Pulmonary Aspiration Of Gastric Contents Research Articles

A multicentre prospective cohort study of the accuracy of conventional landmark technique for cricoid localisation using ultrasound scanning

Cricoid pressure is employed during rapid sequence induction to reduce the risk of pulmonary aspiration. Correct application of cricoid pressure depends on knowledge of neck anatomy and precise identification of surface landmarks. Inaccurate localisation of the cricoid cartilage during rapid sequence induction risks incomplete oesophageal occlusion, with potential for pulmonary aspiration of gastric contents. It may also compromise the laryngeal view for the anaesthetist. Accurate localisation of the cricoid cartilage therefore has relevance for the safe conduct of rapid sequence induction. We conducted a multicentre, prospective cohort study to determine the accuracy of cricoid cartilage identification in 100 patients. The cranio-caudal midpoint of the cricoid cartilage was identified by a qualified anaesthetic assistant using the conventional landmark technique and marked. While maintaining the patient in the same position, a second mark was made by identifying the midpoint of the cricoid cartilage using ultrasound scanning. The mean (SD) distance between the two marks was 2.07 (8.49) mm. In 41% of patients the midpoint was incorrectly identified by a margin greater than 5mm. This error was uniformly distributed both above and below the midpoint of the cricoid cartilage. The Pearson correlation coefficient of this error with respect to body mass index was 0.062 (p=0.539) and with age was -0.020 (p=0.843). There were also no significant differences in error between male and female patients. Identification of cricoid position using a landmark technique has a high degree of variability and has little correlation with age, sex or body mass index. These findings have significant implications for the safe application of cricoid pressure in the context of rapid sequence induction.

Ultrasound dynamics of gastric content volumes after the ingestion of coconut water or a meat sandwich. A randomized controlled crossover study in healthy volunteers

BackgroundAdequate preoperative fasting is critical in preventing pulmonary aspiration of gastric content. We proposed to study the sonographic gastric content dynamics after the ingestion of liquid or solid food in healthy volunteers and confront it with current guidelines for preoperative fasting times. MethodsWe performed a prospective, crossover, evaluator-blinded study involving 17 healthy volunteers of both sexes. Each participant fasted for 10h and was subjected to a baseline gastric ultrasound, intake of 400mL of coconut water or a 145g, 355kcal meat sandwich, and sonographic gastric evaluations after 10min and every hour until the stomach was completely empty. ResultsAt baseline, all subjects had an empty stomach. At 10min, gastric content [mean + standard deviation (SD)] was 240.4 + 69.3 and 248.2 + 119.2mL for liquid and solid foods, respectively (p>0.05). Mean + SD gastric emptying times were 2.5 + 0.7 and 4.5 + 0.9h for liquid and solid foods, respectively (p<0.001). For the drink, the stomach was completely empty in 59% and 100% of the subjects after two and four hours, and for the sandwich, 65% and 100% of the subjects after four and seven hours, respectively. ConclusionsSonographic gastric dynamics for coconut water and a meat sandwich resulted in complete gastric emptying times higher and lower, respectively, than those suggested by current guidelines for preoperative fasting.

Assessment of effectiveness of cricoid pressure in preventing gastric insufflation during bag and mask ventilation: A randomized controlled trial.

Background:Rapid sequence induction and intubation (RSII) with application of “Cricoid pressure” and avoidance of “facemask ventilation” (FMV) is believed to minimize the risk of pulmonary aspiration of gastric contents during general anesthesia. However, some patients may be at risk of developing hypoxemia and may benefit from FMV during RSII. The purpose of this study was to assess the effectiveness of “cricoid pressure” in preventing gastric insufflation during FMV using gastric ultrasonography.Materials and Methods:Eighty-four adult patients were randomized to receive cricoid pressure (CP) or no cricoid pressure (NCP), during FMV after induction of general anesthesia. Gastric antral cross-sectional area (CSA) was measured with ultrasonography before and after FMV in supine and right lateral decubitus positions (LDP). Appearance of “comet tail” artifacts created by acoustic shadows of gas in the gastric antrum was noted.Results:The incidence of insufflation indicated by “comet tail” artifacts during FMV was lower in group CP (17 vs 71%; P < 0.001). The lowest Paw at which gastric insufflation occurred was higher in group CP (20 vs 14 cmH2O). The change in mean gastric antral CSA was significantly lower in group CP than in group NCP in supine (0.02 vs 0.36 cm2, P = 0.012) and right LDP (0.03 vs 0.67 cm2, P < 0.001).Conclusion:Cricoid pressure is effective in preventing gastric insufflation during FMV at Paw less than 20 cmH2O. Observation of comet tail artifacts in gastric antrum along with measurement of change in antral CSA on ultrasound examination is a feasible and reliable method to detect gastric insufflation.

Preoperative assessment of gastric contents and volume using bedside ultrasound in adult patients: A prospective, observational, correlation study.

Background and Aims:Pulmonary aspiration of gastric contents is a serious complication of anaesthesia. The aim of this study was to determine, with the help of ultrasound, the gastric volume and content in fasted patients presenting for elective surgeries and correlate the results with fasting times and co-morbidities of the patients.Methods:The study was conducted in 100 adult patients presenting for elective surgery. A preoperative bedside gastric ultrasound scan was done in supine and right lateral position. Gastric contents were noted, and gastric volume was calculated at the level of the gastric antrum. Gastric volume was estimated by measuring antral cross-sectional area (CSA) and using a mathematical model. Gastric volume in the right lateral decubitus (RLD) position was taken as the final reading. Analysis of variance and Student's t-test were done for statistical significance and P < 0.05 was considered statistically significant.Results:Six out of 100 patients had solid gastric contents and 16 had >1.5 ml/kg clear liquids, although they had been fasting between 10 and 15 hours. Patients suffering from diabetes and chronic kidney disease had statistically significant increase in CSA in both supine and RLD. We also found increase in estimated gastric volume as the BMI of the patients increased.Conclusion:Our study showed that fasting for more than 6–10 hours does not guarantee an empty stomach. Those with co-morbidities like diabetes mellitus, obesity and chronic kidney disease (CKD) appear more prone to have unsafe gastric contents.

Ultrasound assessment of gastric content in the immediate postpartum period: a prospective observational descriptive study.

Pulmonary aspiration of gastric contents in pregnant women undergoing general anesthesia or sedation/analgesia in the peripartum period is a feared complication in obstetric anesthesia. We assessed the changes in antral cross-sectional area (CSA) with ultrasonography in laboring women and in the immediate postpartum period. In an observational study in a university-affiliated maternity, gastric ultrasonography examinations were performed in non-consecutive laboring women, after epidural analgesia insertion and after childbirth. Assessment of antral CSA, difficulty of performance on a numerical scale, and factors that could influence gastric content were noted. A cut-off value of 381mm2 was taken for the diagnosis of empty stomach. One hundred women were enrolled in the study. Median antral CSA was 469mm2 [25th-75th] [324-591] after epidural insertion and 427mm2 [316-574] after delivery. Antral CSA was ≥381mm2 in 59 of 90 women (65%) after epidural insertion vs. 48 of 100 women (48%) after delivery (P=0.59). Median variation of antral CSA between two measurements was 36mm2 [-42 to 114]. Gastric ultrasonography was significantly more difficult to perform during labor than immediately post-delivery (median difficulty score 5 [2-7] vs. 2 [1-4], P<0.0001). No risk factors (pain, anxiety, diabetes, smoking) were significantly associated with the occurrence of full stomach post-delivery. This study demonstrated that 48% of parturients in the immediate postpartum period presented an antral CSA≥381mm2 , cut-off being accepted for diagnosis of empty stomach and emphasizes the need for re-assessing before any general anesthetic procedure.

Assessment of Aspiration-Induced lung Injuries among Acute Drug Poisoning Patients; Loghman Hakim Hospital, Poisoning center

Background: Following pulmonary aspiration of gastric contents, a variety of conditions occurs ranging from the acute inflammatory response (aspiration pneumonitis) to an infectious process (aspiration pneumonia). They cause due to the failure of protecting mechanism of airway patency following poisoning toxicity. Methods: Patients with acute drug poisoning for assessment of aspiration-induced lung injury evaluated during the twelfth months. Results: 410 participants followed the study. Of those, 249 (61 %) were male and 161 (39%) female. They ranged between 17-55 years. The mode was 25-39 years with frequency of 38%. The mean±SD of age was 32.3±14.5 (Female 34% and Male 27% respectively). The mean age ±SD of females was lower than males (27.3±12.4 vs. 34.4±14.4 years old). An episode of vomiting was recorded positive in 62% (254) of patients. They were recorded by self-reported or witnessed by someone else within the first hours of poisoning. The chest radiograph abnormality was observed mostly in both lungs (45%, 185). They consisted of multifocal patchy infiltrates in lungs 44% (178), diffuse bilateral infiltration 35% (144), and bilateral perihilar consolidation 18% (72) and lobular consolidation 4% (16) mainly in both lung fields (45%, 185). Aspiration related pulmonary complications attributed to pneumonitis 43.5% (178) including ARDS 35% (144), pneumonia 18% (72), and lung abscess 4% (16). There was a significant relationship with vomiting (P=0. 04). Conclusion: Aspiration pulmonary abnormalities were the commonest lung manifestation of drug toxicities. Chest x-ray abnormalities associated with vomiting presentation are clues to finding pulmonary complications of acute drug toxicity.

Case Report: The use of gastric ultrasound to assess risk of pulmonary aspiration

Pulmonary aspiration of gastric contents is a dreaded complication of general anesthesia, as it carries significant patient morbidity and mortality. Subsequent aspiration pneumonia can lead to prolonged mechanical ventilation, and a mortality rate of up to 5%. To minimize the risk of pulmonary aspiration, patients are required – as per the American Society of Anesthesiology’s “Practice Guidelines for Preoperative Fasting” – to fast prior to elective surgery in order to ensure that the stomach is empty prior to induction of general anesthesia.

Ultrasound assessment of the gastric contents for the guidance of the anaesthetic strategy in infants with hypertrophic pyloric stenosis: a prospective cohort study

BackgroundEvacuation of gastric content through a nasogastric tube, followed by rapid sequence induction, is usually recommended in infants undergoing pyloromyotomy. However, rapid sequence induction may be challenging, and is therefore controversial. Some anaesthetists regularly perform classical non-rapid induction technique, after blind aspiration of the gastric contents, although this aspiration may have been incomplete. This prospective observational study aimed to assess whether the ultrasound monitoring of the aspiration of the stomach contents, may be useful to appropriately guide the choice of the anaesthetic induction technique, in infants undergoing pyloromyotomy. MethodsInfants undergoing pyloromyotomy were consecutively included. Ultrasound assessment of the antrum was performed before and after the aspiration of the gastric contents through a 10 French gastric tube. The stomach was defined as empty when no content was seen in both supine and right lateral positions. The correlation between antral area and the aspirated gastric volume was also tested. ResultsWe analysed 34 infants. Ultrasound examination of the antrum failed in three infants. The stomach was empty in 30/34 infants (nine before aspiration, 21 after aspiration), allowing to perform a non-rapid induction technique in 88.2% of the infants. There was a significant correlation between antral area measured in right lateral decubitus and the aspirated gastric volume. ConclusionsOur results suggest that the qualitative ultrasound assessment of the antral content may be a simple and useful point-of-care tool, for the choice of the most appropriate anaesthetic technique for pyloromyotomy according to the estimated risk of pulmonary aspiration of gastric contents.

Place of rapid sequence induction in paediatric anaesthesia

### Key points Stept and Safar1 introduced the concept of rapid sequence induction (RSI) in 1970 after Snow and Nunn had found that the commonest cause of anaesthesia-related deaths in 1958 were because of aspiration.2 The perceived benefit of RSI in reducing the risk of aspiration, in high-risk patients, has led to it becoming the standard level of care, despite the lack of quality evidence.3 The development of the RSI technique is based upon adult practice. In children a ‘classical’ RSI may not always be the correct choice because of psychological, anatomical, and physiological differences. A survey of UK anaesthetists found that only around 50% would routinely perform an RSI for a child with a presumed full stomach despite having comparable aspiration risk as an adult.4 This article examines the evidence for the use of ‘classical’ RSI and its place in contemporary paediatric anaesthetic practice. Pulmonary aspiration of gastric contents under anaesthesia was not described as a problem until Mendelson famously described its deleterious effects in 1946. However, practice at that time included many risks for aspiration: no routine fasting combined with placing patients in a 20° head down position, undoubtedly increased the number who suffered from passive regurgitation. The first neuromuscular blocking agent, tubocurarine, was invented in the early 1940s. Although not used widely in 1946, it is only fully effective after 2–3 min, thereby allowing a prolonged period without protective airway reflexes. Despite the consideration of fasting times and gastric emptying taking a more prominent place since the 1940s and the invention …

Evaluation of six different airway devices regarding regurgitation and pulmonary aspiration during cardio-pulmonary resuscitation (CPR) – A human cadaver pilot study

BackgroundChest compressions and ventilation are lifesaving tasks during cardio-pulmonary resuscitation (CPR). Besides oxygenation, endotracheal intubation (ETI) during CPR is performed to avoid aspiration of gastric contents. If intubation is difficult or impossible, supraglottic airway devices are utilized. We tested six different airway devices regarding their potential to protect against regurgitation and aspiration during CPR in a randomized experimental human cadaver study. MethodsFive-hundred ml of 0.01% methylene-blue-solution were instilled into the stomach of 30 adult human cadavers via an oro-gastric tube. The cadavers were then randomly assigned to one of six groups, resulting in 5 cadavers in each group. Airway management was performed with either bag-valve ventilation, Laryngeal Tube, EasyTube, Laryngeal Mask (Classic), I-Gel, or ETI. Thereafter 5min of CPR were performed according to the 2010 Guidelines of the European Resuscitation Council. Pulmonary aspiration was defined as the presence of methylene-blue-solution below the vocal cords or the ETI cuff as assessed by fiber-optic bronchoscopy. ResultsThirty cadavers were included (14 females, 16 males). Aspiration was detected in three out of five cadavers receiving bag-valve ventilation and in two out of five intubated with LMA or I-Gel. In cadavers intubated with the LT, aspiration occurred in one out of five cases. No aspiration could be detected in cadavers intubated with ETI and EasyTube. ConclusionThis study provides experimental evidence that, during CPR, ETI offers superior protection against regurgitation and pulmonary aspiration of gastric contents than supraglottic airway devices or bag-valve ventilation.

Determining the Optimal Time of Gastric Emptying in Cats Using Dry or Wet Food

Background: Pulmonary aspiration of gastric content can result in intraoperative and postoperative complications, such as regurgitation, gastro-esophageal reflux and esophagitis. There are variations among authors about the ideal period of solid and liquid fasting. Determination of the appropriate amount of food abstinence in surgical patients is important, because of the metabolic disorders that interfere in response to anesthetic protocol or surgical intervention. Thereby, this research aimed to evaluate the appropriate period of fasting for elective anesthesia and surgical procedures in cats, by analysis of gastric emptying time based on the daily energy requirement.Materials, Methods &amp; Results: Seven cats of mixed breed, health and with an average weight of 2.857 ± 0.3780 were evaluated by gastroscopy for the presence of food and obtaining tissue samples. To evaluate the gastric emptying time, dry and moist food were offered at two different times, 8 h and 4 h before each evaluation, with an interval of seven days between each food treatment (dry and moist). There was no significant difference in all biochemical parameters evaluated (cholesterol, glucose, and lactate) in both fasting times and food types (P &gt; 0.05). All animals underwent gastric biopsy for histological evaluation and urease test, to discard morphological changes. After 4 h it was observed dry food in all cat’s stomach, however just five cats presented food in their stomach after eight hours. In other hand all the animals, which ate moist food, did not present any gastric content after four hours and eight hours of feeding. Gastric mucosa were considered normal in all cats with moderate amount of Helicobacter sp.Discussion: The difficulty of a consensus on the fast time in cats, and the great variability of the emptying time according to the feeding type, makes this study useful as basis for future studies on fasting with wet food, as well as providing immediate clinical application in surgical routine. Only a moderate gastritis related to helicobacter sp. was detected, but even healthy animals can carry Helicobacter sp. Four h of fasting time if feed the patient with 80% humidity ration improve anesthetic security of the patient with typical biochemical values. As shown, the appropriate preoperative fasting directly implies on decrease in the number of complications related to full stomach. Thus, always should take into account the possibility to perform fast in an appropriate period to prevent vomiting and aspiration, without the risk of hypoglycemia benefiting the patient and reassuring the anesthesiologist, especially in situations requiring urgent or emergency intervention. As observed through endoscopy, even eight hours of fasting with dry feed is inappropriate due to significant gastric volume of food in almost all cats. This suggests that prolonged preoperative fasting is no guarantee of low stomach volume. Wet feed can be an option for elderly and debilitated patients requiring surgical intervention within a short period of fasting. The time varies with type and volume of food that is variable according patients and different species and digestive conditions. The research were conducted with none complications. By means, this experiment it was concluded that the fasting time of 4 h with 80% humidity moist food allows complete gastric emptying without any complication.

Is postoperative nausea and vomiting still the big "little" problem?

Postoperative nausea and vomiting (PONV) is usually defined as any nausea, retching, or vomiting occurring within the first 24–48 hours of surgery. PONV can be extremely distressing to patients and is one of the most common causes of patient dissatisfaction and discomfort after anesthesia. The average incidence of PONV after general anesthesia is about 30% in all post-surgical patients but up to 80% in high-risk patients despite advances in anesthetics and anesthesia techniques [1,2,3]. In addition, PONV is rated highly in preoperative surveys, as the clinical anesthesia outcome that the patient would most like to avoid [4]. Therefore it is not surprising that patients express a high willingness-to-pay ($50–100) to avoid PONV [5,6]. While bleeding, wound dehiscence, pulmonary aspiration of gastric contents, esophageal perforation, and other serious complications associated with PONV are rare, nausea and vomiting is still an unpleasant, unwanted and all-too-common postoperative morbidity that can delay patient discharge from the postanesthesia care unit, require expanded levels of nursing care and increase unanticipated overnight hospital admissions in outpatients. The public now believes that anesthesia is extraordinarily safe from catastrophic outcomes, including major organ dysfunction or failure and even death. Therefore, many patients are more concerned about pain and PONV than surgical outcomes, such as whether the surgery would improve their condition. This is especially true for the majority of patients undergoing less invasive surgery. Moreover, minimally invasive surgery is now increasingly and routinely used across almost all surgical specializations. An important aspect of the quality of anesthetic care is the satisfaction of the patient with their care. Possible strategies to prevent the incidence of PONV include the prophylactic use of antiemetics such as dexamethasone or 5-HT3 antagonists, and avoiding use of emetic drugs such as inhalational anesthetics or opioids. However, no drug is completely effective at preventing PONV. If we can avoid drugs that cause PONV, all the better. The etiology of PONV remains unclear, but involves anesthetic, surgical and patient factors. Well-known risk factors are female gender, non-smoking status, a history of motion sickness or previous PONV, inhalational anesthetics, certain types of surgery, and opioid use [7]. Among the risk factors for PONV, the use of postoperative opioids is one of four major risk factors in the simplified risk-scoring system introduced by Apfel et al. [8]. In this month's Korean Journal of Anesthesiology, Lim et al. [9] report a study focusing on the effects of intraoperative opioid use on the incidence and severity of PONV and the effects of a single bolus administration of fentanyl during anesthesia induction versus intraoperative infusion of remifentanil on PONV. In a previous randomized controlled trial in over 5000 patients, the use of a short-acting opioid, like remifentanil, instead of fentanyl did not decrease the incidence of PONV [10]. However, in that study, patients who had been assigned to receive intraoperative remifentanil were given 50 µg of morphine per kilogram or an equivalent opioid at the end of surgery. Therefore, the current study has meaningful results based on comparing only fentanyl versus remifentanil itself, without the other factors that affect PONV. They demonstrated that a single bolus administration of fentanyl during anesthesia induction increased the incidence of PONV, while an intraoperative remifentanil infusion did not affect the incidence and severity of PONV. These results should have a marked synergistic effect with antiemetic prophylaxis. It should be kept in mind that even a single bolus administration of fentanyl during anesthesia induction can increase the incidence of PONV in high-risk patients.

Prevention of aspiration of gastric contents during attempt in tracheal intubation in the semi-lateral and lateral positions.

Pulmonary aspiration of gastric contents during tracheal intubation is a life-threatening complication in emergency patients. Rapid sequence intubation is commonly performed to prevent aspiration but is not associated with low risk of intubation related complications. Although it has been considered that aspiration can be prevented in the lateral position, few studies have evaluated the ability to prevent aspiration. Moreover, this position is not always a favorable position for tracheal intubation. If aspiration can be prevented in a clinically relevant semi-lateral position, it may be advantageous. We assessed the ability to prevent aspiration in the lateral position and various degrees of the semi-lateral position using a vomiting-regurgitation manikin model. A manikin's head was placed in the neutral, simple extension, or sniffing position. The amount of aspirated saline into the bronchi during simulated vomiting was measured at semi-lateral position angles of 0º to 90º in 10º increments. The difference in the vertical height between the mouth corner and the inferior border of the vocal cord was measured radiologically at each semi-lateral position in the three head-neck positions. Pulmonary aspiration was prevented at the ≥70º, ≥80º, and 90º semi-lateral positions in the neutral, simple extension, and sniffing positions, respectively. The mouth was lower than the vocal cord in the semi-lateral position in which aspiration was prevented. The lateral or excessive semi-lateral position was necessary to protect the lung from aspiration in the head-neck positions commonly used for tracheal intubation. Prevention of aspiration was difficult within clinically relevant semi-lateral positions.

Interrater Reliability of Qualitative Ultrasound Assessment of Gastric Content in the Third Trimester of Pregnancy

Background Pulmonary aspiration of gastric contents in pregnant women undergoing general anaesthesia is one of the most feared complications in obstetric anaesthesia. Bedside gastric ultrasonography is a feasible imaging tool to assess the gastric content. The purpose of this study was to investigate the reliability of qualitative bedside assessment of the gastric content performed by anaesthesiologists on third trimester pregnant women. Methods Pregnant women (≥32 weeks gestational age) were randomized to undergo ultrasound (US) assessments of their stomach in a fasting state (>8 h), or after ingestion of clear fluids only, or solid food. Three anaesthesiologists trained in gastric ultrasonography performed the assessments using a low-frequency curved-array US transducer (5–2 MHz). Primary outcome of the study was the consistency of raters in diagnosing the correct status of the gastric content, which was used to determine the interrater reliability among the three anaesthesiologists. Secondary outcomes were overall proportion of correct and incorrect diagnoses and the specific proportions of correct diagnosis across the three gastric content groups. Results We analysed 32 pregnant women. The interrater reliability displayed a kappa statistic of 0.74 (bias corrected 95% CI: 0.68–0.84). The overall proportion of correct diagnosis was 87.5% (84 of 96). The odds of correct diagnosis for ‘solid contents' were 16.7 times the odds for ‘empty', and 14.3 times for ‘clear fluid'. Conclusions Our results show the consistency of the qualitative US assessment of gastric contents of pregnant women in the third trimester by anaesthesiologists. A kappa of 0.74 suggests substantial agreement in terms of interrater reliability for this diagnostic measurement. Clinical trial registration ClinicalTrials.gov identifier: NCT01564030.

Interrater Reliability of Qualitative Ultrasound Assessment of Gastric Content in the Third Trimester of Pregnancy

Arzola, C.*; Cubillos, J.*†; Perlas, A.‡; Downey, K.*; Carvalho, J. C. A.* Author Information

Effect of acute cigarette smoking on gastric contents in regular smoker volunteers. A prospective randomized cross-over study

The authors sought to assess the effect of acute smoking on gastric contents in regular smoker volunteers. The primary endpoint was the variation in antral area during the 120-min study period after cigarette smoking. Regular smoker volunteers were included in this prospective randomized single blind cross-over study. Volunteers attended two separate study sessions: Control and Smoking sessions. The study started with an initial ultrasound measurement of the antral area, immediately followed by a 30-min periods of waiting (Control session) or of two-cigarettes smoking (Smoking session). Ultrasound measurements of the antral area were then performed 30, 60, 90 and 120 min after the initial ultrasonography, allowing for the calculations of the variation rates in antral area during the periods 0-30, 0-60, 0-90 and 0-120 min in both sessions. The variation in antral area during the period 0-120 min was equivalent in both sessions, as the difference in the variation rates between both sessions was -1.2%, with 90% confidence interval of the difference including 0 and lying entirely within the range of equivalence of -10% to 10%. No equivalence was found for the periods 0-30, 0-60 and 0-90 min, because of a non-significant decrease in antral area in the Smoking sessions during these periods. Preoperative acute smoking did not affect the variation in the gastric volume in regular smoker volunteers during the study period. These results allow for the suggestion that acute preoperative smoking does not probably change the risk of pulmonary aspiration of gastric contents in healthy regular smokers. NCT 02080598.

Point-of-care ultrasound defines gastric content and changes the anesthetic management of elective surgical patients who have not followed fasting instructions: a prospective case series.

Pulmonary aspiration of gastric contents is a major cause of anesthesia morbidity and mortality. Point-of-care gastric ultrasound provides information regarding the type and volume of gastric content. The hypothesis of this prospective cohort study was that the addition of point-of-care gastric ultrasound to standard patient assessment results in changes in anesthetic management in at least 30% of elective surgical patients who do not follow fasting instructions. Following Research Ethics Board approval and informed consent, elective surgical patients who did not follow fasting instructions were included in this prospective study. Documentation included the type of food ingested, the timing of the ingestion relative to the planned surgical time, and the treating anesthesiologist's management plan based on history alone. Next, an independent anesthesiologist not involved in the medical decision-making performed a focused gastric ultrasound examination. The results of the ultrasound exam were documented in a standardized fashion and made available to the attending anesthesiologist who then confirmed or revised the initial management plan. The treating anesthesiologist's actual (post-test) patient management was documented in a standardized fashion and compared with the initial (pre-test) management plan. Thirty-eight patients were included in this case series. Following point-of-care gastric ultrasound, there was a change in either the timing of anesthesia or the anesthetic technique (or both) in 27 patients (71%), with a net change towards a lower incidence of surgical delays. This prospective case series suggests that a standardized point-of care gastric ultrasound examination informs anesthesiologists' perceived level of aspiration risk and leads to changes in anesthetic management in a significant proportion of elective patients who did not follow fasting instructions.

Early Extracorporeal Membrane Oxygenation for Massive Aspiration during Anesthesia Induction

Although the incidence is not high in the general surgical population, pulmonary aspiration of gastric contents can result in serious long-term morbidity and mortality. We report a case of early use of extracorporeal membrane oxygenation (ECMO) to correct severe hypoxemia refractory to conventional mechanical ventilation in a patient with massive aspiration of gastric contents immediately followed by acute lung injury during general anesthesia induction. A 64-year-old woman diagnosed with stomach cancer was scheduled for elective diagnostic laparoscopy. Although there was no sign of gastrointestinal tract obstruction and midnight Nil per Os (NPO) was performed before the operation, pulmonary aspiration occurred during the induction of anesthesia. Despite the endotracheal intubation with mechanical ventilation, severe hypoxemia with hypercapnea persisted. Medical team agreed with applying veno-venous (VV) ECMO, and her blood gas analysis results became stable. ECMO was weaned successfully 9 days after the first aspiration event had occurred. Based on this case, early application of extracorporeal life support can have survival benefits.

Comparative study between succinylcholine, rocuronium and magnesium sulphate with rocuronium in rapid sequence induction

Background Rapid sequence induction usually applies when tracheal intubation must be performed in a patient who is suspected of having a full stomach and who is at risk of pulmonary aspiration of gastric contents. Succinylcholine is the traditional depolarizing neuromuscular-blocking agent used in rapid sequence induction. However, it has a number of undesirable side effects. Magnesium may have a role in potentiation of neuromuscular blockade produced by neuromuscular blockers such as rocuronium. Aim The aim of this study was to investigate the effects of magnesium sulphate pretreatment on intubating conditions and cardiovascular responses during rapid sequence tracheal intubation (RSI). Patients and methods A total of 60 adult patients were randomly allocated to three groups: the succinylcholine group, which received 1 mg/kg succinylcholine; the rocuronium group, which received 1.2 mg/kg rocuronium preceded 15 min with 500 ml normal saline; and the magnesium rocuronium group, which received 1.2 mg/kg rocuronium preceded 15 min with 60 mg/kg magnesium sulphate in 500 ml normal saline infusion. Anaesthesia was induced with fentanyl, propofol and a neuromuscular-blocking drug on the basis of the studied group. An anaesthesiologist, blinded to the rocuronium group assignments, performed RSI and assessed the onset time, intubating conditions and clinical duration of neuromuscular block in the different groups. Haemodynamics were recorded before magnesium sulphate or normal saline infusion, after anaesthesia induction and every minute after intubation for 5 min. Results The onset time was shortest in the succinylcholine and magnesium groups. The intubating conditions were significantly better in the magnesium group (P Conclusion Magnesium sulphate administered before RSI using fentanyl, propofol and rocuronium may shorten the onset time and improve the intubating conditions comparable to those of succinylcholine and suppress the haemodynamic stress response to intubation.

Przydatność ultrasonograficznej oceny zawartości treści żołądka. Opis przypadków

The paper presents the use of ultrasound assessment of gastric content in anesthesiological practice. Factors influencing pulmonary aspiration of gastric content and the risk of a complication in the form of aspiration pneumonia are discussed. The examination was performed on two patients hospitalized in a state of emergency who required surgical intervention. The first patient, a 46-year-old male with a phlegmon of the foot, treated for type 2 diabetes, ischemic heart disease and renal insufficiency, required urgent incision of the phlegmon. The second patient, a 36-year-old male with a post-traumatic pericerebral hematoma, qualified for an urgent trepanation. Interviews with the patients and their medical documentation indicated that they had been fasting for the recommended six hours before the surgery. However, during a gastric ultrasound examination it was found that food was still present in the stomach, which caused a change in the anesthesiological procedure chosen. The authors present a method of performing gastric ultrasound examination, determining the nature of the food content present and estimating its volume.