Abstract

Diaphragm plication surgery is conducted to remove dyspnea, which results from mediastinal shift, atelectasia, and ventilation/perfusion dyssynchrony in lungs that occur because of an eventrated diaphragm. This study aims to determine whether diaphragm plication has any effect on respiration by analyzing the patients' changing values in the respiratory function test (RFT) after plication surgery. Sixteen patients who underwent diaphragm plication surgery in our clinic because of plication eventration or paralysis were examined prospectively. Diaphragm eventration values were assessed using a calculation method that uses posteroanterior pulmonary radiographies taken during patient admission and control, then, these data were recorded. The amount of changes in the eventration levels and in restrictive respiratory failure parameters—forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) of RFTs—conducted in pre- and postoperative control periods were compared using statistical analysis methods. The compatibility between the amounts of RFT changes was examined through a satisfaction survey—using a questionnaire that consisted of multiple choice questions with answer options such as “better, ” “the same, ” and “worse”—to understand preoperative and postoperative symptom levels in the 12th month of postoperative control. According to postoperative levels, a decrease between 19% and 23% was observed in eventration amounts within the 1st postoperative month, 6th postoperative month, and 12th postoperative month. In addition, the highest average increase in FEV1 liter (lt) values was 0.2 lt and 0.25 in FVC (lt) values. Researchers of this study believe that more distinctive decisions need to be taken while identifying patients for surgery in unilateral diaphragm eventrations, especially in the adult patient group, surgical option should be used for cases in which the eventrated diaphragm results in mediastinal shift and respiratory failure.

Abstract

Diazinon (DZN) is an organophosphate insecticide which exerts its effect through the inhibition of acetylcholinesterase enzyme (AChE). In this work, we studied the development of tolerance to subchronic p.o. administration of DZN in rats, under both in vivo and in vitro conditions. A group of 20 rats (2 groups, n = 10) was administered p.o. the 1/10 of established LD50 DZN (namely 55.87 mg/kg bw) for 28 days. On the 14th and 28th day of study with isolated diaphragm and ileum, we examined the downregulation of nicotinic and muscarinic receptor function through Electrical Field Stimulation (EFS). Maximum contractility of the diaphragm was recorded on the 14th day of the study (25% higher compared to the non-treated rats), while on the 28th day the contractions almost did not differ from the values found in non-treated rats. EFS of isolated ileum on the 14th day of study caused significantly higher contractions compared to the non-treated rats, but after 28 days, ileum contractions decreased approximately to the level of contractions in non-treated rats. On the 14th study day, we also recorded increased amplitude of spontaneous ileum contractions, compared to non-treated rats. The application of increasing ACh concentrations caused dose-dependent ileum contractions, without statistically significant differences of median effective concentration (EC50 ) values in non-treated and treated rats. Tolerance to subchronic DZN administration develops due to various adaptation mechanisms, including the most important one—downregulation of nicotinic and muscarinic receptor function.