Title: Correlation between End-Tidal Carbon Dioxide Pressure and Arterial Carbon Dioxide Partial Pressure in Patients Undergoing Craniotomy
Authors: Dr Meena M.Pimpare, Dr Devanand B. Deosarkar
DOI: https://dx.doi.org/10.18535/jmscr/v5i3.43
Abstract
Background: End-tidal carbon dioxide pressure (ETCO2) is commonly used as an indicator of arterial partial pressure of carbon dioxide (PaCO2) which reflects adequacy of ventilation during major surgeries. While accurate determination of PaCO2 level is an important aspect of anesthetic management of the patient it is all the way more important in neurosurgeries where changes in PaCO2 can have a profound effect on cerebral blood flow. Moreover practice of reducing intracranial pressure by means of hyperventilation is often used to reduce intracranial pressure in neurosurgical patients. There has also been some controversy in recent anesthetic literature about whether end tidalCO2 (ETCO2) is an accurate reflection of PaCO2. This study was aimed to evaluate the relationship between ETCO2 and arterial PaCO2 in neurosurgical patients undergoing craniotomy and to assess the predictive value of ETCO2 as an indicator of PaCO2 level.
Aims and Objectives:
1. To study the correlation in between arterial to end tidal CO2 in neurosurgical patients undergoing
craniotomy.
1. To study the correlation in between arterial to end tidal CO2 in neurosurgical patients undergoing craniotomy.
Materials and Methods: This was a prospective study conducted on 30 patients aged between 18 to 60 years who were posted for elective craniotomy under general anaesthesia at a major hospital in an urban area. The patients were included in the study after approval of the institutional ethical committee and written informed valid consent obtained from the patient. Patients were taken to operation theatre and routine pre anesthetic examination was done. Vitals were noted. All patients were anaesthetized using standard balanced general anaesthesia as per attending anesthesiologist and set protocol for neurosurgery cases. PaCO2 and PETCO2 were recorded immediately after induction followed by every hourly till end of surgery. Data was collected and statistical analysis was done with the help of SPSS Software version 15.
Results: Total 30 patients were studied. Out of these cases 18 were males and 12 were females with a maleto female ratio being 1: 0.66. The analysis of age group of the patients revealed that majority (36.66%) of the patients belonged to age group of 31-40 years. The percentage of patients in the age group of 21-30 years and 41-50 years was similar (20%). 12 (40%) patients belonged to ASA I category and 18 (60%) patients belonged to ASA II category. There was no patient belonging to other ASA categories as belonging to ASA I or ASA II category was the inclusion criteria of our study. Most common indication for surgery was meaningioma which was seen in 15 (50%) patients followed by glioma, Cerebellopontine angle tumor, schwannoma and glioblastoma which was seen in 6 (20%), 4 (13.33%), 3 (10%) and 2 (7.66%) patients respectively. All surgeries were uneventful. The analysis of PaCO2 and ETCO2 with respective to mean and standard deviations of pulse rate, Mean arterial pressure and central venous pressure during surgeries showed stable pulse rate, MAP and CVP throughout the surgical procedures thereby ruling out the fluctuations of these parameters as a cause of changes in PaCO2 and ETCO2. The data was analyzed for correlation between PaCO2 and ETCO2 at different intervals during craniotomy. Statistically significant correlation was found between PaCO2 and ETCO2 at baseline, 1hr, 2hr, 3hr and 4hrduring surgery.
Conclusion: In Our study there was a statistically significant correlation between PaCO2 and ETCO2 during elective neurosurgery patients undergoing craniotomy under general anaesthesia. Our study concludes that end-tidal CO2 (ETCO2) reflects arterial CO2 with acceptable accuracy and hence capnometry can be relied upon as a reflection of arterial PaCO2 in neurosurgical patients undergoing craniotomy.
Keywords: End tidal Co2, PaCO2, capnometry, Craniotomy.
References
1. Benallal H, Busso T. Analysis of end-tidal and arterial PCO2 gradients using a breathing model. Eur J Appl Physiol 2000; 83:402-8.
2. Nunn JF: In Nunn JF Applied Respiratory Physiology. 3rd edition London: Butterworths, 1987, pp 207-34.
3. Russell GB, Graybeal JM. End-tidal carbon dioxide as an indicator of arterial carbon dioxide in neurointensive care pati-ents. J Neurosurg Anesth 1992; 4:245-9.
4. Isert PR. Arterial to end-tidal CO2 difference during neurosurgical procedures. Can J Anesth 1996; 43:196-7.
5. McCarter T, Shaik Z, Scarfo K, Thompson LJ. Capnography Monitoring Enhances Safety of Postoperative Patient-Controlled Analgesia. American Health & Drug Benefits. 2008;1(5):28-35.
6. Casati A, Salvo I, Torri G, Calderini E. Arterial to end-tidal carbon dioxide gradient and physiological dead space monitoring during general anaesthesia: effects of patients' position. Minerva Anestesiol. 1997 Jun;63(6):177-82.
7. Gelb AW, Craen RA, Rao GS, Reddy KR, Megyesi J, Mohanty B, Dash HH, Choi KC, Chan MT. Does hyperventilation improve operating condition during supratentorial craniotomy? A multicenter randomized crossover trial. Anesth Analg. 2008 Feb;106(2):585-94.
8. Yoon S, Zuccarello M, Rapoport RM. pCO2 and pH regulation of cerebral blood flow. Frontiers in Physiology. 2012;3:365.
9. Puppo C, Fariña G, López FL, Caragna E, Biestro A. Cerebral CO2 reactivity in severe head injury. A transcranial Doppler study. Acta Neurochir Suppl. 2008; 102:171-5.
10. Rangel-Castillo L, Gopinath S, Robertson CS. Management of Intracranial Hyperte-nsion. Neurologic clinics. 2008;26(2):521-541.
11. Dennis LJ, Mayer SA. Diagnosis and management of increased intracranial pressure. Neurol India. 2001 Jun;49 Suppl 1:S37-50.
12. Agus MS, Alexander JL, Mantell PA. Continuous non-invasive end-tidal CO2 monitoring in pediatric inpatients with diabetic ketoacidosis. Pediatr Diabetes. 2006 Aug;7(4):196-200.
13. Owen R, Castle N. EtCO2: the key to effective prehospital ventilation. Emerge-ncy Medicine Journal : EMJ. 2006;23 (7):578-579.
14. Xu A-J, He Z-G, Xia X-H, Xiang H-B. Anesthetic management for craniotomy in a patient with massive cerebellar infarction and severe aortic stenosis: a case report. International Journal of Clinical and Experimental Medicine. 2015;8(7): 11534-11538.
15. Ferber J, Juniewicz HM, Lechowicz-Głogowska EB, Pieniek R, Wroński J. Arterialto end-tidal carbon dioxide difference during craniotomy in severely head-injured patients. Folia Med Cracov. 2001;42(4):141-52.
16. Garfield B. Russell, MD, FRCPC, and John M. Graybeal Anesth Analg 1995;81:806-10.
17. Kerr ME, Zempsky J, Sereika S, Orndoff P, Rudy EB, “Relationship between arterial carbon dioxide and end-tidal carbon dioxide in mechanically ventilated adults with severe head trauma.” Crit Care Med. 1996 May; 24(5):785-90.
18. Fauzia Khan, Mueenullah Khan, Shemila Abbasi, Department of Anaesthesia, Aga Khan University, Karachi, studied “Arterial to End-Tidal Carbon Dioxide Difference in Neurosurgical Patients undergoing Craniotomy: A Review of Practice”. JPMA 57;446:2007.
19. Husaini J , Y C Choy, “End-tidal to arterial carbon dioxide partial pressure difference during craniotomy in anaesthetised patients.” Med J Malaysia , 2008 Dec;63(5):384-7.
20. Lee SW, Hong YS, Han C, Kim SJ, Moon SW, Shin JH, Baek KJ, “Concordance of end-tidal carbon dioxide and arterial carbon dioxide in severe traumatic brain injury.” J Trauma 2009 Sep;67(3):526-30.