- Email: [email protected]
Legal abortion mortality and general anesthesia
Alcalay et al.
We thank Ms. Alice Burnett for preparing the manuscript. REFERENCES 1. Holmes RC, Black MM. The specific dermatoses of pregnancy. JAm Acad Dermatol1983;8:405. 2. Ittrich G. Eine neue Methode zur chemischen Bestimmung der oestrogenen Hormone in Harn. Hoppe Seyler Z Physiol Chern 1958;312:1. 3. Lawley TJ, Hertz KC, Wade TR, et a!. Pruritic urticarial papules and plaques ofpregnancy.JAMA 1979;241:1696.
February 1988 Am J Obstet Gynecol
4. Yancey KB, Hall RP, Lawley TJ. Pruritic urticarial papules and plaques of pregnancy: clinical experience in twentyfive patients. JAm Acad Dermatol 1984;10:473. 5. Alcalay J, Ingber A, David M, Hazaz B, Sandbank M. Pruritic urticarial papules and plaques of pregnancy-a review of twenty one cases. J Reprod Med 1987;32:315. 6. Spangler AS, Reddy W, Bardawil WA, Roby CC, Emerson K. Papular dermatitis of pregnancy. A new clinical entity? JAMA 1962;181:577. 7. Spangler AS, Emerson K. Estrogen levels and estrogen therapy in papular dermatitis of pregnancy. AM J 0BSTET GYNECOL 1971;110:534.
Legal abortion mortality and general anesthesia Hani K. Atrash, MD, MPH, Theodore G. Cheek, MD, and Carol). R. Hogue, PhD, MPH Atlanta, Georgia, and Philadelphia, Pennsylvania Legal abortion-related mortality as reported to the Centers for Disease Control declined eightfold between 1972 and 1981. However, the causes of legal abortioo mortality have changed over time. We reviewed all legal abortion-related deaths that occurred between 1972 and 1985 in the United States. We found that, although the absolute number of legal abortion-related deaths caused by general anesthesia complications did not increase, the proportion of such deaths increased significantly, from 7.7% between 1972 and 1975 to 29.4% between 1980 and 1985. Women who died of general anesthesia complications did not differ by age, presence of preexisting medical conditions, or type of facility from women who died of other causes. However, the proportion of deaths from general anesthesia complications was significantly higher among women of black and other races, women obtaining abortions during the first trimester, and women obtaining abortions in the Northeast. Our results indicate that at least 23 of the 27 deaths were due to hypoventilation and/or loss of airway resulting in hypoxia. Persons administering general anesthesia for abortion must be skilled in airway management as well as the provision of general anesthesia. (AM J 0BSTET GYNECOL 1988;158:420-4.)
Key words: Abortion mortality, general anesthesia, maternal mortality Legal abortion-related mortality as reported to the Centers for Disease Control experienced an eightfold decline between 1972 and 1981, falling from 4.1 deaths per 100,000 abortions in 1972 to 0.5 deaths per 100,000 abortions in 1981. 1 The number of legal abortionrelated deaths also declined, from 24 in 1972 to seven in 1981. However, the New York City Department of Health recently reported seven legal abortion-related deaths that occurred between 1980 and 1985. The cause of death in all cases was attributed directly to general anesthesia. 2 Moreover, during our investigation of legal abortion-related deaths we have noted that an increasing proportion of these were anesthesia-related
From the Division of Reproductive Health, Center for Health Promotion and Education, Centers for Disease Control, and the Department of Anesthesia, University of Pennsylvania. Received for publication April20, 1987; revised August 11, 1987; accepted September 14, 1987. Reprints not available.
420
deaths, and that most deaths resulting from cardiopulmonary arrest associated with general anesthesia occurred in the recovery room. We reviewed all legal abortion-related deaths that occurred between 1972 and 1985 to determine the role of general anesthesia in legal abortion mortality and to identify factors that place women seeking abortion at higher risk of dying from general anesthesia complications. Methods
Legal abortion-related deaths were identified by the Centers for Disease Control's Nationwide Surveillance of Abortion Mortality initiated in 1972, details of which have been previously reported. 1 All reported cases were investigated by medical epidemiologists and the causes of death were determined based on data collected from death certificates, medical records and autopsy reports (when available). In our study, deaths were classified as related to general anesthesia (or caused by general an-
Volume 158 Number2
esthesia complications) and deaths from other causes. Deaths were considered to be caused by general anesthesia if they could be attributed to the administration of the anesthetic agent or to the agent itself, or if so determined by autopsy findings in the absence of other conditions that could have caused the death. General anesthesia-related cases were further reviewed by one of the authors (T. G. C.), an anesthesiologist, and, independently, by two other anesthesiologists to determine the underlying cause of death. Because denominator data are lacking (number of abortion procedures by type of anesthesia), we used proportional mortality ratios to compare the characteristics of women dying after general anesthesia complications with those dying of other causes; we calculated 95% confidence intervals around the ratio to determine statistical significance. 3 We then used the same procedure to compare the proportions of women dying of general anesthesia complications during different time intervals (1972 to 1975, 1976 to 1979, and 1980 to 1985), in different geographic regions (as defined by the U.S. Bureau of the Census), and at different types of facilities (hospitals and clinics).
Results The Centers for Disease Control's Pregnancy Epidemiology Branch, through the Epidemiologic Surveillance of Abortion Mortality, has identified and investigated 193 legal abortion-related deaths between 1972 and 1985. In 27 cases ( 14%) death was determined to be a result of general anesthesia complications. No remarkable change in the absolute number of general anesthesia-related deaths was observed over time. However, because of the significant decrease in the number of deaths from other causes, the proportion of legal abortion-related deaths that were caused by general anesthesia complications increased significantly, from 7.7% between 1972 and 1975 to 29.4% between 1980 and 1985 (Table 1). The characteristics of women dying of general anesthesia complications and those dying of other causes are shown in Table II. The proportions of women dying of general anesthesia complications were not higher for any particular age group, for women who had concurrent sterilization, for women with preexisting medical conditions, or for women obtaining legal abortions in hospitals compared with women obtaining abortions in nonhospital facilities. However, significantly higher proportions of legal abortion-related deaths were caused by general anesthesia complications among women of black and other races, women who had their abortions during the first trimester, and women who died from legal aborti(;)n in the Northeast United States. The difference in racial composition among the groups of women dying of general anesthesia compli-
Abortion mortality and general anesthesia 421
Table I. Legal abortion-related deaths by cause of death and time interval in the United States General anesthesia
Other causes
Interval
No.I
%
No.I
%
1972-1975 1976-1979 1980-1985*
8 9 10
7.7 16.4 29.4
96 46 24
92.3 83.6 70.6
Proportional mortality ratio (95% confidence limits) Referent 2.1 (0.5-5.1) 3.8 (1.7-8.6)
*Data for 1984 to 1985 are not complete.
cations and those dying of other causes persisted after adjusting for age, gestational age, and abortion facility. The difference disappeared when we adjusted for geographic region of death. Of the 24 anesthetic deaths during the first trimester, 23 (95.8%) involved suction curettage abortions. The proportion of suction curettage abortion among women dying of other causes during the first trimester was not significantly different (63 of 65, or 97.0%). Between 1972 and 1975, 75% of women dying of general anesthesia complications obtained abortions in hospitals and 25% obtained abortions in free-standing clinics. Between 1980 and 1985, 40% died in hospitals and 60% died in clinics. The proportion of abortionrelated deaths that were caused by general anesthesia complications in hospitals increased, from 8.2% between 1972 and 1975 to 28.6% between 1980 and 1985. A similar increase from 8.3% to 30% occurred in freestanding clinics. A significantly higher proportion of abortion-related deaths was caused by general anesthesia complications in the Northeast than in other regions of the United States. The proportion was higher for the total period from 1972 to 1985 as well as from 1972 to 1975, 1976 to 1979, and 1980 to 1985 (Table III). The type of anesthetic used was known in 23 of the 27 cases (85.2%). Twenty-one women received shortacting barbiturates (15 received methohexital [Brevital], three received thiopental [Pentothal], two received thiamylal [Surital], and one woman received an unspecified short-acting barbiturate); one woman was given droperidol [lnapsine] and one woman was given nitrous oxide and ether. Of the 15 women receiving Brevital, six arrested during or within the last 5 minutes of anesthesia, six arrested in the recovery room, and in three cases we could not determine the time of arrest in relation to anesthesia termination. Of the six women receiving other barbiturates, one aspirated during induction, one arrested during the operation, and four arrested within 15 minutes of the procedure's conclusion. All of the other six women who were given different or unknown anesthetics arrested during the op-
422 Atrash, Cheek, and Hogue
February 1988 Am J Obstet Gynecol
Table II. Characteristics of women dying of legal abortions by cause of death in the United States, 1972 to 1985* General anesthesia
I
No. Age (yr) .;;:19 20-29 ;;.30 Race White Black and other Gestational age (wk) .;;:12 ;;.13 Abortion facility Hospital Clinic Preexisting condition Yes No Region South West Northeast North Central Concurrent sterilization Yes No
%
Proportional mortality ratio (95% confidence limits)
Other causes
%
No.
J
5 14 8
11.4 13.7 17.0
39 88 39
88.6 86.3 83.0
Referent 1.2 (0.5-3.1) 1.5 (0.5-4.2)
7 20
8.0 18.9
80 86
92.0 81.1
2.3 (l.l-5.1)t
24 3
27.0 2.9
65 101
73.0 97.1
9.3 (3.7-23.3)t
14 13
12.3 18.8
101 56
87.7 81.2
1.5 (0.8-3.1)
9 12
11.1 14.0
72 74
88.9 86.0
1.3 (0.6-2.8)
6 1 18 2
9.4 2.8 28.6 5.7
58 35 45 33
90.6 97.2 71.4 94.3
3.4 (0.5-23.3) Referent 10.3 (2.4-44.5)t 2.1 (0.2-20.8)
5 23
18.5 13.1
22 153
81.5 86.9
0. 7 (0.3-1. 7)
*Data for 1984 to 1985 are not complete. tSignificant at p < 0.05.
Table III. Legal abortion-related deaths caused by complications of general anesthesia by region of death and interval South Interval 1972-1975 1976-1979 1980-1985*
No.I % 2 3 1
25.0 33.3 10.0
West No.I
%
1 0 0
12.5
Northeast
North Central
No.I %
No.J %
5 5 8
62.5 55.6 80.0
0 1 1
11.1 10.0
*Data for 1984 to 1985 are not complete.
eration. Autopsy was done on 25 women. The direct causes of death were determined to be the following: cardiopulmonar y arrest from cerebral hypoxia (24); drug reaction (one); and aspiration during induction (two). The anesthesiologists who reviewed the cases independently agreed, based on clinical history and without previous knowledge of the autopsy results, that the underlying cause of death in all 24 women dying of cerebral hypoxia was inadequate ventilation. The amount of Brevital given was known in nine cases only; it ranged between 50 and 500 mg. Amounts of the other anesthetics are not known. Brevital was given by intravenous drip or by intravenous push. All13 women who died in free-standing clinics were given short-acting
barbiturates (12 received Brevital and one received Pentothal) and were not intubated. Of the 14 women who died in hospitals, three were intubated (one received thiopental, one received thiopental plus nitrous oxide and Ethrane, and one received anesthetics of unknown nature), seven were not intubated, and in the remaining four cases we could not determine if the women were intubated for general anesthesia. Nine of the 27 women who died of general anesthesia complications had preexisting medical conditions that included asthma (one), hypertension and obesity (one), multiple sclerosis (one), fever and diarrhea (one), cervical cone biopsy (one), and obesity (four).
Comment The type of anesthesia used for performing legal abortion, as is the case for any other surgical procedure, depends on several economic, social, medical, and personal factors. Very often the type of anesthesia used is dictated by the policy of the provider (clinic or hospital). Some providers use only general anesthesia, others use only local or regional anesthesia, and still others use both types of anesthesia, based frequently on patients' preference.• Since the early 1970s, reports have been published on large series of abortions performed exclusively under local anesthesia, indicating the convenience, econ-
Volume 158 Number 2
omy, and safety oflocal anesthesia for performing legal abortions during the first trimester.'· 6 Patient acceptance has also been reported to be excellent. 7 However, in a series of 592 cases from New York in 1971, Rovinsky" reported that mild sedation and paracervical local anesthesia were not sufficient to provide analgesia or to prevent agitation and abrupt pelvic movements , which contributed to higher complication rates. More than 25% of his patients had to receive supplemen tation with short-actin g barbiturate s or inhalation anesthesia. Studies have shown that major complication rates associated with the use of local or general anesthesia were not significantly different,"· 10 but general anesthesia use was associated with different kinds of complications, e.g., general anesthesia had a detrimenta l effect on rates of uterine cervical injury. 9 • 11 The only study published on abortion-re lated mortality concerning general anesthesia showed that general anesthesia was associated with a twofold to fourfold increased risk of death from abortions at ,..12 weeks of gestation in the United States between 1972 and 1977. 12 We found that the distribution s of women dying of general anesthesia by age, gravidity, abortion facility, preexisting conditions, and concurrent sterilization did not differ significantly from the distribution s of women dying of other causes. The increased risk for women of black and other races disappeare d when adjusted for geographic region, indicating regional rather than racial differences . Approxima tely 30% of all legal abortion deaths in the Northeast were due to general anesthesia complications, compared with <10% in other regions. This can be explained in part by the higher proportion oflegal abortions performed under general anesthesia in the Northeast compared with other parts of the country. 2 The apparent increased risk among women of black and other races resulted in part because a higher proportion of women obtaining legal abortions in the Northeast are of black and other races than in other parts of the United States (in 1981, 34.7% of legal abortions in the Northeast were obtained by women of black and other races, compared with 28.8% in the other three regions). 1 Another factor that may have contributed to the increased proportion of blacks among general anesthesia -related deaths is the delayed recognition of cyanosis accompany ing hypoxia in women of dark complexion . The increased proportion of deaths in clinics is probably because of the increased proportion of abortions performed in clinics (almost 80% of abortions were performed in nonhospita l facilities in 1980, compared with <50% in 1973). 13 The most common reported, preventabl e causes of death from general . anesthesia are hypoventilation (with ensuing hypoxia) and drug overdose. 12• 14 Other causes that may be preventabl e include aspiration of
Abortion mortality and general anesthesia 423
gastric contents during anesthesia, severe bronchospasm, equipment failure, and human error. Independe nt data inspection from this study by three anesthesiologists indicate that between 23 and 25 of 27 deaths were attributable to hypoventil ation and/or loss of airway resulting in hypoxia. Other less frequent causes include aspiration of gastric contents, irreversible bronchospa sm, and drug overdose or reaction. These results agree with maternal mortality studies from the United States 15 and the United Kingdom, 16 where inability to maintain ventilation was the leading cause of death. Only three of 27 patients who died were known to have endotrache al tubes assuring airway patency. Short-actin g barbiturate s (primarily Brevital) were the most commonly used agents. However, narcotics (Demerol), sedative tranquilize rs (Valium), and potent inhalation drugs (Ethrane) were also given. It is well known that pregnancy increases the sensitivity to the respiratory depressant effects of all these agents. I?, Is The anesthetist's skill and amount of training are also important factors in anesthetic risk. 16 Unfortunat ely, the records do not indicate who administer ed the anesthetics or what the individuals' levels of training in anesthesia were. Nine deaths occurred in the recovery period, which indicates inadequate surveillance of patient respiratory status by recovery room personnel. A serious limitation to our analysis is the lack of denominators (numbers of induced abortions performed using general anesthesia). By using proportion al mortality ratios we are treating deaths due to general anesthesia as cases and comparing them with deaths due to other causes as controls. This assumes that deaths due to causes other than general anesthesia complications are representat ive of all abortions for the studied factors. If this assumption is not true, our conclusions based on characteristics of the "cases" and "controls" may be biased. However, our niain findings of the increasing proportion of deaths due to general anesthesia and their preventabil ity do not rely on this assumption , and are therefore not affected by its validity. These findings show that the number of anesthesia related deaths for legal abortion has not decreased. Accurate data on numbers of abortions by anesthesia type are not available to determine if the death-to-case rate has decreased. The most common cause of death from general anesthesia is hypoventil ation leading to cerebral hypoxia and cardiac arrest. These events are preventabl e if patient airway patency and the presence of ventilatory exchange are attended to both during the operation and in the recovery period. Persons administering anesthesia for abortion must be highly skilled in airway manageme nt as well as the provision of general anesthesia. They should be fully aware of the drugs' potent respiratory and cardiac depressant
424 Atrash, Cheek, and Hogue
effects as well as the correct dose. They must als9 know the potentiating effect of pregnancy on sensitivity to anesthetics and be capable of appropriately treating any adverse drug reactions. New advances in patient monitoring, such as pulse oximetry, may enhance the early detection and treatment of hypoxia in both the operating room and the recovery room. REFERENCES 1. Centers for Disease Control. Abortion surveillance, 1981. Atlanta: Centers for Disease Control, 1985. 2. Chavkin W, Fernandez L, Harris M, eta!. Maternal deaths associated with barbiturate anesthesia-New York City. MMWR 1986;35:579. 3. Monson RR. Occupational epidemiology. Boca Raton, Fla: CRC Press Inc, 1980:86-7. 4. Henshaw SK. Freestanding abortion clinics: services, structure, fees. Fam Plann Perspect 1982;14:248. 5. Hodgson1E, Portmann KC. Complications of 10,453 consecutive first-trimester abortions: a prospective study. AM 1 0BSTET GYNECOL 1974;120:802. 6. Nathanson B. Ambulatory abortion: experience with 26,000 cases. N Engl1 Med 1972;286:403. 7. Strausz IV, Schulman H. 500 outpatient abortions performed under local anesthesia. Obstet Gynecpl 1971; 38:199. 8. Rovinsky 1J. Abortion in New York City: preliminary experience with a permissive abortion statute. Obstet Gynecol 1971;38:333.
February 1988 Am J Obstet Gynecol
9. Grimes DA, Schulz KF, Cates W, et. al. Local versus general anesthesia: which is safer for performing suction curettage abortion? AM1 0BSTET GYNECOL 1979;135:1030. 10. Tietze C, Lewit S. The joint program for the study of abortion UPSA): Early medical complications of legal abortion. Stud Fam Plann 1972;3:97. 11. Schulz KF, Grimes DA, Cates W. Measures to prevent cervical injury during suction curretage during abortion. Lancet 1983; 1:1182. 12. Petersen HB, Grimes DA, Cates W, eta!. Comparative risk of death from induced abortion at .;:12 weeks gestation performed with local general anesthesia. AM 1 OBSTET GYNECOL 1981;141:763. 13. Henshaw SK, Forrest 1D, Sullivan E, et a!. Abortion services in the United States, 1979-1980. Fam Plann Perspect 1982;14:5. 14. Taylor G, Larson CP, Prestwich R. Unexpected cardiac arrest during anesthesia and surgery. An environmental study. 1AMA 1976;236:2758. 15. Kaunitz AM, Hughes 1M, Grimes DA, et a!. Causes of maternal mortality in the United States. Obstet Gynecol 1985;65:605. 16. Great Britain Department of Health and Social Security. Report on confidential enquiries into maternal deaths in England and Wales 1976-1978. London: Her Majesty's Stationery Office, 1982. 17. Gutsche BB. Maternal physiologic alterations in pregnancy. In: Shnider S, ed. Anesthesia for obstetrics. Baltimore: Williams & Wilkins, 1978:9. 18. Levinson G. Systemic medication for labor and delivery. In: Shnider S, ed. Anesthesia for obstetrics. Baltimore: Williams & Wilkins, 1978:75-92.
We thank Ms. Alice Burnett for preparing the manuscript. REFERENCES 1. Holmes RC, Black MM. The specific dermatoses of pregnancy. JAm Acad Dermatol1983;8:405. 2. Ittrich G. Eine neue Methode zur chemischen Bestimmung der oestrogenen Hormone in Harn. Hoppe Seyler Z Physiol Chern 1958;312:1. 3. Lawley TJ, Hertz KC, Wade TR, et a!. Pruritic urticarial papules and plaques ofpregnancy.JAMA 1979;241:1696.
February 1988 Am J Obstet Gynecol
4. Yancey KB, Hall RP, Lawley TJ. Pruritic urticarial papules and plaques of pregnancy: clinical experience in twentyfive patients. JAm Acad Dermatol 1984;10:473. 5. Alcalay J, Ingber A, David M, Hazaz B, Sandbank M. Pruritic urticarial papules and plaques of pregnancy-a review of twenty one cases. J Reprod Med 1987;32:315. 6. Spangler AS, Reddy W, Bardawil WA, Roby CC, Emerson K. Papular dermatitis of pregnancy. A new clinical entity? JAMA 1962;181:577. 7. Spangler AS, Emerson K. Estrogen levels and estrogen therapy in papular dermatitis of pregnancy. AM J 0BSTET GYNECOL 1971;110:534.
Legal abortion mortality and general anesthesia Hani K. Atrash, MD, MPH, Theodore G. Cheek, MD, and Carol). R. Hogue, PhD, MPH Atlanta, Georgia, and Philadelphia, Pennsylvania Legal abortion-related mortality as reported to the Centers for Disease Control declined eightfold between 1972 and 1981. However, the causes of legal abortioo mortality have changed over time. We reviewed all legal abortion-related deaths that occurred between 1972 and 1985 in the United States. We found that, although the absolute number of legal abortion-related deaths caused by general anesthesia complications did not increase, the proportion of such deaths increased significantly, from 7.7% between 1972 and 1975 to 29.4% between 1980 and 1985. Women who died of general anesthesia complications did not differ by age, presence of preexisting medical conditions, or type of facility from women who died of other causes. However, the proportion of deaths from general anesthesia complications was significantly higher among women of black and other races, women obtaining abortions during the first trimester, and women obtaining abortions in the Northeast. Our results indicate that at least 23 of the 27 deaths were due to hypoventilation and/or loss of airway resulting in hypoxia. Persons administering general anesthesia for abortion must be skilled in airway management as well as the provision of general anesthesia. (AM J 0BSTET GYNECOL 1988;158:420-4.)
Key words: Abortion mortality, general anesthesia, maternal mortality Legal abortion-related mortality as reported to the Centers for Disease Control experienced an eightfold decline between 1972 and 1981, falling from 4.1 deaths per 100,000 abortions in 1972 to 0.5 deaths per 100,000 abortions in 1981. 1 The number of legal abortionrelated deaths also declined, from 24 in 1972 to seven in 1981. However, the New York City Department of Health recently reported seven legal abortion-related deaths that occurred between 1980 and 1985. The cause of death in all cases was attributed directly to general anesthesia. 2 Moreover, during our investigation of legal abortion-related deaths we have noted that an increasing proportion of these were anesthesia-related
From the Division of Reproductive Health, Center for Health Promotion and Education, Centers for Disease Control, and the Department of Anesthesia, University of Pennsylvania. Received for publication April20, 1987; revised August 11, 1987; accepted September 14, 1987. Reprints not available.
420
deaths, and that most deaths resulting from cardiopulmonary arrest associated with general anesthesia occurred in the recovery room. We reviewed all legal abortion-related deaths that occurred between 1972 and 1985 to determine the role of general anesthesia in legal abortion mortality and to identify factors that place women seeking abortion at higher risk of dying from general anesthesia complications. Methods
Legal abortion-related deaths were identified by the Centers for Disease Control's Nationwide Surveillance of Abortion Mortality initiated in 1972, details of which have been previously reported. 1 All reported cases were investigated by medical epidemiologists and the causes of death were determined based on data collected from death certificates, medical records and autopsy reports (when available). In our study, deaths were classified as related to general anesthesia (or caused by general an-
Volume 158 Number2
esthesia complications) and deaths from other causes. Deaths were considered to be caused by general anesthesia if they could be attributed to the administration of the anesthetic agent or to the agent itself, or if so determined by autopsy findings in the absence of other conditions that could have caused the death. General anesthesia-related cases were further reviewed by one of the authors (T. G. C.), an anesthesiologist, and, independently, by two other anesthesiologists to determine the underlying cause of death. Because denominator data are lacking (number of abortion procedures by type of anesthesia), we used proportional mortality ratios to compare the characteristics of women dying after general anesthesia complications with those dying of other causes; we calculated 95% confidence intervals around the ratio to determine statistical significance. 3 We then used the same procedure to compare the proportions of women dying of general anesthesia complications during different time intervals (1972 to 1975, 1976 to 1979, and 1980 to 1985), in different geographic regions (as defined by the U.S. Bureau of the Census), and at different types of facilities (hospitals and clinics).
Results The Centers for Disease Control's Pregnancy Epidemiology Branch, through the Epidemiologic Surveillance of Abortion Mortality, has identified and investigated 193 legal abortion-related deaths between 1972 and 1985. In 27 cases ( 14%) death was determined to be a result of general anesthesia complications. No remarkable change in the absolute number of general anesthesia-related deaths was observed over time. However, because of the significant decrease in the number of deaths from other causes, the proportion of legal abortion-related deaths that were caused by general anesthesia complications increased significantly, from 7.7% between 1972 and 1975 to 29.4% between 1980 and 1985 (Table 1). The characteristics of women dying of general anesthesia complications and those dying of other causes are shown in Table II. The proportions of women dying of general anesthesia complications were not higher for any particular age group, for women who had concurrent sterilization, for women with preexisting medical conditions, or for women obtaining legal abortions in hospitals compared with women obtaining abortions in nonhospital facilities. However, significantly higher proportions of legal abortion-related deaths were caused by general anesthesia complications among women of black and other races, women who had their abortions during the first trimester, and women who died from legal aborti(;)n in the Northeast United States. The difference in racial composition among the groups of women dying of general anesthesia compli-
Abortion mortality and general anesthesia 421
Table I. Legal abortion-related deaths by cause of death and time interval in the United States General anesthesia
Other causes
Interval
No.I
%
No.I
%
1972-1975 1976-1979 1980-1985*
8 9 10
7.7 16.4 29.4
96 46 24
92.3 83.6 70.6
Proportional mortality ratio (95% confidence limits) Referent 2.1 (0.5-5.1) 3.8 (1.7-8.6)
*Data for 1984 to 1985 are not complete.
cations and those dying of other causes persisted after adjusting for age, gestational age, and abortion facility. The difference disappeared when we adjusted for geographic region of death. Of the 24 anesthetic deaths during the first trimester, 23 (95.8%) involved suction curettage abortions. The proportion of suction curettage abortion among women dying of other causes during the first trimester was not significantly different (63 of 65, or 97.0%). Between 1972 and 1975, 75% of women dying of general anesthesia complications obtained abortions in hospitals and 25% obtained abortions in free-standing clinics. Between 1980 and 1985, 40% died in hospitals and 60% died in clinics. The proportion of abortionrelated deaths that were caused by general anesthesia complications in hospitals increased, from 8.2% between 1972 and 1975 to 28.6% between 1980 and 1985. A similar increase from 8.3% to 30% occurred in freestanding clinics. A significantly higher proportion of abortion-related deaths was caused by general anesthesia complications in the Northeast than in other regions of the United States. The proportion was higher for the total period from 1972 to 1985 as well as from 1972 to 1975, 1976 to 1979, and 1980 to 1985 (Table III). The type of anesthetic used was known in 23 of the 27 cases (85.2%). Twenty-one women received shortacting barbiturates (15 received methohexital [Brevital], three received thiopental [Pentothal], two received thiamylal [Surital], and one woman received an unspecified short-acting barbiturate); one woman was given droperidol [lnapsine] and one woman was given nitrous oxide and ether. Of the 15 women receiving Brevital, six arrested during or within the last 5 minutes of anesthesia, six arrested in the recovery room, and in three cases we could not determine the time of arrest in relation to anesthesia termination. Of the six women receiving other barbiturates, one aspirated during induction, one arrested during the operation, and four arrested within 15 minutes of the procedure's conclusion. All of the other six women who were given different or unknown anesthetics arrested during the op-
422 Atrash, Cheek, and Hogue
February 1988 Am J Obstet Gynecol
Table II. Characteristics of women dying of legal abortions by cause of death in the United States, 1972 to 1985* General anesthesia
I
No. Age (yr) .;;:19 20-29 ;;.30 Race White Black and other Gestational age (wk) .;;:12 ;;.13 Abortion facility Hospital Clinic Preexisting condition Yes No Region South West Northeast North Central Concurrent sterilization Yes No
%
Proportional mortality ratio (95% confidence limits)
Other causes
%
No.
J
5 14 8
11.4 13.7 17.0
39 88 39
88.6 86.3 83.0
Referent 1.2 (0.5-3.1) 1.5 (0.5-4.2)
7 20
8.0 18.9
80 86
92.0 81.1
2.3 (l.l-5.1)t
24 3
27.0 2.9
65 101
73.0 97.1
9.3 (3.7-23.3)t
14 13
12.3 18.8
101 56
87.7 81.2
1.5 (0.8-3.1)
9 12
11.1 14.0
72 74
88.9 86.0
1.3 (0.6-2.8)
6 1 18 2
9.4 2.8 28.6 5.7
58 35 45 33
90.6 97.2 71.4 94.3
3.4 (0.5-23.3) Referent 10.3 (2.4-44.5)t 2.1 (0.2-20.8)
5 23
18.5 13.1
22 153
81.5 86.9
0. 7 (0.3-1. 7)
*Data for 1984 to 1985 are not complete. tSignificant at p < 0.05.
Table III. Legal abortion-related deaths caused by complications of general anesthesia by region of death and interval South Interval 1972-1975 1976-1979 1980-1985*
No.I % 2 3 1
25.0 33.3 10.0
West No.I
%
1 0 0
12.5
Northeast
North Central
No.I %
No.J %
5 5 8
62.5 55.6 80.0
0 1 1
11.1 10.0
*Data for 1984 to 1985 are not complete.
eration. Autopsy was done on 25 women. The direct causes of death were determined to be the following: cardiopulmonar y arrest from cerebral hypoxia (24); drug reaction (one); and aspiration during induction (two). The anesthesiologists who reviewed the cases independently agreed, based on clinical history and without previous knowledge of the autopsy results, that the underlying cause of death in all 24 women dying of cerebral hypoxia was inadequate ventilation. The amount of Brevital given was known in nine cases only; it ranged between 50 and 500 mg. Amounts of the other anesthetics are not known. Brevital was given by intravenous drip or by intravenous push. All13 women who died in free-standing clinics were given short-acting
barbiturates (12 received Brevital and one received Pentothal) and were not intubated. Of the 14 women who died in hospitals, three were intubated (one received thiopental, one received thiopental plus nitrous oxide and Ethrane, and one received anesthetics of unknown nature), seven were not intubated, and in the remaining four cases we could not determine if the women were intubated for general anesthesia. Nine of the 27 women who died of general anesthesia complications had preexisting medical conditions that included asthma (one), hypertension and obesity (one), multiple sclerosis (one), fever and diarrhea (one), cervical cone biopsy (one), and obesity (four).
Comment The type of anesthesia used for performing legal abortion, as is the case for any other surgical procedure, depends on several economic, social, medical, and personal factors. Very often the type of anesthesia used is dictated by the policy of the provider (clinic or hospital). Some providers use only general anesthesia, others use only local or regional anesthesia, and still others use both types of anesthesia, based frequently on patients' preference.• Since the early 1970s, reports have been published on large series of abortions performed exclusively under local anesthesia, indicating the convenience, econ-
Volume 158 Number 2
omy, and safety oflocal anesthesia for performing legal abortions during the first trimester.'· 6 Patient acceptance has also been reported to be excellent. 7 However, in a series of 592 cases from New York in 1971, Rovinsky" reported that mild sedation and paracervical local anesthesia were not sufficient to provide analgesia or to prevent agitation and abrupt pelvic movements , which contributed to higher complication rates. More than 25% of his patients had to receive supplemen tation with short-actin g barbiturate s or inhalation anesthesia. Studies have shown that major complication rates associated with the use of local or general anesthesia were not significantly different,"· 10 but general anesthesia use was associated with different kinds of complications, e.g., general anesthesia had a detrimenta l effect on rates of uterine cervical injury. 9 • 11 The only study published on abortion-re lated mortality concerning general anesthesia showed that general anesthesia was associated with a twofold to fourfold increased risk of death from abortions at ,..12 weeks of gestation in the United States between 1972 and 1977. 12 We found that the distribution s of women dying of general anesthesia by age, gravidity, abortion facility, preexisting conditions, and concurrent sterilization did not differ significantly from the distribution s of women dying of other causes. The increased risk for women of black and other races disappeare d when adjusted for geographic region, indicating regional rather than racial differences . Approxima tely 30% of all legal abortion deaths in the Northeast were due to general anesthesia complications, compared with <10% in other regions. This can be explained in part by the higher proportion oflegal abortions performed under general anesthesia in the Northeast compared with other parts of the country. 2 The apparent increased risk among women of black and other races resulted in part because a higher proportion of women obtaining legal abortions in the Northeast are of black and other races than in other parts of the United States (in 1981, 34.7% of legal abortions in the Northeast were obtained by women of black and other races, compared with 28.8% in the other three regions). 1 Another factor that may have contributed to the increased proportion of blacks among general anesthesia -related deaths is the delayed recognition of cyanosis accompany ing hypoxia in women of dark complexion . The increased proportion of deaths in clinics is probably because of the increased proportion of abortions performed in clinics (almost 80% of abortions were performed in nonhospita l facilities in 1980, compared with <50% in 1973). 13 The most common reported, preventabl e causes of death from general . anesthesia are hypoventilation (with ensuing hypoxia) and drug overdose. 12• 14 Other causes that may be preventabl e include aspiration of
Abortion mortality and general anesthesia 423
gastric contents during anesthesia, severe bronchospasm, equipment failure, and human error. Independe nt data inspection from this study by three anesthesiologists indicate that between 23 and 25 of 27 deaths were attributable to hypoventil ation and/or loss of airway resulting in hypoxia. Other less frequent causes include aspiration of gastric contents, irreversible bronchospa sm, and drug overdose or reaction. These results agree with maternal mortality studies from the United States 15 and the United Kingdom, 16 where inability to maintain ventilation was the leading cause of death. Only three of 27 patients who died were known to have endotrache al tubes assuring airway patency. Short-actin g barbiturate s (primarily Brevital) were the most commonly used agents. However, narcotics (Demerol), sedative tranquilize rs (Valium), and potent inhalation drugs (Ethrane) were also given. It is well known that pregnancy increases the sensitivity to the respiratory depressant effects of all these agents. I?, Is The anesthetist's skill and amount of training are also important factors in anesthetic risk. 16 Unfortunat ely, the records do not indicate who administer ed the anesthetics or what the individuals' levels of training in anesthesia were. Nine deaths occurred in the recovery period, which indicates inadequate surveillance of patient respiratory status by recovery room personnel. A serious limitation to our analysis is the lack of denominators (numbers of induced abortions performed using general anesthesia). By using proportion al mortality ratios we are treating deaths due to general anesthesia as cases and comparing them with deaths due to other causes as controls. This assumes that deaths due to causes other than general anesthesia complications are representat ive of all abortions for the studied factors. If this assumption is not true, our conclusions based on characteristics of the "cases" and "controls" may be biased. However, our niain findings of the increasing proportion of deaths due to general anesthesia and their preventabil ity do not rely on this assumption , and are therefore not affected by its validity. These findings show that the number of anesthesia related deaths for legal abortion has not decreased. Accurate data on numbers of abortions by anesthesia type are not available to determine if the death-to-case rate has decreased. The most common cause of death from general anesthesia is hypoventil ation leading to cerebral hypoxia and cardiac arrest. These events are preventabl e if patient airway patency and the presence of ventilatory exchange are attended to both during the operation and in the recovery period. Persons administering anesthesia for abortion must be highly skilled in airway manageme nt as well as the provision of general anesthesia. They should be fully aware of the drugs' potent respiratory and cardiac depressant
424 Atrash, Cheek, and Hogue
effects as well as the correct dose. They must als9 know the potentiating effect of pregnancy on sensitivity to anesthetics and be capable of appropriately treating any adverse drug reactions. New advances in patient monitoring, such as pulse oximetry, may enhance the early detection and treatment of hypoxia in both the operating room and the recovery room. REFERENCES 1. Centers for Disease Control. Abortion surveillance, 1981. Atlanta: Centers for Disease Control, 1985. 2. Chavkin W, Fernandez L, Harris M, eta!. Maternal deaths associated with barbiturate anesthesia-New York City. MMWR 1986;35:579. 3. Monson RR. Occupational epidemiology. Boca Raton, Fla: CRC Press Inc, 1980:86-7. 4. Henshaw SK. Freestanding abortion clinics: services, structure, fees. Fam Plann Perspect 1982;14:248. 5. Hodgson1E, Portmann KC. Complications of 10,453 consecutive first-trimester abortions: a prospective study. AM 1 0BSTET GYNECOL 1974;120:802. 6. Nathanson B. Ambulatory abortion: experience with 26,000 cases. N Engl1 Med 1972;286:403. 7. Strausz IV, Schulman H. 500 outpatient abortions performed under local anesthesia. Obstet Gynecpl 1971; 38:199. 8. Rovinsky 1J. Abortion in New York City: preliminary experience with a permissive abortion statute. Obstet Gynecol 1971;38:333.
February 1988 Am J Obstet Gynecol
9. Grimes DA, Schulz KF, Cates W, et. al. Local versus general anesthesia: which is safer for performing suction curettage abortion? AM1 0BSTET GYNECOL 1979;135:1030. 10. Tietze C, Lewit S. The joint program for the study of abortion UPSA): Early medical complications of legal abortion. Stud Fam Plann 1972;3:97. 11. Schulz KF, Grimes DA, Cates W. Measures to prevent cervical injury during suction curretage during abortion. Lancet 1983; 1:1182. 12. Petersen HB, Grimes DA, Cates W, eta!. Comparative risk of death from induced abortion at .;:12 weeks gestation performed with local general anesthesia. AM 1 OBSTET GYNECOL 1981;141:763. 13. Henshaw SK, Forrest 1D, Sullivan E, et a!. Abortion services in the United States, 1979-1980. Fam Plann Perspect 1982;14:5. 14. Taylor G, Larson CP, Prestwich R. Unexpected cardiac arrest during anesthesia and surgery. An environmental study. 1AMA 1976;236:2758. 15. Kaunitz AM, Hughes 1M, Grimes DA, et a!. Causes of maternal mortality in the United States. Obstet Gynecol 1985;65:605. 16. Great Britain Department of Health and Social Security. Report on confidential enquiries into maternal deaths in England and Wales 1976-1978. London: Her Majesty's Stationery Office, 1982. 17. Gutsche BB. Maternal physiologic alterations in pregnancy. In: Shnider S, ed. Anesthesia for obstetrics. Baltimore: Williams & Wilkins, 1978:9. 18. Levinson G. Systemic medication for labor and delivery. In: Shnider S, ed. Anesthesia for obstetrics. Baltimore: Williams & Wilkins, 1978:75-92.