Awake intubation and awake prone positioning of a morbidly obese patient for lumbar spine surgery

Awake Tracheal Intubation: An Update

Awake tracheal intubation (ATI) remains the "gold standard" technique in securing a definitive airway in conscious, self-ventilating patients with predicted or known difficult airways and the procedure is associated with a low failure rate. Since its inception a variety of techniques to achieve ATI have emerged and there have been accompanying advancements in pharmaceuticals and technology to support the procedure. In recent years there has been a growing focus on the planning, training and human factors involved in performing the procedure. The practice of ATI, does however, remain low around 1% to 2% of all intubations despite an increase in those with head and neck pathology. ATI, therefore, presents a skill that is key for the safety of patients but may not be practised with regularity by many anesthetists. In this article we therefore aim to highlight relevant guidance, recent literature and provide an update on the practical methods fundamental for successful ATI. We also discuss the crucial aspects of a safe airway culture and how this can help to embed training and maintenance of skills.

Adverse Events Associated With Disparity Between Patients' BMI and Operating Table Size-A Need for Improved Surgical Innovations

BACKGROUND

The lack of proper equipment to accommodate patients with high BMI can jeopardize the safety of the patients and medical staff. In this review, we aim to discuss the availability of obesity accommodations in the operating room, along with its impact, implications, and future recommendations.

METHODS

Four databases were searched for articles pertaining to surgical table dimensions and the implications for safety, with a special focus on patients with larger BMIs. Articles were separated into 4 categories: Existing OR Table Options, Safety Implications for Patients, Reported Adverse Events Associated with Operating Table Inadequacy, and Safety Implications for Medical Staff.

RESULTS

A total of 18 articles and documents were included in this review. Most of the literature that discusses surgical tables with higher weight capacity is specific only to weight loss surgeries. Operating table dimensions have changed little in the past 100 years and standard operating tables have weight limits of 500 pounds. Several case reports underline the hazards of inadequately sized surgical tables.

CONCLUSIONS

This review demonstrates that a lack of proper equipment, such as surgical tables with adequate width and weight limits, can be a major contributor to the endangerment of bariatric surgical patients and the medical professionals who care for them. Further research and surgical innovation may be required to develop superior operating tables to address the unique concerns of this patient populations.

Awake Prone Positioning in Nonintubated Patients With Acute Hypoxemic Respiratory Failure

BACKGROUND

Awake prone positioning research focuses primarily on improving oxygenation and reducing intubation and mortality rates. Secondary outcomes concerning patient safety have been poorly addressed.

OBJECTIVE

To summarize current evidence on the frequency of adverse events during awake prone positioning and the effects on patients' safety, comfort, and tolerance.

METHODS

This scoping review used the Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews. MEDLINE/PubMed and CINAHL databases were the primary sources for the systematic search.

RESULTS

The review included 19 original studies involving 949 patients who underwent awake prone positioning. No major complications such as death, severe respiratory compromise, or hemodynamic disease were reported. Ten studies reported the following secondary adverse events related to awake prone positioning: skin breakdown (1%-6% of patients), pain (12%-42%), discomfort (35%-43%), vomiting (2%-7%), intolerance (3%-47%), and vascular catheter dislodgment (5%). The duration of awake prone positioning sessions varied widely (0.3-19 hours). Seven studies reported that nurses helped patients during prone positioning maneuvers, including monitoring and surveillance, and 3 studies reported patients placing themselves in the prone position. In 6 studies light or moderate sedation was employed in the procedures.

CONCLUSIONS

Awake prone positioning was not related to cardiorespiratory consequences but was associated with pain, intolerance, discomfort, and patients' refusal. Patients should receive education regarding awake prone positioning to improve their acceptance. Health care professionals should optimize pain control, communication, patient comfort, patient adherence, and correct positioning.

A Comparison of a Standard Macintosh Blade Laryngoscope, Pentax-AWS Videolaryngoscope and Intubrite Videolaryngoscope for Tracheal Intubation in Manikins in Sitting and Prone Positions: A Randomized Cross-Over Study

Background: Intubation of a patient in different positions may be done not only in emergency settings, but also in routine anesthesia (e.g., prone position for lumbar spine surgery). Methods: The aim of the study was to compare the classic Macintosh blade laryngoscope with two videolaryngoscopes: the Pentax-AWS and the Intubrite in a simulated scenario of a manikin placed in a sitting and prone position. Additionally, intubation with the use of all three devices was performed in a standard supine position as the control group. The time of intubation and the pressure exerted on the tongue was assessed. The ANOVA Friedman (analysis of variance) and Wilcoxon with Bonferroni correction tests were used for statistical analysis. Results: The time of intubation in a prone position was significantly shorter for the Pentax-AWS videolaryngoscope compared to the Macintosh and the Intubrite. There were no significant differences in the obtained results of the evaluated devices in sitting and standard positions. The lowest pressure exerted on the tongue was with the Pentax-AWS, followed by the Intubrite and the Macintosh laryngoscopes. Conclusions: The use of the Pentax-AWS was associated with faster tracheal intubation, creating lower pressure on tongue when compared with standard Macintosh and Intubrite laryngoscopes in both prone and sitting positions.

Complexities of spine surgery in obese patient populations: a narrative review

The obese population is particularly challenging to the spine surgeon in all phases of care. A narrative literature review was performed to review difficulties in spine surgery on the obese patient population and techniques for mitigation. We specifically aimed to assess several topics with regard to this population: patient selection and preoperative care; intraoperative and surgical techniques; and postoperative care, outcomes, and complications. The literature review demonstrated that obese patients are at increased surgical risk with spine surgery due to a variety of factors at all stages of intervention. Preoperatively, obese patients have worse outcomes with physical therapy and present technical difficulties for injections. Transport to a hospital, imaging, resuscitation, and intubation are all challenged by increased body habitus. Intraoperatively, obese patients have increased operative times, blood loss, surgical site infections, and nerve palsies. Patient positioning and intraoperative imaging may be limited. Surgery itself may be technically challenging due to body habitus and minimally invasive techniques are becoming more prevalent in this population. Postoperatively, several studies demonstrate that obese patients have inferior outcomes compared with nonobese counterparts. Patient selection is a key for elective interventions, and appropriate infrastructure aids in the ultimate outcomes for both elective and nonelective surgical treatments. Overall, obese patients present several challenges to the spine surgeon, and certain precautions can be undertaken preoperatively, intraoperatively, and postoperatively to mitigate the associated risks to optimize outcomes.

Risk Factors for Perioperative Complications in Morbidly Obese Patients Undergoing Elective Posterior Lumbar Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The prevalence of obesity-related low back pain and degenerative disc disease is on the rise. Past studies have demonstrated that obesity is associated with higher perioperative complication rates, but there remains a gap in the literature regarding additional risk factors that further predispose this already high-risk patient population to poor surgical outcomes following elective posterior lumbar fusion (PLF). The aim of the study is to identify independent risk factors for poor 30-day perioperative outcomes in morbidly obese patients undergoing elective PLF.

METHODS

We identified 22 909 patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent elective PLF. There were 1861 morbidly obese patients. Baseline patient demographics and medical comorbidities were collected. Univariate analysis was performed to compare perioperative complication rates between non-morbidly obese and morbidly obese patients. The 5 most common complications in the morbidly obese group were then selected for multivariate regression analysis to identify independent risk factors for poor 30-day outcomes.

RESULTS

Morbidly obese patients had a higher perioperative complication rate. The 5 most common complications were prolonged hospitalization, blood transfusion, readmission, wound complications, and reoperation. Independent risk factors for these complications were age ≥65 years, super obesity (ie, BMI > 48.6), chronic steroid use, American Society of Anesthesiology classification ≥3, poor functional status, long length of fusion ≥4 levels, and extended operative time (ie, operative time ≥318 minutes).

CONCLUSIONS

Morbidly obese patients are at higher risk of perioperative complications following elective PLF. Modifiable risk factors for the most common complications are obesity and preoperative steroid use.

Effect of Body Mass on Oxygenation and Intra-Abdominal Pressure When Using a Jackson Surgical Table in the Prone Position During Lumbar Surgery

STUDY DESIGN

Prospective observational study.

OBJECTIVE

To test the hypothesis that different types of surgical frame and the patient's body mass index (BMI) can affect pulmonary compliance, intra-abdominal pressure (IAP), and oxygenation.

SUMMARY OF BACKGROUND DATA

The oxygenation index (PaO2/FiO2) and IAP are known to be associated with BMI when patients are in the supine position. However, there are few reports on the correlation between BMI, the oxygenation index, and IAP in the prone position, especially when a Jackson surgical table is used.

METHODS

Thirty-seven adult patients were divided into two groups according to BMI: normal-weight patients (n = 19, BMI: 18.5-24.9 kg m) and overweight patients (n = 18, BMI ≥ 25 kg m). After the induction of general anesthesia, patients were turned to the prone position onto either a Jackson surgical table (Mizuho OSI) or a general surgical table (MAQUET; foam pad, China). The patient's IAP, peak airway pressure, pulmonary dynamic compliance (Cdyn), and oxygenation index were recorded.

RESULTS

In overweight patients, there was a greater increase in peak airway pressure and a greater decrease in Cdyn observed when a general surgical table was used compared with the Jackson surgical table. When the Jackson surgical table was used, there was a greater increase in the oxygenation index and a greater decrease in IAP. There was a significant negative correlation between the oxygenation index and BMI and a significant positive correlation between IAP and BMI in the prone position.

CONCLUSION

Turning patients from the supine to the prone position during anesthesia results in an increase in the oxygenation index and a decrease in IAP. Both of these factors are dependent upon the type of surgical frame used and the patient's BMI. The reduction in IAP was particularly significant when a Jackson surgical table was used for overweight patients.

LEVEL OF EVIDENCE

4.

More risks and complications for elective spine surgery in morbidly obese patients

Background:

The vast majority of studies emphasize the greater morbidity/mortality for elective spine surgery in morbidly obese patients.

Methods:

This review focuses on the increased morbidity/mortality of performing elective spinal operations in morbidly obese patients. There are two definitions of morbid obesity; a body mass index (BMI) of equal to or greater than 35 plus two major comorbid factors (e.g., hypertension, diabetes, etc.) or a BMI (morbidly obese III) of =≥40 kg/m².

Results:

For patients undergoing spinal surgery, morbid obesity increases perioperative morbidity/mortality for various reasons. The quality of preoperative and intraoperative imaging is often compromised potentially leading to mistaken preoperative diagnoses, and wrong level surgery. Resultant major technical surgical limitations include poor/inadequate operative exposure, and the risk of suboptimal placement of instrumentation There is also increased exposure to major perioperative complications such as deep venous thrombosis, pulmonary embolism, infection, pneumonia, cardiac complications, blindness in the prone position, brachial and lumbar plexus injuries, increased anesthetic risks (e.g., even using awake intubation/awake positioning), and postoperative wound seromas/hematomas.

Conclusions:

Most of the spinal literature documents the marked increased perioperative morbidity/mortality for morbidly obese patients undergoing elective spine surgery. If elective surgery is warranted in these patients, the risks and timing of surgical intervention should include consideration of major preoperative weight loss strategies including bariatric procedures to optimize outcomes.

Comparison of Enk Fibreoptic Atomizer with translaryngeal injection for topical anaesthesia for awake fibreoptic intubation in patients at risk of secondary cervical injury: A randomised controlled trial

BACKGROUND

Two methods of topical anaesthesia for awake fibreoptic intubation (FOI) in patients at risk of secondary cervical injury were compared: the translaryngeal injection (TLI) technique and the Enk Fibreoptic Atomizer.

OBJECTIVE

The objective of this study was to determine which system of topical anaesthesia provides the fastest and most comfortable awake FOI, using the oral approach.

DESIGN

A randomised controlled study.

SETTING

A single centre trial between 2009 and 2011.

PATIENTS

One hundred and twenty patients (63 women, 57 men) who underwent neurosurgery of the spine at Klinikum St. Georg Leipzig were randomly allocated into two groups (group TLI, 61 patients; group ENK-ATOMIZER, 59 patients). Inclusion criteria were an American Society of Anesthesiology (ASA) physical status of 1 to 3, age 18 to 80 years, and those who met any one of three indications for FOI - cervical instability, predicted difficult airway, a BMI greater than 40 kg m(-2), and who gave written informed consent.Exclusion criteria were emergency awake FOI, mental disability/delirium, polytrauma and contraindication to TLI.

INTERVENTIONS

Two anaesthesiologists experienced in both techniques performed all anaesthesia procedures within the study.

MAIN OUTCOME MEASURES

The primary outcome was the timing sequence of awake FOI. The incidence of coughing/gagging, ease of tracheal tube placement, mucosal bleeding, cardiopulmonary stability and postoperative outcomes were also investigated.

RESULTS

Awake FOI was significantly faster using the TLI technique (mean, 191 s; range, 123 to 447 s; SD, 83.5) than the Enk Fibreoptic Atomizer [mean, 430 s; range, 275 to 773 s; SD, 124.9; (P = 0.0001)]. Patients in group TLI exhibited significantly less gagging (P = 0.047) but more mucosal bleeding (P <  .001).

CONCLUSION

Awake FOI using the TLI technique was faster and provided better topical anaesthesia with less gagging during endoscopic intubation. However, the TLI technique was also more invasive.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00948350.