"Cannot intubate, cannot oxygenate": A novel 2-operator technique for cannula tracheotomy in an infant animal model-a feasibility study.

BACKGROUND: Evidence regarding optimal management of the "Cannot Intubate, Cannot Oxygenate" (CICO) scenario in infants is scarce. When inserting a transtracheal cannula for front of neck access direct aspiration to confirm intratracheal location is standard practice. This postmortem "infant airway" animal model study describes a novel technique for cannula tracheotomy. AIMS: To compare a novel technique of cannula tracheotomy to an accepted technique to assess success and complication rates. METHODS: Two experienced proceduralists repeatedly performed tracheotomy using an 18-gauge BD InsyteTM cannula (BD, Franklin Lakes, NJ, USA) in 6 postmortem White New Zealand rabbits. Cannulas were attached either directly to a 5ml syringe (Direct Aspiration) or via a 25 cm length minimum volume extension tubing set (TUTA Healthcare Lidcombe, NSW, Australia) (Indirect Aspiration, 2 operator technique). Each technique was attempted a maximum of 12 times per rabbit with an ENT surgeon assessing success and complication rates endoscopically for each attempt. RESULTS: 72 tracheotomy attempts were made in total, 36 for each technique. Initial aspiration through the needle was achieved in 93% (97.2% direct versus 89% indirect). Advancement of the cannula and continued aspiration (success) into the trachea occurred in 67% for direct compared with 64% for indirect aspiration. Direct aspiration was associated with higher rates of lateral (10.3% versus 5.6%) and posterior (19.4% versus 13.9%) wall injury compared with the indirect 2-operator technique. CONCLUSION: Cannula tracheotomy in infant-sized airways is technically difficult and seems frequently associated with tracheal wall injury. The reduced incidence of injury in the indirect group warrants further investigation in preclinical and clinical trials.

The 'Can't Intubate Can't Oxygenate' scenario in Pediatric Anesthesia: a comparison of different devices for needle cricothyroidotomy.

BACKGROUND: Little evidence exists to guide the management of the 'Can't Intubate, Can't Oxygenate' (CICO) scenario in pediatric anesthesia. OBJECTIVES: To compare two intravenous cannulae for ease of use, success rate and complication rate in needle tracheotomy in a postmortem animal model of the infant airway, and trial a commercially available device using the same model. METHODS: Two experienced proceduralists repeatedly attempted cannula tracheotomy in five postmortem rabbits, alternately using 18-gauge (18G) and 14-gauge (14G) BD Insyte(™) cannulae (BD, Franklin Lakes, NJ, USA). Attempts began at the first tracheal cartilage, with subsequent attempts progressively more caudad. Success was defined as intratracheal cannula placement. In each rabbit, an attempt was then made by each proceduralist to perform a cannula tracheotomy using the Quicktrach Child(™) device (VBM Medizintechnik GmbH, Sulz am Neckar, Germany). RESULTS: The rabbit tracheas were of similar dimensions to a human infant. 60 attempts were made at cannula tracheotomy, yielding a 60% success rate. There was no significant difference in success rate, ease of use, or complication rate between cannulae of different gauge. Successful aspiration was highly predictive (positive predictive value 97%) and both sensitive (89%) and specific (96%) for tracheal cannulation. The posterior tracheal wall was perforated in 42% of tracheal punctures. None of 13 attempts using the Quicktrach Child(™) were successful. CONCLUSION: Cannula tracheotomy in a model comparable to the infant airway is difficult and not without complication. Cannulae of 14- and 18-gauge appear to offer similar performance. Successful aspiration is the key predictor of appropriate cannula placement. The Quicktrach Child was not used successfully in this model. Further work is required to compare possible management strategies for the CICO scenario.

The use of ultrasound to guide time-critical cannula tracheotomy when anterior neck airway anatomy is unidentifiable.

BACKGROUND AND OBJECTIVE: Transtracheal or transcricothyroid placement of a cannula is a practice used in a number of aspects of airway management in anaesthesia and intensive care. In this study, we aimed to investigate whether the use of ultrasound will facilitate cannula placement in a time-critical situation in patients with difficult anterior neck airway anatomy. METHOD: Fifty anaesthetists were randomised to either ultrasound-guided or conventional unguided attempts, at cannula insertion into a model simulating a patient with unidentifiable anterior neck anatomy. Endpoints were the success, and time to success, of cannula placement. RESULTS: There was a significant increase in success rate (83 vs. 43%, P = 0.011) and a significant decrease in time to successful placement (median time to successful cannulation 57 vs. 110 s, P = 0.008) using ultrasound guided compared to unguided cannula placement. CONCLUSION: If a 'can't intubate, can't oxygenate' scenario occurs in a patient with unidentifiable anterior neck airway anatomy in a location where an ultrasound machine is immediately available, we recommend that consideration is given to the use of ultrasound-guided cannula tracheotomy as the first-line rescue technique.

Sedation monitoring of children by the Bispectral Index in the pediatric intensive care unit.

OBJECTIVE: To compare the Bispectral Index with clinical sedation assessment using the Ramsay score in normal sedated and paralyzed critically ill children. DESIGN: Prospective observational study. SETTING: Multidisciplinary 18-bed pediatric intensive care unit at a university-affiliated children's hospital. PATIENTS: A total of 48 pediatric intensive care unit patients requiring mechanical ventilation and sedation. Of these, 24 patients were not paralyzed. MEASUREMENTS AND MAIN RESULTS: Twenty-four pediatric intensive care unit children with normal mentation who were sedated and being ventilated in the intensive care unit were included in the study. The Ramsay score as assessed by the nurses was compared with the blinded Bispectral Index score. The regression coefficient between the Bispectral Index score and Ramsay score was 0.77 (p < 0.0001). The second group of patients included normal children similar to the previous group but paralyzed. The Ramsay score, as expected, was a poor tool for sedation assessment in a paralyzed patient. The nurse assessment only detected 8% of those patients at risk for awareness and recall (Bispectral Index score, > or = 80). Nurse assessment for oversedation (Bispectral Index score, < 40) was better with a sensitivity of 89.7% but a poor specificity of 38.6%. CONCLUSIONS: The Bispectral Index correlates well with the Ramsay score in the normal sedated child. The Ramsay score and bedside nurse assessment are inadequate for monitoring the depth of sedation in paralyzed children. The Bispectral Index is a useful adjunct in assessing sedation in a paralyzed patient.

Methadone dosage for prevention of opioid withdrawal in children.

BACKGROUND: Opioids are frequently used for sedation in the Paediatric Intensive Care Unit (PICU). With time the dosing often increases because of tolerance. On cessation of the sedation there is a risk of the opioid withdrawal syndrome. The aim of our study was to evaluate methadone dosing as a risk factor for opioid withdrawal and to determine optimal dose and efficacy of methadone to prevent withdrawal. METHOD: We undertook a clinical, retrospective, chart review study. Data were analysed from the quality improvement initiative database of a tertiary-care 18 bed PICU. RESULTS: Data from 30 children who received an opioid infusion for >/=7 days and subsequently received methadone for opioid withdrawal (between January 2000 and July 2001) were analysed. Nurses documented the presence or absence of withdrawal signs daily. Our unit protocol has recommended converting the patient's opioid dose into fentanyl equivalents and a dose of methadone equal to the total daily dose of fentanyl to be given three times a day. Twenty patients had no or minimal withdrawal symptoms and 10 experienced significant withdrawal. Age, weight, PRISM score, lorazepam dose, muscle relaxant use and fentanyl dose were not statistically significantly between these groups. Receiver Operator Characteristics analysis showed that 80% of the suggested methadone dose was effective in minimizing withdrawal symptoms. The odds ratio for withdrawal with <80% of the predicted methadone dose was 21. CONCLUSIONS: Inadequate methadone is a risk factor for opioid withdrawal. A daily starting methadone dose equivalent to 2.5 times the daily fentanyl dose is effective in minimizing withdrawal symptoms.