Decrease In Pulmonary Compliance Research Articles

Cardiorespiratory changes during robotic pelvic surgeries- A prospective observational Study

Introduction: Robot assisted pelvic surgeries are associated with cardiorespiratory changes due to conjunction of carboperitoneum and steep Trendelenburg position for prolonged durations. Aim: To determine the changes in cardiovascular and respiratory systems in patients undergoing elective robot assisted pelvic surgeries under general anesthesia.Materials and Methods: A prospective observational study was conducted in 35 patients scheduled for elective robot assisted pelvic surgeries. Patients belonging to ASA class I and II were included and their intraoperative hemodynamic and respiratory parameters were noted post induction (baseline), at pneumoperitoneum, at and every 15 minutes after steep Trendelenburg positioning, at resuming supine position, at deflation of pneumoperitoneum and post-deflation. Primary outcome was mean arterial pressure. Secondary outcomes were systolic and diastolic blood pressures, heart rate, central venous pressure, airway pressures (peak, plateau and mean), pulmonary compliance, minute ventilation, end tidal carbondioxide levels and blood gas values.

Perioperative management of post-COVID-19 surgical patients: Indian Society of Anaesthesiologists (ISA National) Advisory and Position Statement.

Perioperative management of post-COVID-19 surgical patients: Indian Society of Anaesthesiologists (ISA National) Advisory and Position Statement.

Pulmonary gas exchange in diving

Diving-related pulmonary effects are due mostly to increased gas density, immersion-related increase in pulmonary blood volume, and (usually) a higher inspired Po(2). Higher gas density produces an increase in airways resistance and work of breathing, and a reduced maximum breathing capacity. An additional mechanical load is due to immersion, which can impose a static transrespiratory pressure load as well as a decrease in pulmonary compliance. The combination of resistive and elastic loads is largely responsible for the reduction in ventilation during underwater exercise. Additionally, there is a density-related increase in dead space/tidal volume ratio (Vd/Vt), possibly due to impairment of intrapulmonary gas phase diffusion and distribution of ventilation. The net result of relative hypoventilation and increased Vd/Vt is hypercapnia. The effect of high inspired Po(2) and inert gas narcosis on respiratory drive appear to be minimal. Exchange of oxygen by the lung is not impaired, at least up to a gas density of 25 g/l. There are few effects of pressure per se, other than a reduction in the P50 of hemoglobin, probably due to either a conformational change or an effect of inert gas binding.

Three simple steps during closed laparoscopic entry may minimize major injuries

To describe three steps: (1) the initial Veress pressure (VIP-Pressure), (2) transient high-pressure pneumoperitoneum (HIP-Entry) prior to trocar/cannula insertion, and (3) visual entry with a trocarless cannula during closed laparoscopic entry, which may reduce major injuries. Prospective observational cohort study (Canadian Task Force Classification II-2). University-affiliated teaching hospital. VIP-Pressure. During laparoscopic entry, the initial VIP pressure was measured and correlated against the body habitus and parity of 365 consecutive women. HIP-Entry was performed in 2,498 consecutive cases. In 100 women, the CO(2) volume, heart rate, blood pressure, oxygen saturation, and pulmonary compliance were recorded at pressures of 10, 15, 20, 25, and 30 mmHg. Visual entry with a trocarless blunt cannula was performed in 776 women. The cannula, housing a 0 degrees laparoscope, was rotated clockwise applying minimal downward force. VIP-Pressure. Pneumoperitoneum was established after one, two or three Veress needle attempts at the umbilicus in 82.4%, 10.9%, and 4.0% of women, respectively. In seven (2.2%), pneumoperitoneum was established at the left upper quadrant (LUQ) during the fourth attempt, and in two (0.6%) entry was abandoned. Median initial Veress pressure was 4 mmHg (range 2-10 mmHg). The VIP pressure correlated positively with women's weight (r = 0.518, p < 0.001) and body mass index (BMI) (r=0.545, p<0.001), and negatively with parity (r= -0.179, p<0.001). HIP-Entry. The abdomen was insufflated to 25-30 mmHg prior to primary trocar/cannula insertion. There were no changes in cardiovascular parameters between 15 and 30 mmHg. A 21% decrease in pulmonary compliance from 15 to 30 mmHg was of no clinical significance. No injury has been experienced with the visual cannula in 776 cases. (1) A VIP-Pressure (<10 mmHg) indicates intraperitoneal placement of the Veress needle. (2) The use of transient HIP-Entry does not adversely affect cardiopulmonary function in healthy women. (3) Visual cannula offers an additional step towards safer entry.

Vergleichende Messungen der Lungen-Compliance und der Atemarbeit mit anderen Lungenfunktionsparametern bei männlichen Probanden

Dynamic and static pulmonary compliance as well as the work of breathing are essential parameters for describing respiratory mechanics. However, current reference values or correlations with other pulmonary function variables have been established only in studies with small numbers of participants. Therefore, the aim of the present study was to compare pulmonary compliance and the work of breathing with different pulmonary function parameters in a large number of men. In 208 healthy men, aged 20 to 70 years, spirometry, bodyplethysmography and carbon monoxide transfer factor measurements were conducted. The esophageal pressure method was used to measure dynamic (C (dyn)) and static (C (stat)) compliance. C (dyn) and C (stat) were significantly correlated with total lung capacity (TLC), vital capacity (VC), forced expiratory volume in the first second (FEV (1)) and carbon monoxide transfer factor (T (LCO)). C (dyn) decreased with increasing age, while C (stat) was correlated with height. The elastic and non-elastic work of breathing were significantly correlated with airway resistance, but not with aging. Lung volumes are important for the interpretation of pulmonary compliance and the work of breathing and therefore have to be considered in the assessment of respiratory mechanics. In contrast, the work of breathing is essentially influenced by the airway resistance. With increasing age there is only a small decrease in pulmonary compliance and the work of breathing.

Acute effects of vecuronium on pulmonary function and hypoxemic episodes in preterm infants

Varying effects of pancuronium on neonatal pulmonary mechanics have been documented, including a decrease in pulmonary compliance or no significant change in compliance; but measurements of respiratory mechanics or quantification of episodes of hypoxemia in preterm newborns receiving vecuronium (Norcuron, Bedford Labs, Bedford, OH, USA) have not been reported. The objective of the present study was to quantify the short-term effects of vecuronium on pulmonary mechanics and episodes of hypoxemia in preterm infants receiving mechanical ventilation. A total of 15 preterm infants (birthweight 610-1560 g, gestational age 25-32 weeks, postnatal age 0.2-22 days) was studied. The initial dose of vecuronium used for the study was 0.2 mg/kg i.v. Measurements of respiratory mechanics were obtained 1 h prior to and 1 h after the initial dose of vecuronium at comparable ventilator settings and fractional inspired oxygen concentration (FiO(2)). Dynamic respiratory compliance and respiratory resistance were calculated by two-factor least mean square analysis. Pulse oximeter oxygen saturation (SpO(2)) was measured during both 1 h intervals with the Nellcor N-200 oximeter, a computer, and a software program for quantification of episodes of hypoxemia. Heart rate and blood pressure were also monitored. There were no significant differences in tidal volume, respiratory compliance, or respiratory resistance when comparing measurements obtained before and after vecuronium administration. However, fewer episodes of hypoxemia (SpO(2) < 85%, P = 0.025; and SpO(2) < 80%, P = 0.04) were observed during muscle relaxation. No significant changes in heart rate or blood pressure were noted. The preliminary data indicate: (i) a single dose of vecuronium does not significantly change respiratory compliance or respiratory resistance in preterm infants and (ii) during muscle relaxation fewer episodes of desaturation (hypoxemia) are observed.

High-pressure laparoscopic entry does not adversely affect cardiopulmonary function in healthy women

High-pressure laparoscopic entry does not adversely affect cardiopulmonary function in healthy women

Airway pressure release ventilation in the acute respiratory distress syndrome following traumatic injury.

Respiratory insufficiency that occurs following a traumatic injury is due to both mechanical and physiological disruption of pulmonary integrity. Although an overall decrease in pulmonary compliance (Δ V/Δ P) is a component of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS)*, this may not be a homogeneous process. Changes in compliance may actually occur at varying degrees throughout the lung parenchyma in a heterogeneous fashion. Attempting to open or recruit collapsed alveoli without causing lung injury by overdistention or stretch of alveoli with more normal compliance remains a clinical challenge. Airway pressure release ventilation (APRV) is a ventilator mode that incorporates features that optimize the spectrum of alveolar mechanics present in ARDS/ALI. In the past, the focus on ventilator support was on conforming the patient to the ventilator; alternatively, APRV accommodates the patient's breathing pattern and superimposes ventilation onto a pressure framework to support spontaneous breathing, 1 - 3 and thereby conforms the ventilator to the patient. APRV differs from other modes of positive-pressure ventilation in that it delivers a continuous positive airway pressure (CPAP) that releases periodically to augment CO 2 exchange. The patient's breathing is spontaneous and unrestricted throughout the entire ventilator cycle, allowing infinite inspiratory/expiratory ratios. Studies have shown that APRV can augment ventilation with lower pulmonary artery pressures and improved efficiency compared to traditional modes of ventilatory support; these elements may reduce the risk of ventilator-associated lung injury while improving oxygenation. After a brief review of the incidence and outcome of traumatic ARDS, we will present basic concepts of ventilator management with APRV and then will address the use of APRV in the patient with respiratory failure secondary to trauma.

Tracheal Injury

Tracheal Injury

Decreased Pulmonary Compliance Is an Early Indicator of Pulmonary Oxygen Injury

Decreased Pulmonary Compliance Is an Early Indicator of Pulmonary Oxygen Injury

Double-lung transplantation in the rat: An acute, syngeneic in situ model

Double-lung transplantation in the rat: An acute, syngeneic in situ model

Pulmonary hypertension, pulmonary edema, and decreased pulmonary compliance produced by increased ICP in cats.

Cats, anesthetized with sodium pentobarbital, were cannulated to measure pulmonary, systemic, and left atrial pressures and pulmonary ventilation, compliance, and resistance. Intracranial pressure was elevated to 30 mm Hg by injecting silicone oil into the extradural space. After an average time of 56 minutes, pulmonary systolic and diastolic pressures more than doubled, systemic systolic pressure sometimes rose and sometimes fell, and diastolic pressure rose 5%. Left atrial pressure never exceeded 8 cm of saline. Pulmonary compliance decreased by one-half, but airway resistance was unchanged. Pulmonary edema was estimated from histological sections. The pulmonary hypertension may be the result of a sympathetic discharge confined to the lung, since no remarkable changes in heart rate or systemic blood pressure occurred. The decrease in pulmonary compliance followed the rise in pulmonary arterial pressure, and is interpreted as the result of interstitial edema. There was no evidence that left heart failure or elevated left atrial pressure caused the pulmonary edema.

Changes in the biophysical properties and ultrastructure of lungs, and intrapulmonary fibrin deposition in experimental acute pancreatitis.

Using an experimental model of acute pancreatitis in the rat, we have studied changes in the biophysical properties of lungs and intrapulmonary fibrin deposition in this condition. Acute pancreatitis is associated with a significant decrease in pulmonary compliance (p less than 0.01) and a significant increase in lung weight (p less than 0.01) compared with a control sham operation group. These changes are associated with a 24% increase in intrapulmonary 125I fibrinogen deposition (p less than 0.01), and an 18% increase in 125I fibrinogen deposition per gram of lung tissue (p less than 0.05) in acute pancreatitis, compared with a control sham operation group. The increased fibrinogen deposition is abolished by treatment with low dose heparin. Using the same animal model changes in pulmonary ultrastructure are shown using scanning electron microscopy. The results indicate that pulmonary abnormalities are associated with intrapulmonary fibrin deposition in experimental acute pancreatitis and these findings may be relevant to the well described respiratory complications of the condition in man.

Respiratory response of guinea pigs to low levels of sulfuric acid

Respiratory response of guinea pigs to low levels of sulfuric acid

Comparative irritant potency of sulfate salts

Comparative irritant potency of sulfate salts

Functional and biochemical effects on the lung following inhalation of cigarette smoke and constituents. I. High- and low-nicotine cigarettes in mice

Functional and biochemical effects on the lung following inhalation of cigarette smoke and constituents. I. High- and low-nicotine cigarettes in mice

Case against the use of d-tubocurarine in operant studies of the cardiovascular system.

After reviewing evidence showing a high degree of integration between the autonomic and somatic systems, it is shown that d-tubocurarine alters both the central and peripheral perception and response patterns. Many of the observations made upon curarized animals can be explained by a central motor theory. Experimental use of curarine is hindered by the release of histamine in response to administration of curarine. Among other artifacts, curarine-induced release of histamine caused a progressive decrease of pulmonary compliance. When artificial respiration is given to curarized animals, the use of positive pressure ventilation and failure to monitor pulmonary gases are further sources of artifacts. It is noted that some investigators use the respiratory rate initially to adjust heart rate to ptedetermined levels.

Toxicity of aerosol propellants on the respiratory and circulatory systems III. Influence of bronchopulmonary lesion on cardiopulmonary toxicity in the mouse

Toxicity of aerosol propellants on the respiratory and circulatory systems III. Influence of bronchopulmonary lesion on cardiopulmonary toxicity in the mouse

Clinical application of continuous monitoring of respiratory failure.

The management of respiratory failure has improved greatly in recent years. This has been due to some extent to an improved understanding of respiratory physiology, but the major reason lies in the application of this knowledge to patients, particularly in intensive care units. Why the creation of such specialized areas ' was so long delayed is a mystery, the need having been obvious for so many years. Historically, it is probably fair to say that coronary intensive care units were the first to achieve widespread accep­ tance. In these units continuous monitoring was relatively easy to achieve, requiring electrocardiography and, less often, the continuous recording of arterial and central venous pressures. Equipment had been standardized, was relatively uncomplicated, and could be understood readily by medical and paramedical personnel. The patient in respiratory failure presents a more difficult challenge. His condition can deteriorate in seconds, and for reasons which are hard to un­ derstand graduates of medical and nursing schools continue to this day to be depressingly unaware of the measures needed to prevent and treat such de­ terioration. Respiratory depression and obstruction are poorly understood, and the necessity for adequate removal of CO2 from and the addition of O2 to blood in the lungs is often given little heed. Even in respiratory intensive care areas it is common to note a gradual decrease in pulmonary compliance during the night as the result of inadequate suctioning of respiratory tract secretions. It may require several hours in the morning to recover the ground lost during the night. This review wiIl deal with the continuous monitoring of patients in re­ spiratory failure, although it must be admitted at once that the state of the art is primitive. At this moment, for example, there is not available a satis­ factory method for the continuous measurement of the most essential pa­ rameter in respiratory care-arterial blood oxygen tension. Nonetheless, much has been learned, and recent visits to various laboratories suggest that the future will see gratifying developments in the field, hopefully, soon.

Cardiopulmonary function in uranium miners.

Respiratory physiologic studies in 34 uranium miners with known cumulative radiation exposure showed relatively mild airway obstruction, pulmonary overinflation, decrease in pulmonary compliance, reduced oxygen uptake during exercise, hyperventilation, reduced arterial oxygen saturation following exercise, and increase in physiologic dead space. The degree of physiologic abnormality was more severe in those miners with evidence on chest films of nodular silicosis or diffuse pulmonary fibrosis than in those with a normal chest film, but there was no qualitative difference in the results between the two groups. Four subjects, 3 of whom had normal chest films, had pulmonary artery hypertension during exercise, and in 2 of these, pulmonary arterial wedge pressure was also abnormal. The findings are interpreted as indicative of a widespread pathologic process, probably fibrotic in nature and located so as to impair function at the bronchiolar, arteriolar, and, in some instances, venular levels. Although the re...