As a retrospective study, there are limitations based on thesource of data acquisition. We used routine anesthesia vari-ables obtained intraoperatively for all patients and recordedmanually by the anesthesiologist. The variables chosen forthis study are used by the anesthetist to monitor any patientduring surgical anesthesia. The measured parametersETCO2 and O2 saturation are indirect reflection of arterialcarbon dioxide and oxygen tension. Nyarwaya et al18 vali-dated the reliability of these parameters to predict oxygentension and arterial carbon dioxide accurately. The rest ofthe study parameters were directly measured.

CONCLUSIONS

We provided data regarding the impact of extraperitonealand intraperitoneal laparoscopic urological surgery on hemo-dynamic and respiratory variables in pediatric patients. Al-though our data are limited due to the retrospective nature ofthe study, and comparison between the intraperitoneal andextraperitoneal groups is somewhat difficult due to patientage and surgical time differences, we documented significantchanges following CO2 insufflation. Such data will enableurologists to better select patients for laparoscopic urologicalsurgery, and the anesthetists may be able to better predictpossible physiological changes during the laparoscopic proce-dure. Further prospective studies are needed to provide soliddata regarding the effect of the laparoscopic extraperitonealapproach to urological surgery on pediatric cardiorespiratoryperformance.

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versus extraperitoneal insufflation of carbon dioxide as forlaparoscopy. J Endourol, 9: 63, 1995

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EDITORIAL COMMENT

The spectrum of laparoscopic urological surgery in children con-tinues to widen. The level of complexity of these cases is associatedwith longer operative times until we become more proficient. Inaddition, the best surgical approach to many surgical procedures, ietransperitoneal or extraperitoneal, remains debatable. As such, thephysiological impact of insufflation on children becomes a criticallyimportant factor.

The authors evaluated the effect of insufflation on several hemo-dynamic and respiratory parameters during the course of extraperi-toneal and transperitoneal laparoscopic surgeries. These changeswere more significant for children placed in the left lateral position,and there were variable differences between cases performed via anextraperitoneal or transperitoneal approach.

This article should serve as a springboard for further evaluation ofthe metabolic effects of insufflation in children undergoing laparo-scopic surgery. The stratification of patients is presented well. Ad-ditional numbers or pooled data collected in a standard fashionwould allow for validation of these findings. The information gleanedfrom this study will allow us, along with our anesthesia colleagues,to best manage the metabolic demands that are placed on thesechildren. As we continue to expand our horizons and seek to optimizeour laparoscopic capabilities, these metabolic and physiological fac-tors will become increasingly more important.

Lane S. PalmerDivision of Pediatric UrologySchneider Children’s Hospital of the North Shore-Long Island

Jewish Health SystemNew Hyde Park, New York

REPLY BY AUTHORS

Our study was stimulated by the lack of information on the impactof CO2 insufflation on child physiology despite the growing use oflaparoscopy in the pediatric population. Since cardiopulmonaryphysiology in children is far more fragile compared to the adult, wewere prompted to look at the hemodynamic and respiratory changesduring pediatric urological laparoscopic surgeries. Although ourfindings shed some light on the cardio-respiratory changes inducedby transperitoneal and retroperitoneal laparoscopy, the limitation ofthis study is that it is retrospective. The comparison between theretroperitoneal and transperitoneal groups was further limited byvariation in patient age and operative surgical time.

Presently in collaboration with our general surgery and anesthesiacolleagues, we are prospectively evaluating the impact of CO2 insuf-flation, body position (lateral, supine and Trendelenburg) and sur-gical technique (retroperitoneal, transperitoneal) on cardiopulmo-nary and cerebral blood flow changes. Such a prospective study willhopefully provide accurate information on the impact of laparoscopyin children. This will not only help us identify the physiologicalchallenges associated with laparoscopic surgeries, but also may helpto better select patients for this approach.

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