CASE REPORT Suspected Arterial Gas Embolism After Glossopharyngeal Insuffl ation in a Breath-Hold Diver Mats H. Linér , and Johan P. A. Andersson L INÉR MH, A NDERSSON JPA. Suspected arterial gas embolism after pulmonary pressures as high as 80 cmH2 O have been glossopharyngeal insuffl ation in a breath-hold diver. Aviat Space reported ( 9 ). Such pressures could possibly lead to pul- Environ Med 2010; 81:74 – 6. Introduction: Many competitive breath-hold divers employ the tech- monary barotraumas ( 4,11,15 ) and arterial gas embolism nique of glossopharyngeal insuffl ation in order to increase their lung gas is one conceivable consequence. Remarkably, there are volume for a dive. After a maximal inspiration, using the oral and pha- few reports about pulmonary complications associated ryngeal muscles repeatedly, air in the mouth is compressed and forced with glossopharyngeal insuffl ation, even though com- into the lungs. Such overexpansion of the lungs is associated with a high transpulmonary pressure, which could possibly cause pulmonary petitive breath-hold divers frequently perform this tech- barotrauma. Case Report: We report a case of transient neurological nique ( 15 ). Jacobsen et al. ( 4 ) reported an asymptomatic signs and symptoms occurring within 1 min after glossopharyngeal in- pneumomediastinum in one of their subjects after per- suffl ation in a breath-hold diver. He complained of paresthesia of the forming glossopharyngeal insuffl ation. Lindholm et al. right shoulder and a neurological exam revealed decreased sense of touch on the right side of the neck as compared to the left side. Motor ( 6 ) presented accounts from three elite breath-hold div- function was normal. The course of events in this case is suggestive of ers who had experienced neurological symptoms sug- arterial gas embolism. Discussion: Although the diver recovered com- gestive of arterial gas embolism after glossopharyngeal pletely within a few minutes, the perspective of a more serious insult insuffl ation. Here we report the case of one breath-hold raises concerns in using the glossopharyngeal insuffl ation technique. In addition to a neurological insult, damage to other organs of the body has diver with transient neurological signs and symptoms to be considered. Both acute and long-term negative health effects are occurring within 1 min after glossopharyngeal insuffl a- conceivable. tion. The authors directly witnessed the incidence. In- Keywords: glossopharyngeal insuffl ation , lung packing , pulmonary formed consent was obtained for publication of the barotrauma , volutrauma , apnea , competitive breath-hold diving . diver’s details in this report. CASE REPORT REATH-HOLD DIVING as a competitive sport has The diver in this case participated as an experimental B gained increasing interest in recent years, with re- subject at our laboratory in a breath-holding experiment cords showing an unprecedented development. Cur- not related to the presented incident. He was an 18-yr- rently, the world record for “ static apnea ” (apnea during old, healthy nonsmoker (height 177 cm and weight rest at the surface of a pool) is 11 min 35 s, for “ dynamic 65 kg) and had been breath-hold diving competitively with fi ns ” (horizontal underwater swim) it is 250 m for 1 yr. He was training for breath-hold diving 5-6 h a ( ; 820 ft), and for “ no limits ” (maximal depth with the week and performed an additional 5-6 h per wk of other help of ballast weight and equipment-assisted ascent) it forms of physical exercise (swimming, running, and is 214 m. In order to increase the time and depth of a gym training). He routinely practiced glossopharyngeal dive, divers use special techniques or maneuvers. One insuffl ation in association with breath-hold dives. At the such technique used to increase the gas volume of the beginning of the experiment the subject performed three lungs during the dive is called “ glossopharyngeal insuf- vital capacity measurements in the standing position fl ation ” or “ lung packing. ” After a maximum inspira- and three measurements in the supine position, all with- tion, a mouthful of air is taken with the glottis closed. Thereafter the air in the mouth is compressed using the From the Department of Clinical Sciences, Section of Anesthesiol- oral and pharyngeal muscles, the glottis opened and the ogy and Intensive Care and the Department of Cell and Organism air forced into the lungs ( 7,11 ). This maneuver is per- Biology, Lund University, Lund, Sweden. This manuscript was received for review in May 2009 . It was ac- formed repeatedly. With glossopharyngeal insuffl ation, cepted for publication in September 2009 . the diver can increase the lung gas volume for the dive Address correspondence and reprint requests to: Mats H. Linér, by up to 4 L above the normal total lung capacity ( 9 ). Heart and Lung Center, EB15, Lund University Hospital, SE-221 85 Due to the fact that the lung has a low compliance at Lund, Sweden; [email protected] . Reprint & Copyright © by the Aerospace Medical Association, high lung volumes, glossopharyngeal insuffl ation is as- Alexandria, VA. sociated with a high transpulmonary pressure. Trans- DOI: 10.3357/ASEM.2571.2010 74 Aviation, Space, and Environmental Medicine x Vol. 81, No. 1 x January 2010 AGE IN A BREATH-HOLD DIVER — LINER & ANDERSSON out glossopharyngeal insuffl ation. The protocol con- ( 13,14 ). At 1 atm, arterial gas embolism has been associ- sisted of 20 apneas of submaximal duration with an ated with mechanical ventilation in cases where relative inhaled lung volume corresponding to 85% of vital ca- high ventilatory pressures and volumes had to be used. pacity in the supine position, i.e., glossopharyngeal in- Most reports deals with treatment in neonates, but suffl ation was not part of the experimental protocol. adults are also at risk ( 5 ). Regardless of its origin, de- During apneas, all variables were recorded using nonin- pending on the size and localization of the arterial gas vasive equipment. The experimental protocol lasted for embolism, neurological signs and symptoms can vary about 3 h. from minor short lasting, to more serious, to death. After completion of the planned experiment, the diver Thus, even though the breath-hold divers in the present used, by his own request, our spirometer in order to case and in the cases reported by Lindholm et al. ( 6 ) re- measure maximal exhaled volume from the lungs after covered completely, the perspective of a serious insult is glossopharyngeal insuffl ation. This is a frequent request alarming. from competitive breath-hold divers volunteering for Besides the risk of a neurological insult, other organs various types of experiments at our laboratory. In the of the body, for instance the heart, might also be at risk standing position he performed a maximal inhalation of a serious insult in association with an arterial gas em- and glossopharyngeal insuffl ation followed by a maxi- bolism. Furthermore, overexpansion of a lung with de- mal exhalation through the spirometer mouthpiece. The creased strength of the visceral pleura, such as pleural exhaled volume was 8.66 L, as compared to the vital ca- blebs, might bring about a pneumothorax. Pleural blebs pacity of 6.79 L measured at the beginning of the experi- are not uncommon (6%) among young healthy adults mental session. About 30-60 s after the measurement the ( 1 ). In addition, the possibility of long-term damage to diver appeared uncomfortable and expressed feelings of the lungs by glossopharyngeal insuffl ation is of concern. distress. He complained of paresthesia of his right shoul- Possible mechanisms may be related to the pathology der. A neurological exam revealed decreased sense of involved in ventilator-induced lung injury. Overexpan- touch on the right side of the neck as compared to the left sion of the lungs during mechanical ventilation has been side. Motor function was normal. After a further 2-3 min, blamed for contributing to persistent lung function ab- the paresthesia had disappeared, but the decreased sense normalities after neonatal respiratory distress syndrome of touch on the right side of the neck was still present. and acute respiratory distress syndrome ( 18 ). Those The latter was normal 1 min later. We supervised the abnormalities include bronchopulmonary dysplasia in diver for 60 min without any new signs or symptoms. neonates and a restrictive defect with abnormal transfer The diver claimed that he had never experienced any factor in adults. similar symptoms from the technique previously. Never- The glossopharyngeal insuffl ation technique also has theless, we informed him about our concerns regarding circulatory effects. Increases in intrathoracic pressure re- any future use of glossopharyngeal insuffl ation. duce venous return and cardiac performance ( 3 ). It has During the most recent contact with the diver, 18 mo been reported that glossopharyngeal insuffl ation causes after the incident, he disclosed that he has continued to reductions in cardiac output ( 10 ) and biventricular sys- practice glossopharyngeal insuffl ation. However, on ac- tolic dysfunction ( 12 ). With these changes, the arterial count of his own concerns caused by the incident, he has blood pressure is markedly reduced during glossopha- refrained from maximizing the amount of volume added ryngeal insuffl ation ( 10,12 ). The fall in blood pressure to the lungs by the technique. He has not experienced may lead to syncope and such an adverse event has re- any new incidents involving comparable symptoms cently been reported ( 2 ). The hypotension and syncope brought about by glossopharyngeal insuffl ation. were associated with cardiac dysrhythmias, including periods of asystole, and increased serum myoglobin concentrations after the incident, possibly indicating DISCUSSION myocardial ischemia ( 2 ). As a fi nal point, West et al. ( 17 ) This report describes neurological signs and symp- state that both an increase in capillary pressure and toms occurring shortly after overexpansion of the lungs high states of lung infl ation are important factors for by glossopharyngeal insuffl ation in a breath-hold diver, stress failure of pulmonary capillaries.