End-tidal carbon dioxide for monitoring primary closure of gastroschisis

End-Tidal By Nikola

Carbon Dioxide for Monitoring Gastroschisis K. Puffinbarger,

Denise V. Taylor, Oklahoma

0 Previous criteria for primary reduction of the herniated viscera in newborn infants with gastroschisis included intraoperative respiratory rate, cardiac indices, degree of visceroabdominal disproportion, size of defect, and lower extremity turgor. From 1976 through 1993,129 neonates with gastroschisis were treated at Children’s Hospital of Oklahoma. lntraoperative end-tidal carbon dioxide (ETCOr) monitoring was standard therapy beginning in 1985 The authors evaluated the effect of abdominal closure on ETCOr to determine if there was a particular ETCOr level at which closure was not feasible. There was no difference in overall mortality, birth weight, or postoperative ventilation requirements between children who had closure before 1985 (ie, without ETCOs monitoring) and those who had repair after 1985. However, more cases in the 1985-1993 group had primary closure, and none of these required conversion to a staged procedure. An ETCOs of ~50 suggests that primary closure may be unsafe. These data su9gest that infants with gastroschisis can have primary closure based on intraoperative ETCOs monitoring; no additional invasive monitoring would be necessary to assess closure. Copyright @ 7996 by W.B. Saunders Company INDEX WORDS: abdominal wall

Gastroschisis, defects.

end-tidal

carbon

dioxide,

E

XPERIENCE has shown improved survival rates and minimized complications in gastroschisis if primary closure can be accomplished. Reports suggest that, in comparison to staged closure, primary closure of gastroschisis results in earlier return of gastrointestinal function as well as reduced exposure to the possibility of contamination.iJ However, surgical cIosure of gastroschisis rest&s in increased intraabdominal pressure. This excessive abdominal tension may lead to a compromise of ventilation or other complications. In an attempt to ensure safety of closure, a variety of intraoperative measurements have been used. Criteria have included measurements of intragastric pressure, respiratory rate, cardiac indexes, degree of visceroabdominal disproportion, defect size, and lower extremity perfusion.3-5 More recently at our institution, since the availability

City,

David W. Tuggle,

Primary Closure of and William

P. Tunell

Oklahoma

of monitoring end-tidal carbon dioxide (ETC02) with a nonbreathing circuit ventilator (SERVO 900-C; Siemens-Elema, Sweden) we have used primary reduction of gastroschisis for neonates who could maintain an ETC02 of 5 50 mm Hg.6 Constant intraoperative monitoring of ETC02 allows for immediate assessment of the child’s ventilatory status. If the child is unable to maintain this level after reduction of the viscera and attempted closure of the fascia, a silo is placed while the patient is still in the operating room. Since the use of ETC02 monitoring to assess successful closure, we have not had to convert any primary gastroschisis closure to a silo postoperatively. MATERIALS

AND METHODS

From January 1976 through December 1984,64 newborns with gastroschisis were treated at Children’s Hospital of Oklahoma (CHO) without the ability to assess ETCOs. The decision to use primary closure in these children was based on clinical assessment (ie, evidence of decreasing lower extremity perfnsion and other ventilator parameters such as decreased oxygen saturation and peak inspiratory pressures). In late 1985, CHO obtained access to the Siemens ventilator and began monitoring intraoperative ETCOr using the sidestream method. The medical records of all 129 patients were reviewed to assess the number of primary closures, staged closures, and cases converted to staged closure postoperatively. We noted the association of successful primary closure with an ETCOs of <50. In addition, birth weight, postoperative ventilator days, total parenteral nutrition days, morbidity, and mortality were compared between the two groups (non-ETCOs v ETCOs), Where applicable, the Fisher’s exact test and x2 statistical analysis were used. RESULTS

From the Department oy Surgery, Section of Pediatric Surgery, Universi~ of Oklahoma College of MedicineJChildren’s Hospital of Oklahoma, Oklahoma City, OK Presented at the 28th Annual Meeting of the Pacific Association of Pediatric Sqeons, Huatulco, Oaxaca, Mexico, May 14-18, 1995, Address reprint requests to David W. Tuggle, MD, Pediatric Surgery, PO Box 24307, Oklahoma City, OK 73126. Copyright @ 1996 by W.B. Saunders Company 0022-3468/96/3IO2-0017$03.OOfO

The number of deaths was the same for the two groups. The causes of death varied within each group. The non-ETC02 deaths in patients who had primary closure were related to bowel ischemia after midgut volvulus (1.5 months after discharge), SIDS (1 month after discharge), and cardiac arrest secondary to hypotension (converted to silo). The non-ETC02 staged child died after final closure. This was felt to be caused by to a “too tight” fascia that resulted in respiratory arrest. Of the two ETC02 primary closure deaths, one was caused by hypothermia (which occurred during transport) and the other by ischemic encephalopathy with persistent seizures. Of the two ETC02 staged infant deaths, one was a result of unresolvable sepsis and the other of persistent bowel dysmotility with a large amount of small bowel removed secondary to ischemia at birth. This child

280

Journa/ofPec/iatric

Surgery,

Vol31,

No 2 (February),

1996: pp 280-282

END-TIDAL

Table No. of Patients

64 65

CO2 FOR MONITORING

I.

Comparison

Between

Birth Weight k7)

2,527.5 2,561.l

NOTE. There Darameter.

Mortality

Postoperative Ventilator Days

7.12 zk 4.88

1

6.94 ck 2.86

1

differences

Moftali~

No. of Patients

4 (I staged) 4 (2 staged)

54 8

I0 Silo

2 1

Silo Silo

Morbidiv

k 505.6

no significant

Table

and Morbidity

2 506.2

were

281

GASTROSCHISIS

with

respect

to any

died at home while on total paremeral nutrition (TPN). Morbidity included any type of pulmonary complication that presented while the child was hospitalized for initial repair. One patient in the non-ETCOZ group with a silo had evidence of hyperactive airway disease (HRAD), and one patient in the ETCOZ group without a silo had evidence of HRAD. There was no significant difference between the two groups with respect to any parameter (Table 1). A greater number of patients in the non-ETCO? required staged repair (P < .05) (Table 2). No ETCOZ case required conversion to a siIo postoperatively. In contrast, one non-ETCOZ patient had conversion to a silo on postoperative day 1 in the neonatal intensive care unit because of respiratory distress. This child eventually died. The available anesthesia records were reviewed and summarized (Table 3). The highest ETCOZ in the primary closure group was 44 mm Hg (range, 24 to 44). This was the highest ETCO* after closure and before transfer to the recovery room. Eight of the 11 patients in the staged group had ETCO? of more than 50 mm Hg with attempted closure; the highest recorded value on the anesthesia sheet was 52 mm Hg (range, 51 to 52) (Table 3). In the comments section, the anesthesia records indicated that the surgeons had been notified that the ETCOZ was increasing. If the trend continued, the repair was converted to a staged procedure after the ETCOZ reached 2 50 mm Hg. However, between 1985 and 1993, three patients in the staged group had silos placed for reasons that were not consistent with elevated ETCOZ. Two patients had large amounts of ischemic/necrotic bowel and did not have primary closure because a next-day second-Iook procedure was anticipated to assess salvageable bowel. Both children later died. The other patient suffered an anesthesia complication before the initiation of surgery. The patient had difficulty oxygenating because of a right-lower-lobe collapse believed to be a consequence of right-mainstemTable

2. Distribution

of Staged

ClOSlJ~fJ

3. ETCOz Levals

ETCOz Available

Highest ETCOZ

Average Birth Weight(g)

40 8

44 51

2,585 2 474

2 Not recorded

20 Not recorded

2,427 k 612

bronchus intubation. Because the surgeons thought that the child could not tolerate primary closure from a respiration standpoint, a silo was placed and closure obtained without difficulty on postoperative day 4. The average birth weight of the primary ETCOZ group was 2,585 & 474; g that of the 11 silo-placed ETCOZ group was 2,427 2 612 g. However, the difference was not significant (Table 3). A comparison of the TPN requirements between the two groups appears in Table 4. More infants in the non-ETCOZ group required TPN, but none of these required home TPN. However, there were no significant differences among the TPN parameters analyzed. There also was no difference between staged TPN and nonstaged TPN requirements within either group. DISCUSSION

Children with gastroschisis at our institution have an incidence of primary closure that is higher than that of most previous series. The number of CHO patients who have survived primary closure has increased over the last decade because of the anticipatory use of TPN and mechanical ventilation. In addition, few children have had a morbid shortage of abdominal wall or insoluble problems in ventilatory management.’ Since late 1985, ventilatory management has included the use of Siemens nonrebreathing ventilators during surgical repair and postoperative management. The Siemens ventilator contains an inspiratory valve that interrupts the flow of fresh gas at the completion of inspiration, allowing undiluted alveolar gas to be sampled during the expiratory phase. ETCOZ measured from this sample of gas during the expiratory phase accurately predicts PacoZ.aj9 Real-time analysis of exhaled CO2 can provide rapid assessment of ventilatory adequacy or acute changes in perfusion.9Jo When closure was attempted in the staged group, there was an increase in ETCOZ reelected in the

Closures Table 4. TPN Requirements

No. of Patients

NO. Staged

NO. Converted to Silo

Total Silo Cases

1976-1984

64

24(38%)

1

25

1985-1993

65

11(17%)

0

11 I

P < .05

1976-1984 1985-1993

Total No. of Patients

No. on TPN

Mean No. of Days on TPN

No. on Home TPN

64 65

61 57

28.03 2 29.8 24.04 2 18.2

0 2

282

PUFFINBARGER

constantly projected capnogram. However, in only four of these eight patients was there also an associated decrease in oxygen saturation as measured by pulse oximetiy. Pulse oximetry may indicate respiratory difficulties later than ETC02, secondary to circulatory delay, nature of the oxyhemoglobin dissociation curve, or influence of hypothermia on probe detection.iO Therefore, ETC02 may be a quicker, more reliable indicator of decreasing ventilatory status secondary to increased intraabdominal pressure in the patient with gastroschisis. All primary closures in the ETC02 group remained closed. It must be emphasized that we continue to monitor ETC02 intraoperatively, as well as other physiological and clinical parameters. For example, decreased peripheral perfusion, presence of a large amount of necrotic bowel, large visceroabdominal

ET AL

disproportion, and/or any decrease in ventilatory status (eg, inspiratory pressure above 40 cm H20) or oxygen would necessitate use of a silo. Although there were no significant differences in TPN parameters, two infants in the ETC02 group required home TPN. Both had primary closure with ostomy. We do not believe that the need for home TPN was related to the type of closure, because both children had associated ileal malformations (ileal atresia, ileal agenesis). In conclusion, ETC02 monitoring may be a useful, noninvasive adjunct to current parameters used to determine the potential for successful primary closure in patients with gastroschisis. The use of ETC02 may eliminate the need for more invasive monitoring (eg, of intragastric pressure) while closure is attempted.

REFERENCES 6. Badgwell J, Heavner D, May W, et ah End-tidal PCO~ monitoring in infants and children ventilated with either a partial rebreathing or a non-rebreathing circuit. Anesthesiology 66:405410,1987 7. Tune11 W, Puffinbarger N, Tuggle D, et al: Abdominal wall defects in infants: Survival and implications for adult life. Ann Surg 221:525-530,1995 8. Pascucci R, Schena J, Thompson J, et al: Comparison of a sidestream and mainstream capnometer in infants. Crit Care Med 1?560-562,1989 9. Shannon D: Rational monitoring of respiratory function during mechanical ventilation of infants and children. Intensive Care Med 15:Sl3-Sl6,1989 (suppl) 10. Meredith K, Monaco Fz Evaluation of a mainstream capnometer and end-tidal carbon dioxide monitoring in mechanically ventilated infants. Pediatr Pulmonol9:254-259,199O

1. Tune11 WP: Omphalocele and gastroschisis, in Ashcraft KW, Holder TM (eds): Pediatric Surgery, chap 44. Philadelphia, PA, Saunders, 1993, pp 546-556 2. Chang P, Yeh M, Sheu J, et al: Experience with treatment of gastroschisis and omphalocele. J Formosan Med Assoc 91:447-451, 1992 3. Yaster M, Buck J, Dudgeon D, et al: Hemodynamic effects of primary closure of omphalocele/gastroschisis in human newborns. Anesthesiology 6984~881988 4. Fonkalsrud E, Smith M, Shaw K, et al: Selective management of gastroschisis according to the degree of visceroabdominal disproportion. Ann Surg 218:742-747,1993 5. Wesley J, Drongowski R, Coran A: lntragastric pressure measurement: A guide for reduction and closure of the SILASTIC chimney in omphalocele and gastroschisis. J Pediatr Surg 16:264269,198l