Ultrasound-guided percutaneous dilatational tracheostomy with laryngeal mask airway control in a morbidly obese patient

Complication Rate of Percutaneous Dilatational Tracheostomy in Critically Ill Adults With Obesity: A Systematic Review and Meta-analysis

Importance

Obesity has traditionally been described as a relative contraindication to percutaneous dilatational tracheostomy (PDT). Increased familiarity with the technique and use of bronchoscopy or real-time ultrasonography to enhance visualization have led many practitioners to expand the indication for PDT to patients historically deemed to have high risk of perioperative complications.

Objective

To assess the reported complication rate of PDT in critically ill adults with obesity and compare it with that of open surgical tracheostomies (OSTs) in this patient population and with that of PDT in their counterparts without obesity.

Data Sources

In this systematic review and meta-analysis, Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from January 1, 2000, to March 1, 2022. Key terms related to percutaneous tracheostomy and obesity were included.

Study Selection

Original investigations of critically ill adult patients (age ≥18 years) with obesity who underwent PDT that reported at least 1 complication of interest were included. Case reports or series with fewer than 5 patients were excluded, as were studies in a language other than English or French.

Data Extraction and Synthesis

Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) were used, with independent extraction by multiple observers. Frequencies were reported for all dichotomous variables. Relative risks for complications were calculated using both fixed-effects and random-effects models in the meta-analysis.

Main Outcomes and Measures

Main outcomes included mortality directly associated with the procedure, conversion to OST, and complications associated with the procedure (subclassified into life-threatening or non-life-threatening adverse events).

Results

Eighteen studies were included in the systematic review, comprising 1355 patients with obesity who underwent PDT. The PDT-related complication rate was 16.6% among patients with obesity overall (791 patients, 17 studies), most of which were non-life-threatening. Only 0.6% of cases (8 of 1314 patients, 17 studies) were aborted or converted to an OST. A meta-analysis of 12 studies (N = 4212; 1078 with obesity and 3134 without obesity) showed that patients with obesity had a higher rate of complications associated with PDT compared with their counterparts without obesity (risk ratio, 1.78; 95% CI, 1.38-2.28). A single study compared PDT with OST directly for critically ill adults with obesity; thus, the intended meta-analysis could not be performed in this subgroup.

Conclusions and Relevance

The findings suggest that the rate of complications of PDT is low in critically ill individuals with obesity, although the risk of complications may be higher than in individuals without obesity.

Tracheostomy in Adult Intensive Care Unit: An ISCCM Expert Panel Practice Recommendations

BACKGROUND AND AIM

Critically ill patients on mechanical ventilation undergo tracheostomy to facilitate weaning. The practice in India may be different from the rest of the world and therefore, in order to understand this, ISCCM conducted a multicentric observational study "DIlatational percutaneous vs Surgical tracheoStomy in intEnsive Care uniT: A practice pattern observational multicenter study (DISSECT Study)" followed by an ISCCM Expert Panel committee meeting to formulate Practice recommendations pertinent to Indian ICUs.

MATERIALS AND METHODS

All existing International guidelines on the topic, various randomized controlled trials, meta-analysis, systematic reviews, retrospective studies were taken into account to formulate the guidelines. Wherever Indian data was not available, international data was analysed. A modified Grade system was followed for grading the recommendation.

RESULTS

After analyzing the entire available data, the recommendations were made by the grading system agreed by the Expert Panel. The recommendations took into account the indications and contraindications of tracheostomy; effect of timing of tracheostomy on incidence of ventilator associated pneumonia, ICU length of stay, ventilator free days & Mortality; comparison of surgical and percutaneous dilatational tracheostomy (PDT) in terms of incidence of complications and cost to the patient; Comparison of various techniques of PDT; Use of fiberoptic bronchoscope and ultrasound in PDT; experience of the operator and qualification; certain special conditions like coagulopathy and morbid obesity.

CONCLUSION

This document presents the first Indian recommendations on tracheostomy in adult critically ill patients based on the practices of the country. These guidelines are expected to improve the safety and extend the indications of tracheostomy in critically ill patients.

HOW TO CITE THIS ARTICLE

Gupta S, Dixit S, Choudhry D, Govil D, Mishra RC, Samavedam S, Tracheostomy in Adult Intensive Care Unit: An ISCCM Expert Panel Practice Recommendations. Indian J Crit Care Med 2020;24(Suppl 1):S31-S42.

Effectiveness of limited airway ultrasound education for medical students: a pilot study

Objective

The point-of-care ultrasound of the airway (POCUS-A) is a useful examination method but there are currently no educational programs for medical students regarding it. We designed a POCUS-A training curriculum for medical students to improve three cognitive and psychomotor learning domains: knowledge of POCUS-A, image acquisition, and image interpretation.

Methods

Two hours of training were provided to 52 medical students in their emergency medicine (EM) rotation. Students were evaluated for cognitive and psychomotor skills before and immediately after the training. The validity measures were established with the help of six specialists and eight EM residents. A survey was administered following the curriculum.

Results

Cognitive skill significantly improved after the training (38.7±12.4 vs. 91.2±7.7) and there was no significant difference between medical students and EM residents in posttest scores (91.2±7.7 vs. 90.8±4.6). The success rate of overall POCUS-A performance was 95.8%. The students were confident to perform POCUS-A on an actual patient and strongly agreed to incorporate POCUS-A training in their medical school curriculum.

Conclusion

Cognitive and psychomotor skills of POCUS-A among medical students can be improved via a limited curriculum on EM rotation.

Ultrasound Is Superior to Palpation in Identifying the Cricothyroid Membrane in Subjects with Poorly Defined Neck Landmarks

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Success of a cricothyrotomy is dependent on accurate identification of the cricothyroid membrane. The objective of this study was to compare the accuracy of ultrasonography versus external palpation in localizing the cricothyroid membrane.

Methods

In total, 223 subjects with abnormal neck anatomy who were scheduled for neck computed-tomography scan at University Health Network hospitals in Toronto, Canada, were randomized into two groups: external palpation and ultrasound. The localization points of the cricothyroid membrane determined by ultrasonography or external palpation were compared to the reference midpoint (computed-tomography point) of the cricothyroid membrane by a radiologist who was blinded to group allocation. Primary outcome was the accuracy in identification of the cricothyroid membrane, which was measured by digital ruler in millimeters from the computed-tomography point to the ultrasound point or external-palpation point. Success was defined as the proportion of accurate attempts within a 5-mm distance from the computed-tomography point to the ultrasound point or external-palpation point.

Results

The percentage of accurate attempts was 10-fold greater in the ultrasound than external-palpation group (81% vs. 8%; 95% CI, 63.6 to 81.3%; P < 0.0001). The mean (SD) distance measured from the external-palpation to computed-tomography point was five-fold greater than the ultrasound to the computed-tomography point (16.6 ± 7.5 vs. 3.4 ± 3.3 mm; 95% CI, 11.67 to 14.70; P < 0.0001). Analysis demonstrated that the risk ratio of inaccurate localization of the cricothyroid membrane was 9.14-fold greater with the external palpation than with the ultrasound (P < 0.0001). There were no adverse events observed.

Conclusions

In subjects with poorly defined neck landmarks, ultrasonography is more accurate than external palpation in localizing the cricothyroid membrane.

Percutaneous dilatational tracheostomy versus fibre optic bronchoscopy-guided percutaneous dilatational tracheostomy in critically ill patients: a randomised controlled trial

BACKGROUND

To determine whether fibre optic bronchoscopy-guided percutaneous dilatational tracheostomy (FOB-PDT) is a better option in critically ill patients, we compared the efficacy and incidence of procedure complications between PDT with and without FOB.

METHODS

We included 90 patients with oral intubation and mechanical ventilation who received PDT with (n = 45, FOB-PDT group) and without (n = 45, PDT group) FOB. For all patients, a simplification of the Griggs technique was used in this study with a central venous catheter set and dilating forceps. Demographic data, body mass index (BMI), Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, rate of first-time success, complication rate and time of procedure were evaluated in both groups. PDT was performed guided by FOB only in the FOB-PDT group.

RESULTS

The rate of major complications, including minor or major haemorrhage requiring intervention and subcutaneous emphysema in the neck or pneumothorax, was significantly higher in the PDT group than in the PDT-FOB group (40% vs. 20%, P < 0.05). Significant differences were observed between the two groups with respect to the rate of first-time success (64.4% vs. 93.3%, P < 0.05); the rate of first-time success puncture with the puncture needle in the PDT-FOB group was higher than that in the PDT group (93.3% vs. 75.6%, P < 0.05). The mean procedure duration was significantly longer in the PDT group than in the PDT-FOB group (12.9 ± 1.1 vs. 9.8 ± 1.2 min, P < 0 .05).

CONCLUSIONS

PDT with FOB offers the advantages of a high rate of first-time success, a low complication rate and short-procedure duration. Thus, FOB-PDT is a better option in critically ill patients.

Comparison of Bronchoscopy-Guided and Real-Time Ultrasound-Guided Percutaneous Dilatational Tracheostomy: Safety, Complications, and Effectiveness in Critically Ill Patients

OBJECTIVE

To compare the efficacy, safety, and incidence of complications between fiber-optic bronchoscopy-guided percutaneous dilatational tracheostomy (FOB-PDT) and ultrasound-guided percutaneous dilatational tracheostomy (US-PDT) and to determine whether US-PDT is a viable alternative to FOB-PDT.

METHODS

This randomized prospective study was carried out in 80 patients who were randomly divided into US-PDT and FOB-PDT groups. Demographic data and Acute Physiology and Chronic Health Evaluation II (APACHE II), procedure duration, hemorrhage status, complications, procedure difficulty, displacement of entry location after US, and hemodynamic data were evaluated in both groups. Tracheal incision was performed with real-time US and a transverse probe position in the out-of-plane mode.

RESULTS

No significant differences were observed between the 2 groups in terms of demographic data, oral intubation time, APACHE II values, difficulty of the procedure, or the number of needle interventions ( P > .05). The mean hemorrhage ratio of the FOB-PDT group was significantly higher than that of the US-PDT group ( P < .05). The entry location was changed in 6 patients in the US-PDT group following neck examination with US. The mean duration of the procedure for the FOB-PDT group was significantly longer than that for the US-PDT group ( P < .05).

CONCLUSION

Ultrasound-guided percutaneous dilatational tracheostomy is a safe procedure for critically ill patients and has the advantages of a low complication rate, short duration of procedure, being informative with regard to neck anatomy, and facilitating prevention of vascular puncture. Thus, US-PDT can be used as an alternative to FOB-PDT.

Management of the chronically ventilated patient with a tracheostomy

Tracheostomy is the most common surgical procedure performed on critically ill patients. For those who survive their critical illnesses but remain ventilator-dependent, tracheostomy provides patients with a secure airway that frees the mouth for oral nutrition, enhances verbalized speech, and promotes generalized comfort. Avoiding complications from tracheostomy requires a skilled multi-disciplinary approach to ensure that the benefits outweigh the risks of the procedure.

The role of ultrasound in percutaneous dilatational tracheostomy

Background: The use of ultrasound to evaluate cervical anatomy and to guide tracheal puncture in real-time has been advocated to improve safety and efficacy of percutaneous dilatational tracheostomy (PDT) in intensive care. Objective: To review the potential role, attributed theoretical benefits and supporting literature for ultrasound during PDT. Results: A significant number of mostly observational studies and case series support this modality. Real-time guidance enables clear visualisation of anatomical landmarks and results in a consistently high success and low complication rate, with appropriate positioning of the tracheal puncture. Recognition of unconventional vascular anatomy enables selection of an appropriate alternative puncture site or an elective open surgical approach. Conclusion: Current literature supports that using ultrasound for percutaneous tracheostomy is quick, safe, reliable and offers a plausible advantage over the traditional landmark guided procedure, especially in select patient groups, such as those who are morbidly obese or have difficult to palpate cervical anatomy.

Ultrasound: A promising tool for contemporary airway management

Airway evaluation and its management remains an ever emerging clinical science. Present airway management tools are static and do not provide dynamic airway management option. Visualized procedures like ultrasound (US) provide point of care real time dynamic views of the airway in perioperative, emergency and critical care settings. US can provide dynamic anatomical assessment which is not possible by clinical examination alone. US aids in detecting gastric contents and the nature of gastric contents (clear fluid, thick turbid or solid) as well. US can help in predicting endotracheal tube size by measuring subglottic diameter and diameter of left main stem bronchus. US was found to be a sensitive in detecting rotational malposition of LMA in children. Also, US is the fastest and highly sensitive tool to rule out a suspected intraoperative pneumothorax. In intensive care units, US helps torule out causes of inadequate ventilation, determine the tracheal width and distance from the skin to predict tracheotomy tube size and shape and assist with percutaneous dilatational tracheostomy. US can help in confirming the correct tracheal tube placement by dynamic visualisation of the endotracheal tube insertion, widening of vocal cords (children), and bilateral lung-sliding and diaphragmatic movement. Thus, ultrasonography has brought a paradigm shift in the practise of airway management. With increasing awareness, portability, accessibility and further sophistication in technology, it is likely to find a place in routine airway management. We are not far from the time when all of us will be carrying a pocket US machine like stethoscopes to corroborate our clinical findings at point of care.

Ultrasound Improves Cricothyrotomy Success in Cadavers with Poorly Defined Neck Anatomy

Background

Misidentification of the cricothyroid membrane in a “cannot intubate-cannot oxygenate” situation can lead to failures and serious complications. The authors hypothesized that preprocedure ultrasound-guided identification of the cricothyroid membrane would reduce complications associated with cricothyrotomy.

Methods

A group of 47 trainees were randomized to digital palpation (n = 23) and ultrasound (n = 24) groups. Cricothyrotomy was performed on human cadavers by using the Portex® device (Smiths Medical, USA). Anatomical landmarks of cadavers were graded as follows: grade 1—easy = visual landmarks; 2—moderate = requires light palpation of landmarks; 3—difficult = requires deep palpation of landmarks; and 4—impossible = landmarks not palpable. Primary outcome was the complication rate as measured by the severity of injuries. Secondary outcomes were correct device placement, failure to cannulate, and insertion time.

Results

Ultrasound guidance significantly decreased the incidence of injuries to the larynx and trachea (digital palpation: 17 of 23 = 74% vs. ultrasound: 6 of 24 = 25%; relative risk, 2.88; 95% CI, 1.39 to 5.94; P = 0.001) and increased the probability of correct insertion by 5.6 times (P = 0.043) in cadavers with difficult and impossible landmark palpation (digital palpation 8.3% vs. ultrasound 46.7%). Injuries were found in 100% of the grades 3 to 4 (difficult–impossible landmark palpation) cadavers by digital palpation compared with only 33% by ultrasound (P &lt; 0.001). The mean (SD) insertion time was significantly longer with ultrasound than with digital palpation (196.1 s [60.6 s] vs. 110.5 s [46.9 s]; P &lt; 0.001).

Conclusion

Preprocedure ultrasound guidance in cadavers with poorly defined neck anatomy significantly reduces complications and improves correct insertion of the airway device in the cricothyroid membrane.

Accuracy of conventional digital palpation and ultrasound of the cricothyroid membrane in obese women in labour

Success of cricothyroidotomy depends on accurate identification of anatomical neck landmarks. Anaesthetists palpated the cricothyroid membrane of 28 obese and 28 non-obese women in labour (cut-off BMI 30 kg.m(-2) ) and marked the entry point for device insertion with an ultraviolet invisible pen. Ultrasonography was used to mark the midpoint of the cricothyroid membrane and the distance between the two marks was measured. The median (IQR [range]) distance between the two marks was significantly greater in the obese than the non-obese patients (5 (2-9.5 [0-34]) mm vs 1.8 (0.1-6 [0-15]) mm, respectively; p = 0.02). The cricothyroid membrane was accurately identified with digital palpation in only 39% (11/28) of obese compared with 71% (20/28) of non-obese patients (p = 0.03). Increased neck circumference in obese patients was significantly associated with inaccuracy in locating the cricothyroid membrane. Percutaneous identification of the cricothyroid membrane in obese women in labour was poor. Pre-procedural ultrasound may help improved the identification of neck landmarks for cricothyroidotomy.

Use of ultrasound guidance to improve the safety of percutaneous dilatational tracheostomy: a literature review

Patients in ICUs frequently require tracheostomy for long-term ventilator support, and the percutaneous dilatational tracheostomy (PDT) method is preferred over surgical tracheostomy. The use of ultrasound (US) imaging to guide ICU procedures and interventions has recently emerged as a simple and noninvasive tool. The current evidence regarding the applications of US in PDT is encouraging; however, the exact role of US-guided dilatational tracheostomy (US-PDT) remains poorly defined. In this review, we describe the best available evidence concerning the safety and efficacy of US-PDT and briefly delineate the general principles of US image generation for the airway and of US-PDT procedures.

Impact of real-time ultrasound guidance on complications of percutaneous dilatational tracheostomy: a propensity score analysis

Introduction

Recent studies have demonstrated the feasibility of real-time ultrasound guidance during percutaneous dilatational tracheostomy, including in patients with risk factors such as coagulopathy, cervical spine immobilization and morbid obesity. Use of real-time ultrasound guidance has been shown to improve the technical accuracy of percutaneous dilatational tracheostomy; however, it is unclear if there is an associated reduction in complications. Our objective was to determine whether the peri-procedural use of real-time ultrasound guidance is associated with a reduction in complications of percutaneous dilatational tracheostomy using a propensity score analysis.

Methods

This study reviewed all percutaneous dilatational tracheostomies performed in an 8-year period in a neurocritical care unit. Percutaneous dilatational tracheostomies were typically performed by trainees under guidance of the attending intensivist. Bronchoscopic guidance was used for all procedures with addition of real-time ultrasound guidance at the discretion of the attending physician. Real-time ultrasound guidance was used to guide endotracheal tube withdrawal, guide tracheal puncture, identify guidewire entry level and confirm bilateral lung sliding. The primary outcome was a composite of previously defined complications including (among others) bleeding, infection, loss of airway, inability to complete procedure, need for revision, granuloma and early dislodgement. Propensity score analysis was used to ensure that the relationship of not using real-time ultrasound guidance with the probability of an adverse outcome was examined within groups of patients having similar covariate profiles. Covariates included were age, gender, body mass index, diagnosis, Acute Physiology and Chronic Health Evaluation II score, timing of tracheostomy, positive end-expiratory pressure and presence of risk factors including coagulopathy, cervical spine immobilization and prior tracheostomy.

Results

A total of 200 patients underwent percutaneous dilatational tracheostomy during the specified period, and 107 received real-time ultrasound guidance. Risk factors for percutaneous dilatational tracheostomy were present in 63 (32%). There were nine complications in the group without real-time ultrasound guidance: bleeding (n = 4), need for revision related to inability to ventilate or dislodgement (n = 3) and symptomatic granuloma (n = 2). There was one complication in the real-time ultrasound guidance group (early dislodgement). The odds of having an adverse outcome for patients receiving real-time ultrasound guidance were significantly lower (odds ratio = 0.08; 95% confidence interval, 0.009 to 0.811; P = 0.032) than for those receiving a standard technique while holding the propensity score quartile fixed.

Conclusions

The use of real-time ultrasound guidance during percutaneous dilatational tracheostomy was associated with a significant reduction in procedure-related complications.

Real time ultrasound-guided percutaneous tracheostomy: Is it a better option than bronchoscopic guided percutaneous tracheostomy?

BACKGROUND

The purpose of this study was to evaluate the efficacy of ultrasound guided percutaneous tracheostomy (USPCT) and bronchoscopic guided percutaneous tracheostomy (BPCT) and the incidence of complications in critically ill, obese patients.

METHODS

Seventy four consecutive patients were included in a prospective study and randomly divided into USPCT and BPCT. Incidence of complications, ease and efficacy were compared in obese USPCT (n = 38)and BPCT (n = 36). Results are expressed as the median (25th-75th percentile) or number (percentage).

RESULTS

The median times for tracheostomy were 12 min (9-14) in USPCT patients and 18 min (12-21.5) in BPCT (p = 0.05). The overall complication rate was higher in BPCT than USPCT patient group (75% vs. 321%, p < 0.05). Most complications were minor (hypotension, desaturation, tracheal cuff puncture and minor bleeding) and of higher number in the BPCT. Ultrasound-guided PCT was possible in all enrolled patients and there were no surgical conversions or deaths.

CONCLUSIONS

This study demonstrated that real US-guided PCT is a favourable alternative to BPCT with a low complication rate and ease, thus proving more efficacious. A US examination provides information on cervical anatomy, vasculature etc. and hence modifies and guides choice of the PCT puncture site.

Traditional landmark versus ultrasound guided tracheal puncture during percutaneous dilatational tracheostomy in adult intensive care patients: a randomised controlled trial

Introduction

Long-term ventilated intensive care patients frequently require tracheostomy. Although overall risks are low, serious immediate and late complications still arise. Real-time ultrasound guidance has been proposed to decrease complications and improve the accuracy of the tracheal puncture. We aimed to compare the procedural safety and efficacy of real-time ultrasound guidance with the traditional landmark approach during percutaneous dilatational tracheostomy (PDT).

Methods

A total of 50 patients undergoing PDT for clinical indications were randomly assigned, after obtaining informed consent, to have the tracheal puncture procedure carried out using either traditional anatomical landmarks or real-time ultrasound guidance. Puncture position was recorded via bronchoscopy. Blinded assessors determined in a standardised fashion the deviation of the puncture off midline and whether appropriate longitudinal position between the first and fourth tracheal rings was achieved. Procedural safety and efficacy data, including complications and number of puncture attempts required, were collected.

Results

In total, 47 data sets were evaluable. Real-time ultrasound guidance resulted in significantly more accurate tracheal puncture. Mean deviation from midline was 15 ± 3° versus 35 ± 5° (P = 0.001). The proportion of appropriate punctures, defined a priori as 0 ± 30° from midline, was significantly higher: 20 (87%) of 23 versus 12 (50%) of 24 (RR = 1.74; 95% CI = 1.13 to 2.67; P = 0.006). First-pass success rate was 20 (87%) of 23 in the ultrasound group and 14 (58%) of 24 in the landmark group (RR = 1.49; 95% CI = 1.03 to 2.17; P = 0.028). The observed decrease in procedural complications was not statistically significant: 5 (22%) of 23 in the ultrasound group versus 9 (37%) of 24 in the landmark group (RR = 0.58; 95% CI = 0.23 to 1.47; P = 0.24).

Conclusions

Ultrasound guidance significantly improved the rate of first-pass puncture and puncture accuracy. Fewer procedural complications were observed; however, this did not reach statistical significance. These results support wider general use of real-time ultrasound guidance as an additional tool to improve PDT.

Trial registration

Australian New Zealand Clinical Trials Registry ID: ACTRN12611000237987 (registered 4 March 2011)

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0514-0) contains supplementary material, which is available to authorized users.

Ultrasonography for clinical decision-making and intervention in airway management: from the mouth to the lungs and pleurae

OBJECTIVES

To create a state-of-the-art overview of the new and expanding role of ultrasonography in clinical decision-making, intervention and management of the upper and lower airways, that is clinically relevant, up-to-date and practically useful for clinicians.

METHODS

This is a narrative review combined with a structured Medline literature search.

RESULTS

Ultrasonography can be utilised to predict airway difficulty during induction of anaesthesia, evaluate if the stomach is empty or possesses gastric content that poses an aspiration risk, localise the essential cricothyroid membrane prior to difficult airway management, perform nerve blocks for awake intubation, confirm tracheal or oesophageal intubation and facilitate localisation of tracheal rings for tracheostomy. Ultrasonography is an excellent diagnostic tool in intraoperative and emergency diagnosis of pneumothorax. It also enables diagnosis and treatment of interstitial syndrome, lung consolidation, atelectasis, pleural effusion and differentiates causes of acute breathlessness during pregnancy. Patient safety can be enhanced by performing procedures under ultrasound guidance, e.g. thoracocentesis, vascular line access and help guide timing of removal of chest tubes by quantification of residual pneumothorax size.

CONCLUSIONS

Ultrasonography used in conjunction with hands-on management of the upper and lower airways has multiple advantages. There is a rapidly growing body of evidence showing its benefits.

TEACHING POINTS

• Ultrasonography is becoming essential in management of the upper and lower airways. • The tracheal structures can be identified by ultrasonography, even when unidentifiable by palpation. • Ultrasonography is the primary diagnostic approach in suspicion of intraoperative pneumothorax. • Point-of-care ultrasonography of the airways has a steep learning curve. • Lung ultrasonography allows treatment of interstitial syndrome, consolidation, atelectasis and effusion.

Ultrasound-guided percutaneous tracheostomy in critically ill obese patients

Introduction

The purpose of this study was to evaluate the feasibility of ultrasound (US)-guided percutaneous tracheostomy (PCT) and the incidence of complications in critically ill, obese patients.

Methods

Fifty consecutive patients were included in a prospective study in two surgical and critical care medicine departments. Obesity was defined as a body mass index (BMI) of at least 30 kg/m². The feasibility of PCT and the incidence of complications were compared in obese patients (n = 26) and non-obese patients (n = 24). Results are expressed as the median (25^th-75^th percentile) or number (percentage).

Results

The median BMIs were 34 kg/m² (32-38) in the obese patient group and 25 kg/m² (24-28) in the non-obese group (p < 0.001). The median times for tracheostomy were 10 min (8-14) in non-obese patients and 9 min (5-10) in obese-patients (p = 0.1). The overall complication rate was similar in obese and non-obese patient groups (35% vs. 33%, p = 0.92). Most complications were minor (hypotension, desaturation, tracheal cuff puncture and minor bleeding), with no differences between obese and non-obese groups. Bronchoscopic inspection revealed two cases of granuloma (8%) in obese patients. One non-obese patient developed a peristomal skin infection, which was treated with intravenous antibiotics. Ultrasound-guided PCT was possible in all enrolled patients and there were no surgical conversions or deaths.

Conclusions

This study demonstrated that US-guided PCT is feasible in obese patients with a low complication rate. Obesity may not constitute a contra-indication for US-guided PCT. A US examination provides information on cervical anatomy and hence modifies and guides choice of the PCT puncture site.

Trial registration

ClinicalTrials.gov: NCT01502657.

Ultrasonography in the management of the airway

In this study, it is described how to use ultrasonography (US) for real-time imaging of the airway from the mouth, over pharynx, larynx, and trachea to the peripheral alveoli, and how to use this in airway management. US has several advantages for imaging of the airway - it is safe, quick, repeatable, portable, widely available, and it must be used dynamically for maximum benefit in airway management, in direct conjunction with the airway management, i.e. immediately before, during, and after airway interventions. US can be used for direct observation of whether the tube enters the trachea or the esophagus by placing the ultrasound probe transversely on the neck at the level of the suprasternal notch during intubation, thus confirming intubation without the need for ventilation or circulation. US can be applied before anesthesia induction and diagnose several conditions that affect airway management, but it remains to be determined in which kind of patients the predictive value of such an examination is high enough to recommend this as a routine approach to airway management planning. US can identify the croicothyroid membrane prior to management of a difficult airway, can confirm ventilation by observing lung sliding bilaterally and should be the first diagnostic approach when a pneumothorax is suspected intraoperatively or during initial trauma-evaluation. US can improve percutaneous dilatational tracheostomy by identifying the correct tracheal-ring interspace, avoiding blood vessels and determining the depth from the skin to the tracheal wall.

Real-time ultrasound-guided percutaneous dilatational tracheostomy: a feasibility study

Introduction

Ultrasound (US) performed prior to percutaneous tracheostomy (PT) may be useful in avoiding injury to pretracheal vascular structures and in avoiding high placement of the tube. Bedside real-time US guidance with visualization of needle path is routinely utilized for other procedures such as central venous catheterization, and may enhance the safety and accuracy of PT without causing airway occlusion or hypercarbia. Our objective was to demonstrate that PT performed under real-time US guidance with visualization of needle path during tracheal puncture is feasible, including in patients with features that increase the technical difficulty of PT.

Methods

Mechanically ventilated patients with acute brain injury requiring tracheostomy underwent US guided PT. The orotracheal tube was withdrawn using direct laryngoscopy. The trachea was punctured under real-time US guidance (with visualization of the needle path) while using the acoustic shadows of the cricoid and the tracheal rings to identify the level of puncture. After guidewire passage the site and level of entry was verified using the bronchoscope, which was then withdrawn. Following dilatation and tube placement, placement in the airway was confirmed using auscultation and the "lung sliding" sign on US. Bronchoscopy and chest X-ray were then performed to identify any complications.

Results

Thirteen patients successfully underwent US guided PT. Three patients were morbidly obese, two were in cervical spine precautions and one had a previous tracheostomy. In all 13 patients bronchoscopy confirmed that guidewire entry was through the anterior wall and between the first and fifth tracheal rings. There was no case of tube misplacement, pneumothorax, posterior wall injury, significant bleeding or other complication during the procedure.

Conclusions

Percutaneous tracheostomy performed under real-time ultrasound guidance is feasible and appears accurate and safe, including in patients with morbid obesity and cervical spine precautions. Larger studies are required to further define the safety and relative benefits of this technique.

Trial registration

UMIN Clinical Trials Registry, UMIN000005023.

[Extraglottic airway devices in the intensive care unit]

Extraglottic airway devices (EGA) are not only used in routine anaesthesia practice, they also have a distinct value for in-hospital and out-of-hospital difficult airway management. In the environment of the intensive care unit (ICU) EGA are not used on a regular basis. However, expertise and knowledge regarding EGA coming from the operating theatre or the out-of-hospital setting may also be of value for the ICU setting. This review presents the potential indications for EGA on the ICU for the management of difficult airway situations as well as during percutaneous tracheotomy. Furthermore, the possible advantages of EGA during postoperative recovery from anaesthesia as well as termination of controlled ventilation for intensive care patients are discussed.

Applications of ultrasonography in ENT: airway assessment and nerve blockade

This article presents a comprehensive narrative review of the published literature relating to ultrasound imaging relevant to anesthesia for ear, nose, and throat (ENT) surgery. The review comprises 2 main subject areas: the use of ultrasonography related to assessment and management of the airway, and the use of ultrasonography related to nerve blockade for ENT surgery. The relevant sonoanatomy and suitable probe placement are illustrated in relation to applicable regional anatomy (they are not discussed). The possible value of the use of ultrasonography to improve existing clinical practice in these areas is explored.

Laryngeal mask airways in ear, nose, and throat procedures

The use of laryngeal mask airway (LMA) and its variants in ear, nose, and throat procedures have been extensively described in case reports, retrospective reviews, and randomized clinical trials. The LMA has developed a considerable following because of its lack of tracheal stimulation, which can be a considerable advantage in ear, nose, and throat (ENT) procedures. The incidence of coughing on emergence has been shown to be lower with the LMA than with the endotracheal tube (ETT). Although other approaches to smooth emergence have been described, few would argue that it is as easy to achieve a smooth emergence with an ETT as with an LMA. Although patients certainly exist for whom the LMA is contraindicated, many will experience better results with the LMA because of the features delineated in this article.

[Dilatation tracheotomy update : indications, limitations and management of complications]

Percutaneous dilatational tracheotomy is a standard procedure today for transient airway management in intensive care units. When correctly indicated and applied, preferably following interdisciplinary case discussion with the otolaryngologist, PDT seems to be as safe as classical surgical tracheotomy. The latter is the alternative when PDT is contraindicated. There is currently a trend towards one-step PDT procedures. In addition to the permanent necessity for an alternative airway, there is a series of clearly defined contraindications to PDT. In such cases, only surgical tracheotomy is viable. In contrast to surgical tracheotomy, PDT presents more challenges to the physicians and nursing staff in order to avoid specific complications such as re-cannulation into a via falsa followed by acute dyspnea. The otolaryngologist is an important partner in the management of PDT-related complications due to his discipline-specific experience. Further prospective trials, especially concerning long-term complications, are needed to answer the question of whether PDT or surgical tracheotomy is the best method in situations with overlapping indications.

Airway management in the obese patient

Airway management is a major factor underlying morbidity and mortality in the obese population. The validity of anthropomorphic prediction model in assessing a difficult airway is less accurate compared with lean subjects. Preoperative evaluation and anticipation of potential complications are critical for safe and successful intubation. Application of noninvasive positive airway pressure can prevent atelectasis and improve oxygenation during the anesthetic induction as well during the postoperative period and after liberation from mechanical ventilation. When performed by trained operators, bedside percutaneous dilatation tracheostomy in obese patients has a safety profile comparable to surgical tracheostomy but provides advantages including ease of performance and lesser cost, and obviates transporting a critically ill patient outside the intensive care unit.

Use of sonography for airway assessment: an observational study

OBJECTIVE

The purpose of this study was to evaluate the feasibility of sonography in identifying the anatomic structures of the upper airway and to describe their appearance on sonography.

METHODS

We enrolled 24 healthy volunteers, placed them supine with their head extended and neck flexed (the "sniffing" position), and performed a systematic sonographic examination of their upper airway from the floor of the mouth to the suprasternal notch.

RESULTS

We were able to visualize all relevant anatomic structures in all of the participants using either a linear or curved transducer oriented in 1 of 3 planes: sagittal, parasagittal, and transverse. Bony structures (eg, the mandible and hyoid) were brightly hyperechoic with an underlying hypoechoic acoustic shadow. Cartilaginous structures (eg, the epiglottis, thyroid cartilage, cricoid cartilage, and tracheal rings) were hypoechoic, and their intraluminal surface was outlined by a bright air-mucosa interface. The vocal cords were readily visualized through the thyroid cartilage. However, the posterior pharynx, posterior commissure, and posterior wall of the trachea could not be visualized because of artifacts created by an intraluminal air column.

CONCLUSIONS

Sonography of the upper airway is capable of providing detailed anatomic information and has numerous potential clinical applications.

Role of ultrasound in the airway management of critically ill patients

Ultrasound imaging of the upper airway in critically ill patients offers a number of attractive advantages compared with competitive imaging techniques or endoscopy. It is widely available, portable, repeatable, relatively inexpensive, pain-free, and safe. In this review article, I describe ultrasonographic anatomy of the upper respiratory organs and present the main potential applications of ultrasonography in airway management. The role of ultrasound in endotracheal tube placement, including preintubation assessment, verification of tube position, double-lumen intubation, and extubation outcome, are explained. Also, ultrasound-guided percutaneous tracheostomy, the role of ultrasound in using the laryngeal mask airway, and upper airway anesthesia are described.

The Use of the Laryngeal Mask Airway During Guidewire Dilating Forceps Tracheostomy

Percutaneous tracheostomy has become a common alternative to the classical open tracheostomy because of its convenience, cost effectiveness, and decreased complication rates. We retrospectively reviewed our intensive care practice using a guidewire dilatating forceps percutaneous tracheostomy technique with an endotracheal tube, as compared with the Classic Laryngeal Mask Airway (LMA) for these procedures. From 1998 to 2004, 274 patients underwent a tracheostomy procedure. Two-hundred-fifty-four (92.7%) of these patients underwent a guidewire dilatating forceps tracheostomy and 20 (7.3%) underwent a surgical tracheostomy. In the guidewire dilatating forceps group, 188 (74%) were performed by endoscopy via LMA-guided bronchoscopy, and 66 (26%) were performed through an endotracheal tube. Endoscopic views obtained via the LMA were subjectively better than those obtained with the endotracheal tube. Acute complications were significantly more frequent when using an endotracheal tube as compared with the LMA (6 of 66 versus 4 of 188; P = 0.022 Fisher's exact test, odds ratio = 4.6). There was a significant difference in terms of acute (10 of 254 versus 6 of 20; P < 0.001, odds ratio = 10.5) and chronic (0 of 254 versus 4 of 20; P < 0.001) complications between the 2 groups. There were no ventilatory complications or reports of gastric aspiration. The LMA provides a safe and effective alternative to an endotracheal tube for airway management during guidewire dilatating forceps tracheostomies in selected patients.