclusions: In hypoxic respiratory failure HFNC offers a good balance between oxygenation and comfort compared to NIV and Venturi mask and seems to be well tolerated by patients.

Differences in subjective and objective respiratory parameters in patients with chronic obstructive pulmonary disease with and without pain.

BackgroundFew studies have evaluated the associations between respiratory parameters and pain in chronic obstructive pulmonary disease (COPD). The purpose of this study is to evaluate the differences in respiratory parameters between COPD patients who did and did not have pain.MethodsIn this cross-sectional study respiratory parameters were measured by spirometry and the St Georges Respiratory Questionnaire. Patients responded to a single question that asked if they were generally bothered by pain.ResultsOf the 100 patients, 45% reported that they were generally bothered by pain. Patients who had pain reported a higher number of comorbidities (P < 0.001) and higher breathlessness scores (P = 0.003). Physical dimensions of breathlessness were significantly associated with pain (P ≤ 0.03). The results of logistic regression analysis determined that a higher number of comorbidities (OR = 0.28; P = 0.026) and higher breathlessness scores (OR = 1.03; P = 0.003) made significant unique contributions to the prediction of pain group membership.ConclusionsComorbidity and breathlessness were risk factors for pain and the physical dimensions of breathlessness were associated with pain.

Evaluation of Respiratory Parameters in Patients with Acute Lung Injury Receiving Adaptive Support Ventilation

Background: Adaptive support ventilation (ASV), an automated closed-loop ventilation mode, adapts to the mechanical characteristics of the respiratory system by continuous measurement and adjustment of the respiratory parameters. The adequacy of ASV was evaluated in the patients with acute lung injury (ALI). Methods: A total of 36 patients (19 normal lungs and 17 ALIs) were enrolled. The patients' breathing patterns and respiratory mechanics parameters were recorded under the passive ventilation using the ASV mode. Results: The ALI patients showed lower tidal volumes and higher respiratory rates (RR) compared to patients with normal lungs (7.1±0.9 mL/kg vs. 8.6±1.3 mL/kg IBW; 19.7±4.8 b/min vs. 14.6±4.6 b/min; p＜0.05, respectively). The expiratory time constant (RCe) was lower in ALI patients than in those with normal lungs, and the expiratory time/RCe was maintained above 3 in both groups. In all patients, RR was correlated with RCe and peak inspiratory flow ( rs=−0.40; rs=0.43; p＜0.05, respectively). In ALI patients, significant correlations were found between RR and RCe (rs=−0.76, p＜0.01), peak inspiratory flow and RR (rs=−0.53, p＜0.05), and RCe and peak inspiratory flow (rs=−0.53, p＜0.05). Conclusion: ASV was found to operate adequately according to the respiratory mechanical characteristics in the ALI patients. Discrepancies with the ARDS Network recommendations, such as a somewhat higher tidal volume, have yet to be addressed in further studies.

Effect of induced hypothermia on respiratory parameters in mechanically ventilated patients

Therapeutic hypothermia is applied to reduce hypoxia-induced organ injury. In the past decades, the use of hypothermia has increased in critically ill patients who are mechanically ventilated (MV). Data on the effect of hypothermia on gas exchange and lung mechanics in these patients are limited. In this retrospective study, we describe the effect of induced hypothermia and rewarming on respiratory parameters in patients after a cardiac arrest.

Quantification of respiratory parameters in patients with temporal lobe epilepsy

Dysfunction affecting cardiac or pulmonary systems has been postulated as a major factor in sudden death in epilepsy (SUDEP). Whilst the majority of studies of cardiorespiratory function have focused on changes during seizures, here we investigate whether epilepsy influences basal respiratory parameters in patients with temporal lobe epilepsy (TLE) during the interictal period. Spirometry was performed in 10 females and 10 males. Measurements of Vital Capacity (VC), Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1) and ratios of FEV1 to FVC (FEV1/FVC) were obtained, and these values were analyzed as percentages of predicted values. None of the patients had chronic obstructive pulmonary disease and no significant alterations in respiratory function tests were found among these patients. No association between seizure frequency, antiepileptic drugs and SUDEP could be found in this study. Although the study did not identify any specific respiratory abnormality in TLE patients during the interictal period, re-evaluation of clinical data on pulmonary disorders in people with epilepsy should be better investigated.

Comparative Analysis of Different Scintigraphic Approaches to Assess Pulmonary Ventilation

A study was carried out to investigate the predictive value of 81-metastable-krypton (81mKr) distribution, high-size 99-metastable-technetium (99mTc) aerosol deposition and low-size 99mTc aerosol (Technegas) deposition on the pulmonary ventilation evaluated by 133-xenon (133Xe) lung scintigraphy, and to assess the correlation between the 81mKr distribution, the 99mTc aerosols deposition, and the respiratory parameters of patients with chronic obstructive pulmonary disease (COPD). Twenty COPD patients were included. The 81mKr, 133Xe, and 99mTc aerosol lung scintigraphies were successively carried out. The 81mKr distribution and 99mTc deposition were compared to the 133Xe distribution at equilibrium and to the 133Xe clearance. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 81mKr and Technegas lung scintigraphies to detect alterations in ventilation revealed by 133Xe were defined. The 81mKr distribution and 99mTc deposition according to respiratory parameters were described using a principal component analysis. Compared to 133Xe distribution, a significantly higher distribution of 81mKr in the upper parts of the lungs in the more severe patients (p = 0.05), a significantly higher deposition of Technegas in the lower parts of the lungs (p = 0.0008), and a significantly higher deposition in the central parts of the high-size 99mTc aerosol were observed (p = 0.0001). The PPV and the NPV were, respectively, 0.54 and 0.58 for 81mKr and 0.54 and 0.55 for Technegas. There was a significant negative correlation between 81mKr distribution and 133Xe clearance (p = 0.0001) between Technegas deposition and 133Xe clearance (p = 0.0007), and between 99mTc diethylene-triamino-penta-acetate (DTPA) deposition and 133Xe clearance (p = 0.001). Both the 81mKr peripheral distribution and Technegas peripheral deposition correlated negatively with increased obstruction, as measured by forced expiratory volume in 1 sec (FEV1). Peripheral deposition of the high-size 99mTc aerosol deposition correlated with the inspiration/expiration time ratio. In conclusion, 81mKr and 99mTc aerosols' lung scintigraphies do not reflect exactly the pulmonary ventilation as measured by 133Xe scintigraphy.

Effects of smaller tidal volumes during basic life support ventilation in patients with respiratory arrest: good ventilation, less risk?

Objective: When ventilating an unintubated patient in cardiac or respiratory arrest, smaller tidal volumes of 500 ml instead of 800–1200 ml may be beneficial to decrease peak airway pressure, and to minimise stomach inflation. The purpose was to determine the effects of small (∼500 ml) versus large (∼1000 ml) tidal volumes given with paediatric versus adult self-inflatable bags and ∼50% oxygen on respiratory parameters in patients during simulated basic life support ventilation. Methods: While undergoing induction of anaesthesia, patients were randomised to three minutes of ventilation with either an adult ( n=40) or paediatric ( n=40) self-inflatable bag. Results: When compared with an adult self-inflatable bag, the paediatric bag resulted in significantly lower mean (±standard deviation) exhaled tidal volume (365±55 versus 779±122 ml; P<0.0001), peak airway pressure (20±2 versus 25±5 cm H 2O; P<0.0001), but comparable oxygen saturation (97±1% versus 98±1%; NS (nonsignificant)). Stomach inflation occurred in five of 40 patients ventilated with an adult self-inflatable bag, but in no patients who were ventilated with a paediatric self-inflatable bag ( P=0.054). Conclusion: Administering smaller tidal volumes with a paediatric instead of an adult self-inflatable bag in unintubated adult patients with respiratory arrest maintains good oxygenation and carbon dioxide elimination while decreasing peak airway pressure, which makes stomach inflation less likely.

Recording Respiratory Parameters in Patients with Epileps)

Anecdotal evidence and data from small studies suggest that respiratory changes occur in both complex partial and generalized seizures. Our understanding of sudden unexpected death in epilepsy (SUDEP) may be furthered by recording and analyzing these changes. Investigators at the Jules Thorn Telemetry Unit at the National Hospital for Neurology and Neurosurgery have documented a range of respiratory parameters (respiratory effort, airflow, oxygen saturation) in conjunction with time-locked audio-video electroencephalograms and electrocardiograms to provide a more complete picture of the physiologic changes that occur during seizures. Cardiorespiratory information on 79 seizures (70 complex partial, nine generalized) in 37 patients (20 male, 17 female) is presented. Whereas tachycardia was a common ictal feature, bradycardia was seen only rarely and tended to follow a period of apnea. Apnea occurred in 100% of generalized seizures and 39% of complex partial seizures. Apnea was predominantly central and lasted for 10-75 s (mean duration 29 s). Central apnea may be one of the major, although by no means exclusive, ictal events predisposing to SUDEP.