Endotracheal Tube Size Research Articles

The Role of Proton Pump Inhibitors in Reducing Laryngeal Injury During Prolonged Intubation

Methods: Adult subjects were prospectively enrolled and underwent video-recorded transnasal fiberoptic laryngoscopy following extubation in the medical intensive care unit. Variables recorded include: duration of intubation, size of endotracheal tube, and administration of proton pump inhibitor versus H-2 blocker during intubation. The laryngoscopy examinations were blindly reviewed and laryngeal injuries that were documented include: presence of vocal fold immobility, vocal fold granuloma, and laryngeal erythema or ulceration.

Reducing Unplanned Extubations in a Pediatric Intensive Care Unit: A Systematic Approach

Objective. To prospectively determine the rate of unplanned extubations and contributing factors and determine whether a targeted intervention program would be successful in decreasing the rate of unplanned extubations. Design. Prospective, observational study. Setting. A 10-bed Pediatric Intensive Care Unit (PICU). Patients. All intubated pediatric patients during two time periods: September 1, 2000–March 31, 2001 and November 1, 2001–April 30, 2002. Interventions. After determining the rate and causes of unplanned extubation, a program was developed consisting of education and a formalized endotracheal tube taping policy. Data were then collected after implementation of the program. Measurements and Main Results. Prior to the implementation of the program, there were 10 (14.7%) unplanned extubations for a rate of 6.4 unplanned extubations per 100 ventilated days. Of the ten unplanned extubations, reintubation was required in 2 (20%). Inadequate sedation, poor taping, and improper position of the endotracheal tube were the items most frequently cited as causing an unplanned extubation. Following the program, there were two (3.4%) unplanned extubations for 1.0 unplanned extubations per 100 ventilated days. Neither patient required reintubation. There were no significant differences (P > .05) in age, weight, endotracheal tube size, or duration of intubation in the two time periods. However, there was a significant decrease in both the number (P = .03) and the rate (P = .04) of unplanned extubations after the implementation of the quality improvement program. Conclusions. The rate of unplanned extubation in a PICU can be decreased with a quality improvement program that targets the institution's specific needs.

An unusual cause of hypercapnia

SIRAn 11 year old, 30 kg, ASA grade 1, male child was booked for inguinal hernia repair at Lok Nayak Hospital, New Delhi, India. History and physical examination were normal and hematological investigations were within normal limits. In the operating room, Electrocardiogram (ECG), Pulse oximeter (SPO2) and Non-Invasive Blood Pressure (NIBP) monitors were attached. Intravenous access was established using a 20 G cannula and fentanyl 60 mic was given i.v. Anesthesia was induced using propofol 80 mg and rocuronium bromide 30 mg i.v was given to facilitate muscle relaxation. After mask ventilation using Bain’s circuit, trachea was intubated with cuffed endotracheal tube size 6.5. Anesthesia was maintained using O2, N20 and isoflurane in closed circuit. The surgery was started thereafter. End tidal carbon-dioxide (ETCO2) levels were monitored in addition to ECG, SPO2 and NIBP.

The Cuff Leak Test is Not Predictive of Successful Extubation

In intubated patients the presence of a cuff leak (CL) is used as a predictor of successful extubation. CL is proposed to indicate laryngeal edema and predict which patients may develop complications such as postextubation stridor and eventual reintubation. Our objective was to evaluate the reliability of CL in our population of critically ill trauma patients. A retrospective chart review was performed of patients admitted to the trauma service who required mechanical ventilation. All patients undergo the CL test by a single respiratory therapist team before attempted extubation. Data collected included body mass index (BMI), endotracheal tube (ETT) size, length of time of mechanical ventilation, tidal volumes (Vt), and the size of the patient's trachea based on CT scan. The test is performed by the respiratory therapists and involves measuring expired Vt before and after the ETT cuff has been deflated and listening for an audible leak. A positive test result is defined as a CL greater than 10 per cent of Vt or, when volumes are not available, as audible air expired. From October 2005 to May 2006, 150 mechanically ventilated patients were identified and 49 charts were available for review. Forty-one patients had a cuff leak (+CL), whereas eight did not (-CL). The two cohorts were similar in age (+CL = 36.5 years, -CL = 38.1 years, P = 0.82), male gender (+CL = 70%, -CL = 50%, P = 0.25) ETT size (+CL = 7.4, -CL = 7.4, P = 0.57), and BMI (+CL = 28 kg/m2, -CL = 27 kg/m2, P = 0.71). The average tracheal diameter (+CL = 17.4 mm, -CL = 17.5 mm, P = 0.90) as well as the ratio of ETT and tracheal diameter was similar for the two cohorts (+CL = 0.65, -CL = 0.64, P = 0.73). Four patients (10%) in the +CL cohort failed extubation, whereas none of the -CL cohort failed (0%) (P = 0.40). The CL test does not reliably identify those patients who will require reintubation in our trauma population. In addition, the ratio of ETT and tracheal diameter is not predictive of successful extubation.

Improving documentation of endotracheal intubation in an adult emergency department

To evaluate the effect of an educational intervention and documentary pro forma on the adequacy of documentation of intubation in an adult ED. A structured medical record review was performed before and after a multi-pronged educational programme and introduction of a specifically designed guide to documentation. Records were assessed for adequacy of documentation by the presence or absence of predetermined elements. Analysis focused on five aspects considered to be most important for future clinical care: drugs and doses used, grade of view, size of endotracheal tube, confirmation of placement and adverse events/difficulties encountered. Sixty-one and sixty-eight charts were included in the pre-intervention and post-intervention groups, respectively. The drugs and doses used were documented in 92% and 93%. The endotracheal tube size was recorded 82% and 91% of the time. Grade of laryngoscopy was documented in 35% and 46%. Confirmation of endotracheal tube placement was 69% and 84%. Presence or absence of adverse events was recorded in 37% and 54%. All five elements were present in 8.2% and 25% of medical records. Documentation improved slightly following the intervention, but was still unsatisfactory. We believe that to achieve an adequate level of documentation in the medical record for an episode of intubation, there needs to be a formal and structured mechanism, either via mandatory use of a specifically designed form and/or by participation in an organized data registry.

Mainstream Time-Capnography: An Aid to Select an Appropriate Uncuffed Endotracheal Tube in Small Children

Uncuffed endotracheal tubes are commonly used in children in an attempt to decrease the potential for pressure induced tracheal injury. However, uncuffed endotracheal tube may increase the risk of aspiration and lead to erratic delivery of preset tidal volume during mechanical ventilation. Therefore, it is desirable to intubate trachea with an appropriate but not an oversized endotracheal tube. In children, for selecting an endotracheal tube, a variety of formulas and techniques are used to find the endotracheal tube size that minimizes both pressure induced tracheal injury and aspiration potential or variable ventilation. Air-leak following tracheal intubation can be recognized by the presence of audible leak, by auscultation over the trachea, by palpation over the trachea and by observing effects of positive end-expiratory pressure on inspiratory expiratory tidal volume difference during mechanical ventilation. We describe mainstream time-capnograph as an aid to recognize leak around the endotracheal tube and its utility to determine appropriate endotracheal tube size in small children.

Ischemic subglottic damage following a short-time intubation

The objective of this study is to report a case of ischemic subglottic damage after a short-time intubation with a large, overinflated endotracheal tube cuff in a child. The study uses individual case report. A 6-year-old boy was admitted to the pediatric intensive care unit after a head trauma intubated with a 5.5-mm inner diameter cuffed endotracheal tube overinflated with 16 ml of air that produced a pressure of more than 120 cm H2O. The endotracheal tube cuff pressure produced by inflation was reduced after 4 h. The child presented postextubation stridor with subglottic edema. Inappropriate handling of tracheal intubation without accurate measurement of endotracheal tube size and intracuff pressures of endotracheal tubes, can cause airway trauma and place patients at risk.

Dysphagia Development after Surgery Unrelated to Laryngeal and Pharyngeal Structures

The aim of this study was to retrospectively investigate swallowing capacity and dysphagia severity using VFSS and to determine their relationships to intra- and postoperative factors in long-lasting dysphagia patients who had undergone an operation unrelated to pharyngeal and laryngeal structures. Twenty-six patients without a definite cause of dysphagia were selected from among patients admitted to our hospital from January 2006 to December 2007. Videofluoroscopic dysphagia scale (VDS) and ASHA NOMS swallowing level (ASHA level) at 1 month postoperatively were used to determine dysphagia severity and swallowing capacity. Intraoperative factors (endotracheal tube size, intubation time, and total anesthetic time) and postoperative factors (tracheostomy history, vocal cord palsy, and postoperative delirium) were investigated to determine their relationships with VDS and ASHA level. No significant relationship was found between these factors and VDS or ASHA level by Pearson's or Spearman's correlation testing. Further prospective studies are required to identify the causative factors of long-lasting dysphagia after surgical procedures unrelated to pharyngeal and laryngeal structures.

Peri-operative management of the oesphagectomy patient

Carcinoma of the oesophagus is increasing in incidence in the West and the only current cure is surgical resection. Other treatments (neo-adjuvant chemotherapy and radiotherapy) can render previously unresectable tumours operable but controversy remains as to the overall benefit of these therapies and ongoing trial results are awaited. Approximately 200 oesophagectomies are performed annually in England with a 30-day mortality was between 9.5 and 10.5%. Pre-operative investigations should evaluate cardiorespiratory co-morbidities, particularly with respect to the risks of intra-operative one-lung ventilation, post operative respiratory failure and potential overall outcome. Cardiopulmonary exercise testing and shuttle testing are recent additions to the investigative armamentarium that may augment the accuracy of morbidity and mortality prediction. The size and type of double lumen endotracheal tube can be gauged from assessment of the left main bronchus on the CXR. Intra-operative management includes consideration of positioning and preparation for one-lung ventilation. Careful fluid management and judicious fluid restriction help to limit post operative complications. Analgesia is important and the thoracic epidural or paravertebral blocks are said to be beneficial post operatively. Complications include anastomotic breakdown and cardiovascular complications such as acute coronary syndrome and arrhythmias (most commonly atrial fibrillation) which occur in approximately 15–25% of cases. Chylothorax occurs in 2–3% of cases. It is likely that increasing numbers of patients will present with resectable oesophageal tumours. A systematic approach to pre-assessment, pre-optimisation, intra-operative management and post operative care can bear dividends for patients and anaesthetist alike.

Morphometric Study on the Anatomy of the Fetal Cricoid Cartilage and Comparison between its Inner Diameter and Endotracheal Tube Sizes

The high incidence of respiratory disorders is one of the main problems in perinatal medical care. With the increased use of intubation, the incidence of laryngeal injury causing stenosis has also increased. The principal constriction point in the infant's larynx is the midcricoid area. We sought to provide detailed morphometric data on the anatomy of the cricoid cartilage and its relationship with growth and body characteristics of fetuses at 5 to 9 months of gestational age. Nineteen larynges obtained from 17 stillborn infants and 2 newborn infants ranging in gestational age from 5 to 9 months were studied. Measurements of the cricoid cartilage were made with a millimeter-graded caliper. Weight was the variable most correlated with cricoid measurements. The cricoid lumen configuration showed an almost elliptic shape and did not change with gestational age. The mean inner subglottic cricoid area was 19.27 +/- 9.62 mm2 and was related to weight and body surface area. Cricoid growth was more pronounced at the outer portion of the cartilage. The cricoid lumen configuration was elliptic, and its mean area was smaller than that of available endotracheal tubes. This lumen area was most influenced by weight and height.

Post-anaesthetic Respiratory Complaints Following Endotracheal Anaesthesia In Lower Abdominal Obstetric And Gynaecology Surgery

Postanaesthetic respiratory complications represent a significant negative aspect of surgical care. To assess the incidence and possible associated risk factors for postanaesthestic respiratory complaints following endotracheal anaesthesia in lower abdominal surgery in obstetric and gynecology patients in our hospital. A Teaching Hospital in Nigeria. Prospective study All consenting adult patients, aged 16-45 years, undergoing caesarean section and major gynaecological abdominal operations, under general anaesthesia with endotracheal intubation, over a period of 8months, were studied. Postoperative respiratory symptoms, (sorethroat, hoarseness and cough), were assessed in the ward, by direct questioning method, daily for 5 days. Those presenting with cough had their chest examined, and fever (T degrees > 37 degrees C), was noted. Patients with positive chest signs had radiological examinations of the chest done for confirmation. A total of 202 patients were studied. Out of these, 152 (75.2%) patients had various forms of postoperative respiratory complaints. Overall, it was observed that caesarean section patients were more likely, than gynaecology patients, to report these respiratory complications in the postoperative period (88.4% vs. 58.9%). This difference was statistically significant (p < 0.05). The incidence of sorethroat directly correlated with the size of the endotracheal tube used (r = 0.936). There was a statistically significant difference in the incidence of sorethroat between the caesarean section patients and gynaecology patients (p < 0.00), particularly with endotracheal tube sizes larger than 7.5mm ID (p < 0.03). Duration of intubation, which was slightly longer in gynaecology patients (mean = 72.48 +/- 30.62), and number of intubation attempts, did not have statistically significant effect on the incidence of respiratory complaints. The use of small endotracheal tube sizes (< 8.5mm) should be preferred in women, particularly in obstetric anesthesia (6.5-7.5mm), to minimize the incidence of postoperative respiratory complications.

Evaluation of Two Methods of Endotracheal Tube Selection in Dogs

This study evaluated two methods of endotracheal tube selection using 28 fresh canine carcasses of various ages, weights, and genders. The two selection methods were 1) nasal septal width pairing with outer diameter of an endotracheal tube, and 2) digital palpation of the tracheal outer diameter to determine the endotracheal tube size. All dogs were dolichocephalic breeds. Results of this study showed that the canine nasal septal width method of endotracheal tube selection was correlated with the size of the tracheal internal (r=0.72) and outer (r=0.73) diameters. However, evidence shows that the digital palpation method is slightly more effective than the nasal width method in selecting the best-fitting endotracheal tube. The percentage of the best-fit tube selection for the nasal septal width method was 21%, while the digital palpation method was 46%. With these two methods, selecting an endotracheal tube that is too small is possible, especially when the tube internal diameter is > or =7 mm.

Negative Tracheal Pressure During Neonatal Endotracheal Suction

Endotracheal tube (ETT) suction is the most frequently performed invasive procedure in ventilated newborn infants and is associated with adverse effects related to negative tracheal pressure. We aimed to measure suction catheter gas flow and intratracheal pressure during ETT suction of a test lung and develop a mathematical model to predict tracheal pressure from catheter and ETT dimensions and applied pressure. Tracheal pressure and catheter flow were recorded during suction of ETT sizes 2.5-4.0 mm connected to a test lung with catheters 5-8 French Gauge and applied pressures of 80-200 mm Hg. The fraction of applied pressure transmitted to the trachea was calculated for each combination, and data fitted to three nonlinear models for analysis. Tracheal pressure was directly proportional to applied pressure (r = 0.82-0.99), and catheter flow fitted a turbulent flow model (R = 0.85-0.96). With each ETT, increasing catheter size resulted in greater catheter flow (p < 0.0001) and thus lower intratracheal pressure (p < 0.0001). The fraction of applied pressure transmitted to the trachea was accurately modeled using ETT and catheter dimensions (R = 0.98-0.99). Negative tracheal pressure during in vitro ETT suction is directly proportional to applied pressure. This relationship is determined by ETT and catheter dimensions.

Can ultrasound be useful for predicting the size of a left double-lumen bronchial tube? Tracheal width as measured by ultrasonography versus computed tomography

Study Objective To correlate tracheal width as measured by ultrasound with width measured by computed tomography (CT), and to evaluate the possible role of ultrasound in the selection of the proper size of left-sided double-lumen endotracheal tubes (LDLTs). Design Two independent, prospective, observational clinical studies (Study 1 and Study 2). Setting University hospital. Patients Study 1 included 25 patients and Study 2 included 20 adult thoracic surgery patients who required a LDLT during anesthesia. Interventions and Measurements In Study 1, CT measurements of tracheal width were made at the coronary plane 0.5 cm above the sternoclavicular joint; CT measurements of the left main bronchus diameter were made 1 cm below the carina. Ultrasound measurement of tracheal width was performed just above the sternoclavicular joint in the transversal section. In Study 2, patients' tracheas were intubated with a LDLT based on ultrasound measurements. The frequencies of incorrect selections of LDLT and unsatisfactory lung collapse were analyzed. Main Results There was a strong correlation between tracheal width as measured by ultrasound and tracheal width ( r = 0.882, P < 0.001) and left main bronchus width ( r = 0.832, P < 0.001) as measured by CT. In 5 cases (25%), the incorrect LDLT by ultrasound was selected; and one (5%) was found to have an unsatisfactory lung collapse. Conclusion Measurement of the outer tracheal width by ultrasound can be a useful method for predicting the diameter of left main bronchus and for selecting a LDLT.

The Sophistication of Simplicity . . . Optimizing Emergency Dosing

The Sophistication of Simplicity . . . Optimizing Emergency Dosing

Role of Balloon Dilation in the Management of Adult Idiopathic Subglottic Stenosis

We evaluated the efficacy of balloon dilation for adjunctive and symptomatic management of isolated idiopathic subglottic stenosis in adults. Adults with airway obstruction symptoms classified as idiopathic subglottic stenosis based on history and findings of a single discrete stenotic area on microlaryngoscopy and bronchoscopy were included in this series. Patients who met these criteria underwent dilation with a 10- to 14-mm balloon in a single procedure or in 2 consecutive dilations within 7 days. The patients were followed for up to 30 months after dilation. Six patients met the criteria. One of the 6 had prior laser treatments and a cricotracheal resection. One patient had a previous scar band lysis procedure. The remaining 4 patients had no prior procedures. The airway sizes prior to dilation ranged from a 2.5 endotracheal tube to a 5.0 endotracheal tube. In all cases the airway was dilated to 2.0 to 3.5 endotracheal tube sizes larger than the initial size. To date, 4 patients have been followed for 10 to 30 months without symptoms of recurrent airway stenosis. One patient was symptom-free for 22 months, then presented with progressive airway difficulty following an upper respiratory tract infection, and has undergone a repeat dilation. No patients had adverse effects or complications from the procedure. Balloon dilation of idiopathic subglottic stenosis in adults is a relatively safe and effective method to manage this disease entity for cases of isolated and discrete lesions. Patients who underwent a single procedure have remained symptom-free for up to 30 months after balloon dilation.

Prevention of Pediatric Drug Calculation Errors by Prehospital Care Providers

Objective. Calculating weight-based drug doses for pediatric patients is difficult, with significant error potential. In the prehospital setting, few safeguards currently avert pediatric drug administration errors. We sought to determine whether use of a protocol-specific pediatric code card enables prehospital care providers to calculate more consistently accurate weight-based drug doses, volumes of administration, andage-appropriate endotracheal tube sizes. Methods. Questionnaires requiring calculations of medication doses, volumes, andendotracheal tube sizes were administered to prehospital care providers between June andNovember 2006 in fire department continuing education classes in the State of Maryland andthe District of Columbia. Half of the participants performed the calculations with the pediatric code card as an aid, andhalf without. Calculations done by the two groups were compared for rate andextent of errors. We evaluated the error frequency in calculations of pediatric medication doses andendotracheal tube sizes. Results. Of the 523 advanced life support prehospital care providers questioned, 246 answered questions using the pediatric code card, and277 answered questions without using the card. The mean individual percentages of correct responses were 94% for the group aided by the code card and65% for the group unaided by the card (percentage difference, 29%; 95% confidence interval [CI], 25–31%; p < 0.001). Ninety-eight percent of the aided group and23% of the unaided group calculated the correct endotracheal tube size (percentage difference, 75%; 95% CI, 70–81%; p < 0.001). Conclusions. The use of the pediatric code card enabled prehospital care providers to determine weight-based drug doses, volumes of administration, andendotracheal tube sizes more accurately than peers without access to the code card.

Commentary: Morrow B, Futter M, Argent A. (2006). Effect of endotracheal suction on lung dynamics in mechanically‐ventilated paediatric patients

AbstractEndotracheal suctioning is performed regularly in ventilated infants and children to remove obstructive secretions. The effect of suctioning on respiratory mechanics is not known. This study aimed to determine the immediate effect of endotracheal suctioning on dynamic lung compliance, tidal volume and airway resistance in mechanically ventilated paediatric patients by means of a prospective observational clinical study. Lung mechanics were recorded for 5 min before and 5 min after a standardized suctioning procedure in 78 patients intubated with endotracheal tubes of ≤4·0 mm internal diameter. Twenty‐four patients with endotracheal tube leaks ≥20% were excluded from analysis. There was a significant overall decrease in dynamic compliance (p &lt; 0·001) and mechanical expired tidal volume (p = 0·03) following suctioning with no change in the percentage of endotracheal tube leak (p = 0·41). The change in dynamic compliance was directly related to both endotracheal tube and catheter sizes. There was no significant change in expiratory or inspiratory airway resistance following suctioning (p &gt; 0·05). Although most of the patients (68·5%) experienced a drop in dynamic compliance following suctioning, dynamic compliance increased in 31·5% of patients after the procedure. This study demonstrates that endotracheal suctioning frequently causes an immediate drop in dynamic compliance and expired tidal volume in ventilated children with variable lung pathology, intubated with small endotracheal tubes, probably indicating loss of lung volume caused by the suctioning procedure. There is no evidence that suctioning reduces airway resistance. Abstract reprinted from the Australian Journal of Physiotherapy volume 52, Morrow B et al., ‘Effect of endotracheal suction on lung dynamics in mechanically‐ventilated paediatric patients’, pages 121–126. © 2006, reproduced with permission from the Australian Physiotherapy Association.

Difficult intubation due to interarytenoid adhesion - A case report -

Interarytenoid adhesion of the vocal cords, with a triangular anterior opening and a smaller posterior rounded opening, is one of the complications of intubation. The vocal cords are tethered to each other and they are restricted with narrow abduction, causing difficult intubation. A 57-year-old woman was scheduled to undergo lung wedge resection. The patient had experienced a prolonged intubation 15 years previously. Thereafter, she had undergone two operations and intubation was difficult to perform with using small size endotracheal tubes (6.5 and 6.0 mm inner diameter, respectively). Despite this past medical history, anesthesia was performed without further evaluation because of the patient's refusal. After the failure of an initial trial of intubation with a double lumen endobronchial tube, we tried to intubate with a small sized endotracheal tube (5.0 mm). But it was impossible to pass the tube through the vocal cords. Endobronchial endoscopy revealed interarytenoid adhesion of her vocal cords. After tracheostomy, she received wedge resection. Therefore, the possibility of difficult intubation due to interarytenoid adhesion of the vocal cords should be considered for a patient with a past history of intubation. (Korean J Anesthesiol 2008; 55: 367～70)

The dilemma of paediatric drug dosing and equipment sizing in the era of patient safety

The dilemma of paediatric drug dosing and equipment sizing in the era of patient safety