Correspondence
Future prospective randomized studies comparing this novel blower and cover to conventional forced-air warming systems would be important and desirable (16). Conflict of interests
Lars Witt1, Robert S€ umpelmann1, Anselm Br€auer2 Department of Anaesthesiology and Intensive Care Medicine, Hanover Medical School, Hanover, Germany 2 Department of Anaesthesiology, Emergency and Intensive Care Medicine, University Medical Centre Go¨ttingen, Go¨ttingen, Germany Email: [email protected] 1
AB has acted as a paid consultant to Laryngeal Mask Airway Group, Germany, and 3M Deutschland GmbH, Germany, and received a fee for speaking from Medisize Corporation, Germany. LW and RS have no conflict of interests to declare.
doi:10.1111/pan.12273
References 1 Buisson P, Bach V, Elabbassi EB, et al. Assessment of the efficiency of warming devices during neonatal surgery. Eur J Appl Physiol 2004; 92: 694–697. 2 Cassey J, Armstrong P, Smith G, et al. The safety and effectiveness of a modified convection heating system for children during anesthesia. Pediatr Anesth 2006; 16: 654–662. 3 Tander B, Baris S, Karakaya D, et al. Risk factors influencing inadvertent hypothermia in infants and neonates during anesthesia. Pediatr Anesth 2005; 15: 574–579. 4 Azzam FJ, Krock JL. Thermal burns in two infants associated with a forced air warming system. Anesth Analg 1995; 81: 661. 5 Truell KD, Bakerman PR, Teodori MF, et al. Third-degree burns due to intraoperative use of a Bair Hugger warming device. Ann Thorac Surg 2000; 69: 1933–1934. 6 Shorrab AA, El-Sawy ME, Othman MM, et al. Prevention of hypothermia in children under combined epidural and general anesthesia: a comparison between upper- and
7
8 9
10
11
lower-body warming. Pediatr Anesth 2007; 17: 38–43. Pearce B, Christensen R, Voepel-Lewis T. Perioperative hypothermia in the pediatric population: prevalence, risk factors and outcomes. J Anesth Clin Res 2010; 1: 1–4. Barker L, Carr AS. The Bair that did not hug. Paediatr Anaesth 2000; 10: 346–347. Witt L, Dennhardt N, Eich C, et al. Prevention of intraoperative hypothermia in neonates and infants: results of a prospective multicentre observational study with a new forced-air warming system with increased warm air flow. Pediatr Anesth 2013; 23: 469–474. Eich C, Zink W, Schwarz S, et al. A combination of convective and conductive warming ensures pre- and post-bypass normothermia in paediatric cardiac anaesthesia. Appl Cardiopulm Pathophysiol 2009; 13: 3–10. Schlunzen L, Vestergaard AL, MollerNielsen I, et al. Convective warming blankets improve peroperative heat preservation in
12
13
14
15
16
congenital heart surgery. Paediatr Anaesth 1998; 8: 397–401. Brauer A, English MJ, Steinmetz N, et al. Efficacy of forced-air warming systems with full body blankets. Can J Anaesth 2007; 54: 34–41. Brauer A, Quintel M. Forced-air warming: technology, physical background and practical aspects. Curr Opin Anaesthesiol 2009; 22: 769–774. Cassey J, King R, Armstrong P. Is there thermal benefit from preoperative warming in children. Pediatr Anesth 2010; 20: 63–71. Bissonnette B, Sessler DI, LaFlamme P. Intraoperative temperature monitoring sites in infants and children and the effect of inspired gas warming on esophageal temperature. Anesth Analg 1989; 69: 192–196. Sessler DI. Forced-air warming in infants and children. Pediatr Anesth 2013; 23: 467–468.
Cricoid pressure can be useful! SIR—We read with great interest the retrospective cohort analysis of 1001 consecutive children with a known or suspect full stomach who underwent controlled rapid sequence induction and intubation (cRSII) at the Zurich Children’s Hospital (1). These data confirm that in trained hands, this approach is at least as safe as classic rapid sequence induction: this is a timely and welcome clinical support to the literature already dedicated to this topic (2). Moreover, the authors kindly added their local standard operating procedure in the publication: this will no doubt help many departments adopt the technique. © 2013 John Wiley & Sons Ltd Pediatric Anesthesia 23 (2013) 1224–1227
We were, however, surprised to read that they recommend applying cricoid pressure in situations at risk for a ‘full esophagus’: achalasia, Zenker’s diverticulum, or former esophageal replacement. These pathologies are indeed at high risk for regurgitation during induction of anesthesia, but is cricoid pressure really protective? Recent MRI studies in adults have shown that cricoid pressure does not occlude the esophageal lumen but only partly compresses the hypopharynx: it is thus not an effective protection against regurgitation (3). In the situations reported above, gently emptying the esophageal lumen with a large suction tube before induction is more 1225
Correspondence
efficient. Moreover, the presence of an esophageal diverticulum is generally considered as a contraindication to cricoid pressure as it could empty its content into the esophageal lumen (4). But cricoid pressure can be useful: as demonstrated years ago, it allows facemask ventilation without gastric inflation (5). More recently, Lagarde et al. (6) evaluated the risk of gastric insufflation using a pressure-controlled mask ventilation model with no cricoid pressure in 100 children aged 1 day to 16 years: in their series, gastric insufflation was already observed at a peak inspiratory pressure (PIP) of 10 cmH2O in five of 23 infants
Future prospective randomized studies comparing this novel blower and cover to conventional forced-air warming systems would be important and desirable (16). Conflict of interests
Lars Witt1, Robert S€ umpelmann1, Anselm Br€auer2 Department of Anaesthesiology and Intensive Care Medicine, Hanover Medical School, Hanover, Germany 2 Department of Anaesthesiology, Emergency and Intensive Care Medicine, University Medical Centre Go¨ttingen, Go¨ttingen, Germany Email: [email protected] 1
AB has acted as a paid consultant to Laryngeal Mask Airway Group, Germany, and 3M Deutschland GmbH, Germany, and received a fee for speaking from Medisize Corporation, Germany. LW and RS have no conflict of interests to declare.
doi:10.1111/pan.12273
References 1 Buisson P, Bach V, Elabbassi EB, et al. Assessment of the efficiency of warming devices during neonatal surgery. Eur J Appl Physiol 2004; 92: 694–697. 2 Cassey J, Armstrong P, Smith G, et al. The safety and effectiveness of a modified convection heating system for children during anesthesia. Pediatr Anesth 2006; 16: 654–662. 3 Tander B, Baris S, Karakaya D, et al. Risk factors influencing inadvertent hypothermia in infants and neonates during anesthesia. Pediatr Anesth 2005; 15: 574–579. 4 Azzam FJ, Krock JL. Thermal burns in two infants associated with a forced air warming system. Anesth Analg 1995; 81: 661. 5 Truell KD, Bakerman PR, Teodori MF, et al. Third-degree burns due to intraoperative use of a Bair Hugger warming device. Ann Thorac Surg 2000; 69: 1933–1934. 6 Shorrab AA, El-Sawy ME, Othman MM, et al. Prevention of hypothermia in children under combined epidural and general anesthesia: a comparison between upper- and
7
8 9
10
11
lower-body warming. Pediatr Anesth 2007; 17: 38–43. Pearce B, Christensen R, Voepel-Lewis T. Perioperative hypothermia in the pediatric population: prevalence, risk factors and outcomes. J Anesth Clin Res 2010; 1: 1–4. Barker L, Carr AS. The Bair that did not hug. Paediatr Anaesth 2000; 10: 346–347. Witt L, Dennhardt N, Eich C, et al. Prevention of intraoperative hypothermia in neonates and infants: results of a prospective multicentre observational study with a new forced-air warming system with increased warm air flow. Pediatr Anesth 2013; 23: 469–474. Eich C, Zink W, Schwarz S, et al. A combination of convective and conductive warming ensures pre- and post-bypass normothermia in paediatric cardiac anaesthesia. Appl Cardiopulm Pathophysiol 2009; 13: 3–10. Schlunzen L, Vestergaard AL, MollerNielsen I, et al. Convective warming blankets improve peroperative heat preservation in
12
13
14
15
16
congenital heart surgery. Paediatr Anaesth 1998; 8: 397–401. Brauer A, English MJ, Steinmetz N, et al. Efficacy of forced-air warming systems with full body blankets. Can J Anaesth 2007; 54: 34–41. Brauer A, Quintel M. Forced-air warming: technology, physical background and practical aspects. Curr Opin Anaesthesiol 2009; 22: 769–774. Cassey J, King R, Armstrong P. Is there thermal benefit from preoperative warming in children. Pediatr Anesth 2010; 20: 63–71. Bissonnette B, Sessler DI, LaFlamme P. Intraoperative temperature monitoring sites in infants and children and the effect of inspired gas warming on esophageal temperature. Anesth Analg 1989; 69: 192–196. Sessler DI. Forced-air warming in infants and children. Pediatr Anesth 2013; 23: 467–468.
Cricoid pressure can be useful! SIR—We read with great interest the retrospective cohort analysis of 1001 consecutive children with a known or suspect full stomach who underwent controlled rapid sequence induction and intubation (cRSII) at the Zurich Children’s Hospital (1). These data confirm that in trained hands, this approach is at least as safe as classic rapid sequence induction: this is a timely and welcome clinical support to the literature already dedicated to this topic (2). Moreover, the authors kindly added their local standard operating procedure in the publication: this will no doubt help many departments adopt the technique. © 2013 John Wiley & Sons Ltd Pediatric Anesthesia 23 (2013) 1224–1227
We were, however, surprised to read that they recommend applying cricoid pressure in situations at risk for a ‘full esophagus’: achalasia, Zenker’s diverticulum, or former esophageal replacement. These pathologies are indeed at high risk for regurgitation during induction of anesthesia, but is cricoid pressure really protective? Recent MRI studies in adults have shown that cricoid pressure does not occlude the esophageal lumen but only partly compresses the hypopharynx: it is thus not an effective protection against regurgitation (3). In the situations reported above, gently emptying the esophageal lumen with a large suction tube before induction is more 1225
Correspondence
efficient. Moreover, the presence of an esophageal diverticulum is generally considered as a contraindication to cricoid pressure as it could empty its content into the esophageal lumen (4). But cricoid pressure can be useful: as demonstrated years ago, it allows facemask ventilation without gastric inflation (5). More recently, Lagarde et al. (6) evaluated the risk of gastric insufflation using a pressure-controlled mask ventilation model with no cricoid pressure in 100 children aged 1 day to 16 years: in their series, gastric insufflation was already observed at a peak inspiratory pressure (PIP) of 10 cmH2O in five of 23 infants
