Study of the safe threshold of apneic period in children during anesthesia induction

A Descriptive Analysis of Air Medical Pediatric Rapid Sequence Intubation: Successes and Opportunities

OBJECTIVE

Advanced airway management, including the use of rapid sequence intubation (RSI), is fundamental in resuscitation. However, the reported experience with pediatric airway management is limited because of the relatively low number of emergency RSI procedures in children. The aim of this study was to document the experience with pediatric RSI in a large air medical database and explore opportunities for improvement.

METHODS

All pediatric patients (age < 18 years) undergoing RSI by air medical crews between 2015 and 2019 were included in this analysis. Subjects were divided a priori into 3 age subgroups (0-2 years, 3-8 years, and 9-17 years). The primary variables of interest included overall intubation success, first-attempt intubation success, and first-attempt intubation success without desaturation. The rates of positive-pressure ventilation (PPV) use for preoxygenation and oxygen desaturation were also explored.

RESULTS

A total of 1,091 pediatric RSI patients were included. The overall intubation success rate was 98% (0-2 years = 96%, 3-8 years = 97%, and 9-17 years = 98%), with 91% intubated on the first attempt (0-2 years = 86%, 3-8 years = 90%, and 9-17 years = 92%) and 87% intubated on the first attempt without oxygen desaturation (0-2 years = 80%, 3-8 years = 88%, and 9-17 years = 90%). A sharp decline in intubation success was observed with preoxygenation SpO2 values < 97% across all patients. Younger patients (0-2 years) had lower initial SpO2 values and decreased first-attempt success rates with and without desaturation. These patients were less likely to receive PPV during preoxygenation attempts and had lower use of video laryngoscopy or a bougie on the initial intubation attempt.

CONCLUSION

In this study, we documented high success rates for air medical pediatric RSI. Higher target SpO2 values may be justified during preoxygenation. Intubation success, PPV use for preoxygenation, video laryngoscopy, and the use of a bougie were lower for younger patients.

The Pediatric Rigid Stylet Improves First-Pass Success Compared With the Standard Malleable Stylet and Tracheal Tube Introducer in a Simulated Pediatric Emergency Intubation

BACKGROUND

Pediatric emergency intubation is a high-acuity, low-occurrence procedure. Despite advances in technology, the success of this procedure remains low and adverse events are very high. Prospective observational studies in children have demonstrated improved success with the use of video laryngoscopy (VL) compared with direct laryngoscopy, although reported first-pass success (FPS) rates are lower than that reported for adults. This may in part be due to difficulty directing the tracheal tube to the laryngeal inlet considering the cephalad position of the larynx in infants. Using airway adjuncts such as the pediatric rigid stylet (PRS) or a tracheal tube introducer (TTI) may aid with intubation to the cephalad positioned airway when performing VL. The objectives of this study were to assess the FPS and time to intubation when intubating an infant manikin with a standard malleable stylet (SMS) compared with a PRS and TTI.

METHODS

This was a randomized cross-over study performed at an academic institution both with emergency medicine (EM) and combined pediatric and EM (EM&PEDS) residency programs. Emergency medicine and EM&PEDS residents were recruited to participate. Each resident performed intubations on a 6-month-old infant simulator using a standard geometry C-MAC Miller 1 video laryngoscope and 3 different intubation adjuncts (SMS, PRS, TTI) in a randomized fashion. All sessions were video recorded for data analysis. The primary outcome was FPS using the 3 different intubation adjuncts. The secondary outcome was the mean time to intubation (in seconds) for each adjunct.

RESULTS

Fifty-one participants performed 227 intubations. First-pass success with the SMS was 73% (37/51), FPS was 94% (48/51) with the PRS, and 29% (15/51) with the TTI. First-pass success was lower with the SMS (-43%; 95% confidence interval [CI], -63% to -23%; P < 0.01) and significantly lower with the TTI compared with PRS (difference -65%; 95% CI, -81% to -49%; P < 0.01). First-pass success while using the PRS was higher than SMS (difference 22%, 7% to 36%; P < 0.01). The mean time to intubation using the SMS was 44 ± 13 seconds, the PRS was 38 ± 11 seconds, and TTI was 59 ± 15 seconds. The mean time to intubation was higher with SMS (difference 15 seconds; 95% CI, 10 to 20 seconds; P < 0.01) and significantly higher with the TTI compared with PRS (difference 21 seconds; 95% CI, 17 to 26 seconds; P < 0.01). Time to intubation with the PRS was lower than SMS (difference -7 seconds; 95% CI, -11 to -2 seconds; P < 0.01). The ease of use was significantly higher for the PRS compared with the TTI when operators rated them on a visual analog scale (91 vs 20 mm).

CONCLUSIONS

Use of the PRS by EM and EM&PEDS residents on an infant simulator was associated with increased FPS and shorter time to intubation. Clinical studies are warranted comparing these intubation aids in children.

[Update 2022: interdisciplinary statement on airway management with supraglottic airway devices in pediatric emergency medicine-The laryngeal mask is and remains state of the art : Joint statement of the Institute for Emergency Medicine and Medicine Management (INM), the University Clinic Munich, LMU Munich, Germany, the Working Group for Pediatric Critical Care and Emergency Medicine of the German Interdisciplinary Society for Critical Care and Emergency Medicine (DIVI), the Medical Directors of Emergency Medical Services in Bavaria (ÄLRD), the Scientific Working Group for Pediatric Anesthesia (WAKKA) of the German Society for Anesthesiology and Intensive Care Medicine (DGAI), the Scientific Working Group for Emergency Medicine of the German Society for Anesthesiology and Intensive Care Medicine (DGAI) and the Society of Neonatology and Pediatric Critical Care Medicine (GNPI)]

BACKGROUND

Airway management with supraglottic airway devices (SGA) in life-threatening emergencies in children is increasingly being used. Different specifications of laryngeal masks (LM) and the laryngeal tube (LT) are commonly used devices for this purpose. We present a literature review and interdisciplinary consensus statement of different societies on the use of SGA in pediatric emergency medicine.

MATERIAL AND METHODS

Literature review in the PubMed database and classification of studies according to the criteria of the Oxford Centre for Evidence-based Medicine. Levels and consensus finding within the group of authors.

RESULTS

The evidence for successful applications of the various types of LM is significantly higher than for LT application. Reported smaller series of successful applications of LT are currently limited to selected research groups and centers. Especially for children below 10 kg body weight there currently exists insufficient evidence for the successful application of the LT and therefore its routine use cannot be recommended. SGAs used for emergencies should have a gastric drainage possibility.

DISCUSSION

Considering the scientific data and the large clinical experience with the LM in medical routine and emergency situations in children currently only the LM can be recommended for alternative (i.e., non-intubation) emergency airway management in children. If alternative airway management is part of a local emergency strategy, the LM should be provided in all pediatric sizes (1, 1½, 2, 2½, 3) for out of hospital use and in hospital emergency use and all users should regularly be trained in its application.

Does perioperative respiratory event increase length of hospital stay and hospital cost in pediatric ambulatory surgery?

OBJECTIVE

We examined the consequences of perioperative respiratory event (PRE) in terms of hospitalization and hospital cost in children who underwent ambulatory surgery.

METHODS

This subgroup analysis of a prospective cohort study (ClinicalTrials.gov: NCT02036021) was conducted in children aged between 1 month and 14 years who underwent ambulatory surgery between November 2012 and December 2013. Exposure was the presence of PRE either intraoperatively or in the postanesthetic care unit or both. The primary outcome was length of stay after surgery. The secondary outcome was excess hospital cost excluding surgical cost. Financial information was also compared between PRE and non-PRE. Directed acyclic graphs were used to select the covariates to be included in the multivariate regression models. The predictors of length of stay and excess hospital cost between PRE and non-PRE children are presented as adjusted odds ratio (OR) and cost ratio (CR), respectively with 95% confidence interval (CI).

RESULTS

Sixty-three PRE and 249 non-PRE patients were recruited. In the univariate analysis, PRE was associated with length of stay (p = 0.004), postoperative oxygen requirement (p <0.001), and increased hospital charge (p = 0.006). After adjustments for age, history of snoring, American Society of Anesthesiologists physical status, type of surgery and type of payment, preoperative planned admission had an effect modification with PRE (p <0.001). The occurrence of PRE in the preoperative unplanned admission was associated with 24-fold increased odds of prolonged hospital stay (p <0.001). PRE was associated with higher excess hospital cost (CR = 1.35, p = 0.001). The mean differences in contribution margin for total procedure (per patient) (PRE vs non-PRE) differed significantly (mean = 1,523; 95% CI: 387, 2,658 baht).

CONCLUSION

PRE with unplanned admission was significantly associated with prolonged length of stay whereas PRE regardless of unplanned admission increased hospital cost by 35% in pediatric ambulatory surgery.

TRIAL REGISTRATION

ClinicalTrials.gov registration number NCT02036021.

Transnasal humidified rapid-insufflation ventilatory exchange during rapid sequence induction in children

BACKGROUND

The objective of this study was to measure the incidence of arterial oxygen desaturation during rapid sequence induction intubation in children following apnoeic oxygenation via transnasal humidified rapid-insufflation ventilatory exchange (THRIVE).

METHODS

In this prospective observational study, arterial desaturation < 95% SaO₂ before intubation was recorded following apnoeic RSI combining an intravenous hypnotic agent, suxamethonium and THRIVE (used during the apnoeic period). The incidence of desaturation was calculated in the whole cohort and according to patients' age (older or younger than 1 year).

RESULTS

Complete data were collected for 79 patients, 1 day to 15 years of age. Nine patients (11.4%) exhibited arterial desaturation before tracheal intubation and received active facemask ventilation. Patients exhibiting desaturation were more likely to be less than 1 year of age (9/9, (100%) versus 37/70, (52.9%); P = 0.005), to be reported as difficult intubations (5/9, (55.6%) versus 1/70, (1.4%), p < 0.001), and to have regurgitation at induction (2/9, (22.2%) versus 0/70, (0%), p = 0.01).

CONCLUSIONS

Results of the current study indicated that almost 91% of RSI can be performed without desaturation when THRIVE is used. A comparative controlled study is required to confirm these findings. Specific situations and conditions limiting the efficacy of THRIVE during RSI should also be investigated.

Optimizing Rapid Sequence Intubation for Medical and Trauma Patients in the Pediatric Emergency Department

Introduction

Rapid sequence intubation (RSI) is a critical procedure for severely ill and injured patients presenting to the pediatric emergency department (PED). This procedure has a high risk of complications, and multiple attempts increase this risk. We aimed to increase successful intubation within two attempts, focusing on medical and trauma patients separately to identify improvement barriers for each group.

Methods

A multifaceted intervention was implemented using quality improvement methods. The analysis included adherence to the standardized process, successful intubation within two attempts, and frequency of oxygen saturations <92% during laryngoscopy. Trauma and medical patients were analyzed separately as team composition differed for each.

Results

This project began in February 2018, and we included 290 patients between April 2018 and December 2019. Adherence to the standardized process was sustained at 91% for medical patients and a baseline of 55% for trauma patients with a trend toward improvement. In May 2018, we observed and sustained special cause variations for medical patients' successful intubations within two attempts (77-89%). In September 2018, special cause variation was observed and sustained for the successful intubation of trauma patients within two attempts (89-96%). The frequency of oxygen saturation of <92% was 21% for medical patients; only one trauma patient experienced oxygen desaturation.

Conclusion

Implementation of a standardized process significantly improved successful intubations within two attempts for medical and trauma patients. Trauma teams had more gradual adherence to the standardized process, which may be related to the relative infrequency of intubations and variable team composition.

Comparison of bolus- and filtering-based EIT measures of lung perfusion in an animal model

OBJECTIVE

Two main functional imaging approaches have been used to measure regional lung perfusion using electrical impedance tomography (EIT): venous injection of a hypertonic saline contrast agent and imaging of its passage through the heart and lungs, and digital filtering of heart-frequency impedance changes over sequences of EIT images. This paper systematically compares filtering-based perfusion estimates and bolus injection methods to determine to which degree they are related.

APPROACH

EIT data was recorded on seven mechanically ventilated newborn lambs in which ventilation distribution was varied through changes in posture between prone, supine, left- and right-lateral positions. Perfusion images were calculated using frequency filtering and ensemble averaging during both ventilation and apnoea time segments for each posture to compare against contrast agent-based methods using Jaccard distance score.

MAIN RESULTS

Using bolus-based EIT measures of lung perfusion as the reference frequency filtering techniques performed better than ensemble averaging and both techniques performed equally well across apnoea and ventilation data segments.

SIGNIFICANCE

Our results indicate the potential for use of filtering-based EIT measures of heart-frequency activity as a non-invasive proxy for contrast agent injection-based measures of lung perfusion.

Risk prediction tool for use and predictors of duration of postoperative oxygen therapy in children undergoing non-cardiac surgery: a case-control study

BACKGROUND

We aimed to construct a prediction tool for postoperative oxygen therapy and determine predictors of duration of use among children undergoing non-cardiac surgery.

METHODS

Data from this case-control study was obtained from a database of 9820 children aged < 15 years who underwent general anesthesia between January 2010 and December 2013 at a tertiary care hospital in southern Thailand. The primary outcomes were the use and duration (hours) of postoperative oxygen therapy (cases). Cases were matched with controls on age group and year of surgery in a ratio of 1:4. A negative binomial hurdle model was used to obtain significant predictors of any use and number of hours of oxygen therapy. A risk score was derived from the coefficients of the significant predictors. The risk score, adjusted odds ratio (OR) for any use and count ratio (CR) for duration of postoperative oxygen therapy and 95% confidence interval (CI) were determined.

RESULTS

A total of 288 cases and 1152 controls were included. The median (inter-quartile range) duration of oxygen therapy delivered was 17 (9-22) hours. An optimal risk score for predictors of oxygen use was 12 (0-32) giving an area under the receiver operating characteristic curve of 0.93. Predictors of high risk need for oxygen therapy (score ≥ 12) were thoracic surgery (OR = 278, 95% CI = 44.6-1733) and having desaturation perioperatively (OR = 459.8, 95% CI = 169.7-1246). Intermediate risk factors (score 8-11) were having bronchospasm (OR = 92.4, 95% CI = 29.7-287.5) and upper airway obstruction/laryngospasm (OR = 61.5, 95% CI = 14.4-262.4) perioperatively. Significant predictors of duration of oxygen therapy were probably difficult airway (CR = 2.2, 95% CI = 1.4-3.5), history of delayed development (CR = 2.3, 95% CI = 1.5-3.6), airway (CR = 3.0, 95% CI = 1.6-5.8), orthopedic (CR = 2.1, 95% CI = 1.1-4.3), thoracic (CR = 4.9, 95% CI = 2.3-10.1) and abdominal surgery (CR = 4.2, 95% CI = 2.1-8.1), compared to eye surgery.

CONCLUSIONS

Our risk prediction tool for the use of postoperative oxygen therapy provided a high predictive ability. Children who have thoracic surgery, desaturation, bronchospasm, upper airway obstruction or laryngospasm will most likely need postoperative oxygen therapy, regardless of other factors, while those with a probably difficult airway, history of delayed development, or thoracic/abdominal surgery will most likely need longer duration of oxygen therapy.

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

BACKGROUND

Evacuation 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.

METHODS

Infants 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.

RESULTS

We 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.

CONCLUSIONS

Our 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.

Apnoeic oxygenation by nasal cannula during airway management in children undergoing general anaesthesia: a pilot randomised controlled trial

Background

Airway management is a core clinical skill in anaesthesia. Pre-oxygenation prior to induction of anaesthesia is a standard practice to prevent desaturation. Apnoeic oxygenation in adults is effective and prolongs the time to desaturation. The effectiveness of apnoeic oxygenation in the adult is well documented; however, evidence in the paediatric is lacking. Therefore, the aim of this study was to investigate the effectiveness of apnoeic oxygenation during airway management in children.

Methods

This was a pilot randomised controlled trial. Patients were randomised to receive either apnoeic oxygenation or standard care during the induction of anaesthesia. The primary outcome was the duration of safe apnoea, defined as a composite of the time to first event, either time for SpO2 to drop to 92% or time to successfully secure the airway, and the lowest SpO2 observed during airway management. Secondary outcomes were the number of patients whose SpO2 dropped below 95% and the number of patients whose SpO2 dropped below 92%.

Results

A total of 30 patients were randomised, 15 to apnoeic oxygenation and 15 to standard care. No significant difference was observed in the time to first event (p = 0.870). However, patients randomised to apnoeic oxygenation had significantly higher SpO2 observed compared to the standard care group (p = 0.004). All patients in the apnoeic oxygenation group maintained SpO2 of 100% during airway management, compared to only six in the standard care group. SpO2 dropped below 92% in one patient, with the lowest SPO₂ recorded 73%.

Conclusion

This study suggests that providing 3 l/min oxygen by nasal cannula following pre-oxygenation contributes to maintaining high levels of oxygen saturation during airway management in children, contributing to increased patients’ safety during general anaesthesia.

Trial registration

Retrospectively registered at ClinicalTrials.gov, NCT03271827. Registered: 4 September 2017.

[Interdisciplinary consensus statement on alternative airway management with supraglottic airway devices in pediatric emergency medicine: Laryngeal mask is state of the art]

BACKGROUND

Airway management with supraglottic airway devices (SGA) in life-threatening emergencies involving children is becoming increasingly more important. The laryngeal mask (LM) and the laryngeal tube (LT) are devices commonly used for this purpose. This article presents a literature review and consensus statement by various societies on the use of SGA in pediatric emergency medicine.

MATERIAL AND METHODS

Literature search in the database PubMed and classification of studies according to the criteria of the Oxford Centre for Evidence-based Medicine levels of evidence.

RESULTS

The evidence for successful application of the various types of LM is significantly higher than for LT application. Reports of smaller series of successful applications of LT are currently limited to selected research groups and centers. Insufficient evidence currently exists for the successful application of the LT especially for children below 10 kg body weight and, therefore, its routine use cannot currently be recommended. SGAs used for emergencies should have a possibility for gastric drainage.

DISCUSSION

Considering the scientific data and the large clinical experience with the LM in medical routine and emergency situations in children, currently only the LM can be recommended for alternative (i.e. non-intubation) airway management in children. If alternative airway management is part of a local emergency strategy, the LM should be provided in all pediatric sizes (1, 1.5, 2, 2.5, 3, 4 and 5) for prehospital and in-hospital emergency use and all users should be regularly trained in its application.

Comparison of intelligence, weight and height in children after general anesthesia with and without perioperative desaturation in non-cardiac surgery: a historical and concurrent follow-up study

Purpose

To determine whether perioperative desaturation (PD) in preschool children undergoing non-cardiac surgery is associated with subsequent impairment of intelligence or subsequent change in age-specific weight and height percentile.

Method

A historical-concurrent follow-up study was conducted in children aged ≤ 60 months who underwent general anesthesia (GA) for non-cardiac surgery between January 2008 and December 2011 at Songklanagarind Hospital. Children who developed PD (PD group) and children who did not develop perioperative respiratory events (no-PRE group) were matched on sex, age, year of having index GA, type of surgery and choice of anesthesia. The children’s age-specific weight and height percentile and intelligence quotient (IQ) scores by Standford Binet-LM or Wechsler Intelligence Scale for Children, 3rd edition 12–60 months after GA were compared using Student’s t- test and Wilcoxon’s rank sum test. Multivariate linear regression models for standardized IQ and multivariate mixed effects linear regression models for the change of age-specific weight and height percentile from the time of index GA to the time of IQ test were performed to identify independent predictors. The coefficients and 95% confidence intervals (CI) were displayed and considered significant if the F test p-values were < 0.05.

Results

Of 103 subjects in each group (PD vs no-PRE), there were no statistically significant differences in IQ (94.7 vs 98.3, p = 0.13), standardized IQ (−0.1 vs 0.1, p = 0.14) or age-specific weight percentile (38th vs 63th, p = 0.06). However, age-specific height percentile in the PD group at the time of IQ test was significantly lower (38th vs 50th, p = 0.02). In the multivariate analysis, PD was not a significant predictor for standardized IQ (coefficient: −0.06, 95% CI: −0.3, 0.19, p = 0.57), change in age-specific weight percentile (coefficient: 4.66, 95% CI: −2.63, 11.95, p = 0.21) or change in age-specific height percentile (coefficient: −1.65, 95% CI: −9.74, 6.44, p = 0.69) from the time of index GA to the time of IQ test after adjusting for family and anesthesia characteristics.

Conclusion

Our study could not demonstrate any serious effect of PD on subsequent intelligence or on the change in age-specific weight and height percentile of children after non-cardiac surgery.

Electronic supplementary material

The online version of this article (doi:10.1186/2193-1801-3-164) contains supplementary material, which is available to authorized users.

Risk over time and risk factors of intraoperative respiratory events: a historical cohort study of 14,153 children

Background

The variation in the rate of intraoperative respiratory events (IRE) over time under anesthesia and the influence of anesthesia-related factors have not yet been described. The objectives of this study were to describe the risk over time and the risk factors for IRE in children at a tertiary care hospital in southern Thailand.

Methods

The surveillance anesthetic database and chart review of IRE of 14,153 children who received surgery at Songklanagarind Hospital during January 2005 to December 2011 were used to obtain demographic, surgical and anesthesia-related data. Incidence density of IRE per person-time was determined by a Poisson modelling. Risk of IRE over time was displayed using Kaplan Meier survival and Nelson-Aalen curves. Multivariate Cox regression was employed to identify independent predictors for IRE. Adjusted hazard ratios (HR) and their 95% confidence intervals (CI) were obtained from the final Cox model.

Results

Overall, IRE occurred in 315 out of 14,153 children. The number (%) of desaturation, wheezing or bronchospasm, laryngospasm, reintubation and upper airway obstruction were 235 (54%), 101 (23%), 75 (17%), 21 (5%) and 4 (1%) out of 315 IRE, respectively. The incidence density per 100,000 person-minutes of IRE at the induction period (61.3) was higher than that in the maintenance (13.7) and emergence periods (16.5) (p < 0.001). The risk of desaturation, wheezing and laryngospasm was highest during the first 15, 20 and 30 minutes of anesthesia, respectively. After adjusting for age, history of respiratory disease and American Society of Anesthesiologist (ASA) classification, anesthesia-related risk factors for laryngospasm were assisted ventilation via facemask (HR: 18.1, 95% CI: 6.4-51.4) or laryngeal mask airway (HR: 12.5, 95% CI: 4.6-33.9) compared to controlled ventilation via endotracheal tube (p < 0.001), and desflurane (HR: 11.0, 95% CI: 5.1-23.9) compared to sevoflurane anesthesia (p < 0.001).

Conclusions

IRE risk was highest in the induction and early maintenance period. Assisted ventilation via facemask or LMA and desflurane anesthesia were anesthesia-related risk factors for laryngospasm. Therefore, anesthesiologists should pay more attention during the induction and early maintenance period especially when certain airway devices incorporated with assisted ventilation or desflurane are used.

"ABC-SBAR" training improves simulated critical patient hand-off by pediatric interns

OBJECTIVES

This study was done to assess whether a modified "ABC-SBAR" mnemonic (airway, breathing, circulation followed by situation, background, assessment, and recommendation) improves hand-offs by pediatric interns in a simulated critical patient scenario.

METHODS

Each of 26 interns reviewed a scenario involving a decompensating pediatric patient and gave a simulated hand-off to a responder. They received a didactic session on ABC-SBAR, then performed a second hand-off using another scenario. Two blinded reviewers assessed 52 video-recorded hand-offs for inclusion, order, and elapsed time to essential hand-off information using a scoring tool.

RESULTS

Mean score of hand-offs increased after ABC-SBAR training (preintervention: 3.1/10 vs postintervention: 7.8/10, P < 0.001). In hand-offs after ABC-SBAR training, the reason for the emergency call was more often prioritized before background information (preintervention: 4% vs postintervention: 81%, P < 0.001) and stated earlier (elapsed time preintervention: 19 seconds vs postintervention: 7 seconds, P < 0.001). Hand-offs including an airway or breathing assessment increased after training (preintervention: 35% vs postintervention: 85%, P = 0.001), and this information was also stated earlier (preintervention: 25 seconds vs postintervention: 5 seconds, P < 0.001). Total hand-off duration was increased (preintervention: 29 seconds vs postintervention: 36 seconds, P = 0.004).

CONCLUSIONS

Unstructured hand-off by interns in a simulated patient emergency emphasizes background information, leaving essential information (such as reason for the call and ABCs) delayed or omitted. ABC-SBAR was associated with improved inclusion and timeliness of essential information in simulated critical patient hand-offs by pediatric interns; however, hand-off duration was increased. Further studies are needed to elucidate optimal hand-off in an emergency situation.

A clinical evaluation of the intubating laryngeal airway as a conduit for tracheal intubation in children

BACKGROUND

The air-Q Intubating Laryngeal Airway (ILA) (Cookgas LLC, Mercury Medical, Clearwater, FL) is a supraglottic airway device available in pediatric sizes, with design features to facilitate passage of cuffed tracheal tubes when used to guide tracheal intubation. We designed this prospective observational study of the ILA to assess the ease of its placement in paralyzed pediatric patients, determine its position and alignment to the larynx using a fiberoptic bronchoscope, gauge its efficacy as a conduit for fiberoptic intubation with cuffed tracheal tubes, and evaluate the ability to remove the ILA without dislodgement of the tracheal tube after successful tracheal intubation.

METHODS

One hundred healthy children, aged 6 months to 8 years, ASA physical status I to II, and scheduled for elective surgery requiring general endotracheal anesthesia were enrolled in this prospective study. Based on the manufacturer's guidelines, each patient received either a size 1.5 or 2.0 ILA according to their weight. The number of attempts for successful insertion, leak pressures, fiberoptic grade of view, number of attempts and time for tracheal intubation, time for ILA removal, and complications were recorded.

RESULTS

ILA placement, fiberoptic tracheal intubation, and ILA removal were successful in all patients. The size 1.5 ILA cohort had significantly higher rates of epiglottic downfolding compared with the size 2.0 ILA cohort (P < 0.001), despite adequate ventilation variables. When comparing fiberoptic grade of view to weight, a moderate negative correlation was found (r = -0.41, P < 0.001), indicating that larger patients tended to have better fiberoptic grades of view. The size 1.5 ILA cohort had a significantly longer time to intubation (P = 0.04) compared with the size 2.0 ILA cohort. However, this difference may not be clinically significant because there was a large overlap of confidence bounds in the average times of the size 1.5 ILA (27.0 ± 13.0 seconds) and size 2.0 ILA cohorts (22.7 ± 6.9 seconds). When comparing weight to time to tracheal intubation, a weak correlation that was not statistically significant was found (r = -0.17, P = 0.09), showing that time to intubation did not differ significantly according to weight, despite higher fiberoptic grades in smaller patients.

CONCLUSIONS

The ILA was easy to place and provided an effective conduit for tracheal intubation with cuffed tracheal tubes in children with normal airways. Additionally, removal of the ILA after successful intubation could be achieved quickly and without dislodgement of the tracheal tube. Because of the higher incidence of epiglottic downfolding in smaller patients, the use of fiberoptic bronchoscopy is recommended to assist with tracheal intubation through this device.

Factors influencing oxygen store during denitrogenation in the healthy patient

STUDY OBJECTIVE

To define the various factors that influence the rate of effective preoxygenation.

DESIGN

Prospective, randomized study.

SETTING

Procedure room in a teaching hospital.

SUBJECTS

14 ASA physical status I volunteers who performed 4 sessions of breathing in random order. Of these volunteers, 7 performed two extra sessions using vital capacity breathing, which were also completed in random order.

INTERVENTIONS

Using the circle system, volunteers breathed with a mouthpiece and nose-clip until expired nitrogen reached 5%, using either a fresh gas flow of 5 L/min or 10 L/min or a system flushed with O(2).

MEASUREMENTS

End-expired levels of O(2), nitrogen, and CO(2) were recorded.

MAIN RESULTS

Minute ventilation, functional residual capacity, and age were significant factors for rate of denitrogenation. However, height and weight were not significant factors in predicting time to denitrogenation. At low flow rates, flushing with O(2) significantly decreased the time of denitrogenation. There appeared to be little clinical benefit of flushing with O(2) when a 10 L/min O(2) flow was used.

CONCLUSIONS

A high gas flow rate appears critical to achieving rapid preoxygenation.

The airway approach algorithm: a decision tree for organizing preoperative airway information

Anticipatory decision-making in airway management requires the integration of both history and physical examination findings. Though all airways can be managed along some branch of the American Society of Anesthesiologists' (ASA) Difficult Airway Algorithm, by predicting specific difficulties and integrating this information into an airway approach strategy, emergency branches of the ASA algorithm may be avoided. The Airway Approach Algorithm (AAA) consists of five clinical questions, with "yes" or "no" answers, to be addressed prior to the management of the airway. A positive answer to any question leads the clinician to the next, whereas a negative answer directs the operator to a root point of the ASA algorithm. The AAA is introduced with the anticipation that trainees in Anesthesiology, as well as others, will find it helpful in organizing preoperative information concerning the airway.

Preoperative planning of airway management in critical care patients

OBJECTIVE

The aim of this article is to review aspects of airway evaluation that may affect the care of the critical care patient whose airway is to be managed. This information must then be incorporated into the decision-making process of the "airway manager."

DESIGN

Literature review.

RESULTS

Historically used indexes of airway evaluation suffer from low sensitivity and only modest specificity in identifying the difficult-to-intubate patient. Using each index in isolation of others contributes to their poor predictive power. An understanding of anatomical relationships that these indexes measure should help the clinician in evaluating the airway. The clinician's impression of the airway, as well as the likelihood of trouble with supraglottic ventilation, the patient's inability to take food orally, and the patient's general condition can be used to formulate a management plan. This plan should be consistent with the American Society of Anesthesiologist's difficult airway algorithm.

CONCLUSIONS

Rote decision making on airway management, based on commonly used indexes, is not adequate. The vital role of airway in anesthetic management of the critical care patient demands thoughtful consideration. Patient conditions including the need for airway control, the likelihood of difficult laryngoscopy or supraglottic ventilation, the patient's inability to take food orally, and the medical state of the patient must be incorporated.

Comparison of rocuronium and suxamethonium for rapid tracheal intubation in children

BACKGROUND

The purpose of our study was to determine whether a smaller dose of rocuronium than previously reported could provide similar intubating conditions to suxamethonium during rapid-sequence induction of anaesthesia in children.

METHODS

One hundred and twenty ASA I, unpremedicated children, aged 1-10 years, who were undergoing elective surgery, were randomized into three groups to receive rocuronium 0.6 mg.kg-1, rocuronium 0.9 mg.kg-1 or suxamethonium 1.5 mg.kg-1. The study was double-blinded, anaesthesia and timing of injection was standardized to alfentanil 10 microg.kg-1, thiopentone 5 mg.kg-1 and the study drug. Intubation was attempted at 30 s after injection of neuromuscular relaxant and intubating conditions graded as excellent, good, poor or impossible.

RESULTS

All 120 children were successfully intubated within 60 s without need for a second attempt after administration of neuromuscular relaxant. Differences between suxamethonium and rocuronium 0.6 mg.kg-1 and between the two doses of rocuronium were statistically significant (P=0.016 and 0.007, respectively).

CONCLUSIONS

Rocuronium 0.9 mg.kg-1 provides similar intubating conditions to suxamethonium 1.5 mg.kg-1 during modified rapid-sequence induction using alfentanil and thiopentone in children (P=0.671). Rocuronium 0.6 mg.kg-1 was inadequate.

Adverse effects of nicotine and interleukin-1beta on autoresuscitation after apnea in piglets: implications for sudden infant death syndrome

OBJECTIVES

Maternal cigarette smoking is established as a major dose-dependent risk factor for sudden infant death syndrome (SIDS). Both prenatal and postnatal exposures to constituents of tobacco smoke are associated with SIDS, but no mechanism of death attributable to nicotine has been found. Breastfeeding gives a substantial increase in absorbed nicotine compared with only environmental tobacco smoke when the mother smokes, because the milk:plasma concentration ratio of nicotine is 2.9 in smoking mothers. Furthermore, many SIDS victims have a slight infection and a triggered immune system before their death, thus experiencing a release of cytokines like interleukin-1beta (IL-1beta) that may depress respiration. Because apneas in infancy are associated with SIDS, we have tested the hypothesis that postnatal exposure to tobacco constituents and infections might adversely affect an infant's ability to cope with an apneic episode. This is performed by investigating the acute effects of nicotine and IL-1beta on apnea by laryngeal reflex stimulation and on the subsequent autoresuscitation.

DESIGN

Thirty 1-week-old piglets (+/-1 day) were sedated with azaperone. A tracheal and an arterial catheter were inserted during a short halothane anesthesia. The piglets were allowed a 30-minute stabilization period before baseline values were recorded and they were randomized to 4 pretreatment groups (avoiding siblings in the same group): 1) immediate infusion of 10 pmol IL-1beta intravenously/kg (IL-1beta group; n = 8); 2) slow infusion of 5 microg nicotine intravenously/kg 5 minutes later (NIC group; n = 8); 3) both IL-1beta and NIC combined (NIC + IL-1beta group; n = 6); or 4) placebo by infusion of 1 ml .9% NaCl (CTR group; n = 8). Fifteen minutes later, apnea was induced by insufflation of .1 ml of acidified saline (pH = 2) in the subglottic space 5 times with 5-minute intervals, and variables of respiration, heart rate, blood pressure, and blood gases were recorded.

RESULTS

Stimulation of the laryngeal chemoreflex by insufflation of acidified saline in the subglottic space produced apneas, primarily of central origin. This was followed by a decrease in heart rate, a fall in blood pressure, swallowing, occasional coughs, and finally autoresuscitation with gasping followed by rapid increase in heart rate, rise in blood pressure, and (in the CTR group) an increase of respiratory rate. Piglets pretreated with nicotine had more spontaneous apneas, and repeated spontaneous apneas caused an inability to perform a compensatory increase of the respiratory rate after induced apnea. This resulted in a lower SaO(2) than did CTR at 2 minutes after apnea (data shown as median [interquartile range]: 91% [91-94] vs 97% [94-98]). The pretreatment with IL-1beta caused prolonged apneas in piglets and an inability to hyperventilate causing a postapneic respiratory rate similar to the NIC. When nicotine and IL-1beta were combined, additive adverse effects on respiratory control and autoresuscitation compared with CTR were observed: NIC + IL-1beta had significantly more spontaneous apneas the last 5 minutes before induction of apnea (2 [.3-3] vs 0 [0-0]). Apneas were prolonged (46 seconds [39-51] vs 26 seconds [22-31]) and followed by far more spontaneous apneas the following 5 minutes (6.6 [4.0-7.9] vs.5 [.2- .9]). Instead of normal hyperventilation after apnea, a dramatic decrease in respiratory rate was seen (at 20 seconds: -45% [-28 to -53] vs +29% [+24-+50], and at 60 seconds: -27% [-23 to -32] vs +3% [-2-+6), leading to SaO(2) below 90% 3 minutes after end of apnea: 89% (87-93) versus 97% (95-98). These prolonged adverse effects on ventilation were reflected in lowered PaO(2), elevated PaCO(2) and lowered pH 2 minutes, and even 5 minutes, after induction of apnea.

CONCLUSIONS

Nicotine interferes with normal autoresuscitation after apnea when given in doses within the range of what the child of a smoking mother could receive through environmental t

Factors determining the onset and course of hypoxemia during apnea: an investigation using physiological modelling

We used the Nottingham Physiology Simulator to examine the onset and course of hypoxemia during apnea after pulmonary denitrogenation. The following factors, as possible determinants of the hypoxemia profile, were varied to examine their effect: functional residual capacity, oxygen consumption, respiratory quotient, hemoglobin concentration, ventilatory minute volume, duration of denitrogenation, pulmonary venous admixture, and state of the airway (closed versus open). Airway obstruction significantly reduced the time to 50% oxyhemoglobin saturation (8 vs 11 min). Provision of 100% oxygen rather than air to the open, apneic patient model greatly prolonged time to 50% oxyhemoglobin saturation (66 vs 11 min). Hemoglobin concentration, venous admixture, and respiratory quotient had small, insignificant effects on the time to desaturation. Reduced functional residual capacity, short duration of denitrogenation, hypoventilation, and increased oxygen consumption significantly shortened the time to 50% oxyhemoglobin saturation during apnea.

IMPLICATIONS

Reduction in oxygen levels during cessation of breathing is dangerous and common in anesthetic practice. We used validated, mathematical, physiological models to reveal the impact of physiological factors on the deterioration of oxygen levels. This study could not be performed on patients and reveals important information.

Rocuronium versus succinylcholine: are they equally effective during rapid-sequence induction of anesthesia?

The purpose of our study was to assess the onset and quality of muscle paralysis and intubation conditions with succinylcholine (Sch) or rocuronium (Roc) during rapid-sequence induction. Patients were randomly assigned to receive thiopental (5 mg/kg) and Sch (1.5 mg/kg) or thiopental (5 mg/kg) and Roc (1.2 mg/kg). The anesthesiologists performing the endotracheal intubation were blinded by standing with their back to the patient. Thirty seconds after drug administration, laryngoscopy was performed. Intubating conditions were scored, the clinical onset of apnea was noted, and a train-of-four monitor recorded data. All patients were ASA physical status I-III and scheduled for emergency procedures; both groups were demographically similar. Thirteen patients received Roc and 13 received Sch. There was no significant difference between the two groups in the number of patients receiving excellent intubating scores (P = 0.41) or in the combined number of patients receiving good and excellent scores (P = 1.0). There was no significant difference in time of onset of apnea for Sch (22+/-13 s) versus Roc (16+/-8s). The return of the first twitch response was significantly faster with Sch (5.05+/-2.5 min) compared with Roc (17.3+/-21.7 min) (P = 0.0001).

IMPLICATIONS

In pediatric patients scheduled for emergency surgery, thiopental 5 mg/kg and rocuronium 1.2 mg/kg provided conditions for the completion of intubation in <60 s comparable to those provided by thiopental 5 mg/kg and succinylcholine 1.5 mg/kg. We conclude that rocuronium is a reasonable substitute for succinylcholine in children for rapid-sequence intubation when a rapid return to spontaneous respiration is not desired.