How do you prevent gastric distention during CPR?
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Gastric Distention is bloating of the stomach when air is pumped into it. This may be done when someone is performing cardiopulmonary resuscitation and blowing air into the mouth of someone who is not breathing spontaneously. Show
It may also occur when more advanced medical procedures are performed by emergency or hospital personnel, and air leaks past the opening of the lungs and into the stomach. Gastric distention is potentially dangerous since it can cause the contents of the stomach to come up the esophagus (gullet) and spill back down into the lungs. This can cause drowning, by filling the lungs with fluid, if there has been enough material in the stomach, or, with less material, can cause stomach acids to damage the lungs and create a condition known as "aspiration pneumonia". CPR standards issued by the American Heart Association suggest that people suffering gastric distention be turned on their sides and the stomach be compressed gently to push out the air bloating the stomach. By turning the individual on their side into what is known as the recovery position, the stomach contents will often continue past the opening of the lungs and drain out the mouth, thus sparing the victim lung damage or the internal drowning which can be caused by large volumes of stomach material getting into the lungs. Template:Disease-stub Bag-valve-mask ventilation is the first-line ventilation method during cardiopulmonary resuscitation (CPR). Risks include excessive volume delivery and gastric insufflation, the latter increasing the risk of pneumonia. The efficacy of ventilation can also be reduced by airway closure. We hypothesized that continuous chest compression (CC) could limit the risk of gastric insufflation compared to the recommended 30:2 interrupted CC strategy. This experimental study was performed in human “Thiel” cadavers to assess the respective impact of discontinuous vs. continuous chest compressions on gastric insufflation and ventilation during CPR. MethodsThe 30:2 interrupted CC technique was compared to continuous CC in 5 non-intubated cadavers over a 6 min-period. Flow and Airway Pressure were measured at the mask. A percutaneous gastrostomy allowed measuring the cumulative gastric insufflated volume. Two additional cadavers were equipped with esophageal and gastric catheters instead of the gastrostomy. ResultsFor the 7 cadavers studied (4 women) median age of death was 79 [74–84] years. After 6 min of CPR, the cumulative gastric insufflation measured in 5 cadavers was markedly reduced during continuous CC compared to the interrupted CC strategy: (1.0 [0.8–4.1] vs. 5.9 [4.0–5.6] L; p < 0.05) while expired minute ventilation was slightly higher during continuous than interrupted CC (1.9 [1.4–2.8] vs. 1.6 [1.1–2.7] L/min; P < 0.05). In 2 additional cadavers, the progressive rise in baseline gastric pressure was lower during continuous CC than interrupted CC (1 and 2 cmH2O vs. 12 and 5.8 cmH2O). ConclusionContinuous CC significantly reduces the volume of gas insufflated in the stomach compared to the recommended 30:2 interrupted CC strategy. Ventilation actually delivered to the lung is also slightly increased by the strategy. IntroductionSurvival from out-of-hospital cardiac arrest depends on the rapid initiation of cardiopulmonary resuscitation (CPR) and defibrillation to maintain perfusion to vital organs and promptly restore spontaneous circulation.1 The importance of high-quality CPR is strongly emphasized by the International Liaison Committee on Resuscitation but there is considerable debate around the role of ventilation during CPR. Current guideline recommendations are to provide chest compressions and bag-valve-mask ventilation in a 30:2 ratio for adult patients in the absence of an advanced airway.2 Studies have not shown that performing continuous chest compressions with regular, interspersed ventilation cycles resulted in improved outcomes.3, 4 While ventilation is critical for maintaining tissue oxygenation and CO2 elimination, during cardiac arrest, the metabolic demand is decreased due to a low cardiac output and peripheral perfusion. Even if ventilation is necessary for prolonged resuscitation,5 excessive ventilation can have a detrimental physiological effect and lead to adverse patient outcomes. Ventilating with excessive pressure, volume, or rates can also result in gastric insufflation and increased intrathoracic pressure, leading to decreased venous return and cardiac output.6, 7 The efficacy of ventilation can also be reduced by airway closure that was recently described in patients with out of hospital cardiac arrest.8, 9 Gastric gas insufflation may lead to regurgitation and results in the occurrence of aspiration pneumonia or pneumonitis.10 We hypothesized that continuous chest compressions (CC) could limit the risk of gastric inflation without impairing ventilation compared to the recommended 30:2 interrupted CC strategy. The objective of this study was to assess the impact of continuous CC on gastric insufflation and effective ventilation during bag-valve-mask ventilation. Section snippetsHuman cadavers and set-upThe human “Thiel” cadavers came from a specific donation program of the anatomy laboratory of UQTR (Université du Québec à Trois-Rivières) and experiments were conducted in accordance with Canadian regulations after approval from the local Research Ethics Board (CER-14-201-08-03.17). The Thiel embalmed cadavers are the result of a special preparation method that allows for preservation of the tissue elastic properties, flexibility, and texture. In addition, the anatomy of the oropharynx and ResultsFor all the 7 cadavers tested (5 cadavers for experiment 1, and 2 for experiment 2), anthropic characteristics and respiratory mechanics, including the level of airway closure, are listed in Table 1. Experiment 1 (5 cadavers)Number of insufflations, insufflation time, mean and maximal airway pressure (Mean Paw and Max Paw), ventilation and insufflation per minute (MVinsp, MVexp, Insufflgast) are listed in Table 2. Ventilation was delivered at the same rate in both strategies. Gastric insufflation was observed in all the 5 cadavers tested in all conditions, with an amount that depended on the conditions tested. After 3 min of CPR the cumulative volume of gas insufflated into the stomach was reduced on average by Experiment 2 (2 cadavers)The changes in baseline gastric pressure (ΔPgas) over the 3 min induced by gastric insufflation were measured in 2 cadavers during the 2 strategies tested: it amounted to respectively 12.0 and 5.8 cmH20 during interrupted CC but only 1.0 and 2.0 cmH2O during continuous CC (Fig. 4). Esophageal pressure swing due to chest compressions was not significantly different during continuous CC compared to interrupted CC (11.7 [5.3–20.1] vs. 12.8 [6.0–20.5] cmH20; p = 0.49). Main findingsOur study shows that continuous CC significantly reduced the volume of gas insufflated in the stomach compared to the recommended 30:2 interrupted CC strategy. In addition, continuous CC do not impair the amount of ventilation actually delivered to the lungs during manual bag-mask-ventilation. Impact of continuous CC on gastric insufflation and ventilationThe risk of hyperventilation associated with manual bag ventilation during resuscitation has been extensively documented.14, 15 The associated risk of gastric regurgitation is also well described.16, 17 Previous observations suggest that even moderate, gastric distension generated by manual bag insufflation may affect both CPR attempt and post-resuscitation care.18, 19 The most commonly recognised complication of gastric insufflation is regurgitation of gastric content. In a recent large Physiological interpretation of the resultsThe fact that continuous CC significantly reduces gastric distension without impairing lung ventilation could seem counterintuitive at first sight. These findings can be explained by the physiological rules that govern gas motion entering and exhaling the respiratory system during chest compressions. The pressure at which the lower esophageal sphincter opens in alive patient during anaesthesia has been estimated around 20 cmH2O.6, 10 The lower esophageal sphincter pressure has been also measured Clinical implicationsThe main rationale for interrupted 30:2 CC ventilation ratio before advanced airway placement is that continuous CC may jeopardize bag ventilation and favour gastric regurgitation by increasing airway pressure (32). The rational supporting this recommendation is weak and the physiological impact of continuous versus interrupted CC on both ventilation and gastric insufflation has never been specifically investigated. Nevertheless, despite animal and human studies demonstrating the benefit of LimitationsSome limitations of our study deserve to be discussed. First, the cadaveric model is not entirely comparable to a real cardiac arrest patient. However, the lower esophageal opening pressure reported in the present study is higher than previously described immediately after death25, 26 and this may have interfered with our results by limiting gastric insufflation. Second, the method we used to assess gastric insufflation along time, previously reported by Segal et al.24 (i.e., a surgical ConclusionDuring bag-valve-mask ventilation, continuous chest compressions significantly reduce the quantity of gas insufflated into the stomach and increase lung ventilation compared to 30:2 interrupted CC strategy. Conflict of interest•Savary have received research funding from Air Liquide Medical Systems (Antony France) and fee for lectures from Vygon (Ecouen, France). Lesimple and B. Badat are medical engineers employed by the society Air Liquide Medical Systems (Antony, France). •S. Delisle received intermittent stipend from Air Liquide Medical Systems. •Mercat received grants for his research laboratory from Vygon, Fisher-Paykel, Medtronic, personal fees for consulting from Air Liquide Santé and Faron Pharmaceuticals and AcknowledgmentsWe are thankful for the incredible professionalism and availability of the laboratory of anatomy team in the UQTR: Johanne Pellerin, Marie-Ève Lemire and Sophie Plante. We are also in debt to Nathan Prouvez and Manon Hannoucene for their contribution in the organization. References (31)
A new physiological model for studying the effect of chest compression and ventilation during cardiopulmonary resuscitation: the Thiel cadaverResuscitation(2018) Respiratory system compliance decreases after cardiopulmonary resuscitation and stomach inflation: impact of large and small tidal volumes on calculated peak airway pressureResuscitation(1998) Reassessing the need for ventilation during CPRAnn Emerg Med(1996) A randomized trial of continuous versus interrupted chest compressions in out-of-hospital cardiac arrest: rationale for and design of the resuscitation outcomes consortium continuous chest compressions trialAm Heart J(2015) European resuscitation council guidelines for resuscitation 2015: section 2. Adult basic life support and automated external defibrillationResuscitation(2015) 2022, ResearchSquare 2022, Prehospital Emergency Care Research article Arthroscopy: The Journal of Arthroscopic & Related Surgery, Volume 29, Issue 10, 2013, pp. 1623-1627 Show abstractNavigate Down The purpose of this study was to compare suture anchor placement in the acetabular rim between straight and curved drill guides regarding angle and distance of the suture anchor tip from the articular cartilage during labral refixation. A total of 14 fresh-frozen cadaveric hips underwent arthroscopic labral incision from the 12 to 3 o'clock positions and subsequent repair with either a curved drill guide or a straight drill guide. These hips were then compared by computed tomographic imaging analysis by measuring the angle of suture anchor insertion and the distance of the tip of the suture anchor to the articular cartilage at the 1 o'clock, 2 o'clock, and 3 o'clock positions. The curved suture anchor (CSA) guide significantly increased the insertion angle (P = .009) and distance from the articular cartilage to anchor (P = .003) at the 1 o'clock position on the acetabulum. The angle of insertion at the 2 and 3 o'clock positions was greater for the CSA guide compared with the straight suture anchor (SSA) guide but did not reach statistical significance. A CSA guide was shown to be significantly more effective in increasing the angle of insertion of suture anchors and increased the distance of the suture anchor tip to the articular cartilage surface at the 1 o'clock position but not at the 2 or 3 o'clock position. The use of SSA guides can be difficult because of the osseous morphologic characteristics of the acetabular rim, leading to placement of the suture anchor away from the acetabular rim and therefore resulting in a nonanatomical refixation of the acetabular labrum. The use of a curved guide, flexible drill, and flexible suture anchor inserter may provide more precise placement of suture anchors in the acetabular rim. Research article Journal of Plastic, Reconstructive & Aesthetic Surgery, Volume 67, Issue 10, 2014, pp. e250-e251 Research article Journal of Plastic, Reconstructive & Aesthetic Surgery, Volume 67, Issue 4, 2014, pp. e107-e108 Research article A new microsurgical research model using Thiel-embalmed arteries and comparison of two suture techniquesJournal of Plastic, Reconstructive & Aesthetic Surgery, Volume 67, Issue 3, 2014, pp. 389-395 Show abstractNavigate Down To assess the utility of the Thiel arterial model in microsurgical research, we compared interrupted horizontal mattress (HM) sutures to simple interrupted (SI) sutures in human vessels. A microsurgical set-up using an operating microscope and Thiel-embalmed arteries was used to practice ten SI and HM anastomoses. Vessel patency, leak and stricture were evaluated using angiography, and vessel wall architecture was evaluated using light microscopy and scanning electron microscopy (SEM). The technique speed was also assessed. We have successfully evaluated all outcomes. All anastomoses were patent. The stricture rate was higher with HM than with SI (60% vs. 35% surface area reduction). Three minor leaks occurred with HM sutures versus one with SI sutures. Edges were evenly everted without any intimal flaps with HM compared to SI. The anastomoses were performed faster using HM than SI sutures (7:58 min vs. 12:41 min, respectively). This is the first study to evaluate the feasibility of a Thiel-embalmed artery model for research purposes. The HM microvascular suture is a promising technique that requires further in vivo validation. Research article Reintegration & recovery after surviving cardiac arrest: Learning from the VACAR registryResuscitation, Volume 146, 2020, pp. 255-257 Research article A new distraction arthroplasty device using magnetic force; a cadaveric studyClinical Biomechanics, Volume 28, Issue 4, 2013, pp. 423-428 Show abstractNavigate Down It is difficult for an articular cartilage injury to repair spontaneously. There are many procedures for treating cartilage injury, however there is no standard procedure for middle-aged patients who have diffuse knee osteoarthritis, especially of the lateral compartment. Therefore, Ochi developed a new distraction device that uses magnetic power to enlarge a joint space and promote cartilage regeneration with microfracture. The purpose of this study is to evaluate this new distraction arthroplasty system by using the cadaveric knee. This study used ten knees from six cadavers that were embalmed by Thiel's methods. The medial and lateral joint space was measured by AP radiographic view before and after distraction, and after weight-bearing to evaluate the joint distraction. The contact pressure of the medial and lateral compartments at the knee extension position by using a prescale film system was measured before and after weight-bearing with a 15 or 30-kg weight-bearing load to evaluate the effectiveness of this device. The lateral joint space significantly increased from the pre-distraction to the post-distraction; however, it did not change significantly between post-distraction and post-weight-bearing. With a 15 or 30-kg weight-bearing load, the contact pressure of the lateral compartment significantly decreased from the pre-distraction to the post-distraction. The most important advantage of this device is that it maintains a continuous distraction tension and enables almost the full range of motion of the knee. We believe that joint distraction by using magnetic force can be a promising option for cartilage injury in middle-aged patients. CAVIAR (Cardiac Arrest and Ventilation International Association for Research) INSERM 955, Créteil, France. What causes gastric distension during CPR?During cardiopulmonary resuscitation (CPR), positive pressure ventilation may lead to gastric insufflation because of decreased pulmonary compliance and decreased lower esophageal sphincter tone. Essentially, gas delivered will follow the path of least resistance, which may be to the stomach.
What is the recommendation for preventing gastric inflation during breaths?To prevent gastric inflation the airway must be kept open, and breaths delivered slowly… very slowly. Based on my observations no one delivers breaths slow enough. When your own heart rate is going 150 beats per minute, waiting 6 seconds to deliver a breath feels like forever!
When May gastric distention occur during rescue breathing?Gastric Distention is bloating of the stomach when air is pumped into it. This may be done when someone is performing cardiopulmonary resuscitation and blowing air into the mouth of someone who is not breathing spontaneously.
What is the most common cause of gastric distention when using a bag mask for ventilation?Excessive ventilation pressure usually results in gastric distention and may compromise patency. Ventilating large volumes at high pressure with a mask will result in gastric distension and risk of regurgitation.
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