Maternal Mortality - Anesthesia Resources

This chapter concerning maternal mortality due to anaesthesia, reprinted with permission from Saving Mothers' Lives, is the 18th in a series of reports within the Confidential Enquiries into Maternal and Child Health (CEMACH) in the UK. In the years 2003-05 there were six women who died from problems directly related to anaesthesia, which is the same as the 2000-02 triennium. Obesity was a factor in four of these women who died. Two of these deaths were in women in early pregnancy, who received general anaesthesia for gynaecological surgery by inexperienced anaesthetists who failed to manage the airway and ventilation adequately. When trainee anaesthetists are relatively inexperienced their consultants must know the limits of their competence and when close supervision and help may be needed. One death was due to bupivacaine toxicity due to a drug administration error when a bag of dilute local anaesthetic was thought to be intravenous fluid. In a further 31 cases poor perioperative management may have contributed to death. Obesity was again a relevant factor. Other cases could be categorized into poor recognition of women being sick and poor clinical management of haemorrhage, sepsis and of pre-eclampsia. Early warning scores of vital signs may help identify the mother who is seriously ill. Learning points are highlighted in relation to the clinical management of these obstetric complications.

The maternal mortality rate in the United States has stagnated for the past 2 decades. To further lower morbidity and mortality, we must take a broader perspective. When a pregnant woman is treated in a nonobstetric part of the hospital, care must adapt quickly to her special needs. Excessive concern as to medication, radiation, and litigation may render her care neither safe, timely, efficient, effective, nor patient-centered. Anesthesiologists can significantly improve the care of the pregnant patient by applying their uniquely broad-based skills, experience, and knowledge outside the labor unit.

Major obstetric hemorrhage remains the leading cause of maternal mortality and morbidity worldwide, and is associated with a high rate of substandard care. A well-defined and multidisciplinary approach that aims to act quickly and avoid omissions or conflicting strategies is key. The most common etiologies of hemorrhage are abruptio placenta, placenta previa/accreta, uterine rupture in the antepartum period and retained placenta, uterine atony, and genital-tract trauma in the postpartum period. Basic treatment of postpartum hemorrhage relies on manual removal of the placenta or manual exploration of the uterus plus bladder emptying and oxytocin administration. If this does not arrest bleeding, or if there is any suspicion of genital-tract trauma, examination of the vagina and cervix with appropriate valves and analgesia/anesthesia must follow quickly. Postpartum uterine atony resistant to oxytocin must be treated with prostaglandin within 15 to 30 minutes; uterine balloon tamponade can be also useful at this stage. Aggressive transfusion therapy and resuscitation are mandatory in major obstetric hemorrhage. Specific invasive treatment must be considered within no more than 30 to 60 minutes, if previous measures have failed-and even earlier in some particular etiologies. The two main options are radiologic embolization and surgical artery ligations. Recombinant factor VIIa may also be considered, but should not delay the performance of a life-saving procedure such as embolization or surgery. Hysterectomy must be implemented when all other interventions have failed.

BACKGROUND: Maternal Mortality Surveillance has been conducted by the State of Michigan since 1950, and anesthesia-related maternal deaths were most recently reviewed for the years 1972-1984.
METHODS: Records for pregnancy-associated deaths between 1985 and 2003 were reviewed to identify 25 cases associated with a perioperative arrest or major anesthetic complication. Four obstetric anesthesiologists independently classified these cases, and disagreements were resolved by discussion. Precise definitions of anesthesia-related and anesthesia-contributing maternal death were constructed. Anesthesia-related deaths were reviewed to identify the chain of medical errors or care management problems that contributed to each patient death.
RESULTS: Of 855 pregnancy-associated deaths, 8 were anesthesia-related and 7 were anesthesia-contributing. There were no deaths during induction of general anesthesia. Five resulted from hypoventilation or airway obstruction during emergence, extubation, or recovery. Lapses in either postoperative monitoring or anesthesiology supervision seemed to contribute to 5 of the 8 anesthesia-related deaths. Other characteristics common to these cases included obesity (n=6) and African-American race (n=6).
CONCLUSIONS: The 8 anesthesia-related and seven anesthesia-contributing maternal deaths in Michigan between 1985 and 2003 illustrate three key points. First, all anesthesia-related deaths from airway obstruction or hypoventilation took place during emergence and recovery, not during the induction of general anesthesia. Second, system errors played a role in the majority of cases. Of concern, lapses in postoperative monitoring and inadequate supervision by an anesthesiologist seemed to contribute to more than half of the deaths. Finally, this report confirms previous work that obesity and African-American race are important risk factors for anesthesia-related maternal mortality.

PURPOSE OF REVIEW: Although there have been few recent publications about obstetric deaths due to anaesthesia, it is timely to review their occurrence and put them into context. Health services are under constant review and a recent Department of Health publication highlights the need for safer care. Changes, including those related to training and permitted hours of work, may impact on safety. Without knowing where we are now, we cannot know whether these changes are an improvement or not.
RECENT FINDINGS: The UK Confidential Enquiry reports have tracked anaesthetic-related deaths since 1952. During the 1990 s, the numbers became almost irreducible: the last report gave six deaths caused by anaesthesia. This review puts these into a global perspective.
SUMMARY: Medical intervention undoubtedly saves many lives. Concerns about a possible increase in anaesthetic maternal mortality must be kept in perspective with the overall benefits. The growing complexity of problems such as maternal disease, obesity, and the increasing age of motherhood, nevertheless, increases the challenges presented. Multidisciplinary working is all-important.

As anaesthetic-related maternal mortality reduces in the developed world, alternative indicators of obstetric anaesthetic quality are required. Serious morbidity is difficult to define and quantify, but can be reduced by the provision of effective critical care. Regional anaesthesia, although safer than general anaesthesia, is not without risks. Evidence-based strategies exist to reduce the risks.