Do Thresholds for Invasive Ventilation in Hypoxemic Respiratory Failure Exist? A Cohort Study.

Rationale: Invasive ventilation is a significant event for patients with respiratory failure. Physiologic thresholds standardize the use of invasive ventilation in clinical trials, but it is unknown whether thresholds prompt invasive ventilation in clinical practice. Objectives: To measure, in patients with hypoxemic respiratory failure, the probability of invasive ventilation within 3 hours after meeting physiologic thresholds. Methods: We studied patients admitted to intensive care receiving FiO2 of 0.4 or more via nonrebreather mask, noninvasive positive pressure ventilation, or high-flow nasal cannula, using data from the Medical Information Mart for Intensive Care (MIMIC)-IV database (2008-2019) and the Amsterdam University Medical Centers Database (AmsterdamUMCdb) (2003-2016). We evaluated 17 thresholds, including the ratio of arterial to inspired oxygen, the ratio of saturation to inspired oxygen ratio, composite scores, and criteria from randomized trials. We report the probability of invasive ventilation within 3 hours of meeting each threshold and its association with covariates using odds ratios (ORs) and 95% credible intervals (CrIs). Measurements and Main Results: We studied 4,726 patients (3,365 from MIMIC, 1,361 from AmsterdamUMCdb). Invasive ventilation occurred in 28% (1,320). In MIMIC, the highest probability of invasive ventilation within 3 hours of meeting a threshold was 20%, after meeting prespecified neurologic or respiratory criteria while on vasopressors, and 19%, after a ratio of arterial to inspired oxygen of <80 mm Hg. In AmsterdamUMCdb, the highest probability was 34%, after vasopressor initiation, and 25%, after a ratio of saturation to inspired oxygen of <90. The probability after meeting the threshold from randomized trials was 9% (MIMIC) and 13% (AmsterdamUMCdb). In MIMIC, a race/ethnicity of Black (OR, 0.75; 95% CrI, 0.57-0.96) or Asian (OR, 0.6; 95% CrI, 0.35-0.95) compared with White was associated with decreased probability of invasive ventilation after meeting a threshold. Conclusions: The probability of invasive ventilation within 3 hours of meeting physiologic thresholds was low and associated with patient race/ethnicity.

Effect of table inclination angle on videolaryngoscopy and direct laryngoscopy: Operator's muscle activation and laryngeal exposure analysis.

BACKGROUND: Optimal vocal cord visualization depends on the patient's anatomical factors, characteristics of the laryngoscope, and the operator's muscle action. This study evaluated the effect of table inclination and three different laryngoscopic methods on procedural variables. The primary aim of this study is to compare differences in laryngoscopic view among clinicians based on the instrument used and table orientation. The secondary aim is to determine differences in upper extremity muscle activity based on laryngoscope use and table inclination. METHODS: Fifty-five anesthesia providers with different experience levels performed intubations on a manikin using three angles of table inclination and three laryngoscopy methods. Time to intubation, use of optimization maneuvers, glottic view, operator's comfort level, and upper extremity muscle activation measured by surface electromyography were evaluated. RESULTS: Table inclination of 15° and 30° significantly reduced intubation time and the need for optimization maneuvers. Fifteen degrees inclination gave the highest comfort level. Anterior deltoid muscle intensity was decreased when table inclination at 15° and 30° was compared to a flat position. CONCLUSION: Table inclination of 15° reduces intubation time and the need to use optimization maneuvers and is associated with higher operator's comfort levels than 0° and 30° inclination in a simulated scenario using a manikin. Different upper extremity muscle groups are activated during laryngoscopy, with the anterior deltoid muscle exhibiting significantly higher activation levels with direct laryngoscopy at zero-degree table inclination.

Ramped versus sniffing position for tracheal intubation: A systematic review and meta-analysis.

BACKGROUND: Whether the ramped or sniffing laryngoscopy position is better for tracheal intubation is unclear. This study aimed to determine the efficacy and safety of tracheal intubation in the ramped versus sniffing position. METHODS: We conducted a systematic review and meta-analysis of randomized clinical trials to compare the ramped position with the sniffing position for tracheal intubation. We searched the databases of Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Excerpta Medica Database (Embase), ClinicalTrials.gov, and World Health Organization Clinical Trials Registry Platform up to December 2018. We included randomized-controlled trials, trials of participants who required tracheal intubation in any setting, and that compared tracheal intubation in the ramped and the sniffing positions. Two authors independently screened the trials, extracted the data, and assessed the risk of bias. We conducted the meta-analysis using the random-effects model to calculate the pooled risk ratio with 95% confidence interval. RESULTS: Of the 2631 titles/abstracts screened, three studies (representing 513 patients) were included in the meta-analysis. The pooled risk ratio with 95% confidence interval (CI) of the sniffing versus the ramped position was as follows: a first successful attempt, 0.97 (95% CI, 0.86-1.09; I2 = 55%); laryngoscopy attempts ≤2, 1.08 (95% CI, 0.88-1.31; I2 = 93%); and good glottic view with Cormack-Lehane grade ≤ 2, 0.86 (95% CI, 0.69-1.07; I2 = 86%). CONCLUSIONS: This systematic review and meta-analysis indicated no favorable aspects of the ramped position as compared to the sniffing position. Thus, further research is warranted to identify which is better in tracheal intubation. TRIAL REGISTRATION: PROSPERO identifier, CRD42019116819.

Conversion of an oral to nasal intubation in difficult nasal anatomy patients: two case reports.

BACKGROUND: Nasal intubation is indispensable for some cases that require intraoral surgical access, and the fiberoptic bronchoscope is the best tool for difficult airways. However, fiberoptic bronchoscopy is not always possible in cases with altered pharyngeal anatomy. CASE PRESENTATION: In this report, we introduce a novel technique for retrograde endotracheal oral-to-nasal conversion with an ordinary endotracheal tube exchange catheter. A 49-year-old male with a fractured mandible angle and symphysis was scheduled to undergo mandible reconstruction. Secondly, a 45-year-old male who had a bone defect in the mandible angle and ramus was scheduled for mandible and oral cavity reconstruction. We chose to intubate orally first and successfully converted the endotracheal tube from oral to nasal retrogressively using a tube exchange catheter. CONCLUSIONS: Our simple and safe technique, which use a tube exchange catheter retrogressively, provides an alternative method for a difficult airway in which the fiberscope is not helpful.

Ultrasonography indicators for predicting difficult intubation: a systematic review and meta-analysis.

BACKGROUND: Ultrasonography (US) is recently used frequently as a tool for airway assessment prior to intubation (endotracheal tube (ETT) placement), and several indicators have been proposed in studies with different reported performances in this regard. This systematic review and meta-analysis reviewed the performance of US in difficult airway assessment. METHODS: This systematic review and meta-analysis was conducted according to the guideline of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Cochrane book. All the studies that had carried out difficult airway assessments using US, had compared the indicators in difficult and easy groups, and had published the results in English by the time we conducted our search in April 28, 2020, were included. RESULTS: In the initial search, 17,156 articles were retrieved. After deleting the duplicate articles retrieved from multiple databases, 7578 articles remained for screening based on the abstracts and titles. Finally, the full text of 371 articles were assessed and the data from 26 articles were extracted, which had examined a total of 45 US indicators for predicting difficult intubation. The most common US index was the "thickness of anterior neck soft tissue at the vocal cords level". Also, "skin to epiglottis" and "anterior neck soft tissue at the hyoid bone level" were among the most common indicators examined in this area. CONCLUSION: This systematic review showed that US can be used for predicting difficult airway. Of note, "skin thickness at the epiglottis and hyoid levels", "the hyomental distance", and "the hyomental distance ratio" were correlated with difficult laryngoscopy in the meta-analysis. Many other indicators, including some ratios, have also been proposed for accurately predicting difficult intubation, although there have been no external validation studies on them.

Comparison of clinical methods to diagnose pediatric endobronchial intubation-A randomized controlled trial.

BACKGROUND AND AIMS: Diagnosing accurate placement of the tip of the endotracheal tube is crucial in pediatric practice. This study was conducted to find out the efficacy of five clinical methods to ascertain the tube position by a resident anesthesiologist. MATERIAL AND METHODS: This was a randomized crossover study conducted in a research institute. Fifty pediatric patients were enrolled. All patients were randomly allocated to tracheal (group T) or bronchial group (group B). The five clinical methods which were evaluated include the auscultation, observation of chest movements, bag compliance, tube depth, and capnography. In group T, the tube was placed in the trachea and later positioned in bronchus (assisted by fiberoptic bronchoscopy). The vice versa was done in group B. In each position, a single test followed by all tests was performed and after the change of position, the same single test followed by all tests was performed. Correct and incorrect diagnoses by tests in detecting tube positions were made and their sensitivity and odds ratio were estimated. RESULTS: The tube depth and combination of all tests detected endobronchial intubation with a sensitivity of 88% and 97%, respectively, which is more than that of auscultation (70%) and observation (55%). Evaluation of the difference in agreement level of tube depth to detect tube-position showed the odds ratio of 2.28 (0.17-30.95) for detecting endobronchial intubation. CONCLUSION: We observed that the tube-depth was better than the other individual tests in diagnosing endobronchial intubation in pediatric patients. However, its efficacy is lesser than that of performing all clinical tests together.

Conversion of I-gel to definitive airway in a cervical immobilized manikin: Aintree intubation catheter vs long endotracheal tube.

BACKGROUND: After prehospital insertion of i-gel, a popular supraglottic airway (SGA), fiberoptic-guided intubation through i-gel is often required to switch the i-gel to a definitive airway for anticipated difficult airway. The Aintree intubation catheter (AIC) was developed for this purpose yet it requires many procedural steps during which maintenance of adequate ventilation is difficult. We custom-made a long endotracheal tube (LET) which may facilitate this procedure and compared the efficacy of the AIC and LET in a cervical immobilized manikin. METHODS: In this 2 × 2 crossover manikin-based trial, 20 anaesthesiologists and residents performed both methods in random order. Total intubation time, fiberoptic time, and procedure time were recorded. The ease of insertion, procedure failure rate, difficulty score, and participants' preference were recorded. RESULTS: Total intubation time was significantly shorter for the LET than the AIC group (70.8 ± 16.4 s vs 94.0 ± 28.4 s, P = 0.001). The procedure time was significantly shorter in the LET group (51.9 ± 13.8 s vs 76.5 ± 25.4 s, P <  0.001). The ease of insertion score was lower, i.e., easier, in the AIC than the LET group (2.0 [1.0-2.75] vs 1.0 [1.0-1.0], P <  0.001). Fiberoptic time (19.0 ± 6.9 s vs 17.5 ± 12.3 s) and subjective difficulty (4.0 [3.0-6.0] vs 4.0 [3.0-5.75]) were similar between groups. Fourteen participants preferred the LET method (70%) due to its fewer procedural steps. CONCLUSIONS: LET resulted in a shorter intubation time than the AIC during fiberoptic-guided intubation through the i-gel, possibly due to the less procedural steps compared to AIC. TRIAL REGISTRATION: NCT03645174 (ClinicalTrials.gov, Aug 22, 2018).

Comparative evaluation of I-gel vs. endotracheal intubation for adequacy of ventilation in pediatric patients undergoing laparoscopic surgeries.

BACKGROUND AND AIMS: The use of newer supraglottic devices has been extended to laparoscopic procedures. We conducted this study to compare and evaluate the efficacy of these two devices in pediatric laparoscopic surgeries. MATERIAL AND METHODS: Eighty children, 2-8 years of age, scheduled for elective short laparoscopic procedures were randomly allocated to the I-gel or endotracheal tube (ETT) group. Standard anesthesia protocol was followed for inhalational induction. I-gel or ETT was inserted according to the manufacturer's recommendations. Ventilation was set with tidal volume 10 ml/kg and a respiratory rate of 16/min. Carboperitoneum was achieved up to an intra-abdominal pressure of 12 mmHg. STATISTICAL ANALYSIS: The primary outcome variable was adequacy of ventilation (peak airway pressure, end-tidal CO2, minute ventilation, and SPO2). These variables were recorded after securing airway, after carboperitoneum and desufflation of the peritoneal cavity. The oropharyngeal leak pressures were also noted. Statistical analysis was done using SPSS software version 17.0. P <0.05 was considered statistically significant. RESULTS: No significant difference was observed in the heart rate or mean arterial pressure. There was a significant increase in the PECO2 and peak airway pressure after creation of carboperitoneum. There was significant increase in minute ventilation in both groups after creation of carboperitoneum. CONCLUSION: To conclude, I-gel is comparable to endotracheal intubation in terms of adequacy of ventilation. The increase in peak airway pressures is less with I-gel. In addition, postoperative complications are fewer with I-gel.

A comparison of two hyperangulated video laryngoscope blades to direct laryngoscopy in a simulated infant airway: a bicentric, comparative, randomized manikin study.

BACKGROUND: In infants, securing the airway is time-critical because of anatomical and physiological differences related to airway management in children less than 1 year old. The aim of this study was to compare the time to ventilation using two different hyperangulated video laryngoscope blades with the time to ventilation via conventional direct laryngoscopy in a normal airway [NA] and in a simulated difficult airway [DA]. METHODS: This study was a comparative, bicentric, open-label, randomized controlled evaluation. An infant high-fidelity simulator (SimBaby™; Laerdal® Medical, Stavanger, Norway) was used, and two scenarios were proposed, as follows: NA and DA evoked with tongue edema and cervical collar. After theoretical and practical briefing, each participant compared in the two airway scenarios the novel King Vision™ Pediatric aBlade (KV) (Ambu® A/S, Bad Nauheim, Germany) video laryngoscope and the C-MAC™ D-blade Ped (DB) (Karl Storz® SE & Co. KG, Tuttlingen, Germany) video laryngoscope to conventional laryngoscopy using the Miller Blade (MiB) and the Macintosh Blade (MaB) in a random sequence. RESULTS: Eighty physicians (65 AN and 15 PCCM staff) were included. In the NA scenario, the median [IQR] time to successful time to ventilation (TTV) was significantly shorter for the KV at 13 s [12-15 s] than for the MaB at 14.5 s [13-16 s], DB at 14.5 s [13-16] and MiB at 16 s [14-19] (p < 0.001). In DA, the KV also shortened TTV to 14 s [13-16], whereas TTV was 23 s with the MaB [20-26], 19 s with the DB [16-21], and 27 s with the MiB [22-31] (p < 0.001). There were no differences in first-pass intubation success rates (FPAs) between hyperangulated blades and direct laryngoscopes in NA. In DA, the hyperangulated blades enabled 92 (DB) to 100% (KV) FPAs compared with 65 (MiB) to 76% (MaB) for conventional laryngoscopy (p < 0.001). CONCLUSION: Video laryngoscopes with hyperangulated blades were associated with shorter TTV in normal and difficult infant airway situations. The higher FPAs of hyperangulated blades in DA may avoid desaturations and decrease adverse events in pediatric airway management.

Oropharyngeal surfactant can improve initial stabilisation and reduce rescue intubation in infants born below 25 weeks of gestation.

AIM: Minimally aggressive and easily performed techniques that facilitate spontaneous respiratory stabilisation are required to reduce rescue intubation in extremely premature infants. This study evaluated the feasibility and safety of administering surfactant into the pharynx of infants born at <25 weeks immediately after birth. METHODS: This study of 19 infants was conducted from January 2013 to June 2014 in a tertiary perinatal centre in Prague. We administered 1.5 mL of Curosurf as a bolus into the pharynx and simultaneously performed a sustained inflation manoeuvre (SIM). The extent of the interventions, death and severe neonatal morbidity in the study group were compared with 20 controls born before the study period and 20 born after it. RESULTS: All infants received oropharyngeal surfactant within the median (interquartile range) time of 40 seconds (25-75) after cord camping. The surfactant had to be suctioned in one infant because of upper airway obstruction. Although more subsequent surfactant was administered in the study group, significantly fewer study period infants required intubation than the before and after controls (16% versus 75% and 58%, respectively, p < 0.01). CONCLUSION: Oropharyngeal surfactant with simultaneous SIM was feasible and safe and reduced the need for delivery room intubation in these fragile infants.

Computed Tomographic Window Setting for Bronchial Measurement to Guide Double-Lumen Tube Size.

OBJECTIVES: The bronchial diameter measured on computed tomography (CT) can be used to guide double-lumen tube (DLT) sizes objectively. The bronchus is known to be measured most accurately in the so-called bronchial CT window. The authors investigated whether using the bronchial window results in the selection of more appropriately sized DLTs than using the other windows. DESIGN: CT image analysis and prospective randomized study. SETTING: Tertiary hospital. PARTICIPANTS: Adults receiving left-sided DLTs. INTERVENTIONS: The authors simulated selection of DLT sizes based on the left bronchial diameters measured in the lung (width 1,500 Hounsfield unit [HU] and level -700 HU), bronchial (1,000 HU and -450 HU), and mediastinal (400 HU and 25 HU) CT windows. Furthermore, patients were randomly assigned to undergo imaging with either the bronchial or mediastinal window to guide DLT sizes. Using the underwater seal technique, the authors assessed whether the DLT was appropriately sized, undersized, or oversized for the patient. MAIN MEASUREMENTS AND RESULTS: On 130 CT images, the bronchial diameter (9.9 ± 1.2 mm v 10.5 ± 1.3 mm v 11.7 ± 1.3 mm) and the selected DLT size were different in the lung, bronchial, and mediastinal windows, respectively (p < 0.001). In 13 patients (17%), the bronchial diameter measured in the lung window suggested too small DLTs (28 Fr) for adults. In the prospective study, oversized tubes were chosen less frequently in the bronchial window than in the mediastinal window (6/110 v 23/111; risk ratio 0.38; 95% CI 0.19-0.79; p = 0.003). No tubes were undersized after measurements in these two windows. CONCLUSIONS: The bronchial measurement in the bronchial window guided more appropriately sized DLTs compared with the lung or mediastinal windows.

Introduction of laryngeal mask airway in Japan, and its rescue use for newborns.

BACKGROUND: In neonatal resuscitation, laryngeal mask airway (LMA) is recommended when both face mask ventilation and endotracheal intubation fail. Experience of LMA among obstetricians, nurses and midwives in Japan, however, is limited. The aims of the present study were to (i) offer an LMA training course to professionals dealing with low-risk pregnancies at institutions across Japan; and (ii) assess the subsequent use and value of LMA at the participating institutions. METHODS: Between August 2016 and March 2017, a total of 18 training courses for 60 min were provided for around 350 medical personnel from 51 institutes. LMA use over the subsequent 12 months was assessed via a postal questionnaire. RESULTS: After training, a total of 38 institutes introduced LMA. Of 13 254 live births, seven cases of rescue use LMA in "cannot ventilate, cannot intubate" situations were reported. None of these seven newborns had any malformation of the upper airway. LMA insertion resulted in adequate ventilation in all seven cases. CONCLUSION: LMA can be a life-saving tool in neonatal resuscitation. All medical institutions dealing with low-risk pregnancies in Japan should be equipped with this device.

Assessment of awake i-gel™ insertion for fiberoptic-guided intubation in patients with predicted difficult airway: A prospective, observational study.

BACKGROUND AND AIMS: Orotracheal intubation (OTI) with fiberoptic bronchoscope (FOB) in spontaneous ventilation is one of the main techniques for patients with predicted difficult airway. Latest generation supraglottic airway devices have been designed to allow OTI through them. We assessed the safety and effectiveness of FOB-guided OTI through i-gel™ device which was inserted in spontaneously breathing patients with predicted difficult airway. MATERIAL AND METHODS: Eighty-five patients with difficult airway predictors were included. The i-gel was inserted under oropharyngeal local anaesthesia and sedation. After checking the adequate ventilation through the i-gel with capnography curve, general anaesthesia was induced in order to introduce the endotracheal tube guided by FOB. We recorded the i-gel insertion time (t gel), intubation time (t int), O2 saturation in pulse oximetry (SpO2) at different times: basal (t 0), after 3 min of preoxygenation with a face mask at 100% FiO2 (t 1), after i-gel mask insertion (t 2) and after intubation (t 3). Adverse events during the procedure were also recorded. RESULTS: All patients were successfully intubated. SpO2 values were: 96.9 ± 1.2 (t 0), 99.0 ± 0.9 (t 1), 96.2 ± 2.4 (t 2), 96.0 ± 2.5 (t 3). t gel and t int were 38.0 ± 7.8 s and 36.5 ± 5.6 s, respectively. No serious adverse events were recorded and no patient suffered airway trauma. CONCLUSION: I-gel insertion in spontaneous ventilation secures the airway before achieving fiberoptic intubation without the occurrence of adverse events. More studies might be necessary in order to confirm the results presented, but we consider that the technique described is a safe and effective alternative to classic OTI with FOB in spontaneously breathing patients with predicted difficult airway.

The efficacy of GlideScope® videolaryngoscopy compared with direct laryngoscopy in children who are difficult to intubate: an analysis from the paediatric difficult intubation registry.

BACKGROUND: We analysed data from the Paediatric Difficult Intubation Registry examining the use of direct laryngoscopy and GlideScope® videolaryngoscopy. METHODS: Data collected by a multicentre, paediatric difficult intubation registry from 1295 patients were analysed. Rates of success and complications between direct laryngoscopy and GlideScope videolaryngoscopy were analysed. RESULTS: Initial (464/877 = 53% vs 33/828 = 4%, Z-test = 22.2, P < 0.001) and eventual (720/877 = 82% vs. 174/828 = 21%, Z-test = 25.2, P < 0.001) success rates for GlideScope were significantly higher than direct laryngoscopy. Children weighing <10 kg had lower success rates with the GlideScope than the group as a whole. There were no differences in complication rates per attempt between direct laryngoscopy and GlideScope. The direct laryngoscopy group had more complications associated with the greater number of attempts needed to intubate. There were no increased risks of hypoxia or trauma with GlideScope use. Each additional attempt at intubation with either device resulted in a two-fold increase in complications (odds ratio: 2.0, 95% confidence interval: 1.5-2.5, P < 0.001). CONCLUSIONS: During difficult tracheal intubation in children, direct laryngoscopy is an overly used technique with a low chance of success. GlideScope use was associated with a higher chance of success with no increased risk of complications. GlideScope use in children with difficult tracheal intubation has a lower success rate than in adults with difficult tracheal intubation. Children weighing less than 10 kilograms had lower success rates with either device. Attempts should be minimized with either device to decrease complications.

Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill.

RATIONALE: Hypoxemia is common during endotracheal intubation of critically ill patients and may predispose to cardiac arrest and death. Administration of supplemental oxygen during laryngoscopy (apneic oxygenation) may prevent hypoxemia. OBJECTIVES: To determine if apneic oxygenation increases the lowest arterial oxygen saturation experienced by patients undergoing endotracheal intubation in the intensive care unit. METHODS: This was a randomized, open-label, pragmatic trial in which 150 adults undergoing endotracheal intubation in a medical intensive care unit were randomized to receive 15 L/min of 100% oxygen via high-flow nasal cannula during laryngoscopy (apneic oxygenation) or no supplemental oxygen during laryngoscopy (usual care). The primary outcome was lowest arterial oxygen saturation between induction and 2 minutes after completion of endotracheal intubation. MEASUREMENTS AND MAIN RESULTS: Median lowest arterial oxygen saturation was 92% with apneic oxygenation versus 90% with usual care (95% confidence interval for the difference, -1.6 to 7.4%; P = 0.16). There was no difference between apneic oxygenation and usual care in incidence of oxygen saturation less than 90% (44.7 vs. 47.2%; P = 0.87), oxygen saturation less than 80% (15.8 vs. 25.0%; P = 0.22), or decrease in oxygen saturation greater than 3% (53.9 vs. 55.6%; P = 0.87). Duration of mechanical ventilation, intensive care unit length of stay, and in-hospital mortality were similar between study groups. CONCLUSIONS: Apneic oxygenation does not seem to increase lowest arterial oxygen saturation during endotracheal intubation of critically ill patients compared with usual care. These findings do not support routine use of apneic oxygenation during endotracheal intubation of critically ill adults. Clinical trial registered with www.clinicaltrials.gov (NCT 02051816).

Effect of patient weight on first pass success and neuromuscular blocking agent dosing for rapid sequence intubation in the emergency department.

OBJECTIVES: The primary objective of this study was to determine the association between patient weight and first pass success (FPS) during rapid sequence intubation (RSI) in the ED. The secondary objective was to evaluate the association between patient weight and neuromuscular blocking agent (NMBA) dosing. METHODS: This was a retrospective cohort study conducted in a tertiary care academic ED. Consecutive adult patients who underwent RSI in the ED between January 2014 and June 2016 were included. Data were collected on patient, operator and procedural characteristics. The cohort was categorised into the following weight strata: <80 kg, 80 to <100 kg, 100 to <120 kg and ≥120 kg. The primary outcome of interest was FPS. A multivariable logistic regression analysis was conducted to evaluate the relationship between patient weight category and FPS. NMBA dosing was reported descriptively. RESULTS: The sample included 891 patients. FPS for each weight category was as follows: <80 kg (91%), 80 to <100 kg (90%), 100 to <120 kg (91%) and ≥120 kg (76%). After adjusting for potential confounders, the heaviest weight category was associated with decreased odds of FPS (OR 0.2, 95% CI 0.1 to 0.5, p<0.001). Median doses for succinylcholine (based on total body weight) decreased as weight increased: <80 kg (1.5 mg/kg), 80 to <100 kg (1.3 mg/kg), 100 to <120 kg (1.2 mg/kg) and ≥120 kg (1.0 mg/kg). Median doses for rocuronium (based on ideal body weight) were similar across weight categories: <80 kg (1.3 mg/kg), 80 to <100 kg (1.4 mg/kg), 100 to <120 kg (1.3 mg/kg) and ≥120 kg (1.4 mg/kg). CONCLUSIONS: Very heavy patients (>120 kg) undergoing RSI in the ED had a reduced FPS, and succinylcholine was more commonly underdosed than rocuronium in the heavier weight group.

Effect of magnesium sulfate nebulization on the incidence of postoperative sore throat.

BACKGROUND AND AIMS: Postoperative sore throat (POST) is a well-recognized complication after general anesthesia (GA). Numerous nonpharmacological and pharmacological measures have been used for attenuating POST with variable success. The present study was conducted to compare the efficiency of preoperative nebulization of normal saline and magnesium sulfate in reducing the incidence of POST following GA. MATERIALS AND METHODS: Following institutional ethical committee approval and written informed consent, a prospective randomized double-blinded study was conducted in 100 cases divided into two equal groups. Patients included in the study were of either gender belonging to American Society of Anesthesiologist (ASA) status 1 or 2 undergoing elective surgery of approximately 2 h or more duration requiring tracheal intubation. Patients in Group A are nebulized with 3 ml of normal saline and the patients in Group B are nebulized with 3 ml of 225 mg isotonic nebulized magnesium sulfate for 15 min, 5 min before induction of anesthesia. The incidence of POST at rest and on swallowing and any undue complaints at 0, 2, 4, and 24 h in the postoperative period are evaluated. RESULTS: There is no significant difference in POST at rest during 0(th), 2(nd) and 4(th) h between normal saline and MgSO4. Significant difference is seen at 24(th) h, where MgSO4 lessens POST. There is no significant difference in POST on swallowing during 0(th) and 2(nd) h between normal saline and MgSO4. Significant difference is seen at 4(th) h, where MgSO4 has been shown to lessen POST. CONCLUSIONS: MgSO4 significantly reduces the incidence of POST compared to normal saline.

Comparisons of recursive partitioning analysis and conventional methods for selection of uncuffed endotracheal tubes for pediatric patients.

BACKGROUND: Numerous studies have investigated the best method of selecting the appropriate size of endotracheal tube (ETT) for children. However, none of the methods or formulae for selection of ETT size have shown better prediction over another, and they have required complex formulae calculation or even use of cumbersome equipment. Recursive partitioning analysis creates a decision tree that is more likely to enable clearer and easier visualization of decision charts compared to other data mining methods. OBJECTIVES: The aim of the current study was to develop a clinically practical and intuitive chart for prediction of ETT size. METHODS: Pediatric patients aged 2-9 years undergoing general anesthesia were intubated with uncuffed ETT. The tube size was considered optimal when a tracheal leak was detected at an inflation pressure between 10 and 25 cmH2 O. The observed ETT size was compared with the predicted ETT size calculated using Cole's formula, multivariate regression analysis, ultrasonographic measurements, and recursive partitioning tree structure analysis. Preference among the prediction methods was also investigated by asking physicians about their preference of methods. RESULTS: Correct prediction rates were 33.3%, 50%, 61.9%, and 59.5%, and close prediction rates were 61.9%, 83.3%, 88.1%, and 93.7% for Cole's formulae, multivariate regression analysis, ultrasonographic measurements, and recursive partitioning tree model, respectively. Fourteen of 16 physicians prefer to use the easy-to-interpret tree model. CONCLUSIONS: Analysis of the tree model by recursive partitioning structure analysis accomplished a high correct and close prediction rate for selection of an appropriate ETT size. The intuitive and easy-to-interpret tree model would be a quick and helpful tool for selection of an ETT tube for pediatric patients.

Tracheal size variability is associated with sex: implications for endotracheal tube selection.

PURPOSE: Whereas selection of endotracheal tube (ETT) size in pediatric patients benefits from predictive nomograms, adult ETT sizing is relatively arbitrary. We sought to determine associations between cervical tracheal cross-sectional area (CTCSA) and clinical variables. METHODS: One hundred thirty-two consecutive patients undergoing noncontrasted chest computed tomography (CT) at a single tertiary care institution from January 2010 to June 2011 were reviewed. Patients with improper CT technique, endotracheal intubation, and pulmonary/tracheal pathology were excluded. Tracheal luminal diameters in anteroposterior (D1) and transverse (D2) were measured 2 cm inferior to the cricoid and used to determine CTCSA = π*D1*D2*». The demographic variables of age, height, weight, and body mass index (BMI) were tested for association with CTCSA by Spearman correlation. Wilcoxon rank-sum test was used to compare CTCSA by race and sex. Multivariate linear regression was performed including all clinical variables. RESULTS: There were 91 patients who met inclusion criteria. There was no correlation between age, weight, or BMI and CTCSA. There was a significant positive correlation between patient height and CTCSA (P = .001, R = 0.35); however, this was confounded by sex. Female patients had significantly smaller CTCSA (mean = 241 mm(2)) compared to male patients (mean = 349 mm(2), P < .001). Multivariate linear regression stratified by sex revealed that height is correlated with CTCSA only in males (P = .028). Males also had more variability in CTCSA (SD 118.6) compared to females (SD 65.5). CONCLUSION: Our data suggest that selection of ETT size in male patients should include height as a predictive factor. For female patients, it may be appropriate to select a uniformly smaller diameter ETT size.

A review of published case reports of inadvertent pulmonary placement of nasogastric tubes in children.

PROBLEM: Little is known about the incidence of inadvertent pulmonary placement of nasogastric tubes during blind insertions in children. PURPOSE: The purpose of this paper was to conduct a review of published case reports over the past two decades. METHODS: An OVID Medline search was conducted of articles published from 1993 through 2012. RESULTS: Fifteen published case reports were located; four patients died as a result of their malpositioned tubes. The auscultatory bedside method failed to detect the malpositioned tubes in all seven cases in which it was used. CONCLUSIONS: The incidence of inadvertent pulmonary placement of nasogastric tubes is relatively low but can lead to serious and even lethal results in children. The auscultatory method to predict tube location is unreliable.