- Email: [email protected]
In-water resuscitation: a pilot evaluation
Resuscitation 65 (2005) 321–324
In-water resuscitation: a pilot evaluation夽 Gavin D. Perkins∗ Division of Medical Sciences, University of Birmingham, Birmingham, UK Received 28 September 2004; received in revised form 16 November 2004; accepted 3 December 2004
Abstract Introduction: The first and most important treatment for the apnoeic drowning victim is the rapid alleviation of hypoxia by artificial ventilation. Recent studies have suggested that commencing resuscitative efforts with the victim still in the water may be beneficial. The aim of this pilot study was to evaluate the feasibility and efficacy of in-water unsupported rescue breathing. Methods: Three lifeguards were taught how to perform in-water unsupported rescue breathing. Ventilation volume, inflation duration were recorded from a modified Laerdal resuscitation manikin. The rescue duration was recorded and compared to a rescue undertaken without in-water resuscitation. Results: The three lifeguards performed between seven and nine ventilations during each simulated rescue. This gave average inflation volumes for each lifeguard of 711 ml (S.D. 166), 750 ml (S.D. 108), 629 ml (S.D. 182) and average inflation duration of 0.8 s (S.D. 0.3), 0.9 s (S.D. 0.2) and 0.6 s (S.D. 0.1). The rescue duration was increased from an average time of 1 min 10 s to 1 min 24 s by performing in-water resuscitation. Conclusion: This study has demonstrated the feasibility and potential efficacy of in-water unsupported rescue breathing with a victim in deep water. Furthermore, the technique was not associated with an undue prolongation of the rescue duration over a 50 m rescue. In circumstances where the trained lifeguard finds themselves with an apnoeic victim in the water, with no buoyant rescue aid available, they may consider the application of in-water, unsupported rescue breathing, especially if recovery to dry land is likely to be delayed. The effectiveness of this technique, however, remains to be proven in the open water environment. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Out-of-hospital CPR; Mouth-to-mouth resuscitation; Respiratory arrest; Drowning; Cardiopulmonary resuscitation (CPR)
1. Introduction The first and most important treatment for the apnoeic drowning victim is the rapid alleviation of hypoxia by artificial ventilation [1]. Previous studies have reported that the prompt initiation of rescue breathing is associated with improved survival in submersion victims [2]. Szpilman and Soares have recently shown the feasibility and potential benefits of commencing resuscitation with the drowning victim still in the water [3]. Various techniques to enable resuscitation to be performed in water have been described. These include the use of a buoyant rescue aid [3–5] to support
the casualty whilst undertaking rescue breathing, mouth to snorkel in-water resuscitation [1] and resuscitation using an emergency diving regulator [6,7]. The formal evaluation of these techniques is limited with the available literature being largely descriptive. In particular, the technique of unsupported in-water rescue breathing, when the victim is in deep water and no buoyant rescue aid is available, has not been reported previously. The aim of this pilot study was to evaluate the feasibility and efficacy of in-water unsupported rescue breathing.
2. Methods and materials 夽 A Spanish and Portuguese translated version of the Abstract and Keywords of this article appears at doi: 10.1016/j.resuscitation.2004.12.002. ∗ Present address: Lung Investigation Unit, Queen Elizabeth Hospital, Birmingham B15 2TT, UK. Fax: +44 121 443 2494. E-mail address: [email protected].
0300-9572/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.resuscitation.2004.12.002
2.1. Setting and equipment The study was conducted at the Munrow centre indoor swimming pool at the University of Birmingham, UK. A
322
G.D. Perkins / Resuscitation 65 (2005) 321–324
Laerdal adult resuscitation manikin was modified to incorporate a Schiller spirovit sp-1TM pneumotachograph. When immersed in water, the manikin had neutral buoyancy and similar towing characteristics to an adult male casualty. The pneumotachograph was set to tidal volume mode, which produced a graphical printout of inflation time and rescue breathing volume. Data were subsequently analysed from these graphical records. The system was tested and calibrated prior to each test. The coefficient of variation for tidal volumes was 8%.
2.2. Study protocol and rescue technique The University Authorities approved the pilot study and verbal consent was obtained from the volunteers. Three volunteer lifeguards from the Royal Life Saving Society (UK) performed a simulated rescue of the manikin over a distance of 50 m. No in-water rescue breathing was attempted at this stage, but the rescue duration was recorded. The lifeguards were then trained in the technique of in-water unsupported rescue breathing that has previously been described [8]. This technique involves the rescuer treading water alongside the casualty and supporting them by holding the back of the head and the chin. One hand is used on the casualty’s chin to close the mouth and maintain neck extension, whilst the other supports the top of the head (see Fig. 1). The rescuer uses a strong leg kick to lift themselves out of the water and then seals their mouth on the casualty’s nose. Mouth to nose ventilation is then performed in the usual manner. Rescuers were briefed to give one slow ventilation until the chest was clearly seen to rise approximately every 10 s. The time between ventilation is used to tow the casualty towards land/safety. The efficacy of the technique was measured by recording ventilation volumes, inflation time and rescue duration. The lifeguards comments and observation on the technique were also recorded. Data are presented as mean values with standard deviation for each lifeguard.
Fig. 2. Individual tidal volumes (ml) for each lifeguard during the rescue.
Fig. 3. Individual inflation durations for each lifeguard.
3. Results The three lifeguards performed between seven and nine ventilations during each simulated rescue. This gave average inflation volumes for each lifeguard of 711 ml (S.D. 166), 750 ml (S.D. 108), 629 ml (S.D. 182) and average inflation duration of 0.8 s (S.D. 0.3), 0.9 s (S.D. 0.2) and 0.6 s (S.D. 0.1). The ventilation volumes and inflation duration for each breath are displayed in Figs. 2 and 3. The rescue duration was increased from an average time of 1 min 10 s to 1 min 24 s by performing in-water rescue breathing. Feedback from the lifeguards indicated that the technique was technically difficult and physically demanding.
4. Discussion
Fig. 1. In-water resuscitation. The lifeguard closes the mouth and performs mouth to nose ventilation.
This pilot study has demonstrated that in controlled conditions it was possible to perform unsupported rescue breathing whilst in water without greatly increasing the time taken to rescue a casualty. The ventilation volumes achieved were within the currently recommended range of 700–1000 ml for
G.D. Perkins / Resuscitation 65 (2005) 321–324
rescue breathing without supplemental oxygen. The inflation time of less than 1 s is, however, shorter than the 2 s duration recommended in current guidelines [9]. The importance of in-water resuscitation for the apnoeic drowning victim has been recently highlighted by Szpilman and Soares [3]. In this retrospective review of drowning incidents along the costal region of Rio de Janeiro in Brazil, the authors compared outcomes between victims who received immediate in-water resuscitation versus those who received delayed resuscitation on the shore. The authors found that victims who had received immediate, in-water rescue breathing had improved immediate survival (94.7% survival compared to 37% for delayed resuscitation group) and survival at hospital discharge (87.5% compared to 25% in the delayed resuscitation group). Immediate in-water resuscitation was also an independent predictor of improved outcome on multivariate analysis. In this study it appears that on most occasions additional life saving equipment (presumably some form of flotation device/buoyant aid) was used during rescues where in-water resuscitation was undertaken. This is supported by the authors’ treatment algorithm, which suggests that in-water rescue breathing in deep water by a single rescue should only be performed if a buoyancy aid is available. Several different approaches to in-water resuscitation in deep water have been described in the literature. These include mouth to snorkel resuscitation [1], using a surfboard as an adjunct [5] and resuscitation using an emergency diving regulator [6]. Several years ago March studied the use of a special pressure limited diving regulator as a means of providing positive pressure ventilation during in-water CPR (ventilations and compressions) for resuscitating scuba divers whilst still in the water [6,7]. This study reported inadequate chest compressions rates in the water of 34–48 compressions min−1 , although expired minute volumes using the regulator ventilation were between 4 and 6 l min−1 at a rate of 6–8 ventilations min−1 . Techniques of unsupported rescue breathing have been developed and taught to lifesavers and lifeguards worldwide [8]. Due to concerns regarding the efficacy of in-water unsupported rescue breathing, international consensus guidelines [1] and UK rescue organisations [10] no longer advocate this technique on the grounds of its doubtful efficacy. In determining the optimal technique for rescue breathing, several factors need to be taken into consideration. Vomiting or regurgitation is a frequent complication in the resuscitation of drowning victims, with a reported incidence of 68% in casualties requiring rescue breathing and 86% in casualties requiring cardiopulmonary resuscitation [11,4]. The high incidence of vomiting and regurgitation is likely to occur partly due to the large volume of water ingested during drowning and partly due to the effects of gastric inflation associated with rescue breathing. Gastric inflation occurs when the pressure in the oesophagus exceeds the lower oesophageal sphincter opening pressure, allowing the lower oesophageal sphincter to open so that air delivered during rescue breathing
323
enters the stomach in addition to the lungs. In cardiac arrest the lower oesophageal sphincter relaxes which makes gastric inflation more likely [12]. Additional factors that contribute to gastric inflation include a short inspiratory time, large tidal volumes and high airway pressures [9,13]. In drowning, reduced pulmonary compliance and atelectasis are likely to require higher inflation pressures than the normal lung. In the present study, short inflation durations were observed, probably as a reflection of the physical effort required by the lifeguard to lift his own body out of the water in order to form a seal on the casualties nose. It is, therefore, unlikely that the lifeguard will be able to increase the inflation duration easily. The combination of high airway pressures and short inflation duration seen with in-water rescue breathing could be expected to increase the risk of regurgitation or vomiting. This complication is especially difficult to manage whilst the casualty is still in the water. If significant regurgitation does occur it will not be possible to give further ventilations until the airway can be cleared on dry land. Despite a clear physiological rationale for expecting an increase risk of vomiting, Szpilman and Soares found no difference in the frequency of vomiting in the in-water rescue breathing group versus the delayed resuscitation group, with the incidence occurring much less frequently than previously reported (26% versus 33%, respectively) [3]. A second question to consider is the optimal tidal volume for rescue breathing from drowning. In normal subjects Baskett et al. established that the tidal volumes required to cause visible chest movement were in the region of 360–400 ml [14]. However, these smaller tidal volumes are insufficient to maintain adequate oxygenation using room or expired air [15]. In the absence of supplemental oxygen it is, therefore, necessary to deliver larger tidal volumes in the region of 700–1000 ml. In the submersion victim, with profound hypoxaemia due to ventilation/perfusion mismatch, rescue breathing alone is unlikely to reverse the hypoxaemia fully. However, the Szpilman study [3] suggests that the rapid, even partial correction of hypoxaemia, may be more important than delaying resuscitation attempts until oxygen is available. This study evaluated in-water rescue breathing in the controlled conditions of an indoor swimming pool. The experienced lifeguards reported the technique as physically demanding and difficult to perform. However, more than 90% of drownings in the UK occur away from the controlled environment of a swimming pool in open waters such as rivers, the sea or canals [16,17]. Here the effects of underwater currents, waves, cold and fatigue are likely to have a deleterious effect on the ability of lifeguards to perform the technique. In this study, the three lifeguards received detailed tuition and practice in the technique from the study investigator. They were tested immediately after skill mastery was achieved and skill retention was not formally evaluated. The impact of these limitations should be considered when extrapolating these findings to the real life resuscitation of the drowning victim.
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G.D. Perkins / Resuscitation 65 (2005) 321–324
5. Conclusion This study has demonstrated the feasibility and potential efficacy of in-water unsupported rescue breathing with a victim in deep water. Furthermore, the technique did not unduly prolong rescue duration over a 50 m rescue. In circumstances, where the trained lifeguard finds themselves with an apnoeic victim in the water, with no buoyancy rescue aid available, they may consider the application of in-water, unsupported rescue breathing, especially if recovery to dry land is likely to be delayed. However, the effectiveness of this technique remains to be proven in the open water environment.
Acknowledgements I would like to thank Dr. RM Cayton and the Respiratory Physiology Service at Birmingham Heartlands Hospital for advice regarding study design and loan of the pneumotachograph used in this study.
References [1] American Heart Association and International Liaison Committee on Resuscitation. Guidelines 2000: Part 8: advanced challenges in resuscitation. Section 3: special challenges in ECC. 3B: submersion or near-drowning. Resuscitation 2000;46:273–7. [2] Kyriacou DN, Arcinue EL, Peek C, Kraus JF. Effect of immediate resuscitation on children with submersion injury. Pediatrics 1994;94:137–42. [3] Szpilman D, Soares M. In-water resuscitation—is it worthwhile? Resuscitation 2004;63:25–31.
[4] Manolios N, Mackie I. Drowning and near-drowning on Australian beaches patrolled by life-savers: a 10-year study, 1973–1983. Med J Aust 1988;148:165–71. [5] Ghaphery JL. In-water resuscitation. JAMA 1981;245:821. [6] March NF, Matthews RC. New techniques in external cardiac compressions. Aquatic cardiopulmonary resuscitation. JAMA 1980;244:1229–32. [7] March NF, Matthews RC. Feasibility study of CPR in the water. Undersea Biomed Res 1980;7:141–8. [8] Royal Life Saving Society. Resuscitation water skills. London: Royal Life Saving Society; 1978, 50–53. [9] American Heart Association and International Liaison Committee on Resuscitation. Guidelines 2000: Part 3: adult basic life support. Resuscitation 2000;46:29–71. [10] Eaton D. Lifesaving. In: Eaton D, editor. Lifesaving. Studley: Royal Life Saving Society; 1995. p. 60–8. [11] Fenner PJ, Harrison SH, Williamson JA, Williamson BD. Success of surf lifesaving resuscitaitons in Queensland, 1973–1992. Med J Aust 1995;163:580–3. [12] Bowman FP, Menegazzi JJ, Check BD, Duckett TM. Lower esophageal sphincter pressure during prolonged cardiac arrest and resuscitation. Ann Emerg Med 1995;26:216–9. [13] Wenzel V, Keller C, Idris AH, Dorges V, Lindner KH, Brimacombe JR. Effects of smaller tidal volumes during basic life support ventilation in patients with respiratory arrest: good ventilation, less risk? Resuscitation 1999;43:25–9. [14] Baskett P, Nolan J, Parr M, Adam A. Tidal volumes which are perceived to be adequate for resuscitation. Resuscitation 1996;31: 231–4. [15] Dorges V, Ocker H, Hagelberg S, Wenzel V, Idris AH, Schmucker P. Smaller tidal volumes with room-air are not sufficient to ensure adequate oxygenation during bag-valve-mask ventilation. Resuscitation 2000;44:37–41. [16] Royal Society for the Prevention of Accidents. Drowning in the UK. Birmingham: Royal Society for the Prevention of Accidents; 1999. [17] Wyatt JP, Tomlinson GS, Busuttil A. Resuscitation of drowning victims in south-east Scotland. Resuscitation 1999;41:101–4.
In-water resuscitation: a pilot evaluation夽 Gavin D. Perkins∗ Division of Medical Sciences, University of Birmingham, Birmingham, UK Received 28 September 2004; received in revised form 16 November 2004; accepted 3 December 2004
Abstract Introduction: The first and most important treatment for the apnoeic drowning victim is the rapid alleviation of hypoxia by artificial ventilation. Recent studies have suggested that commencing resuscitative efforts with the victim still in the water may be beneficial. The aim of this pilot study was to evaluate the feasibility and efficacy of in-water unsupported rescue breathing. Methods: Three lifeguards were taught how to perform in-water unsupported rescue breathing. Ventilation volume, inflation duration were recorded from a modified Laerdal resuscitation manikin. The rescue duration was recorded and compared to a rescue undertaken without in-water resuscitation. Results: The three lifeguards performed between seven and nine ventilations during each simulated rescue. This gave average inflation volumes for each lifeguard of 711 ml (S.D. 166), 750 ml (S.D. 108), 629 ml (S.D. 182) and average inflation duration of 0.8 s (S.D. 0.3), 0.9 s (S.D. 0.2) and 0.6 s (S.D. 0.1). The rescue duration was increased from an average time of 1 min 10 s to 1 min 24 s by performing in-water resuscitation. Conclusion: This study has demonstrated the feasibility and potential efficacy of in-water unsupported rescue breathing with a victim in deep water. Furthermore, the technique was not associated with an undue prolongation of the rescue duration over a 50 m rescue. In circumstances where the trained lifeguard finds themselves with an apnoeic victim in the water, with no buoyant rescue aid available, they may consider the application of in-water, unsupported rescue breathing, especially if recovery to dry land is likely to be delayed. The effectiveness of this technique, however, remains to be proven in the open water environment. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Out-of-hospital CPR; Mouth-to-mouth resuscitation; Respiratory arrest; Drowning; Cardiopulmonary resuscitation (CPR)
1. Introduction The first and most important treatment for the apnoeic drowning victim is the rapid alleviation of hypoxia by artificial ventilation [1]. Previous studies have reported that the prompt initiation of rescue breathing is associated with improved survival in submersion victims [2]. Szpilman and Soares have recently shown the feasibility and potential benefits of commencing resuscitation with the drowning victim still in the water [3]. Various techniques to enable resuscitation to be performed in water have been described. These include the use of a buoyant rescue aid [3–5] to support
the casualty whilst undertaking rescue breathing, mouth to snorkel in-water resuscitation [1] and resuscitation using an emergency diving regulator [6,7]. The formal evaluation of these techniques is limited with the available literature being largely descriptive. In particular, the technique of unsupported in-water rescue breathing, when the victim is in deep water and no buoyant rescue aid is available, has not been reported previously. The aim of this pilot study was to evaluate the feasibility and efficacy of in-water unsupported rescue breathing.
2. Methods and materials 夽 A Spanish and Portuguese translated version of the Abstract and Keywords of this article appears at doi: 10.1016/j.resuscitation.2004.12.002. ∗ Present address: Lung Investigation Unit, Queen Elizabeth Hospital, Birmingham B15 2TT, UK. Fax: +44 121 443 2494. E-mail address: [email protected].
0300-9572/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.resuscitation.2004.12.002
2.1. Setting and equipment The study was conducted at the Munrow centre indoor swimming pool at the University of Birmingham, UK. A
322
G.D. Perkins / Resuscitation 65 (2005) 321–324
Laerdal adult resuscitation manikin was modified to incorporate a Schiller spirovit sp-1TM pneumotachograph. When immersed in water, the manikin had neutral buoyancy and similar towing characteristics to an adult male casualty. The pneumotachograph was set to tidal volume mode, which produced a graphical printout of inflation time and rescue breathing volume. Data were subsequently analysed from these graphical records. The system was tested and calibrated prior to each test. The coefficient of variation for tidal volumes was 8%.
2.2. Study protocol and rescue technique The University Authorities approved the pilot study and verbal consent was obtained from the volunteers. Three volunteer lifeguards from the Royal Life Saving Society (UK) performed a simulated rescue of the manikin over a distance of 50 m. No in-water rescue breathing was attempted at this stage, but the rescue duration was recorded. The lifeguards were then trained in the technique of in-water unsupported rescue breathing that has previously been described [8]. This technique involves the rescuer treading water alongside the casualty and supporting them by holding the back of the head and the chin. One hand is used on the casualty’s chin to close the mouth and maintain neck extension, whilst the other supports the top of the head (see Fig. 1). The rescuer uses a strong leg kick to lift themselves out of the water and then seals their mouth on the casualty’s nose. Mouth to nose ventilation is then performed in the usual manner. Rescuers were briefed to give one slow ventilation until the chest was clearly seen to rise approximately every 10 s. The time between ventilation is used to tow the casualty towards land/safety. The efficacy of the technique was measured by recording ventilation volumes, inflation time and rescue duration. The lifeguards comments and observation on the technique were also recorded. Data are presented as mean values with standard deviation for each lifeguard.
Fig. 2. Individual tidal volumes (ml) for each lifeguard during the rescue.
Fig. 3. Individual inflation durations for each lifeguard.
3. Results The three lifeguards performed between seven and nine ventilations during each simulated rescue. This gave average inflation volumes for each lifeguard of 711 ml (S.D. 166), 750 ml (S.D. 108), 629 ml (S.D. 182) and average inflation duration of 0.8 s (S.D. 0.3), 0.9 s (S.D. 0.2) and 0.6 s (S.D. 0.1). The ventilation volumes and inflation duration for each breath are displayed in Figs. 2 and 3. The rescue duration was increased from an average time of 1 min 10 s to 1 min 24 s by performing in-water rescue breathing. Feedback from the lifeguards indicated that the technique was technically difficult and physically demanding.
4. Discussion
Fig. 1. In-water resuscitation. The lifeguard closes the mouth and performs mouth to nose ventilation.
This pilot study has demonstrated that in controlled conditions it was possible to perform unsupported rescue breathing whilst in water without greatly increasing the time taken to rescue a casualty. The ventilation volumes achieved were within the currently recommended range of 700–1000 ml for
G.D. Perkins / Resuscitation 65 (2005) 321–324
rescue breathing without supplemental oxygen. The inflation time of less than 1 s is, however, shorter than the 2 s duration recommended in current guidelines [9]. The importance of in-water resuscitation for the apnoeic drowning victim has been recently highlighted by Szpilman and Soares [3]. In this retrospective review of drowning incidents along the costal region of Rio de Janeiro in Brazil, the authors compared outcomes between victims who received immediate in-water resuscitation versus those who received delayed resuscitation on the shore. The authors found that victims who had received immediate, in-water rescue breathing had improved immediate survival (94.7% survival compared to 37% for delayed resuscitation group) and survival at hospital discharge (87.5% compared to 25% in the delayed resuscitation group). Immediate in-water resuscitation was also an independent predictor of improved outcome on multivariate analysis. In this study it appears that on most occasions additional life saving equipment (presumably some form of flotation device/buoyant aid) was used during rescues where in-water resuscitation was undertaken. This is supported by the authors’ treatment algorithm, which suggests that in-water rescue breathing in deep water by a single rescue should only be performed if a buoyancy aid is available. Several different approaches to in-water resuscitation in deep water have been described in the literature. These include mouth to snorkel resuscitation [1], using a surfboard as an adjunct [5] and resuscitation using an emergency diving regulator [6]. Several years ago March studied the use of a special pressure limited diving regulator as a means of providing positive pressure ventilation during in-water CPR (ventilations and compressions) for resuscitating scuba divers whilst still in the water [6,7]. This study reported inadequate chest compressions rates in the water of 34–48 compressions min−1 , although expired minute volumes using the regulator ventilation were between 4 and 6 l min−1 at a rate of 6–8 ventilations min−1 . Techniques of unsupported rescue breathing have been developed and taught to lifesavers and lifeguards worldwide [8]. Due to concerns regarding the efficacy of in-water unsupported rescue breathing, international consensus guidelines [1] and UK rescue organisations [10] no longer advocate this technique on the grounds of its doubtful efficacy. In determining the optimal technique for rescue breathing, several factors need to be taken into consideration. Vomiting or regurgitation is a frequent complication in the resuscitation of drowning victims, with a reported incidence of 68% in casualties requiring rescue breathing and 86% in casualties requiring cardiopulmonary resuscitation [11,4]. The high incidence of vomiting and regurgitation is likely to occur partly due to the large volume of water ingested during drowning and partly due to the effects of gastric inflation associated with rescue breathing. Gastric inflation occurs when the pressure in the oesophagus exceeds the lower oesophageal sphincter opening pressure, allowing the lower oesophageal sphincter to open so that air delivered during rescue breathing
323
enters the stomach in addition to the lungs. In cardiac arrest the lower oesophageal sphincter relaxes which makes gastric inflation more likely [12]. Additional factors that contribute to gastric inflation include a short inspiratory time, large tidal volumes and high airway pressures [9,13]. In drowning, reduced pulmonary compliance and atelectasis are likely to require higher inflation pressures than the normal lung. In the present study, short inflation durations were observed, probably as a reflection of the physical effort required by the lifeguard to lift his own body out of the water in order to form a seal on the casualties nose. It is, therefore, unlikely that the lifeguard will be able to increase the inflation duration easily. The combination of high airway pressures and short inflation duration seen with in-water rescue breathing could be expected to increase the risk of regurgitation or vomiting. This complication is especially difficult to manage whilst the casualty is still in the water. If significant regurgitation does occur it will not be possible to give further ventilations until the airway can be cleared on dry land. Despite a clear physiological rationale for expecting an increase risk of vomiting, Szpilman and Soares found no difference in the frequency of vomiting in the in-water rescue breathing group versus the delayed resuscitation group, with the incidence occurring much less frequently than previously reported (26% versus 33%, respectively) [3]. A second question to consider is the optimal tidal volume for rescue breathing from drowning. In normal subjects Baskett et al. established that the tidal volumes required to cause visible chest movement were in the region of 360–400 ml [14]. However, these smaller tidal volumes are insufficient to maintain adequate oxygenation using room or expired air [15]. In the absence of supplemental oxygen it is, therefore, necessary to deliver larger tidal volumes in the region of 700–1000 ml. In the submersion victim, with profound hypoxaemia due to ventilation/perfusion mismatch, rescue breathing alone is unlikely to reverse the hypoxaemia fully. However, the Szpilman study [3] suggests that the rapid, even partial correction of hypoxaemia, may be more important than delaying resuscitation attempts until oxygen is available. This study evaluated in-water rescue breathing in the controlled conditions of an indoor swimming pool. The experienced lifeguards reported the technique as physically demanding and difficult to perform. However, more than 90% of drownings in the UK occur away from the controlled environment of a swimming pool in open waters such as rivers, the sea or canals [16,17]. Here the effects of underwater currents, waves, cold and fatigue are likely to have a deleterious effect on the ability of lifeguards to perform the technique. In this study, the three lifeguards received detailed tuition and practice in the technique from the study investigator. They were tested immediately after skill mastery was achieved and skill retention was not formally evaluated. The impact of these limitations should be considered when extrapolating these findings to the real life resuscitation of the drowning victim.
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G.D. Perkins / Resuscitation 65 (2005) 321–324
5. Conclusion This study has demonstrated the feasibility and potential efficacy of in-water unsupported rescue breathing with a victim in deep water. Furthermore, the technique did not unduly prolong rescue duration over a 50 m rescue. In circumstances, where the trained lifeguard finds themselves with an apnoeic victim in the water, with no buoyancy rescue aid available, they may consider the application of in-water, unsupported rescue breathing, especially if recovery to dry land is likely to be delayed. However, the effectiveness of this technique remains to be proven in the open water environment.
Acknowledgements I would like to thank Dr. RM Cayton and the Respiratory Physiology Service at Birmingham Heartlands Hospital for advice regarding study design and loan of the pneumotachograph used in this study.
References [1] American Heart Association and International Liaison Committee on Resuscitation. Guidelines 2000: Part 8: advanced challenges in resuscitation. Section 3: special challenges in ECC. 3B: submersion or near-drowning. Resuscitation 2000;46:273–7. [2] Kyriacou DN, Arcinue EL, Peek C, Kraus JF. Effect of immediate resuscitation on children with submersion injury. Pediatrics 1994;94:137–42. [3] Szpilman D, Soares M. In-water resuscitation—is it worthwhile? Resuscitation 2004;63:25–31.
[4] Manolios N, Mackie I. Drowning and near-drowning on Australian beaches patrolled by life-savers: a 10-year study, 1973–1983. Med J Aust 1988;148:165–71. [5] Ghaphery JL. In-water resuscitation. JAMA 1981;245:821. [6] March NF, Matthews RC. New techniques in external cardiac compressions. Aquatic cardiopulmonary resuscitation. JAMA 1980;244:1229–32. [7] March NF, Matthews RC. Feasibility study of CPR in the water. Undersea Biomed Res 1980;7:141–8. [8] Royal Life Saving Society. Resuscitation water skills. London: Royal Life Saving Society; 1978, 50–53. [9] American Heart Association and International Liaison Committee on Resuscitation. Guidelines 2000: Part 3: adult basic life support. Resuscitation 2000;46:29–71. [10] Eaton D. Lifesaving. In: Eaton D, editor. Lifesaving. Studley: Royal Life Saving Society; 1995. p. 60–8. [11] Fenner PJ, Harrison SH, Williamson JA, Williamson BD. Success of surf lifesaving resuscitaitons in Queensland, 1973–1992. Med J Aust 1995;163:580–3. [12] Bowman FP, Menegazzi JJ, Check BD, Duckett TM. Lower esophageal sphincter pressure during prolonged cardiac arrest and resuscitation. Ann Emerg Med 1995;26:216–9. [13] Wenzel V, Keller C, Idris AH, Dorges V, Lindner KH, Brimacombe JR. Effects of smaller tidal volumes during basic life support ventilation in patients with respiratory arrest: good ventilation, less risk? Resuscitation 1999;43:25–9. [14] Baskett P, Nolan J, Parr M, Adam A. Tidal volumes which are perceived to be adequate for resuscitation. Resuscitation 1996;31: 231–4. [15] Dorges V, Ocker H, Hagelberg S, Wenzel V, Idris AH, Schmucker P. Smaller tidal volumes with room-air are not sufficient to ensure adequate oxygenation during bag-valve-mask ventilation. Resuscitation 2000;44:37–41. [16] Royal Society for the Prevention of Accidents. Drowning in the UK. Birmingham: Royal Society for the Prevention of Accidents; 1999. [17] Wyatt JP, Tomlinson GS, Busuttil A. Resuscitation of drowning victims in south-east Scotland. Resuscitation 1999;41:101–4.