Airway problems and new solutions for the obstetric patient

Analysis of Airway Management for Cesarean Delivery: Use of Risk and Proportion Differences

OBJECTIVES

Securing the parturient airway is essential during general anesthesia for cesarean delivery. The purpose of this study was to compare inferior airway views provided by the use of three commonly available laryngoscopy blades-Macintosh, Miller, or Glidescope Mac-Style-to the incidence of difficult orotracheal intubation.

METHODS

Following institutional review board approval, data from 449 electronic medical records in parturients undergoing general anesthesia for cesarean delivery were extracted during a 6-year period. The association of these blades with difficult orotracheal intubation was analyzed with risk and proportion differences measures of effect size.

RESULTS

The overall incidence of difficult orotracheal intubation was 4.2% (95% confidence interval 2.7 - 6.5%), with 6 failed orotracheal intubations (5 laryngeal mask airways rescues and 1 mask rescue). Clinically important increases in risk differences for difficult orotracheal intubation were observed in parturients with restricted mouth openings, modified Mallampati III and IV views, and reduced thyromental distances. When modified Cormack-Lehane views were grouped into III and IV versus I and II cohorts; proportion differences for difficult orotracheal intubation were dependent upon the type of blade used, with the Miller blade providing the lowest proportion difference.

CONCLUSIONS

Miller blade laryngoscopy provided the lowest proportion difference for difficult orotracheal intubation during general anesthesia for cesarean delivery. Miller blade laryngoscopy provides effective procurement of the parturient airway.

Airway Management Equipment in a Metropolitan Region: An Audit

Difficult airway equipment containers are commonly found in operating rooms, but the availability of airway equipment beyond that environment is unknown. Using the Difficult Airway Society (U.K.) and American Society of Anesthesiologists’ guidelines, we conducted an inspection audit of airway equipment at all anaesthetic sites in our region. Staff knowledge about the equipment was assessed and feedback was provided to each site.

Eighteen of the 42 sites had an airway container. Equipment for an unexpected difficult intubation, according to the guidelines, was deficient at all sites. Equipment to detect oesophageal intubation was inadequate. Locations remote from the operating suite lacked emergency invasive airway equipment and were, on average, a 4.3 minute walk from the nearest appropriate equipment. Two clinics had no emergency invasive airway equipment. Half of the airway containers with check lists had items missing. One third of the items with an expiry date were expired. Quality control and implementation of airway guidelines could rectify these deficiencies. Anaesthesia organisations should be encouraged to publish detailed equipment guidelines.

Management of anaesthesia for elective, low-risk (Category 4) caesarean section

An increasing number of caesarean sections are being performed for both elective as well as emergency cases. Category 4 caesarean section refers to a planned elective surgery after 39 weeks of gestation at a time suitable to the mother and the maternity team. For a safe conduct of anaesthesia, the updated obstetric anaesthesia guidelines recommend administration of neuraxial anaesthesia, whenever feasible. The management should include adequate postoperative pain relief, early ambulation, and thromboprophylaxis to ensure early recovery. This review will discuss the anaesthetic management including regional anaesthesia, general anaesthesia, and postoperative analgesia for elective, low-risk (Category 4) caesarean section.

Burns During Pregnancy: Implications for Maternal-Perinatal Providers and Guidelines for Practice

IMPORTANCE

When a major burn is suffered during pregnancy, the obstetric provider is challenged to respond on an evidence basis because personal experience usually is lacking. Currently, there is a paucity of publications to inform the obstetrician, guide practice, and impact early critical decision making.

OBJECTIVE

The aims of this study were to summarize the available information on early management of burns during pregnancy and to identify components of best practices for optimal outcome.

EVIDENCE ACQUISITION

The PubMed database was searched for relevant titles and abstracts involving pregnant patients suffering from second-/third-degree burns. Among these studies, the bibliographies were investigated for further relevant literature. A total of 114 studies were identified during the initial search, and only studies published in English and French were included for a total of 42. Variable data were available for 1141 patients, with complete data for 139 cases. Mediation and regression analysis were used for available data. Insufficient data were available to undertake a systematic review.

RESULTS

Total body surface area of burns (TBSAB) was positively associated with maternal death, and the odds of maternal mortality increase by 1.08 per percentage increase of TBSAB (P < 0.001). Fetal survival depends on maternal survival (P ≤ 0.001). Maternal survival declines incrementally when TBSAB exceeds 55%, and inhalation injury further exacerbates maternal-perinatal risk.

CONCLUSIONS

Emergent assessment of the pregnant burn victimincludes determination of gestational age, extent of TBSAB, presence of inhalation injury, and continuous fetal monitoring. If gestational age is 24 weeks or longer and TBSAB exceeds 55%, urgent cesarean delivery appears desirable for the mother and baby.

RELEVANCE

A specific analysis of maternal-perinatal outcome based on TBSAB and gestational age is relevant to obstetric and emergency providers who provide care to pregnant burn patients.

Multiple, Successful Pregnancies in Pompe Disease

Pompe disease is an autosomal recessive lysosomal storage disease characterized in adult patients by slowly progressive limb-girdle muscle weakness and respiratory insufficiency. Data on pregnancy in women with Pompe disease, intrauterine development of the fetus and parturition are rare. Here we describe a twin pregnancy followed by a second pregnancy in a 38-year-old female patient with Pompe disease. We report the impact of pregnancy on muscle and respiratory functions as well as the neurological and endocrine systems and discuss the medical consequences for anaesthetic management at parturition.

Pregnancy is associated with a decrease in pharyngeal but not tracheal or laryngeal cross-sectional area: a pilot study using the acoustic reflection method

BACKGROUND

The risk of difficult upper airway access is increased during pregnancy, especially in labor. Changes in upper airway calibre have been poorly studied during pregnancy. The acoustic reflection method is a non-invasive technique that allows a longitudinal assessment of the cross-sectional area of the upper airway from the mouth to carina. We used this technique to evaluate upper airway calibre during normal pregnancy.

METHODS

We conducted a prospective, single centre, observational study with a clinical and upper airway acoustic reflection method evaluation of healthy women during the first, second and third trimesters of pregnancy, and up to two days and one month after delivery.

RESULTS

Fifty women participated to the study. The mean pharyngeal cross-sectional area decreased between the first and third trimesters (P < 0.001) with no significant change of the minimal and mean tracheal cross-sectional areas. The Mallampati score increased during pregnancy between the first and third trimesters (P< 0.001).

CONCLUSION

Using measurements with the acoustic reflection method, normal pregnancy is associated with a significant reduction in the cross-sectional area of the pharynx and a concomitant increase in the Mallampati score. No change was observed in the minimal and mean tracheal cross-sectional areas.

Management and outcomes of trauma during pregnancy

Approximately 1% to 4% of pregnant women are evaluated in emergency/delivery room because of traumatic injury, yet there are few educational strategies targeted toward prevention/management of maternal trauma. Use of illicit drugs and alcohol, domestic abuse, and depression contribute to maternal trauma; thus a high index of suspicion should be maintained when treating injured young women. Treating the mother appropriately is beneficial for both the mother and the fetus. Fetal viability should be assessed after maternal stabilization. Pregnancy-related morbidity occurs in approximately 25% of cases and may include placental abruption, uterine rupture, preterm delivery, and the need for cesarean delivery.

The effect of laryngoscope handle size on possible endotracheal intubation success in university football, ice hockey, and soccer players

OBJECTIVE

To assess the effectiveness of a standard long-handle laryngoscope and a short-handle laryngoscope on ease of possible intubation in football, ice hockey, and soccer players.

DESIGN

Prospective crossover study.

SETTING

University Sport Medicine Clinic.

PARTICIPANTS

Sixty-two university varsity football (62 males), 45 ice hockey (26 males and 19 females), and 39 soccer players (20 males, 19 females).

INTERVENTIONS

Athletes were assessed for different airway and physical characteristics. Three different physicians then assessed the use of laryngoscopes of different handle sizes in supine athletes who were wearing protective equipment while in-line cervical spine immobilization was maintained.

MAIN OUTCOME MEASURES

The ease of passage of a laryngoscope blade into the posterior oropharynx of a supine athlete was assessed using both a standard long-handle and a short-handle laryngoscope.

RESULTS

Use of a short-handle laryngoscope was easier for all physicians in all sports as compared with a standard-sized laryngoscope. Passage of a laryngoscope blade into the posterior oropharynx of a supine athlete was easiest in soccer players and most difficult in football and ice hockey players for both sizes of laryngoscope. Interference from chest or shoulder pads was a common cause for difficulty in passing the laryngoscope blade into the posterior oropharynx for football and ice hockey players.

CONCLUSIONS

In the rare instances that an endotracheal intubation is to be attempted on an unconscious athlete, a short-handle laryngoscope may provide the best chance for successful intubation.

Severe glottic stenosis in a parturient with ectodermal dysplasia

Airway stenosis in pregnancy is challenging and the literature does not offer consensus regarding its evaluation and anesthetic management. A 21-year-old nulliparous woman with ectodermal dysplasia and severe glottic stenosis was referred to the obstetric anesthesia team for evaluation and peripartum management recommendations. She had a history of a congenital complete glottic web that required a tracheostomy at birth. After decannulation at age four, she was lost to follow-up. On examination in early pregnancy, she was found to have a dangerously narrow airway with fixed vocal cords and a glottic aperture of 2-3mm. At nine weeks of gestation an elective tracheostomy was performed under local anesthesia. She later underwent an uneventful cesarean delivery under spinal anesthesia. Ultimately, early interdisciplinary planning for an elective tracheostomy helped assure patient safety during advancing pregnancy and delivery.

Jet ventilation for the excision of vocal cord polyps in a pregnant patient

The anaesthetic management of patients presenting with laryngeal tumours and airway obstruction is difficult. We present the case of a pregnant woman at 30 weeks gestation who underwent surgical removal of two vocal cord polyps under general anaesthesia using jet ventilation

Difficult intubation in pregnancy

PURPOSE OF REVIEW

This review focuses on difficult intubation in pregnant patients, particularly during the late pregnancy when physiological, patho-physiological and psychological factors may cause or aggravate difficulties with providing sufficient oxygenation and securing the airway. It is intended to highlight the methodological approach to the difficult airway in this particular patient population and to draw relevant principles in dealing with this problem.

RECENT FINDINGS

There are strong indications for improvement in the outcome of airway management in pregnant patients; however, this is obscured by the growing frequency of caesarean sections and connected to this by more tracheal intubations. Various new airway devices have been suggested as alternative techniques for laryngoscopic intubation if the latter becomes difficult or failed.

SUMMARY

A scenario-oriented approach to the problem of difficult intubation in pregnant patients leads to the recognition of the unpredicted difficult or failed intubation as the main concern. The appropriate means to cope with this rare but life-threatening complication lies in a gradual employment of principles beginning with preferential application of regional anaesthesia techniques, followed by proceeding according to locally adapted simple and comprehensive failed intubation algorithms, design of a suitable difficult airway cart that contains only a few but well chosen items and by implementation of a continuous and mandatory training program to which all personnel are subjected to participate in regular intervals.

Equipment to manage a difficult airway during anaesthesia

Airway complications are a leading cause of morbidity and mortality in anaesthesia. Effective management of a difficult airway requires the timely availability of suitable airway equipment. The Australian and New Zealand College of Anaesthetists has recently developed guidelines for the minimum set of equipment needed for the effective management of an unexpected difficult airway (TG4 [2010] www.anzca.edu.au/resources/professionaldocuments). TG4 [2010] is based on expert consensus, underpinned by wide consultation and an extensive review of the available evidence, which is summarised in a Background Paper (TG4 BP [2010] www.anzca.edu.au/ resources/professional-documents). TG4 [2010] will be reviewed at the end of one year and thereafter every five years or more frequently if necessary. The current paper is reproduced directly from the Background Paper (TG4 BP [2010]).

Direct laryngoscopy and endotracheal intubation in the prone position following traumatic thoracic spine injury

Perioperative airway management in trauma victims presenting with penetrating thoracic spine injury poses a major challenge to the anesthesiologist. To avoid further neurological impairment it is essential to ensure maximal cervical and thoracic spine stability at the time of airway manipulation (e.g., direct laryngoscopy and endotracheal intubation). Airway management in the prone position additionally increases the incidence of cervical/thoracic spine injury, difficult ventilation, and difficult airway instrumentation. Although awake fiberoptic intubation of the trachea is considered the gold standard for airway instrumentation in patients with posterior thoracic/cervical trauma, this technique requires the patient's cooperation, special equipment, and extensive training, all of which might be difficult to accomplish in emergency situations. We herein present the first reported case of an adult trauma patient who underwent direct laryngoscopy and endotracheal intubation under general anesthesia in the prone position. Although the prone position is not the standard position for airway instrumentation with direct laryngoscopy and endotracheal intubation under general anesthesia, our experience indicates that this technique is possible (and relatively easy to perform) and might be considered in an emergency situation.

Anesthesia in pregnant patients for nonobstetric surgery

Anesthesiologists in every subspecialty encounter, with varying regularity, patients presenting for surgery during the course of pregnancy. With the increasing sophistication of surgical and anesthetic techniques, increasingly complex surgeries are being undertaken. In this review, we address the fundamental physiologic principles central to the care of pregnant patients and fetuses in this difficult clinical situation.

Caring for pregnant and postnatal women in intensive care: what do we know?

Critically ill pregnant and postnatal women admitted to intensive care units (ICUs) require highly specialised care, components of which many critical care nurses are unfamiliar with. There are no specialist critical care obstetric centres in Australia, with critically ill obstetric patients admitted to general ICUs. There are no published guidelines and little research that assist critical care nurses to care for such women. Furthermore, the admission of pregnant or postnatal women to ICUs is likely to increase with emerging childbearing patterns in Australia. It is therefore timely to review what we know about caring for critically ill pregnant and postnatal women. This paper analyses the literature on intensive care utilisation by obstetric patients and provides an overview regarding which pregnant and postpartum women require intensive care. The key areas of providing mechanical ventilation to pregnant women and assessment of fetal wellbeing are explored in detail. The most frequent conditions and their treatment, preeclampsia and obstetric haemorrhage, are also reviewed. The establishment of lactation is also considered as the critical carenurse is commonly involved in supporting the woman's endeavour to breastfeed.

Safety culture and crisis resource management in airway management: general principles to enhance patient safety in critical airway situations

Airway management is a cornerstone of patient safety in anaesthesiology and in emergency and critical care medicine. Deficiencies in airway management could have catastrophic results for the patient. In anaesthesia patients, in particular, a high level of safety should be expected. It has been proven in other high-risk and complex industrial fields that obtaining very high levels of safety requires special strategies and safety philosophies in order to guarantee long-term low-risk production. The concept of safety culture has invaded many industries, more recently including medicine. Concepts of the high reliability organizations (HROs) are now ready to be adapted to medicine and offer promising improvements in health care. This paper applies some of the HRO principles to airway management and illustrates how to transform more general strategies to practical application in the clinical world. This includes the use of key elements of crisis resource management (CRM) and the development of a checklist for safety in airway management.

Anesthetic management for laser excision of recurrent respiratory papillomatosis in a third trimester parturient

Recurrent respiratory papillomatosis (RRP) is characterized by the development of laryngeal papillomas, which can produce partial to complete upper airway obstruction. Patients with RRP often require intermittent surgical excision to treat symptoms such as hoarseness and stridor, and to control progression of the lesions. The anesthetic management of such patients is challenging, and it requires carefully coordinated care between an anesthesiologist and otolaryngologist. We present 2 cases of general anesthesia administration during surgical excision of laryngeal papillomas, both occurring during the third trimester of separate pregnancies in the same parturient. The complexity of management was amplified in these cases because of the physiological and anatomical changes associated with pregnancy, along with the need to monitor fetal well-being. Possible complications included complete airway obstruction, pulmonary aspiration of gastric contents, hypoxemia, fetal distress, and preterm labor. Because pregnancy may lead to activation of human papillomavirus, the causative organism of RRP, management guidelines are provided for anesthesiologists who may care for patients with RRP during pregnancy.

Airway problems in pregnancy

OBJECTIVES

To provide a current review of the literature regarding airway problems in pregnancy and management.

BACKGROUND

Obstetrical anesthesia is considered to be a high-risk practice that exposes the anesthesiologist to increased medicolegal liability. Anesthetic management of a parturient is a challenge because it involves simultaneous care of both mother and baby. Failure to appropriately manage a difficult or failed intubation increases the risk of hypoxemic cardiopulmonary arrest and/or pulmonary aspiration, resulting in a high probability of maternal morbidity and mortality.

DATA

Anesthesia is the seventh leading cause of maternal mortality in the United States. Anatomic and physiologic changes during pregnancy place the parturient at increased risk for airway management problems. It is essential to perform a thorough preanesthetic evaluation and identify the factors predictive of difficult intubation. Airway devices such as the laryngeal mask airway, ProSeal, intubating laryngeal mask airway, Combitube, and laryngeal tube are described and have been used during failed intubation in pregnant patients.

CONCLUSION

Teamwork between an anesthesiologist and an obstetrician is absolutely essential for the safety of both the mother and baby. Most of us tend to agree that airway emergencies have a way of occurring at the worst possible times. It is essential that all anesthesia care practitioners must have a preconceived and well thought-out algorithm and emergency airway equipment to deal with airway emergencies during difficult or failed intubation of a parturient.

Cardiac arrest during pregnancy

This case involves cardiac arrest of a 29-week old pregnant African American woman, occurring 2 days after surgical correction of an incarcerated ventral hernia with small bowel obstruction. The patient could not be resuscitated from this arrest. Details of the case are presented, and diagnostic and unique management considerations for this uncommon occurrence are set forth.

What’s new and novel in obstetric anesthesia? Contributions from the 2003 scientific literature

THE PREGNANT PATIENT: Age; maternal disease; prophylactic antibiotics; gastroesophageal reflux; obesity; starvation; genotyping; coagulopathy; infection; substance abuse; altered drug responses in pregnancy; physiological changes of pregnancy. THE FETUS: Fetal monitoring; intrauterine surgery. THE NEWBORN: Breastfeeding; maternal infection, fever, and neonatal sepsis evaluation. OBSTETRIC COMPLICATIONS: Embolic phenomena; hemorrhage; preeclampsia; preterm delivery. OBSTETRIC MANAGEMENT: External cephalic version and cervical cerclage; elective cesarean delivery; fetal malpresentation; vaginal birth after cesarean delivery; termination of pregnancy. OBSTETRIC ANESTHESIA: Analgesia for labor and delivery; anesthesia for cesarean delivery; anesthesia for short obstetric operations; complications of anesthesia. MISCELLANEOUS: Consent; ethics; history; labor support; websites/books/leaflets/journal announcements.

Labor analgesia for the parturient with pregnancy-induced hypertension: what does an obstetrician need to know?

INTRODUCTION

Pregnancy-induced hypertension (PIH), also known as preeclampsia, remains one of the leading causes of maternal death worldwide. The term preeclampsia describes the development of hypertension with proteinuria and/or pathologic edema after the 20th week of gestation. The parturient with PIH usually has multiple organ alterations, which may affect the selection of analgesia and anesthesia for labor and delivery.

DISCUSSION

This article reviews the special concerns posed by PIH, one of the most common medical conditions encountered in pregnancy.

Labor analgesia for the parturient with respiratory disease: what does an obstetrician need to know?

BACKGROUND

Significant alterations occur in the pulmonary system during pregnancy, which primarily serve to meet the increased oxygen consumption by the growing fetus. When pregnancy is complicated by a respiratory tract disorder such as asthma, cystic fibrosis or tobacco-related respiratory complications the peripartum management (both obstetric and anesthetic) may become challenging.

TECHNIQUE

Regional anesthesia remains the technique of choice for these parturients because airway manipulation and endotracheal intubation are avoided.

CONCLUSION

When providing labor analgesia to parturients with asthma, cystic fibrosis, and tobacco-related respiratory disorders every effort should be made to reduce the likelihood of high (thoracic) levels of analgesia and/or anesthesia and subsequent airway compromise.

Algorithms for management of the difficult airway

PURPOSE OF REVIEW

The purpose of this review is to examine recent evidence for the management of the difficult airway.

RECENT FINDINGS

Recent findings still recommend the importance of a predefined, simple strategy for both the anticipated and unanticipated difficult airway. For the former, awake fiberoptic intubation is still the 'gold standard'. For management of the unanticipated difficult airway, the use of the laryngeal mask airway (LMA), intubating laryngeal mask airway (ILMA), the 'gum elastic bougie' and fiber-optics are recommended. If intubation and ventilation fails, cannula or surgical cricothyroidotomy should be an early consideration.

SUMMARY

This review of algorithms for management of the difficult airway strengthens several generally accepted crucial points. What is always needed is expertise, which one can only get and maintain by daily practice.

Airway problems in pregnancy

Obstetric anesthesia is considered to be a difficult, high-risk practice that exposes the anesthesiologist to increased medicolegal liability. Anesthetic management of parturient patients is a challenge, as it involves simultaneous care of two lives. The anesthesia practitioner has a duty to provide safe anesthetic care, including effective airway management when providing regional or general anesthesia. The potential need to manipulate the airway is perhaps the leading cause of concern among obstetric anesthesiologists.