Difficult intubation in acromegalic patients: incidence and predictability

Surgical and non-surgical interventions for primary and salvage treatment of growth hormone-secreting pituitary adenomas in adults

BACKGROUND

Growth hormone (GH)-secreting pituitary adenoma is a severe endocrine disease. Surgery is the currently recommended primary therapy for patients with GH-secreting tumours. However, non-surgical therapy (pharmacological therapy and radiation therapy) may be performed as primary therapy or may improve surgical outcomes.

OBJECTIVES

To assess the effects of surgical and non-surgical interventions for primary and salvage treatment of GH-secreting pituitary adenomas in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, WHO ICTRP, and ClinicalTrials.gov. The date of the last search of all databases was 1 August 2022. We did not apply any language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of more than 12 weeks' duration, reporting on surgical, pharmacological, radiation, and combination interventions for GH-secreting pituitary adenomas in any healthcare setting.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance, screened for inclusion, completed data extraction, and performed a risk of bias assessment. We assessed studies for overall certainty of the evidence using GRADE. We estimated treatment effects using random-effects meta-analysis. We expressed results as risk ratios (RR) for dichotomous outcomes together with 95% confidence intervals (CI) or mean differences (MD) for continuous outcomes, or in descriptive format when meta-analysis was not possible.

MAIN RESULTS

We included eight RCTs that evaluated 445 adults with GH-secreting pituitary adenomas. Four studies reported that they included participants with macroadenomas, one study included a small number of participants with microadenomas. The remaining studies did not specify tumour subtypes. Studies evaluated surgical therapy alone, pharmacological therapy alone, or combination surgical and pharmacological therapy. Methodological quality varied, with many studies providing insufficient information to compare treatment strategies or accurately judge the risk of bias. We identified two main comparisons, surgery alone versus pharmacological therapy alone, and surgery alone versus pharmacological therapy and surgery combined. Surgical therapy alone versus pharmacological therapy alone Three studies with a total of 164 randomised participants investigated this comparison. Only one study narratively described hyperglycaemia as a disease-related complication. All three studies reported adverse events, yet only one study reported numbers separately for the intervention arms; none of the 11 participants were observed to develop gallbladder stones or sludge on ultrasonography following surgery, while five of 11 participants experienced any biliary problems following pharmacological therapy (RR 0.09, 95% CI 0.01 to 1.47; 1 study, 22 participants; very low-certainty evidence). Health-related quality of life was reported to improve similarly in both intervention arms during follow-up. Surgery alone compared to pharmacological therapy alone may slightly increase the biochemical remission rate from 12 weeks to one year after intervention, but the evidence is very uncertain; 36/78 participants in the surgery-alone group versus 15/66 in the pharmacological therapy group showed biochemical remission. The need for additional surgery or non-surgical therapy for recurrent or persistent disease was described for single study arms only. Surgical therapy alone versus preoperative pharmacological therapy and surgery Five studies with a total of 281 randomised participants provided data for this comparison. Preoperative pharmacological therapy and surgery may have little to no effect on the disease-related complication of a difficult intubation (requiring postponement of surgery) compared to surgery alone, but the evidence is very uncertain (RR 2.00, 95% CI 0.19 to 21.34; 1 study, 98 participants; very low-certainty evidence). Surgery alone may have little to no effect on (transient and persistent) adverse events when compared to preoperative pharmacological therapy and surgery, but again, the evidence is very uncertain (RR 1.23, 95% CI 0.75 to 2.03; 5 studies, 267 participants; very low-certainty evidence). Concerning biochemical remission, surgery alone compared to preoperative pharmacological therapy and surgery may not increase remission rates up until 16 weeks after surgery; 23 of 134 participants in the surgery-alone group versus 51 of 133 in the preoperative pharmacological therapy and surgery group showed biochemical remission. Furthermore, the very low-certainty evidence did not suggest benefit or detriment of preoperative pharmacological therapy and surgery compared to surgery alone for the outcomes 'requiring additional surgery' (RR 0.48, 95% CI 0.05 to 5.06; 1 study, 61 participants; very low-certainty evidence) or 'non-surgical therapy for recurrent or persistent disease' (RR 1.22, 95% CI 0.65 to 2.28; 2 studies, 100 participants; very low-certainty evidence). None of the included studies measured health-related quality of life. None of the eight included studies measured disease recurrence or socioeconomic effects. While three of the eight studies reported no deaths to have occurred, one study mentioned that overall, two participants had died within five years of the start of the study.

AUTHORS' CONCLUSIONS

Within the context of GH-secreting pituitary adenomas, patient-relevant outcomes, such as disease-related complications, adverse events and disease recurrence were not, or only sparsely, reported. When reported, we found that surgery may have little or no effect on the outcomes compared to the comparator treatment. The current evidence is limited by the small number of included studies, as well as the unclear risk of bias in most studies. The high uncertainty of evidence significantly limits the applicability of our findings to clinical practice. Detailed reporting on the burden of recurrent disease is an important knowledge gap to be evaluated in future research studies. It is also crucial that future studies in this area are designed to report on outcomes by tumour subtype (that is, macroadenomas versus microadenomas) so that future subgroup analyses can be conducted. More rigorous and larger studies, powered to address these research questions, are required to assess the merits of neoadjuvant pharmacological therapy or first-line pharmacotherapy.

Predictive Value of Modified Mallampati Test and Upper Lip Bite Test Concerning Cormack and Lehane's Laryngoscopy Grading in the Anticipation of Difficult Intubation: A Cross-Sectional Study at a Tertiary Care Hospital, Bhubaneswar, India

Background and objective

Many tests are at hand to predict difficult intubation preoperatively to prevent morbidity and mortality of unanticipated difficult intubation. The present study was conducted to evaluate and compare the efficacy of the modified Mallampati test (MMT) and upper lip bite test (ULBT) to foresee difficult intubation.

Materials and methods

After obtaining written informed consent, this prospective comparative observational study was conducted on 225 patients scheduled for elective surgery under general endotracheal anesthesia. Preoperative MMT and ULBT were performed. MMT Grade III, IV, and ULBT Grade IV were regarded as predictors of difficult intubation. The laryngoscopic view was graded as per Cormack and Lehane's laryngoscopic grading after induction of anesthesia by an experienced anesthesiologist ignorant of preoperative airway evaluation. Patients with Cormack and Lehane Class III and IV were regarded as difficult intubation. Sensitivity, specificity, and positive and negative predictive values of MMT and ULBT were computed. Agreement between two tests with the Cormack Lehane test was determined by the Kappa coefficient.

Results

In our research, the occurrence of difficult intubation was found to be 10.2% (23 cases of difficult intubation out of 225 patients). In our analysis, we found the sensitivity (95.5% vs. 95.4%), specificity (54.8% vs 50.0%), positive predictive value (91.6% vs 93.1%), and negative predictive value (39.1% vs 39.1%) were almost comparable between modified Mallampati test and upper lip bite test. Kappa coefficient for the upper lip bite test (0.492) was slightly higher as compared to modified Mallampati scoring (0.454), but both the values are highly statistically significant (p-value <0.001).

Conclusion

Both the upper lip bite test and modified Mallampati test are comparable with each other and since the upper lip bite test is easy to perform bedside test we recommend it to be used alone or in collaboration with other tests in assessing difficult airways.

Preoperative Medical Treatment for Patient with Acromegaly: yes or no?

Transsphenoidal surgery is the first-line treatment for acromegaly. However, several factors can modify surgical remission rates, such as the initial hormone levels, the size and invasiveness of the tumor, and the degree of experience of the surgeon. Physicians treating patients with acromegaly should thus consider how to improve surgical remission rates. As stated in recent guidelines, the major point is to consider that any patient with acromegaly should be referred to an expert neurosurgeon to maximize the chances of surgical sure. The benefits of presurgical medical treatment, mainly using somatostatin receptor ligands (SRLs), given 3 to 6 months before surgery, remain controversial. By normalizing growth hormone and insulin-like growth factor 1 levels, SRLs may improve the overall condition of the patient, thus decreasing anesthetic and surgical complications. By decreasing the tumor size and modifying the consistency of the tumor, SRLs might also make surgical excision easier. This is however theoretical as published data are contradictory on both points, and only limited data support the use of a systematical presurgical medical treatment. The aim of this review is to analyze the potential benefits and pitfalls of using presurgical medical treatment in acromegaly in view of the contradictory literature data. We also attempt to determine the profile of patients who might most benefit from this presurgical medical treatment approach as an individualized therapeutic management of acromegaly.

Preanesthetic Evaluation and Preparation for Neurosurgical Procedures: An Indian Perspective

Background A questionnaire-based survey was conducted to determine the preanesthetic evaluation (PAE) practices among the members of the Indian Society of Neuroanesthesiology and Critical Care (ISNACC). The survey aimed to assess the current clinical practice of PAE and optimization of neurosurgical patients in India.

Methods An online questionnaire was designed by the working group of ISNACC and circulated among its active members. Response to individual questions was considered significant if 50% or more respondents concurred. The survey questions to which less than 50% of respondents concurred were identified as inconclusive results.

Results Out of 438 active ISNACC members, 218 responded. Responses were obtained from various parts of the country. The majority of participants were practicing neuroanesthesiology. Questions asked were regarding clinical assessment, preoperative optimization, prognostication, and airway management in neurosurgery. More than 50% of practitioners acceded to most of the questions; however, the percentage of responses varied across different questions (50–100%). The questions related to preoperative duplex scanning in chronically immobilized patients, preoperative cognitive testing, and risk stratification during neurosurgical procedures received an inconclusive response (< 50%).

Conclusion The survey highlights the variable PAE practices perused by ISNACC members across the country. A guideline for uniform PAE practices may help to enhance research and improve perioperative care.

Comparison of Cricothyroid Membrane Puncture Anesthesia and Topical Anesthesia for Awake Fiberoptic Intubation: A Double-Blinded Randomized Controlled Trial

Background: Awake fiberoptic intubation (AFOI) is commonly used for patients with a difficult airway. The purpose of this study was to evaluate the efficacy of cricothyroid membrane puncture anesthesia and topical anesthesia during AFOI.

Methods: A total of 70 patients (the American Society of Anesthesiologists score I-III) with anticipated difficult airways scheduled for nonemergency surgery with AFOI were randomly slated to receive cricothyroid membrane puncture anesthesia (n = 35) or topical anesthesia (n = 35). Each group received dexmedetomidine at a dose of 1.0 μg/kg and sufentanil at a dose of 0.2 μg/kg over 10 min for conscious sedation before intubation. The endoscopy intubation, post-intubation condition, and endoscopy tolerance as scored by the anesthetists were observed. The satisfaction of the operator regarding the procedure and the satisfaction of the patient 24 h after the surgery were also recorded. We recorded the success rate of the first intubation, intubation time, and hemodynamic changes during the procedure and also the adverse events.

Results: Better intubation scores, operator satisfaction, and satisfaction of the patient were observed in the cricothyroid membrane puncture anesthesia group than in the topical anesthesia group (p < 0.05). The intubation time in the cricothyroid membrane puncture anesthesia group was less than that in the topical anesthesia group (p < 0.05). There were no significant differences in the patient tolerance scores, the success rate of the first intubation, hemodynamic changes, and adverse events between both the groups.

Conclusion: Compared with topical anesthesia, cricothyroid membrane puncture anesthesia provided better intubation conditions and less intubation time with greater satisfaction of the patient and operator during endoscopic intubation.

Clinical Trial Registration: URL: http://www.chictr.org.cn/showproj.aspx?proj=42636, Identifier: ChiCTR 1900025820.

Insulin-like growth factor-1 as predictive factor of difficult laryngoscopy in patients with GH-producing pituitary adenoma: A pilot study

BACKGROUND

Growth hormone (GH)-producing pituitary tumors account for 10 to 15% of pituitary tumors. The hypersecretion of GH may induce changes in the airway anatomy through the activation of Insulin-like Growth factor 1(IGF-1) pathway. We sought investigate the role IGF-1 as a potential predictive factor of difficult laryngoscopy in patients with GH-producing pituitary adenoma.

METHODS

This study was a single center retrospective study. We included 33 patients undergoing transsphenoidal resection of GH-producing pituitary. We recorded demographic data, el-Ganzouri risk index (EGRI) and modified Look-Evaluate-Mallampati-Obstruction-Neck mobility (mLEMON) score, and pituitary hormone plasma levels. We performed ordinal logistic regression to analyze the relationship between IGF-1 and EGRI, mLEMON, and Cormack-Lehane Grade score and a multiple logistic regression to test the capability of EGRI, mLEMON and IGF-1 levels to predict Cormack-Lehane score. Receiver operating curve (ROC), area under the curve (AUC), and cut-off value of IGF-1 were calculated.

RESULTS

Only 14 (42.8%) and 12 (36.36%) patients showed predictive factors of difficult intubation according to EGRI and mLEMON score, respectively. IGF-1 significantly correlated with Cormack-Lehane (p = 0.005879) but not with mLEMON and EGRI (p = 0.3080 and 0.4146, respectively). In multiple regression model IGF-1 correlated only with Cormack-Lehane grade (p = 0.0089). Area under ROC was 0.8571 and cut-off value of IGF-1 was 186.15 ng/ml.

CONCLUSION

Higher IGF-1 levels correlate with the probability of having a higher Cormack-Lehane score; classical bedside scores, such as mLEMON and EGRI, were not able to predict difficult laryngoscopy in our population.

Anesthetic management during transsphenoidal pituitary surgery

PURPOSE OF REVIEW

Pituitary adenoma resections comprise a large proportion of intracranial tumor surgeries. This patient population is medically and physiologically complex and requires careful perioperative planning and management on the part of the anesthesiologist. This review will summarize anesthetic considerations for pre, intra, and postoperative management of patients undergoing transsphenoidal pituitary surgery.

RECENT FINDINGS

An endoscopic approach is favored for patients undergoing transsphenoidal pituitary surgery. Hemodynamic monitoring is important to maintain cerebral perfusion and avoid risk of bleeding; however, 'controlled' hypotension may have adverse effects. Multimodal analgesia is effective for the management of postoperative pain and may reduce the risk of postoperative complications, including respiratory depression and postoperative nausea and vomiting.

SUMMARY

Transsphenoidal pituitary surgery is a preferred approach for the surgical management of nonfunctioning pituitary macroadenomas with symptoms of mass effect and functioning adenomas that cannot be otherwise managed medically. Understanding tumor pathologies and systemic effects are essential for preoperative planning and providing safe anesthetic care during the perioperative period.

Effects of head positions on awake fiberoptic bronchoscope oral intubation: a randomized controlled trial

Background

There are many factors affecting the success rate of awake orotracheal intubation via fiberoptic bronchoscope. We performed this study was to investigate the effects of head positions on awake Fiberoptic bronchoscope oral intubation.

Methods

Seventy-five adult patients, received general anaesthesia were included in this study. After written informed consent, these patients were undergoing awake orotracheal intubation via fiberoptic-bronchoscope and according to the head position, the patients were randomized allocated to neutral position group (NP group), sniffing position group (SP group) or extension position group (EP group). After sedation the patients were intubated by an experienced anesthesiologist. The time to view the vocal cords, the percentage of glottic opening scores (POGO), the time to insert the tracheal tube into trachea and the visual analog scale (VAS) scores for ease experienced of passing the tracheal tube through glottis, the hemodynamic changes and the adverse events after surgery were recorded.

Results

The time to view the vocal cords was significantly shorter and the POGO scores was significantly higher in the EP group compared with the other two groups (P < 0.05); The SpO₂ in the EP group was higher than NP group at before intubation and higher than SP group and NP group at immediate after intubation (P < 0.05); The time to insert the tracheal tube into trachea, the VAS scores for passing the tracheal tube through glottis, the coughing scores had no significant differences among groups (P > 0.05). There were also no significant differences regard to the incidence of postoperative complications, mean arterial pressure and heart rate among the groups (P > 0.05).

Conclusions

The head at extension position had a best view of glottic opening than neutral position or sniffing position during awake Fiberoptic bronchoscope oral intubation, so extension position was recommended as the starting head position for awake Fiberoptic bronchoscope oral intubation.

Trial registration

Clinical Trials.gov. no. NCT02792855. Registered at https://register.clinicaltrials.gov on 23 september 2017.

Anesthesia and airway management in a patient with acromegaly and tracheal compression caused by a giant retrosternal goiter: a case report

A giant retrosternal goiter can lead to compression of vital organs in the mediastinum with high risk of acute cardiorespiratory decompensation. Additionally, patients with acromegaly are prone to developing severe airway obstruction and ventilation difficulties during anesthetic induction, leading to hypoxia and an increased partial pressure of carbon dioxide. Therefore, more comprehensive airway management strategies are needed. We herein describe a 57-year-old man with acromegaly and severe tracheal obstruction caused by a giant retrosternal goiter. He presented with a 1-week history of progressive dyspnea and was scheduled to undergo right lobe thyroidectomy and retrosternal goiter thyroidectomy. We created a comprehensive emergency plan for a difficult airway, including regional and topical anesthesia for awake endotracheal intubation, sevoflurane inhalation, small doses of midazolam and sufentanil to increase tolerance, self-made extended-length tracheostomy, video laryngoscope-assisted fiber-optic bronchoscopy, extracorporeal membrane oxygenation, and surgical tracheostomy. Importantly, tetracaine was inhaled through an atomizer, and a laryngotracheal topical anesthesia applicator was used to spray the larynx with 1% tetracaine to reduce stimulation during intubation. The giant goiter was successfully removed through the cervical approach. A carefully designed airway management strategy and close communication among a multidisciplinary operation team are the basis of perioperative anesthetic management for these patients.

Assessment of Airway in Patients with Acromegaly Undergoing Surgery: Predicting Successful Tracheal Intubation

Background In the field of anesthesia, acromegaly is considered a cause of difficult tracheal intubation and airway management. There is a high probability of unanticipated difficult intubation in acromegalic patients despite a lower percentage of patients being identified preoperatively as having a difficult airway. In this study, we carried out various airway assessment tests preoperatively and during induction of anesthesia to find out the predictors of easy tracheal intubation in patients with acromegaly.

Methods All patients of either sex, diagnosed as a case of acromegaly and scheduled to undergo pituitary surgery were enrolled over a period of 3 years. Various airway assessment tests were performed prior to surgery, which included modified Mallampati (MP) classification (sitting and supine), mouth opening (MO), upper lip bite test (ULBT), neck movement (NM), thyromental (TM) distance, thyrohyoid (TH) distance, sternomental (SM) distance, hyomental (HM) distance, length of upper incisors (IL), receding mandible (RM), any history of obstructive sleep apnea (OSA), mask ventilation (MV), Cormack-Lehane (CL) III and IV, and external laryngeal manipulation (ELM). Results were reported as odds ratios (95% confidence interval [CI]). The p-value < 0.05 was considered statistically significant.

Results A total of 42 patients were enrolled over a period of 3 years. The male-to-female ratio was 19:23 with a mean age of 37.95 years and mean weight of 72.7 kg. Out of 15 airway assessment parameters, only ULBT and CL grade showed significant results.

Conclusion We conclude that ULBT and CL grading are reliable predictors of easy intubation in patients with acromegaly undergoing surgery.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

A Prospective Randomized Trial Comparing Topical Intranasal Lidocaine and Levobupivacaine in Patients Undergoing Endoscopic Binostril Transnasal Transsphenoidal Resection of Pituitary Tumors

INTRODUCTION

Local anesthetic intranasal packing is used in transnasal surgery to reduce hemodynamic fluctuations. We hypothesized that the long acting local anesthetic levobupivacaine would provide superior hemodynamic stability and postoperative analgesia compared with lidocaine in endoscopic transnasal transsphenoidal (TNTS) surgery.

MATERIALS AND METHODS

In this prospective, randomized, double-blind trial, 48 patients undergoing TNTS surgery were allocated to the 2 groups to receive preoperative intranasal packing with 15 mL of 1.5% lidocaine or 0.5% levobupivacaine each mixed with 60 mg ephedrine. Heart rate and mean arterial blood pressure were recorded immediately before induction of anesthesia, at various time points throughout surgery, and at tracheal extubation. Bleeding in the surgical field, time to extubation, and postoperative pain were also assessed.

RESULTS

There was no significant difference in heart rate between the lidocaine and levobupivacaine groups at any point. Mean arterial pressure was also similar between the 2 groups during surgery, whereas at extubation blood pressure was lower in the lidocaine compared with levobupivacaine group (85±10 vs. 96±16 mm Hg; P=0.0010). There were no differences between the 2 groups in the other outcome variables.

CONCLUSIONS

Preoperative intranasal packing with 1.5% lidocaine or 0.5% levobupivacaine provide similar hemodynamic stability throughout TNTS. Lidocaine packing may be more advantageous for hemodynamic stability during extubation.

Pretreatment with somatostatin analogs does not affect the anesthesiologic management of patients with acromegaly

PURPOSE

Acromegaly may be associated with an increased risk of complex intraoperative management and anesthetic complications. No study addressed whether pretreatment with somatostatin receptor ligands (SRLs) affects anesthesiologic management.

METHODS

We studied 211 consecutive acromegalic patients who had a recorded intraoperative computerized anesthetic record (ICAR) available for analysis. Ninety-six (45.5%) patients were SRL-pretreated while 115 patients were treatment naïve.

RESULTS

Treatment with SRLs reduced mean basal growth hormone level from 23.8 ± 4.2 to 5.9 ± 1.3 µg/L. Normalization of insulin-like growth factor-1 was achieved in 26 patients (27.1%). The frequency of comorbidities at surgery was similar in the two groups. Five patients with difficult intubation were naïve (4.3%) as compared with 5 SRL-pretreated patients (5.2%; P = 1.0). ICAR registration did not show any significant change of intraoperative vital parameters in the two groups of patients as well as in the intraoperative utilization of drugs. Total duration of anesthesia and surgery were similar in the two groups. Four patients with an intraoperative adverse event were naïve (3.5%) as compared with 4 SRL-pretreated patients (4.2%; P = 1.00). Remission of disease occurred in 83 of 114 naïve patients (72.8%) and in 57 of 93 SRL-pretreated patients (61.3%; P = 0.11).

CONCLUSIONS

SRL-pretreatment of patients with acromegaly had no significant impact on intraoperative anesthesiologic management. Despite a better Cormack-Lehane score in SRL-pretreated than in naïve patients, the rate of difficult intubation was similar in both groups. SRL-pretreatment did not affect the rate of surgical remission or complications as well.

Dexmedetomidine in the Management of Awake Fiberoptic Intubation

Awake Fibreoptic Intubation (AFOI) is, nowadays, the gold standard in predicted difficult airway management. Numerous practice guidelines have been developed to assist clinicians facing with a difficult airway. If conducted without sedation, it is common that this procedure may lead to high patient discomfort and severe hemodynamic responses. Sedation is frequently used to make the process more tolerable to patients even if it is not always easy to strike a balance between patient comfort, safety, co-operation, and good intubating conditions. In the last years, many drugs and drug combinations have been described. This minireview aims to discuss the evidence supporting the use of Dexmedetomidine (DEX) in the AFOI management.

Airway physical examination tests for detection of difficult airway management in apparently normal adult patients

BACKGROUND

The unanticipated difficult airway is a potentially life-threatening event during anaesthesia or acute conditions. An unsuccessfully managed upper airway is associated with serious morbidity and mortality. Several bedside screening tests are used in clinical practice to identify those at high risk of difficult airway. Their accuracy and benefit however, remains unclear.

OBJECTIVES

The objective of this review was to characterize and compare the diagnostic accuracy of the Mallampati classification and other commonly used airway examination tests for assessing the physical status of the airway in adult patients with no apparent anatomical airway abnormalities. We performed this individually for each of the four descriptors of the difficult airway: difficult face mask ventilation, difficult laryngoscopy, difficult tracheal intubation, and failed intubation.

SEARCH METHODS

We searched major electronic databases including CENTRAL, MEDLINE, Embase, ISI Web of Science, CINAHL, as well as regional, subject specific, and dissertation and theses databases from inception to 16 December 2016, without language restrictions. In addition, we searched the Science Citation Index and checked the references of all the relevant studies. We also handsearched selected journals, conference proceedings, and relevant guidelines. We updated this search in March 2018, but we have not yet incorporated these results.

SELECTION CRITERIA

We considered full-text diagnostic test accuracy studies of any individual index test, or a combination of tests, against a reference standard. Participants were adults without obvious airway abnormalities, who were having laryngoscopy performed with a standard laryngoscope and the trachea intubated with a standard tracheal tube. Index tests included the Mallampati test, modified Mallampati test, Wilson risk score, thyromental distance, sternomental distance, mouth opening test, upper lip bite test, or any combination of these. The target condition was difficult airway, with one of the following reference standards: difficult face mask ventilation, difficult laryngoscopy, difficult tracheal intubation, and failed intubation.

DATA COLLECTION AND ANALYSIS

We performed screening and selection of the studies, data extraction and assessment of methodological quality (using QUADAS-2) independently and in duplicate. We designed a Microsoft Access database for data collection and used Review Manager 5 and R for data analysis. For each index test and each reference standard, we assessed sensitivity and specificity. We produced forest plots and summary receiver operating characteristic (ROC) plots to summarize the data. Where possible, we performed meta-analyses to calculate pooled estimates and compare test accuracy indirectly using bivariate models. We investigated heterogeneity and performed sensitivity analyses.

MAIN RESULTS

We included 133 (127 cohort type and 6 case-control) studies involving 844,206 participants. We evaluated a total of seven different prespecified index tests in the 133 studies, as well as 69 non-prespecified, and 32 combinations. For the prespecified index tests, we found six studies for the Mallampati test, 105 for the modified Mallampati test, six for the Wilson risk score, 52 for thyromental distance, 18 for sternomental distance, 34 for the mouth opening test, and 30 for the upper lip bite test. Difficult face mask ventilation was the reference standard in seven studies, difficult laryngoscopy in 92 studies, difficult tracheal intubation in 50 studies, and failed intubation in two studies. Across all studies, we judged the risk of bias to be variable for the different domains; we mostly observed low risk of bias for patient selection, flow and timing, and unclear risk of bias for reference standard and index test. Applicability concerns were generally low for all domains. For difficult laryngoscopy, the summary sensitivity ranged from 0.22 (95% confidence interval (CI) 0.13 to 0.33; mouth opening test) to 0.67 (95% CI 0.45 to 0.83; upper lip bite test) and the summary specificity ranged from 0.80 (95% CI 0.74 to 0.85; modified Mallampati test) to 0.95 (95% CI 0.88 to 0.98; Wilson risk score). The upper lip bite test for diagnosing difficult laryngoscopy provided the highest sensitivity compared to the other tests (P < 0.001). For difficult tracheal intubation, summary sensitivity ranged from 0.24 (95% CI 0.12 to 0.43; thyromental distance) to 0.51 (95% CI 0.40 to 0.61; modified Mallampati test) and the summary specificity ranged from 0.87 (95% CI 0.82 to 0.91; modified Mallampati test) to 0.93 (0.87 to 0.96; mouth opening test). The modified Mallampati test had the highest sensitivity for diagnosing difficult tracheal intubation compared to the other tests (P < 0.001). For difficult face mask ventilation, we could only estimate summary sensitivity (0.17, 95% CI 0.06 to 0.39) and specificity (0.90, 95% CI 0.81 to 0.95) for the modified Mallampati test.

AUTHORS' CONCLUSIONS

Bedside airway examination tests, for assessing the physical status of the airway in adults with no apparent anatomical airway abnormalities, are designed as screening tests. Screening tests are expected to have high sensitivities. We found that all investigated index tests had relatively low sensitivities with high variability. In contrast, specificities were consistently and markedly higher than sensitivities across all tests. The standard bedside airway examination tests should be interpreted with caution, as they do not appear to be good screening tests. Among the tests we examined, the upper lip bite test showed the most favourable diagnostic test accuracy properties. Given the paucity of available data, future research is needed to develop tests with high sensitivities to make them useful, and to consider their use for screening difficult face mask ventilation and failed intubation. The 27 studies in 'Studies awaiting classification' may alter the conclusions of the review, once we have assessed them.

Evaluation of the pharyngeal airway using computational fluid dynamics in patients with acromegaly

Objectives

Perioperative airway management may be particularly challenging in patients with acromegaly undergoing trans‐sphenoidal pituitary surgery (TSS). Management for airway obstruction is required prior to pituitary surgery to minimize perioperative hypoxia. The purpose of this retrospective study was to evaluate airway obstruction by simulation of computational fluid dynamics (CFD) using computed tomography (CT) images in patients who had undergone TSS.

Methods

CT images of the nasopharyngeal airways of patients with acromegaly (n = 5) or nonfunctional pituitary adenoma (n = 6) undergoing TSS from April 2012 to January 2017 were used to construct these airways in three dimensions. Estimated airflow pressure and velocity in the retropalatal airway (RA), oropharyngeal airway (OA), and hypopharyngeal airway (HA) were simulated using CFD.

Results

Estimated pharyngeal airflow pressure in the HA, OA, and RA was significantly greater in patients with acromegaly than in those with nonfunctional pituitary adenomas whereas the estimated pharyngeal airflow velocity was significantly impaired only in the RA of patients with acromegaly. Minimum postoperative SpO₂ both within 3 hours and from 3 to 12 hours after the end of anesthesia was significantly lower in the patients with acromegaly. Additionally, estimated volume of tongue and pharyngeal airflow pressure in the HA, OA, and RA correlated with minimum postoperative SpO₂.

Conclusion

Pharyngeal airflow pressure estimated from CT images is high in patients with acromegaly, and these values correlate with postoperative minimum values for SpO₂. Preoperative evaluation of CT images by CFD can predict difficulty in airway management and perioperative hypoxia.

Level of Evidence

4.

High levels of IGF-1 predict difficult intubation of patients with acromegaly

PURPOSE

To investigate the characteristics of difficult intubation and identify novel efficient predictors in patients with acromegaly.

METHODS

Patients with either untreated acromegaly or non-functional pituitary adenomas were enrolled. Patients with acromegaly underwent hormone assays, upper airway computed tomography and magnetic resonance imaging examinations and preoperative overnight polysomnography. The modified Mallampati classification, mouth opening, neck circumference, and neck extension were assessed, and the Cormack-Lehane grades and the time of tracheal intubation were recorded.

RESULTS

Patients with acromegaly had a higher incidence of difficult intubation (62.5%). The time of tracheal intubation was prolonged, the neck circumference was enlarged, and the neck extension was confined. In patients with acromegaly and difficult intubation, the insulin-like growth factor 1 levels and apnea/hypoxia index were significantly higher compared to patients without difficult intubation (1115.40 ± 253.73 vs. 791.67 ± 206.62 ng/ml, P = 0.020; 22.17 ± 23.25 vs. 2.47 ± 2.84, P = 0.026, respectively). The bilateral regression analysis revealed that high levels of insulin-like growth factor 1 were an independent risk factor for developing difficult intubation (p = 0.042, Exp B = 1.006). The modified Mallampati classification was positively correlated with apnea/hypoxia index and could be calculated using the following logarithmic equation: MMC = 0.2982 * ln (AHI) + 2.1836.

CONCLUSIONS

In patients with acromegaly, neck movement is confined, the time of tracheal intubation is prolonged, and the neck circumference is enlarged, and these patients suffer from an increased incidence of difficult intubation (62.5%) during anesthesia induction. The apnea/hypoxia index and insulin-like growth factor 1 levels are both increased in acromegalic patients with difficult intubation, and elevated insulin-like growth factor 1 levels are an independent risk factor of difficult intubation in acromegalic patients.

Acromegaly discovered during a routine out-patient surgical procedure: a case report

Background

Acromegaly is a rare syndrome in which there is unregulated hypersecretion of growth hormone. The anesthetic management of patients with this disorder is particularly challenging due to pre-existing cardiovascular and respiratory dysfunction, as well as recognized difficulties with airway management. Because of the insidious progression of the disease and the presence of nonspecific signs and symptoms, diagnosis is often made late when characteristic acromegalic features become apparent.

Case presentation

We report the management of a 35-year-old African American man with previously undiagnosed acromegaly, who underwent a general anesthetic for same day surgery. Subtle physical features and difficult endotracheal intubation raised our suspicion for the diagnosis of acromegaly. Following an uncomplicated postoperative course he underwent workup for the disease, which was confirmed. In addition, brain magnetic resonance imaging showed a pituitary adenoma. A subsequent transsphenoidal hypophysectomy was performed successfully.

Conclusions

This case underscores the notable absence of recognizing the clinical presentation of acromegaly in this patient by his primary care physician, and the value of thorough history taking, vigilance, and observation in making a new diagnosis that has the potential to alter a patient’s health care and mitigate impending morbidity and/or mortality.

Principles of Pituitary Surgery

Since the description of a transnasal approach for treatment of pituitary tumors, transsphenoidal surgery has undergone continuous development. Hirsch developed a lateral endonasal approach before simplifying it to a transseptal approach. Cushing approached pituitary tumors using a transsphenoidal approach but transitioned to the transcranial route. Transsphenoidal surgery was not "rediscovered" until Hardy introduced the surgical microscope. An endoscopic transsphenoidal approach for pituitary tumors has been reported and further advanced. We describe the principles of pituitary surgery including the key elements of surgical decision making and discuss the technical nuances distinguishing the endoscopic from the microscopic approach.

Effects of airway evaluation parameters on the laryngeal view grade in mandibular prognathism and retrognathism patients

BACKGROUND

Failure to maintain a patent airway can result in brain damage or death. In patients with mandibular prognathism or retrognathism, intubation is generally thought to be difficult. We determined the degree of difficulty of airway management in patients with mandibular deformity using anatomic criteria to define and grade difficulty of endotracheal intubation with direct laryngoscopy.

METHODS

Measurements were performed on 133 patients with prognathism and 33 with retrognathism scheduled for corrective esthetic surgery. A case study was performed on 89 patients with a normal mandible as the control group. In all patients, mouth opening distance (MOD), mandibular depth (MD), mandibular length (ML), mouth opening angle (MOA), neck extension angle (EXT), neck flexion angle (FLX), thyromental distance (TMD), inter-notch distance (IND), thyromental area (TMA), Mallampati grade, and Cormack and Lehane grade were measured.

RESULTS

Cormack and Lehane grade I was observed in 84.2%, grade II in 15.0%, and grade III in 0.8% of mandibular prognathism cases; among retrognathism cases, 45.4% were grade I, 27.3% grade II, and 27.3% grade III; among controls, 65.2% were grade I, 26.9% were grade II, and 7.9% were grade III. MOD, MOA, ML, TMD, and TMA were greater in the prognathism group than in the control and retrognathism groups (P < 0.05). The measurements of ML were shorter in retrognathism than in the control and prognathism groups (P < 0.05).

CONCLUSIONS

Laryngoscopic intubation was easier in patients with prognathism than in those with normal mandibles. However, in retrognathism, the laryngeal view grade was poor and the ML was an important factor.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY DISEASE STATE CLINICAL REVIEW: MANAGEMENT OF ACROMEGALY PATIENTS: WHAT IS THE ROLE OF PRE-OPERATIVE MEDICAL THERAPY?

OBJECTIVE

Acromegaly is a complex disease characterized by growth hormone (GH) excess originating in most cases from a pituitary tumor. The goals of treatment include removing the tumor or reducing tumor burden, normalizing GH secretion and insulin-like growth factor 1 levels, and preserving normal pituitary function if possible. Surgery by an experienced neurosurgeon is still considered first-line therapy, especially in cases with small tumors. In the last few decades, significant progress in the development of selective pharmacologic agents has greatly facilitated the management of active acromegaly, with agents such as somatostatin-receptor ligands (SRLs), GH-receptor antagonists, and dopamine agonists. In addition to adjuvant treatment, pre-operative medical therapy and primary therapy in de novo patients are increasingly employed.

METHODS

A United States National Library of Medicine PubMed search (through July 2014) was conducted for the following terms: acromegaly, pre-operative medical therapy, somatostatin-receptor ligands, and somatostatin analogs. Articles not in English and those not in peer-reviewed journals were excluded. In reviewing pertinent articles, focus was placed on biochemical and other postoperative outcomes of medical therapy.

RESULTS

An analysis of the full effect of pre-operative use of SRLs on surgical outcomes (remission rates and peri-operative complications) is limited by heterogeneity of methodology, low overall surgical cure rates, and different study designs. The assumption that SRL use prior to surgery reduces peri-operative surgical risk has yet to be proven. A variable degree of tumor shrinkage with preoperative SRLs is observed. Likewise, SRL treatment 3 months before surgery may improve surgical remission rates in the short term; however, positive results do not persist in the long term.

CONCLUSION

We consider that medical therapy before surgery could play a role in carefully selected patients, but treatment should be individualized. Primary medical therapy with a SRL may be considered in patients with macroadenomas without local mass effects on the optic chiasm, as SRLs have been shown to reduce tumor size and control GH hypersecretion. However, the data are insufficient to support general use of a SRL prior to surgery in order to improve post-surgery biochemical outcomes. Theoretically, patients with severe cardiac and respiratory complications due to acromegaly could potentially benefit from pre-operative SRLs in order to reduce peri-operative morbidity. Further investigation and investment in large randomized long-term clinical trials are needed to define the precise role and duration of pre-surgical medical treatment in acromegaly patients.

Pros and cons in endocrine practice: pre-surgical treatment with somatostatin analogues in acromegaly

The aim of this commentary is to balance the pros and cons for pre-surgical SSA treatment in a modern perspective ending up with a pragmatic recommendation for treatment based on the current evidence and expertise of the authors. Even though prospective and randomized studies in this particular area are hampered by obvious limitations, the interpretation of the four published trials has in general been in favor of pre-treatment with SSA, showing a better outcome following surgery. However, major drawbacks of these studies, such as non-optimal diagnostic criteria for cure, potential selection bias, and timing of the postoperative evaluation in SSA pre-treated patients, limit their overall interpretation. Three matched-controlled studies showed remarkably similar results with no apparent beneficial effect of SSA pre-treatment on surgical outcome. Both prospective, randomized studies and retrospective studies did not find any significant difference in the rate of endocrine and non-endocrine complications related to surgery, despite the beneficial clinical effects of SSA treatment in most acromegalic patients. The newly diagnosed patient with acromegaly should be carefully evaluated in the trans-disciplinary neuroendocrine team and treatment individualized accordingly. The issue of SSA pre-treatment to improve surgical outcome is yet to be settled and further methodologically sound studies are probably necessary to clarify this point.

Assessment before airway management

It is wise to plan and prepare for the unexpected difficult airway. Although it is essential to take a history and examine every patient prior to airway management, preoperative anticipation of a difficult airway occurs in only 50% of patients subsequently found to have a difficult airway. Bedside screening tests lack accuracy. The modified Mallampati test and the measurement of thyromental distance are unreliable for prediction of difficult tracheal intubation. Knowledge of risk factors for various airway management techniques may help when devising an airway management plan.

Neurosurgical Treatment of Acromegaly

Surgical removal of as much tumor mass as possible is usually considered the first step of treatment in acromegaly, unless the patients are unfit for surgery or refuse an operation. To date, in almost all cases, minimally invasive, transsphenoidal microscopic or endoscopic approaches are used. Whether a curative approach is feasible or a debulking procedure is planned, can be anticipated on the basis of preoperative magnetic resonance imaging. It mostly depends on localization, size, and the invasive character of the lesion. The surgical results depend on tumor-related factors such as size, extension, the presence or absence of invasion, and the magnitude of IGF-1 and growth hormone oversecretion, respectively. However, even surgeon-related factors such as experience and case load of the centers have been shown to strongly affect surgical results and complication rates. A reoperation can be considered at various stages in the treatment algorithm. There are several new technical gadgets which might aid in the surgical procedure: navigation, the Doppler probe, and variants of intraoperative imaging.

Successful pregnancy and delivery in a patient with Carney complex: implications for anesthesiologists

Carney complex is an autosomal dominant condition with widespread manifestations, including cardiac myxomas, nerve sheath tumors, and endocrinopathies. Although often associated with infertility, there are several reports of successful pregnancies in patients with Carney complex. However, none of the previous reports describe anesthetic considerations. Herein, we present a patient with Carney complex who successfully delivered vaginally with labor epidural analgesia.

Endocrinopathies: The current and changing perspectives in anesthesia practice

The gateways to advancements in medical fields have always been accessed through the coalition between various specialties. It is almost impossible for any specialty to make rapid strides of its own. However, the understanding of deeper perspectives of each specialty or super specialty is essential to take initiatives for the progress of the other specialty. Endocrinology and anesthesiology are two such examples which have made rapid progress in the last three decades. Somehow the interaction and relationship among these medical streams have been only scarcely studied. Diabetes and thyroid pathophysiologies have been the most researched endocrine disorders so far in anesthesia practice but even their management strategies have undergone significant metamorphosis over the last three decades. As such, anesthesia practice has been influenced vastly by these advancements in endocrinology. However, a comprehensive understanding of the relationship between these two partially related specialties is considered to be an essential cornerstone for further progress in anesthesia and surgical sciences. The current review is an attempt to imbibe the current and the changing perspectives so as to make the understanding of the relationship between these two medical streams a little simple and clearer.

Preoperative somatostatin analogs treatment in acromegalic patients with macroadenomas. A meta-analysis

BACKGROUND

Several studies have investigated the biochemical remission rate of presurgical somatostatin analogs treatment on acromegaly, but the remission criteria were diversed and the results were contradicting.

OBJECTIVE

Aim of this paper is to provide enhanced evidence for the effectiveness of preoperative SSA treatment to improve on surgical results of macroadenomas in acromegaly.

DATA SOURCE

Literature is cited from the PubMed, Embase and Cochrane Library, dating from December, 1985 to August, 2013.

STUDY ELIGIBILITY CRITERIA

Eligibility criteria included patients with acromegaly caused by GH-secreting pituitary macroadenomas, patients pretreated with somatostatin analogs versus direct surgery and a stricter remission criteria defined as the GH nadir<1μg/l during an oral glucose tolerance test (OGTT) and the age- and sex- adjusted IGF-1 concentration was normal. Primary end points included Short term and long term postoperative biochemical remission.

STUDY APPRAISAL AND SYNTHESIS METHODS

A total of 1421 publications were found by the electronic search. After full-text review, 8 were included in our study. 7 of them focus on the postoperative remission in short term; 3 of them focus on the outcomes in long term. For the analysis of the postoperative biochemical remission, a random effect model was used to account for differences.

RESULTS

The meta analysis shows that patients in the SSA pretreatment groups have had a more significantly cure rate than those in the direct surgery groups (RR=1.72, 95%CI: 1.14-2.60, P=0.009) with a short term follow-up. Subgroup analysis proves benefit from lanreotide pretreated groups (RR=2.27, 95%CI: 1.34-3.84, P=0.002) but not octreotide pretreated groups (RR=1.51, 95%CI: 0.82-2.75, P=0.183). No significant differences appeared between the two groups (RR=1.03, 95%CI: 0.86-1.24, P=0.751) with a long term follow-up.

LIMITATIONS

2 Retrospective trial was included and most of the trials included was designed as single-center study.

CONCLUSIONS

Based on the analysis of this paper, the preoperative SSA treatment was beneficial in the group with short-term follow-up, while it was not advantageous in the group with long-term follow-up. For the limitations in this study, to drawn more solid conclusions, further large, randomized, multi-center, and long-term follow-up trials were required.

Anaesthesiological and intensive care management in craniovertebral junction surgery

The main factors of modern perioperative care of the craniovertebral junction surgery include a comprehensive approach to the patients, including a thorough cardiorespiratory, neurophysiological, and metabolic assessment, intraoperative monitoring of spinal cord function, safe airway management, and judicious use of fluids and blood transfusions. Admission in PICU shortly after the CVJ surgery is mandatory to ensure haemodynamic and respiratory stability and to recognize postoperative complications. Anticipating complications in order to achieve an early treatment and adverse event prophylaxis can contribute to reduced morbidity and mortality and increased patients' safety. Multidisciplinary management of perioperative patient care and careful pain control is mandatory in order to improve the outcomes.

The difficult airway with recommendations for management--part 1--difficult tracheal intubation encountered in an unconscious/induced patient

Background

Previously active in the mid-1990s, the Canadian Airway Focus Group (CAFG) studied the unanticipated difficult airway and made recommendations on management in a 1998 publication. The CAFG has since reconvened to examine more recent scientific literature on airway management. The Focus Group’s mandate for this article was to arrive at updated practice recommendations for management of the unconscious/induced patient in whom difficult or failed tracheal intubation is encountered.

Methods

Nineteen clinicians with backgrounds in anesthesia, emergency medicine, and intensive care joined this iteration of the CAFG. Each member was assigned topics and conducted reviews of Medline, EMBASE, and Cochrane databases. Results were presented and discussed during multiple teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made together with assigned levels of evidence modelled after previously published criteria.

Conclusions

The clinician must be aware of the potential for harm to the patient that can occur with multiple attempts at tracheal intubation. This likelihood can be minimized by moving early from an unsuccessful primary intubation technique to an alternative “Plan B” technique if oxygenation by face mask or ventilation using a supraglottic device is non-problematic. Irrespective of the technique(s) used, failure to achieve successful tracheal intubation in a maximum of three attempts defines failed tracheal intubation and signals the need to engage an exit strategy. Failure to oxygenate by face mask or supraglottic device ventilation occurring in conjunction with failed tracheal intubation defines a failed oxygenation, “cannot intubate, cannot oxygenate” situation. Cricothyrotomy must then be undertaken without delay, although if not already tried, an expedited and concurrent attempt can be made to place a supraglottic device.

Airway management and perioperative concerns in acromegaly patients undergoing endoscopic transsphenoidal surgery for pituitary tumors

OBJECTIVES

Patients with acromegaly present unique challenges to cranial base surgery and anesthesia teams in the perioperative period, especially with regard to airway management. Abnormal airway anatomy may result from soft tissue hypertrophy and bony alterations. Additional perioperative challenges relate to the management of medical comorbidities. We aim to review perioperative airway concerns in acromegalic patients for the skull base surgeon in order to reduce preventable perioperative complications.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary care academic institution.

SUBJECTS

Thirty-two acromegaly patients undergoing endoscopic transsphenoidal pituitary surgery.

RESULTS

Videoscopic direct laryngoscopy intubation was required in 7 of 32 patients (21.9%) and fiberoptic intubation in 4 of 32 patients (12.5%). Overall failure rate for first intubation technique used was 12.5% (4/32). Cardiovascular comorbidities (hypertension and conduction abnormalities predominated) were present in 16 of 32 patients (50%), and obstructive sleep apnea, or other respiratory conditions, existed in 12 of 32 patients (37.5%).

CONCLUSIONS

Acromegaly patients present a particular challenge to the endoscopic skull base surgeon. Despite preoperative anesthesia and otolaryngology evaluation, many of these patients will experience an unanticipated airway challenge during intubation. Preoperative preparation and perioperative awareness of anatomic and physiologic abnormalities of acromegalic patients is essential for successful endoscopic surgery in this unique population.

Predicting difficult laryngoscopy in acromegalic patients undergoing surgery for excision of pituitary tumors: A comparison of extended Mallampati score with modified Mallampati classification

Background:

There are numerous reports of difficult laryngoscopy and intubation in patients with acromegaly. To date, no study has assessed the application of extended Mallampati score (EMS) for predicting difficult intubation in acromegalics. The primary aim of this study was to compare EMS with modified Mallampati classification (MMP) in predicting difficult laryngoscopy in acromegalic patients. We hypothesized that since EMS has been reported to be more specific and better predictor than MMP, it may be superior to the MMP to predict difficult laryngoscopy in acromegalic patients.

Materials and Methods:

For this prospective cohort study with matched controls, acromegalic patients scheduled to undergo pituitary surgery over a period of 3 years (January 2008-December 2010) were enrolled. Preoperative airway assessment was performed by experienced anesthesiologists and involved a MMP and the EMS. Under anesthesia, laryngoscopic view was assessed using Cormack-Lehane (CL) grading. MMP and CL grades of I and II were defined “easy” and III and IV as “difficult”. EMS grade of I and II were defined “easy” and III as “difficult”. Data were used to determine the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MMP and EMS in predicting difficult laryngoscopy.

Results:

Seventy eight patients participated in the study (39 patients in each group). Both MMP and EMS failed to detect difficult laryngoscopy in seven patients. Only one laryngoscopy was predicted to be difficult by both tests which was in fact, difficult.

Conclusion:

We found that addition of neck extension did not improve the predictive value of MMP.

Anesthesia in a 12 year old boy with somatic overgrowth secondary to pericentric inversion of chromosome 12

The management of a splenectomy in a boy with an unusual form of somatic overgrowth is presented. Except for a moderately difficult airway, no unusual reactions to anesthesia and surgery were encountered. Possible anesthetic implications of different somatic overgrowth syndromes in children are presented.

Difficult airway and difficult intubation in postintubation tracheal stenosis: a case report and literature review

Management of a “difficult airway” remains one of the most relevant and challenging tasks for anesthesiologists and pulmonary physicians. Several conditions, such as inflammation, trauma, tumor, and immunologic and metabolic diseases, are considered responsible for the difficult intubation of a critically ill patient. In this case report we present the case of a 46-year-old male with postintubation tracheal stenosis. We will focus on the method of intubation used, since the patient had a “difficult airway” and had to be intubated immediately because he was in a life-threatening situation. Although technology is of utter importance, clinical examination and history-taking remain invaluable for the appropriate evaluation of the critically ill patient in everyday medical life. Every physician who will be required to perform intubation has to be familiar with the evaluation of the difficult airway and, in the event of the unanticipated difficult airway, to be able to use a wide variety of tools and techniques to avoid complications and fatality.

Airway management in neuroanesthesiology

Airway management for neuroanesthesiology brings together some key principles that are shared throughout neuroanesthesiology. This article appropriately targets the cervical spine with associated injury and the challenges surrounding airway management. The primary focus of this article is on the unique airway management obstacles encountered with cervical spine injury or cervical spine surgery, and unique considerations regarding functional neurosurgery are addressed. Furthermore, topics related to difficult airway management for those with rheumatoid arthritis or pituitary surgery are reviewed.

Poor prognostic value of the modified Mallampati score: a meta-analysis involving 177 088 patients

The modified Mallampati score is used to predict difficult tracheal intubation. We have conducted a meta-analysis of published studies to evaluate the Mallampati score as a prognostic test. A total of 55 studies involving 177 088 patients were included after comprehensive electronic and manual searches. The pooled estimates from the meta-analyses were calculated based on a random-effects model and a summary receiver operating curve. Meta-regression analyses were performed to explore sources of possible heterogeneity between the studies. The summary receiver operating curve demonstrated an area under the curve of 0.75. The pooled odds ratio for a difficult intubation with a modified Mallampati score of III or IV was 5.89 [95% confidence interval (CI), 4.74-7.32]. The pooled estimates of the specificity and sensitivity were 0.91 (CI, 0.91-0.91) and 0.35 (CI, 0.34-0.36), respectively. The pooled positive and negative likelihood ratios were 4.13 (CI, 3.60-4.66) and 0.70 (CI, 0.65-0.75), respectively. The meta-analyses had statistical and clinical heterogeneity ranging from 87.2% to 99.4%. Meta-regression analyses did not identify any significant explanation of the heterogeneity. We conclude that the prognostic value of the modified Mallampati score was worse than that estimated by previous meta-analyses. Our assessment shows that the modified Mallampati score is inadequate as a stand-alone test of a difficult laryngoscopy or tracheal intubation, but it may well be a part of a multivariate model for the prediction of a difficult tracheal intubation.