scholarly journals Alteration of the Piglet Diaphragm Contractility In Vivo  and Its Recovery after Acute Hypercapnia

2008 ◽  
Vol 108 (4) ◽  
pp. 651-658 ◽  
Author(s):  
Samir Jaber ◽  
Boris Jung ◽  
Mustapha Sebbane ◽  
Michèle Ramonatxo ◽  
Xavier Capdevila ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Phrenic Nerve ◽  
Contractile Function ◽  
Contractile Force ◽  
Short Exposure ◽  
Control Group ◽  
Partial Recovery ◽  
Carbon Dioxide Insufflation ◽  
Transdiaphragmatic Pressure

Background The effects of hypercapnic acidosis on the diaphragm and its recovery to normocapnia have been poorly evaluated. The authors studied diaphragmatic contractility facing acute variations of arterial carbon dioxide tension (Paco2) and evaluated the contractile function at 60 min after normocapnia recovery. Methods Thirteen piglets weighing 15-20 kg were anesthetized, ventilated, and separated into two groups: a control group (n = 5) evaluated in normocapnia (time-control experiments) and a hypercapnia group (n = 8) in which animals were acutely and shortly exposed to five consecutive ranges of Paco2 (40, 50, 70, 90, and 110 mmHg). Then carbon dioxide insufflation was stopped. Diaphragmatic contractility was assessed by measuring transdiaphragmatic pressure variations obtained after bilateral transjugular phrenic nerve pacing at increased frequencies (20-120 Hz). For each level of arterial pressure of carbon dioxide, pressure-frequency curves were obtained in vivo by phrenic nerve pacing. Results In the hypercapnia group, mean +/- SD transdiaphragmatic pressure significantly decreased from 41 +/- 3 to 29 +/- 3 cm H2O (P < 0.05) between the first (40 mmHg) and fifth (116 mmHg) stages of capnia at the frequency of 100 Hz stimulation. The observed alteration of the contractile force was proportional to the level of Paco2 (r = 0.61, P < 0.01). Normocapnia recuperation allowed a partial recovery of the diaphragmatic contractile force (80% of the baseline value) at 60 min after carbon dioxide insufflation interruption. Conclusion A short exposure to respiratory acidosis decreased diaphragmatic contractility proportionally to the degree of hypercapnia, and this alteration was only partially reversed at 60 min after exposure.

scholarly journals Phrenic nerve preservation using carbon dioxide insufflation during sinus node ablation procedure

2021 ◽  
Author(s):  
Atif AlQubbany ◽  
Fahad Almehmadi ◽  
Amin Zagzoog ◽  
Waad Osta ◽  
Akram Ahmad ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Phrenic Nerve ◽  
Sinus Node ◽  
Carbon Dioxide Insufflation ◽  
Ablation Procedure ◽  
Nerve Preservation

Intraabdominal Carbon Dioxide Insufflation in the Pregnant Ewe

1996 ◽  
Vol 85 (6) ◽  
pp. 1395-1402. ◽  
Author(s):  
Antonio M. Cruz ◽  
Lucy C. Southerland ◽  
Tanya Duke ◽  
Hugh G. G. Townsend ◽  
James G. Ferguson ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Intraabdominal Pressure ◽  
Control Group ◽  
Uterine Blood Flow ◽  
Carbon Dioxide Insufflation ◽  
Carbon Dioxide Pneumoperitoneum ◽  
Arterial Blood ◽  
End Tidal Carbon Dioxide ◽  
End Tidal

Background Laparoscopic surgical procedures are being performed in pregnant women with increasing frequency. Maternal-fetal physiologic changes occurring during intraabdominal carbon dioxide insufflation are poorly understood, and maternal-fetal safety is of concern during carbon dioxide pneumoperitoneum. A previous pilot study using end-tidal carbon dioxide-guided ventilation resulted in maternal and fetal acidosis and tachycardia during carbon dioxide pneumoperitoneum. Using serial arterial PCO2 to guide ventilation, this study was designed to evaluate maternal-fetal cardiopulmonary status, uterine blood flow, and the intraamniotic pressure effects of intraabdominal carbon dioxide insufflation in singleton pregnant ewes between 120 and 135 days of gestation. Methods In a prospective randomized cross-over study, nine ewes were to receive either abdominal insufflation with carbon dioxide to an intraabdominal pressure of 15 mmHg (n = 9; insufflation group) or receive no insufflation (n = 9; control group). Anesthesia was induced with thiopental and maintained with end-tidal halothane (1 to 1.5 minimum alveolar concentration/100% oxygen). Mechanical ventilation was guided by serial maternal arterial blood gas analysis to maintain PaCO2 between 35 and 40 mmHg. Data from insufflated animals were collected during insufflation (60 min) and after desufflation (30 min). Control group data were collected and matched to similar time intervals for 90 min. Ewes were allowed to recover, and after a rest period (48 h) they were entered in the cross-over study. Results During insufflation there was a significant increase (P < 0.05) in maternal PaCO2 to end-tidal carbon dioxide gradient and minute ventilation, with concomitant decreases in maternal end-tidal carbon dioxide and PaO2. Intraamniotic pressure increased significantly during insufflation. No significant changes were observed in maternal hemodynamic variables, fetal variables, or in uterine blood flow during the study. There were no fetal deaths or preterm labor in any of the animals during the experiment. Conclusions During the 1-h insufflation, a marked increase in PaCO2-to-end-tidal carbon dioxide gradient was observed, suggesting that capnography may be an inadequate guide to ventilation during carbon dioxide pneumoperitoneum in the pregnant patient. No other significant circulatory changes were observed.

Diaphragmatic relaxation rate after voluntary contractions and uni- and bilateral phrenic stimulation

1988 ◽  
Vol 65 (2) ◽  
pp. 675-682 ◽  
Author(s):  
P. G. Wilcox ◽  
A. Eisen ◽  
B. J. Wiggs ◽  
R. L. Pardy
Keyword(s):  
Relaxation Rate ◽  
Phrenic Nerve ◽  
External Pressure ◽  
Transdiaphragmatic Pressure ◽  
Relaxation Parameters ◽  
Exponential Decline ◽  
Residual Capacity ◽  
Rate Of Decline ◽  
Voluntary Contractions

We compared the rate of relaxation of the diaphragm (RRdi) after unilateral phrenic nerve stimulation, bilateral phrenic nerve stimulations, and short sharp voluntary contractions (sniffs). RRdi was measured as the maximum rate of decline in transdiaphragmatic pressure (Pdi) corrected for the change in Pdi [maximum relaxation rate (MRR)/delta Pdi], the time constant (tau) of the later exponential decline in Pdi, and the time to half relaxation (1/2 RT). In five subjects there was no difference in mean RRdi apart from a smaller MRR/delta Pdi (P less than 0.05) for left unilateral compared with either right unilateral or bilateral needle stimulation. However, RRdi varied unpredictably between unilateral and bilateral stimulation of the phrenic nerve in individual subjects. In the same five subjects, sniffs were found to have a slower RRdi than bilateral stimulations (MRR/delta Pdi 0.0064 +/- 0.0007 vs. 0.0074 +/- 0.0018/ms, tau 57.2 +/- 8.7 vs. 48.2 +/- 7.4 ms, 1/2 RT 108.9 +/- 10.9 vs. 73.9 +/- 6.0 ms; all P less than 0.05). The application and inflation of an abdominal binder to an external pressure of 60 mmHg resulted in a decrease in functional residual capacity (-710 +/- 70 ml), but there was no effect on relaxation parameters. Our findings suggest that in the evaluation of RRdi 1) unilateral hemidiaphragmatic stimulations may not accurately reflect the in vivo contractile properties of the diaphragm, 2) sniff maneuvers are not voluntary equivalents of phrenic nerve stimulations, and 3) RRdi is not affected by abdominal binder inflation up to 60 mmHg.

scholarly journals Diaphragmatic dysfunction in sepsis due to severe acute pancreatitis complicated by intra-abdominal hypertension

2018 ◽  
Vol 46 (4) ◽  
pp. 1349-1357 ◽  
Author(s):  
Wei-Chao Liao ◽  
Yan-Hong Chen ◽  
Hang-Yang Li ◽  
Ting-Ting Wang ◽  
Peng Lan ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Severe Acute Pancreatitis ◽  
Rat Model ◽  
Contractile Function ◽  
Control Group ◽  
Force Output ◽  
Diaphragmatic Dysfunction ◽  
Abdominal Hypertension ◽  
And Control

Objective This study aimed to examine the mechanism of diaphragmatic dysfunction in sepsis due to severe acute pancreatitis (SAP) with intra-abdominal hypertension (IAH) in a rat model. Methods The rats were assigned at random to four groups: (1) control (n = 5), (2) SAP (n = 5), (3) SAP+IAH (n = 5), and (4) SAP+IAH+SS-31 (n = 5). Length and force output of the diaphragm were analysed in vivo. Histopathological examinations were performed by haematoxylin–eosin. Oxidative stress levels related to protease in diaphragmatic mitochondria were detected with a colorimetric technique. Results In the septic rat model due to SAP complicated by IAH, myofibres were increased. Muscle contractile function was significantly lower in the SAP+IAH group compared with the SAP and control groups. Glutathione peroxidase and superoxide dismutase levels were significantly lower and malondialdehyde levels were higher in the SAP and SAP+IAH groups compared with the control group. Notably, SS-31 could reverse atrophy of myofibres in SAP+IAH rats, as well as contractile dysfunction and mitochondrial dysfunction in the diaphragm. Conclusions Diaphragmatic structure and biomechanics are altered in septic rats due to SAP and IAH. This finding is mainly due to an increase in release of mitochondrial reactive oxygen species.

scholarly journals A method to test contractility of the supraspinatus muscle in mouse, rat, and rabbit

2016 ◽  
Vol 120 (3) ◽  
pp. 310-317 ◽  
Author(s):  
Ana P. Valencia ◽  
Shama R. Iyer ◽  
Stephen J. P. Pratt ◽  
Mohit N. Gilotra ◽  
Richard M. Lovering
Keyword(s):  
Animal Models ◽  
Contractile Function ◽  
Fatty Infiltration ◽  
Clinical Problem ◽  
Contractile Force ◽  
Joint Stability ◽  
Supraspinatus Muscle ◽  
Hindlimb Muscles ◽  
Models Of Injury

The rotator cuff (RTC) muscles not only generate movement but also provide important shoulder joint stability. RTC tears, particularly in the supraspinatus muscle, are a common clinical problem. Despite some biological healing after RTC repair, persistent problems include poor functional outcomes with high retear rates after surgical repair. Animal models allow further exploration of the sequela of RTC injury such as fibrosis, inflammation, and fatty infiltration, but there are few options regarding contractility for mouse, rat, and rabbit. Histological findings can provide a “direct measure” of damage, but the most comprehensive measure of the overall health of the muscle is contractile force. However, information regarding normal supraspinatus size and contractile function is scarce. Animal models provide the means to compare muscle histology, imaging, and contractility within individual muscles in various models of injury and disease, but to date, most testing of animal contractile force has been limited primarily to hindlimb muscles. Here, we describe an in vivo method to assess contractility of the supraspinatus muscle and describe differences in methods and representative outcomes for mouse, rat, and rabbit.

Arterial CO2 partial pressure affects diaphragmatic function

1985 ◽  
Vol 58 (3) ◽  
pp. 823-829 ◽  
Author(s):  
J. Y. Schnader ◽  
G. Juan ◽  
S. Howell ◽  
R. Fitzgerald ◽  
C. Roussos
Keyword(s):  
Partial Pressure ◽  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Phrenic Nerve Stimulation ◽  
Transdiaphragmatic Pressure ◽  
Arterial Pco2 ◽  
Co2 Partial Pressure ◽  
Diaphragmatic Function ◽  
Plaster Casts

The purpose of this study was to examine in an in vivo preparation acute variations of PCO2 on diaphragmatic contractility. Plaster casts were snugly fit around the abdomen of six open-chested dogs, moving the abdominal contents rostrally. Diaphragmatic contractions against this very fixed load in response to phrenic nerve stimulation (supramaximal voltage at 1, 20, 50, and 80 Hz) or during spontaneous inspiratory efforts were virtually isometric (quasi-isometric). Transdiaphragmatic pressure (Pdi) measured by an abdominal balloon was used as an index of diaphragmatic contractility. Arterial PCO2 (PaCO2) was reduced by hyperventilation and raised by increasing PICO2. Pdi values in response to stimulation at 1, 20, 50, and 80 Hz in ranges I (PaCO2 = 0–19 Torr) and II (PaCO2 = 20–34 Torr) did not differ statistically from the control Pdi values (range III; PaCO2 = 35–45 Torr). In range IV (PaCO2 = 46–70 Torr) Pdi values for stimulations of 20, 50, and 80 Hz were significantly lower than control. In range V (PaCO2 = 71–90 Torr), VI (PaCO2 = 91–101 Torr), and VII (PaCO2 greater than or equal to 102 Torr) Pdi values were significantly less than those in range IV at all frequencies of stimulation. In the four dogs measured during spontaneous inspiratory efforts the integrated diaphragmatic electromyogram (Edi) was correlated with the Pdi. As PaCO2 rose (range III to VII), the Pdi values observed at 25, 50, 75, 100% of the maximum Edi (of range III) were significantly lower than the Pdi value of range III.(

Effect of lung volume on in vivo contraction characteristics of human diaphragm

1987 ◽  
Vol 62 (5) ◽  
pp. 1893-1900 ◽  
Author(s):  
J. Smith ◽  
F. Bellemare
Keyword(s):  
Nerve Stimulation ◽  
Lung Volume ◽  
Phrenic Nerve ◽  
Pleural Pressure ◽  
Normal Male ◽  
Contraction Time ◽  
Phrenic Nerve Stimulation ◽  
Transdiaphragmatic Pressure ◽  
Gastric Pressure

We performed transcutaneous bilateral phrenic nerve stimulation at varying lung volumes between residual volume (RV) and total lung capacity (TLC) in six normal male volunteers. Peak twitch transdiaphragmatic pressure declined from 49.1 +/- 9.1 (SD) cmH2O at RV to 19.6 +/- 5.97 (SD) cmH2O at TLC. Twitch contraction time fell from 91.8 +/- 11.3 (SD) ms at RV to 57.7 +/- 7.4 (SD) ms at TLC. There was a good correlation between changes in contraction time and transdiaphragmatic pressure (r = 0.7). The fall in transdiaphragmatic pressure was almost all due to a fall in pleural pressure, with little change in gastric pressure between RV and TLC. At TLC the pleural pressure in response to phrenic nerve stimulation was -0.58 cmH2O. We conclude that, as lung volume increases and the diaphragm shortens, it becomes less effective as a pressure generator and that pressure it generates is less well converted into useful inspiratory pressure. At a lung volume close to TLC, the diaphragm ceases to act as an inspiratory muscle.

scholarly journals Influence of acute lung volume change on contractile properties of human diaphragm

1998 ◽  
Vol 85 (4) ◽  
pp. 1322-1328 ◽  
Author(s):  
Michael I. Polkey ◽  
Carl-Hugo Hamnegård ◽  
Philip D. Hughes ◽  
Gerrard F. Rafferty ◽  
Malcolm Green ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Lung Volume ◽  
Phrenic Nerve ◽  
Stimulus Frequency ◽  
Normal Subjects ◽  
Lung Volumes ◽  
Transdiaphragmatic Pressure ◽  
Residual Capacity ◽  
Interstimulus Intervals

The effect of stimulus frequency on the in vivo pressure generating capacity of the human diaphragm is unknown at lung volumes other than functional residual capacity. The transdiaphragmatic pressure (Pdi) produced by a pair of phrenic nerve stimuli may be viewed as the sum of the Pdi elicited by the first (T1 Pdi) and second (T2 Pdi) stimuli. We used bilateral anterior supramaximal magnetic phrenic nerve stimulation and a digital subtraction technique to obtain the T2 Pdi at interstimulus intervals of 999, 100, 50, 33, and 10 ms in eight normal subjects at lung volumes between residual volume and total lung capacity. The reduction in T2 Pdi that we observed as lung volume increased was greatest at long interstimulus intervals, whereas the T2 Pdi obtained with short interstimulus intervals remained relatively stable over the 50% of vital capacity around functional residual capacity. For all interstimulus intervals, the total pressure produced by the pair decreased as a function of increasing lung volume. These data demonstrate that, in the human diaphragm, hyperinflation has a disproportionately severe effect on the summation of pressure responses elicited by low-frequency stimulations; this effect is distinct from and additional to the known length-tension relationship.

An ATP-sensitive potassium channel blocker decreases diaphragmatic circulation in anesthetized dogs

1994 ◽  
Vol 77 (1) ◽  
pp. 127-134 ◽  
Author(s):  
A. Comtois ◽  
C. Sinderby ◽  
N. Comtois ◽  
A. Grassino ◽  
J. M. Renaud
Keyword(s):  
Blood Flow ◽  
Phrenic Nerve ◽  
Spontaneous Breathing ◽  
Arterial Blood Flow ◽  
Control Group ◽  
Transdiaphragmatic Pressure ◽  
K Channels ◽  
Arterial Blood ◽  
Tension Time ◽  
Experimental Group

The goal of this study was to determine whether in the dog ATP-sensitive K+ channels blocked with glibenclamide affect diaphragmatic blood flow [phrenic arterial blood flow (Qpa)] during both spontaneous breathing at rest and increased diaphragmatic activity. A control group (no glibenclamide; n = 4) and an experimental group (50 mg/kg of glibenclamide; n = 5) were studied. During spontaneous breathing at rest, Qpa was 15.0 ml.min-1 x 100 g-1 and decreased by 5% in the presence of glibenclamide. Diaphragmatic pacing (30 min-1) generated by phrenic nerve pacing produced an initial diaphragmatic tension-time index of 0.25 in both groups. A 50% decay in transdiaphragmatic pressure was reached at 165 s in the experimental group compared with 421 s in the control group. Diaphragmatic pacing increased Qpa by 46% in the experimental group and 65% in the control group, yielding a 63% greater vascular resistance in the experimental group. Phrenic vein K+ content at rest was unchanged by the presence of glibenclamide, being 3.6 +/- 0.16 mmol/l compared with 3.5 +/- 0.19 mmol/l in the control group. Phrenic nerve pacing in the control group produced a 13% increase in phrenic vein K+ content, whereas in the experimental group a 16% decrease was observed. We suggest that ATP-sensitive K+ channels play an important role in the modulation of Qpa.

scholarly journals Transcutaneous Carbon Dioxide Decreases Immunosuppressive Factors in Squamous Cell Carcinoma In Vivo

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Nanae Yatagai ◽  
Takumi Hasegawa ◽  
Rika Amano ◽  
Izumi Saito ◽  
Satomi Arimoto ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Control Group ◽  
Hypoxic Environment ◽  
Combined Use ◽  
Carbon Dioxide Co2 ◽  
Immunosuppressive Factors

Introduction. In recent years, the tumour immunosuppressive mechanism has attracted attention as a cause of tumour chemoresistance. Although chemoresistance and immunosuppression of tumours have been reported to be associated with a hypoxic environment, effective treatments to improve hypoxia in tumours have not yet been established. We have previously applied carbon dioxide (CO2) to squamous cell carcinoma and have shown that improvement in local oxygenation has an antitumour effect. However, the effects of local CO2 administration on tumour immunosuppression, chemoresistance, and combination with chemotherapy are unknown. In this study, we investigated the effects of local CO2 administration on squamous cell carcinoma and the effects of combined use with chemotherapy, focusing on the effects on tumour immunosuppressive factors. Methods. Human oral squamous cell carcinoma (HSC-3) was transplanted subcutaneously into the back of a nude mouse, and CO2 and cisplatin were administered. After administration twice a week for a total of 4 times, tumours were collected and the expression of tumour immunosuppressive factors (PD-L1, PD-L2, and galectin-9) was evaluated using real-time polymerase chain reaction and immunostaining. Results. Compared with the control group, a significant decrease in the mRNA expression of PD-L1 was observed in both, CO2-treated and combination groups. Similarly, the expression of PD-L2 and galectin-9 decreased in the CO2-treated and combination groups. Furthermore, immunostaining also showed a significant decrease in the protein expression of tumour immunosuppressive factors in the CO2-treated and combination groups. Conclusion. It was confirmed that the tumour immunosuppressive factors decreased due to local CO2 administration to the mouse model. CO2 administration has the potential to improve the hypoxic environment in tumours, and combined use with chemotherapy may also improve tumour immunosuppression.

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