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Query: UMLS:C0032290 (aspiration pneumonia)
 2,291 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pulmonary acid aspiration (Mendelson's) syndrome may present after regurgitation and inhalation of acid gastric content during obstetric anesthesia. The stomach contents of 70 mothers were aspirated at caesarean section after pre-operative gastric 'emptying' and alkaline ingestion. The acidity of the gastric aspirate was analysed and volumes were measured. The patients were divided into 5 groups according to the time when gastric aspiration was carried out. A 'safe' gastric pH (pH greater than 3.5) was found in all patients up to 2 hours after antacid ingestion (groups 1-3). However, 2 1/2 hours after antacid ingestion (group 4y, 50% of patients had gastric volumes in excess of 25 ml and a pH of less than 3.5. We therefore recommend that, if general anaesthesia is to be induced or is in progress 2 hours after antacid therapy, the alkaline regimen should be resumed after repeated gastric aspiration.
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PMID:Gastric volume and acidity at caesarean section. 1 50

Mendelson's syndrome is discussed with a review of the literature and presentation of 27 personal cases studies. Accidental aspiration of gastric fluid occurs primarily during anesthesia, in cranial trauma victims, and in toxic coma patients. Tissue damage is proportional to the acidity and the quantity of aspirated fluid. The initial clinical manifestations are often serious, sometimes leading to acute respiratory distress syndrom with pulmonary edema. Frequent infectious complications, often with anaerobic microbes, are deciding factors in the prognosis. Artificial ventilation with positive pressure (sometimes continuous) is often necessary. Administration of corticosteroids at high doses is likely favorable. Prophylactic administration of antibiotics is initially directed against anaerobic agents. The prevention of this serious syndrome should be a primary concern of anesthesiologists and physicians treating comatous patients.
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PMID:[Mendelson's syndrome]. 2 27

Disodium edetate (ethylenediaminetetraacetic acid, disodium salt; disodic EDTA), 3 g, was given, via an intravenous normal saline drip of 30 min, to 25 patients in order to assess a benefit for anaesthesia practice. A significant reduction of both volume and acidity of the gastric secretion was found in all the 10 patients with peptic ulcer having received the drug. The peak of the change was 1 h after administration. In other 10 non-ulcer patients undergoing orthopaedic surgeries under epidural anaesthesia with lidocaine 2%, 5 mg kg-1, pH of the gastric juice unanimously rose, from 2.24 +/- 0.28 to 4.10 +/- 0.21 1 h after EDTA with a P derived from paired difference analysis of less than 0.001. A similar group of patients receiving only normal saline showed no important changes in pH (from 2.37 +/- 0.24 to 2.34 +/- 0.19). The pH of the fundic surface, measured directly under fiberscopic control in further 5 patients suffering from peptic ulcer, was found also to rise from 1.84 +/- 0.21 to 4.62 +/- 0.34 1 h after EDTA, P less than 0.001. Total and ionized calcium changed unsignificantly. Disodic EDTA in the dose and manner used in this study showed no clinical side-effects. The constant and obvious effect of inhibition of the gastric secretion as well as the dynamics of such an action recommend disodic EDTA to be tried in reducing the aspiration pneumonia morbidity.
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PMID:Inhibitory effect of disodium edetate on gastric secretion. 308 72

The use of cimetidine, an H2-receptor antagonist, to minimize the complications of acid aspiration pneumonia is reviewed. Since Mendelson's early description of acid aspiration in 66 obstetrical patients, attempts have been made to decrease gastric acidity by administering perioperative antacids and/or antihistamine drugs such as atropine and glycopyrrolate. In this review of the literature, strict attention is given to study design and subject selection, methods of collecting gastric samples and reporting both pH and volume measurements, and medications taken on admission, given preoperatively, and as anesthetics. Clinical trials evaluating cimetidine alone and compared with other prophylactic regimens were reviewed, detailing the timing, route, and frequency of drug administration. Cimetidine appears to be effective in minimizing complications of acid aspiration since gastric acidity (pH less than 2.5) is a contributing factor in both the morbidity and mortality of this disease state. In general terms, cimetidine 300 mg po 1.5-2.0 h prior to intubation or 45-60 minutes iv before surgery will decrease gastric acidity below the critical level. This effect may be maintained for up to three hours. Perioperative cimetidine administration, to minimize the complications of acid aspiration, appears to be safe in terms of drug-drug interactions and effects on labor, the fetus, and the newborn child.
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PMID:Cimetidine in anesthesia: does it minimize the complications of acid aspiration? 637 13

In this study, pH metry was simultaneously applied with a new technique, the intraluminal multiple electrical impedance (IMP) procedure, for measuring gastrointestinal motility for gastroesophageal reflux (GER) detection. Seventeen infants with clinical symptoms of GER disease such as recurrent apnea, aspiration pneumonia, wheezing, and failure to thrive were investigated during two feeding periods. A single catheter combining a pH electrode with seven electrodes for impedance measurements over a distance of 8.5 cm was used for the investigation. In all patients, 185 acid episodes were detected by pH metry. In 106 of these 185 acid episodes, a unique pattern in the IMP readings was noted, indicated by a retrograde esophageal volume flow. These episodes were regarded as acid GER episodes. Seventy-one of the 185 acid episodes occurred during the clearance process of a preceding acid GER characterized by typical IMP readings of an anterograde bolus transport. Eight of 185 acid episodes were missed in the IMP readings for technical reasons. The IMP pattern described as characteristic for a GER was observed in 490 other episodes not detected by pH metry. More than 75% of all GER detected by IMP reached the pharyngeal space; 73% of all GER occurred during feeding and the first 2 postprandial hours and 27% occurred during the remaining time until the next feeding. Even during the latter period, 34% of GER were detected by IMP only; they were missed by pH metry. Volume clearance indicated by IMP was always completed earlier than acidity clearance. The results show that IMP technique facilitates the detection of all GER, whereas pH metry is confined to the measurement of acid GER. Therefore, this technique might improve the evaluation of GER disease and detection of GER in conditions with gastric hypoacidity.
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PMID:Gastroesophageal reflux in infants: evaluation of a new intraluminal impedance technique. 898 51

Forty-three patients aged 3-6 years, undergoing minor surgery were studied. Parents staying with their children were asked to evaluate the anxiety of their children and themselves by a visual-analogue scale the night before surgery (VAS-N) and just before premedication in the morning (VAS-M). After induction, gastric fluid was collected and the volume and pH were measured. Patients with a VAS-M lower than 5 were considered the low-anxiety group (L-group; n=24) and the remainder comprised the high-anxiety group (H-group; n=19). The gastric volume of the H-group was significantly lower than that of the L-group. No difference was found in pH. A significant overall correlation of VAS-N was found between patients and their parents. These results suggest that the low level anxiety of children and their parents could not reduce the volume and acidity of gastric fluid and consequently the risk of aspiration pneumonia.
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PMID:Preoperative anxiety and volume and acidity of gastric fluid in children. 1063 4

Our greater understanding of gastric physiology and the epidemiology of Mendelson's syndrome has allowed the traditional guidelines for preoperative fasting (nothing by mouth after midnight or 6 hours before surgery) to be changed, based on the results of many scientific studies. The stomach is not emptied of liquids and solids in the same way, and therefore preoperative fasting should not be the same for both. Human milk leaves the stomach more rapidly than infant formulas, and the emptying of non-human milk is similar to that of solids. Fasting does not guarantee that the stomach will be empty or that the pH of gastric juices will be high; moreover, shortening the preoperative fasting period may bring several advantages for the patient. Factors such as premedication, anxiety, age, certain associated diseases or injuries may or may not influence gastric emptying and/or acidity at the time of anesthesia. We review the literature, including the guidelines on fasting of the American Society of Anesthesiologists for application with healthy patients of all ages in elective procedures, excluding, among others, women in childbirth and patients undergoing emergency surgery.
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PMID:[Preoperative fasting regimens and premedication to reduce the risk of pulmonary aspiration]. 1251 96

Pharyngolaryngeal reflux has been generally accepted as a cause for pharyngolaryngitis, hoarseness, aspiration pneumonia, chronic cough, and nocturnal asthma. Although patients who have undergone gastric conduit reconstruction after esophagectomy are at a high risk to pharyngolaryngeal reflux disease (PLRD), PLRD after esophagectomy is still unknown. The aim of this study is to investigate the correlation between reflux pharyngolaryngitis and acid reflux into the hypopharynx and into the cervical esophagus in patients who have undergone cervical esophagogastrostomy. We enrolled 62 patients who received follow-up endoscopy and 24-h pH monitoring after cervical esophagogastrostomy. These included 26 at 1 month after surgery and 36 at 1 year or more after surgery. We investigated: (i) the correlation between the extent of reflux pharyngolaryngitis and that of reflux esophagitis based on endoscopic findings; and (ii) the correlation between the extent of reflux pharyngolaryngitis and that of acid exposure -'% time pH < 4' measured by 24-h pH monitoring - in the hypopharynx and in the cervical esophagus, and of acidity in the gastric conduit. There was no difference in acid exposure between the hypopharynx and the cervical esophagus according to time after surgery. However, the acidity in the gastric conduit was significantly more at one year or more after surgery compared with acidity at 1 month after surgery (P= 0.001). There was a significant correlation between acid exposure in the hypopharynx and that in the cervical esophagus (P < 0.001), although acid exposure in the hypopharynx was significantly less than that in the cervical esophagus (P < 0.001). A significant correlation between reflux pharyngolaryngitis and reflux esophagitis was observed (P < 0.001). There was a significant correlation between reflux pharyngolaryngitis and acid exposure in the hypopharynx (P= 0.021), and also that in the proximal esophagus (P= 0.001). The correlation between the extent of reflux pharyngolaryngitis and the acidity in the gastric conduit was not observed. These findings are consistent with pharyngolaryngitis being caused by gastro-esophago-pharyngolaryngeal reflux in patients after cervical esophagogastrostomy, despite the upper esophageal sphincter strongly preventing acid reflux from the cervical esophagus into the hypopharynx.
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PMID:Pharyngolaryngeal reflux in patients who underwent cervical esophago-gastrostomy following esophagectomy. 2011 23