The Unanticipated Difficult Intubation in Obstetrics

Assessment of pre-anesthesia machine check and airway equipment preparedness: A cross-sectional study

Background

Anesthesia Equipment malfunction is one of the most common factors contributing to intraoperative surgical patient morbidity and mortality. It is impossible to give anesthesia without proper anesthesia machine checks and airway equipment preparation. Therefore, all anesthesia professionals should make sure that the anesthetic machine and equipment are working correctly.

Method

An institutional-based prospective observational study was conducted at the University Comprehensive Specialized Hospital, Operation rooms, from April 10, 2020 to May 10, 2020. About 90 anesthetists were working regularly in the operation theater both emergency and elective patients. Those include; 26 Msc holders, 17 MSc students, 7 BSc anesthetists, and 40 graduating BSc students. These descriptive data were presented with frequency, percentage, and table.

Result

The overall compliance rate was 87%. Whereas; 12.46% of clinicians have not met the standard. Out of standards that were not performed, 25.81% were not available from the setup.

Conclusion

The result shows that there was poor compliance with anesthesia machine check and equipment preparation before anesthesia in the operation theater according.

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It is impossible to give anesthesia without proper anesthesia machine checks and airway equipment preparation.

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Anesthesia Equipment malfunction is one of the most common factors contributing to intraoperative complications.

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The overall compliance rate was (87%).

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There was poor compliance of anesthesia machine check and airway equipment preparation.

Airway Management: Difficulty of Intubation and Range of Movement of the Thyroid Cartilage

PURPOSE

Difficult endotracheal intubation has been associated with a number of anatomic factors. According to our experience, the range of movement of thyroid cartilage can be used as a useful test to determine the difficulty in endotracheal intubation. The aim of this study was to evaluate the association between the range of movement of thyroid cartilage and difficulty in intubation.

DESIGN

Cross-sectional study.

METHODS

This study was carried out on 400 patients at (Shohada Ashayer Hospital, Khorramabad). After obtaining consent letters from the patients who were between 18 and 60 years of age, the patients underwent general anesthesia. The participants were evaluated by Mallampati and other evaluating tests. The range of movement of thyroid cartilage from the midline was measured and recorded.

FINDINGS

There were significant correlation between the range of movement of thyroid cartilage and thyromental distance. In addition, in patients with Cormack-Lehane class 1, the mean range of movement of thyroid cartilage was significantly more than the patients with Cormack-Lehane class 3 and 4.

CONCLUSIONS

The outcomes of our study indicate that the range of movement of thyroid cartilage can be used for predication of difficult intubation. However, further randomized trials should be conducted in this regard.

Management of Nephrolithiasis in Pregnancy: Multi-Disciplinary Guidelines From an Academic Medical Center

Introduction: The management of nephrolithiasis during pregnancy can be stressful for urologists due to concerns for investigations and treatments that may pose risk of fetal harm, and unfamiliarity with optimal management of these complex patients. In response, we created multi-disciplinary evidence-based guidelines to standardize the care for obstetric patients presenting with flank pain and suspicion for nephrolithiasis. Methods: A multi-disciplinary team involving Urology, Obstetric Anesthesiology, Obstetrics and Gynecology, Diagnostic Radiology, and Interventional Radiology from a single academic medical center was assembled. A PubMed search was performed using keywords of pregnancy/antepartum, nephrolithiasis/calculi/kidney stones, ureteroscopy, non-obstetric surgery, complications, preterm delivery, MRI, computerized tomography, renal bladder ultrasound (RBUS), and anesthesia to identify relevant articles. Team members reviewed their respective areas to create a comprehensive set of guidelines. One invited external expert reviewed the guidelines for validation purposes. Results: A total of 54 articles were reviewed for evidence synthesis. Four guideline statements were constructed to guide diagnosis and imaging, and seven statements to guide intervention. Guidelines were then used to create a diagnostic and intervention flowchart for ease of use. In summary, RBUS should be the initial diagnostic study. If diagnostic uncertainty still exists, a non-contrast CT scan should be obtained. For obstetric patients presenting with a septic obstructing stone, urgent decompression should be achieved. We recommend ureteral stent placement as the preferred intervention if local factors allow. Conclusions: We present a standardized care pathway for the management of nephrolithiasis during pregnancy. Our aim is to standardize and simplify the clinical management of these complex scenarios for urologists.

Rescue supraglottic airway devices at caesarean delivery: What are the options to consider?

Tracheal intubation is considered the gold standard means of securing the airway in obstetric general anaesthesia because of the increased risk of aspiration. Obstetric failed intubation is relatively rare. Difficult airway guidelines recommend the use of a supraglottic airway device to maintain the airway and to allow rescue ventilation. Failed intubation is associated with a further increased risk of aspiration, therefore there is an argument for performing supraglottic airway-guided flexible bronchoscopic intubation (SAGFBI). The technique of SAGFBI has a high success rate in the non-obstetric population, it protects the airway and it minimises task fixation on repeated attempts at laryngoscopic tracheal intubation. However, after failed intubation via laryngoscopy, there is a lack of specific recommendations or indications for SAGFBI in current obstetric difficult airway guidelines in relation to achieving tracheal intubation. Our narrative review explores the issues pertaining to airway management in these cases: the use of supraglottic airway devices and the techniques of, and technical issues related to, SAGFBI. We also discuss the factors involved in the decision-making process as to whether to proceed with surgery with the airway maintained only with a supraglottic airway device, or to proceed only after SAGFBI.

Pre-eclampsia through the eyes of the obstetrician and anesthesiologist

Due to the high risk of morbidity and mortality from unrecognized and untreated pre-eclampsia, clinicians should have a high index of suspicion to evaluate, treat and monitor patients presenting with signs concerning for pre-eclampsia. Early blood pressure management and seizure prophylaxis during labor are critical for maternal safety. Intrapartum, special anesthetic considerations should be employed to ensure the safety of the parturient and fetus. Patients who have pre-eclampsia should be aware that they are at high risk for the future development of cardiovascular disease.

Videolaryngoscopy versus fiberoptic bronchoscope for awake intubation - a systematic review and meta-analysis of randomized controlled trials

Background

Awake intubation with videolaryngoscopy (VL) is a novel method that is drawing more and more attention as an alternative to awake intubation with fiberoptic bronchoscope (FOB). This meta-analysis is designed to determine the performance of VL compared to the FOB for awake intubation.

Methods

The Cochrane Central Register of Controlled Trials, PubMed, Embase, and Web of science were searched from database inception until October 30, 2017. Randomized controlled trials comparing VL and FOB for awake intubation were selected. The primary outcome was the overall success rate. Rev-Man 5.3 software was used to perform the pooled analysis and assess the risk of bias for each eligible study. The GRADE system was used to assess the quality of evidence for all outcomes.

Results

Six studies (446 patients) were included in the review for data extraction. Pooled analysis did not show any difference in the overall success rate by using VL and FOB (relative risk [RR], 1.00; P=0.99; high-quality evidence). There was no heterogeneity among studies (I²=0). Subgroup analyses showed no differences between two groups through nasal (RR, 1.00; P=1.00; high-quality evidence) and oral intubations (RR, 1.00; P=0.98; high-quality evidence). The intubation time was shorter by using VL than by using FOB (mean difference, −40.4 seconds; P<0.01; low-quality evidence). There were no differences between groups for other outcomes (P>0.05).

Conclusion

For awake intubation, VL with a shorter intubation time is as effective and safe as FOB. VL may be a useful alternative to FOB.

Association between mode of anaesthesia and severe maternal morbidity during admission for scheduled Caesarean delivery: a nationwide population-based study in Japan, 2010-2013

BACKGROUND

Although the incidence of maternal mortality during Caesarean delivery remains very low, the rate of severe maternal morbidity is increasing. Improvements in obstetric anaesthetic practice have resulted in a dramatic reduction in the risk of maternal death from general anaesthesia. Less clear is whether the risk of severe maternal morbidity differs according to mode of anaesthesia for women undergoing Caesarean delivery. We analysed the association between the mode of anaesthesia and severe maternal morbidity during Caesarean delivery using a nationally representative inpatient database.

METHODS

We identified 89 225 women undergoing scheduled Caesarean delivery from the Diagnosis Procedure Combination database in Japan, 2010-2013. We defined severe maternal morbidity as the presence of any life-threatening complications and identified women with severe maternal morbidity from the database. Propensity score-matched analysis was carried out to compare the odds of severe maternal morbidity between women who underwent general vs neuraxial anaesthesia.

RESULTS

Of 89 225 women, 10 058 received general anaesthesia and 79 167 received neuraxial anaesthesia. In the propensity score-matched analysis with 10 046 pairs, a higher incidence of severe maternal morbidity was observed among patients receiving general (2.00%) rather than neuraxial anaesthesia (0.76%). The odds ratio of severe maternal morbidity was 2.68 (95% CI, 1.97-3.64) among women receiving general compared with neuraxial anaesthesia.

CONCLUSIONS

For scheduled Caesarean delivery, general anaesthesia compared with neuraxial anaesthesia is associated with greater odds for severe maternal morbidity. However, we should be cautious with interpretation of these findings because they may be explained by confounding indications.

Prevalence of difficult intubation and failed intubation in a diverse obstetric community-based population

OBJECTIVE

To describe the incidence of difficult and failed intubations in obstetric patients during a 6 year period monitored by a quality assurance program together with American Society of Anesthesiologists Physical Status (ASA PS) scores, and obesity (body mass index >30 kg/m²).

METHODS

Following Institutional Review Board approval, data about obstetric patients who experienced unanticipated difficult or failed intubations from 2010 to 2015 was obtained from the quality assurance database of a large, community-based anesthesiology group practice. The database employs standardized definitions for difficult intubation (>3 laryngoscopic attempts by experienced providers) and failed intubation (inability to intubate leading to surgical airway or waking up the patient). ASA PS scores and comorbidities were also identified for obstetric general anesthetics using an internally developed quality assurance program, Quantum Clinical Navigation System.

RESULTS

There were 2802 obstetric general anesthetics in the database of which 1085 (38.7%) were deemed as emergencies. There were no cases of failed intubation and seven cases of unanticipated difficult intubations (1:400 cases, 0.25% of all obstetric general anesthetics, 95% confidence interval 0.1-0.5%), six of which occurred during emergency surgery. There was an increase in obesity (p = .003) and ASA PS (p = .02) over the period of the study. The incidence of difficult intubation was not found to be significantly changed (p = .68).

CONCLUSIONS

Despite an increase in ASA PS score and obesity, there was no increase in the incidence of difficult intubation in obstetric patients. Limitations of the study include its retrospective design, and the small number of difficult intubation cases identified.

CXC Chemokine Receptor Type 4 Antagonism Ameliorated Allograft Fibrosis in Rat Kidney Transplant Model

OBJECTIVES

In this study, we evaluated the effects of CXC chemokine receptor type 4 and stromal cell-derived factor 1 signaling in the progression of chronic allograft nephropathy in a rat model.

MATERIALS AND METHODS

Experimental rats were divided into 3 groups: Lewis-to-Lewis isograft transplant (group A), Fisher 344 rat-to-Lewis allograft transplant with immunosuppressant cyclosporine (group B), and Fisher 344 rat-to-Lewis allograft transplant treated with cyclosporine and the CXC chemokine receptor type 4 antagonist AMD3100 (1 mg/kg/d) (group C). On day 90 after the operation, renal graft function, proteinuria, and histologic Banff score were measured. The expression levels of transforming growth factor β1 and collagen IV were determined by quantitative real-time polymerase chain reaction.

RESULTS

Renal function and urinary protein were increased in allografts of groups B and C compared with isografts of group A. The Banff score was significantly decreased in the AMD3100-treated animals (group C), with renal fibrosis being reduced. In addition, overexpressed levels of transforming growth factor β1 and collagen IV in group B allografts were significantly reduced versus that shown with treatment with the CXC chemokine receptor type 4 antagonist in group C.

CONCLUSIONS

Together, these data strongly implicate that CXC chemokine receptor type 4 antagonism alleviated renal interstitial fibrosis in long-term surviving allografts by down-regulating expression of transforming growth factor β1.

Cardiac Arrest in Pregnancy

This is the first scientific statement from the American Heart Association on maternal resuscitation. This document will provide readers with up-to-date and comprehensive information, guidelines, and recommendations for all aspects of maternal resuscitation. Maternal resuscitation is an acute event that involves many subspecialties and allied health providers; this document will be relevant to all healthcare providers who are involved in resuscitation and specifically maternal resuscitation.

Temporal Trends in Anesthesia-related Adverse Events in Cesarean Deliveries, New York State, 2003–2012

Background

Cesarean delivery (CD) is associated with significantly increased risks of anesthesia-related adverse events (ARAEs) and nonanesthetic perioperative morbidity compared with vaginal delivery. Temporal trends in these adverse outcomes remain unknown despite efforts to improve maternal safety. This study examines temporal trends in ARAEs and nonanesthetic perioperative complications in CDs in New York hospitals.

Methods

Data are from the State Inpatient Database for New York, 2003–2012. ARAEs, including minor and major ARAEs, and nonanesthetic perioperative complications were identified through International Classification of Diseases, Ninth Revision, Clinical Modification codes. Statistical significance in time trends was assessed using the Cochran–Armitage test and multivariable logistic regression.

Results

Of the 785,854 CDs studied, 5,715 (730 per 100,000; 95% CI, 710 to 750) had at least one ARAE and 7,040 had at least one perioperative complication (890 per 100,000; 95% CI, 870 to 920). The overall annual rate of ARAEs decreased from 890 per 100,000 in 2003 to 660 in 2012 (25% decrease; 95% CI, 16 to 34; P &lt; 0.0001). The rate of minor ARAEs decreased 23% (95% CI, 13 to 32) and of major ARAEs decreased 43% (95% CI, 23 to 63). No decrease was observed in the rate of ARAEs for CDs performed under general anesthesia. The rate of nonanesthetic complications increased 47% (95% CI, 31 to 63; P &lt; 0.0001).

Conclusions

Anesthesia-related outcomes in cesarean deliveries appear to have improved significantly across hospitals in New York in the past decade. Perioperative nonanesthetic complications remain a serious healthcare issue.

Survey of Accepted Practice following Failed Intubation for Emergency Caesarean Delivery

Background. There is no consensus on the optimum management of failed tracheal intubation in emergency cesarean delivery performed for fetal compromise. The decision making process on whether to wake the patient or continue anesthesia with a supraglottic airway device is an underexplored area. This survey explores perceptions and experiences of obstetric anesthetists managing failed intubation. Methods. Anesthetists attending the Group of Obstetric Anaesthetists London (GOAL) Meeting in April 2014 were surveyed. Results. Ninety-three percent of anesthetists surveyed would not always wake the patient in the event of failed intubation for emergency cesarean delivery performed for fetal compromise. The median (interquartile range) of perceived acceptability of continuing anesthesia with a well-fitting supraglottic airway device, assessed using a visual analogue scale (0–100; 0 completely unacceptable; 100 completely acceptable), was 90 [22.5]. Preoperative patient consent regarding the use of a supraglottic airway device for surgery in the event of failed intubation would affect the decision making of 40% of anaesthetists surveyed. Conclusion. These results demonstrate that a significant body of anesthetists with a subspecialty interest in obstetric anesthesia in the UK would not always wake up the patient and would continue with anesthesia and surgery with a supraglottic airway device in this setting.

Operative care of obstetric patients

The operative care of pregnant patients, whether for delivery of the neonate or for a nonobstetric surgical procedure, must take into consideration many variables. An awareness of maternal physiologic changes, fetal requirements, effects of anesthetic agents on both the mother and the fetus, and the potential for complications is essential for obstetric anesthetists. In addition, a comprehensive evaluation of the parturient, ample preparation of drugs and equipment in the operative suite, and cooperation with the obstetrician and the surgical team are of major importance in ensuring the safe and effective anesthetic care of this special patient population.

The accuracy of locating the cricothyroid membrane by palpation - an intergender study

Background

The cricothyroid membrane (CTM) is the recommended site of access to the airway during cricothyrotomy to provide emergency oxygenation. We sought to compare the ability of physicians to correctly identify the CTM in male and female patients.

Methods

In a prospective observational study, anaesthetists were asked to locate the CTM by palpation which was then identified using ultrasound and the distance between the actual and estimated margin of the CTM was measured. Participants assessed the ease of CTM palpation using a visual analog scale. In a second series, the angulation of the posterior junction of the thyroid laminae was measured using ultrasound.

Results

23 anaesthetists and 44 subjects participated. A total of 36 assessments were carried out in each gender. Incorrect identification of the CTM was more common in females (29/36 vs. 11/36, P < 0.001) and the distance from the CTM in the vertical plane was greater (11.0 [6.5–20.0] vs. 0.0 [0.0–10.0] mm, P < 0.001). In females distance from the CTM correlated positively with neck circumference (P = 0.005) and BMI (P = 0.00005) and negatively with subject height (P = 0.01). Posterior thyroid cartilage angulation was greater in females (118.6 ± 9.4° vs. 95.9 ± 12.9°, P = 0.02) and was lower in patients with correctly identified CTMs (100.0 ± 14.9° vs. 115.6 ± 15.9°, P = 0.02). VRS palpation correlated with decreased posterior thyroid cartilage angulation (P = 0.04).

Conclusions

CTM localisation is more difficult in female subjects irrespective of body habitus. It may be prudent to localize this structure by additional means (e.g. ultrasound) in advance of any airway manoeuvres or to modify the cricothyrotomy technique in the event that it is necessary in an emergency.

Tracheal intubation with a flexible fibreoptic scope or the McGrath videolaryngoscope in simulated difficult airway scenarios: a randomised controlled manikin study

BACKGROUND

Flexible fibreoptic endoscopic (FFE) intubation is considered the 'gold-standard' when difficult airway management is anticipated. Several videolaryngoscopes have been developed to facilitate intubation by laryngoscopy.

OBJECTIVE

The aim of the study was to compare the performance of the McGrath series 5 videolaryngoscope (McGrath videolaryngoscope) and the FFE for tracheal intubation in manikins with a simulated difficult airway, hypothesizing that the McGrath videolaryngoscope intubation would prove faster than FFE intubation.

DESIGN

A randomised controlled study.

SETTING

The Danish Institute for medical simulation between December 2009 and June 2010.

PARTICIPANTS

Twenty-eight anaesthesia residents participating in the Danish mandatory 3-day airway management course.

INTERVENTIONS

All participants received instructions and training in the use of the McGrath videolaryngoscope and FFE. The participants then performed tracheal intubation on a SimMan manikin once with the McGrath videolaryngoscope and once with the FFE in three difficult airway scenarios: (1) pharyngeal obstruction; (2) pharyngeal obstruction and cervical rigidity; (3) tongue oedema.

MAIN OUTCOME MEASURES

We measured successful intubations, defined as intubation within 120  s, and time to tracheal intubation.

RESULTS

The trachea was intubated within 120  s with the McGrath videolaryngoscope in 25 out of 27 (93%), 25 out of 28 (89%) and 18 out of 28 (64%) occasions compared with 11 out of 28 (40%), 11 out of 28 (40%) and 16 out of 28 (57%) with the FFE in scenarios (1), (2) and (3), respectively. Time to tracheal intubation was shorter with the McGrath videolaryngoscope in scenarios (1) and (2) than with the FFE (Wilcoxon signed rank sum test, P < 0.0001).

CONCLUSION

The McGrath videolaryngoscope is a valuable device with higher success rate and a quicker performance in simulated difficult airways. In patients, videolaryngoscopy may have a role in difficult airway algorithms, but the optimal device has yet to be found.

Diagnostic value of the upper lip bite test in predicting difficulty in intubation with head and neck landmarks obtained from lateral neck X-ray

Background:

Unanticipated difficult tracheal intubation remains a primary concern of anaesthesiologists and upper lip bite test (ULBT) is one of the assessments used in predicting difficult intubation. In this study, we aimed to check the utility of lateral neck X-ray measurements in improving the diagnostic value of the ULBT.

Methods:

In a prospective study conducted from January 2007 until December 2010, we recorded personal and demographic data of 4500 patients who entered the study and subjected them to standard lateral neck radiography. Before the induction of anaesthesia, clinical examination and ULBT results were recorded and during induction of anaesthesia laryngoscopic grading was evaluated and recorded in questionnaires. All the compiled data were analysed by SPSS 14.0 (SPSS Inc., Chicago, IL, USA) software. Diagnostic value for each test was calculated and compared.

Results:

Negative predictive values (NPVs) were high in all tests. ULBT had the highest specificity and NPV compared with the other tests. The positive predictive value for all the tests had been low, but marginally high in the ULBT.

Conclusion:

Although all the tests used had relatively acceptable predictive values, combination of tests appeared to be more predictive. Highest sensitivities were observed with ULBT, mandibulohyoid distance and thyromental distance respectively. Use of radiological parameters may not be suitable as screening tools, but may help in anticipating and preparing for a difficult scenario.

Virtual airway simulation to improve dexterity among novices performing fibreoptic intubation

We developed a virtual reality software application (iLarynx) using built-in accelerometer properties of the iPhone(®) or iPad(®) (Apple Inc., Cupertino, CA, USA) that mimics hand movements for the performance of fibreoptic skills. Twenty novice medical students were randomly assigned to virtual airway training with the iLarynx software or no additional training. Eight out of the 10 subjects in the standard training group had at least one failed (> 120 s) attempt compared with two out of the 10 participants in the iLarynx group (p = 0.01). There were a total of 24 failed attempts in the standard training group and four in the iLarynx group (p < 0.005). Cusum analysis demonstrated continued group improvement in the iLarynx, but not in the standard training group. Virtual airway simulation using freely available software on a smartphone/tablet device improves dexterity among novices performing upper airway endoscopy.

Maternal cardiac arrest: a practical and comprehensive review

Cardiac arrest during pregnancy is a dedicated chapter in the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care; however, a robust maternal cardiac arrest knowledge translation strategy and emergency response plan is not usually the focus of institutional emergency preparedness programs. Although maternal cardiac arrest is rare, the emergency department is a high-risk area for receiving pregnant women in either prearrest or full cardiac arrest. It is imperative that institutions review and update emergency response plans for a maternal arrest. This review highlights the most recent science, guidelines, and recommended implementation strategies related to a maternal arrest. The aim of this paper is to increase the understanding of the important physiological differences of, and management strategies for, a maternal cardiac arrest, as well as provide institutions with the most up-to-date literature on which they can build emergency preparedness programs for a maternal arrest.