ISPUB.com / IJA/19/1/12319
  • Author/Editor Login
  • Registration
  • Facebook
  • Google Plus

ISPUB.com

Internet
Scientific
Publications

  • Home
  • Journals
  • Latest Articles
  • Disclaimers
  • Article Submissions
  • Contact
  • Help
  • The Internet Journal of Anesthesiology
  • Volume 19
  • Number 1

Original Article

Pulmonary Aspiration Of Gastric Contents In Anesthesia: A review over 15-year period

F Messahel, A Al-Qahtani

Keywords

complications, gastrointestinal tract

Citation

F Messahel, A Al-Qahtani. Pulmonary Aspiration Of Gastric Contents In Anesthesia: A review over 15-year period. The Internet Journal of Anesthesiology. 2008 Volume 19 Number 1.

Abstract


Objective: Several studies from different countries surveyed the incidence, morbidity and mortality of pulmonary aspiration of gastric contents in anesthesia. No similar studies originated from the Kingdom of Saudi Arabia. This is a study of the incidence, morbidity and mortality of pulmonary aspiration in anesthesia in a Saudi General Hospital over a 15-year period following adoption and application of strict guidelines for the prevention of its occurrence.
Methods: Armed Forces Hospital, Wadi Al-Dawasir, Kingdom of Saudi Arabia, serves military personnel and their families, in addition to eligible civilian members of the community. Anesthetic records were examined to collect demographic details of patients who received a general anesthetic for a surgical procedure from the day of the commission of the hospital on 12.07.1992 until 31.10.2007. This included details of patients who regurgitated and aspirated gastric contents during the course of the anesthetic and recovery.
Results: A total of 12828 patients received general anesthesic during the 15-year period. They included all surgical, trauma, obstetrics and gynecology, and pediatric patients above 12 years. There were 451 patients regurgitated (3,5% of total), out of them 95 (21.1%) were elective and 356 (78.9%) from the emergency group. There were 80 (17.7%) regurgitated at induction and 371 (82.3%) regurgitated at extubation. Chest x-ray was requested for 12 patients and only 2 showed radiological signs of possible aspiration, one of them was admitted to ICU for observation and was discharged after 36 hrs. There was no mortality.
Conclusion: The low incidence and the absence of major morbidity of anesthesia-related pulmonary aspiration in such patient population has demonstrated that adopting quality measures and applying strict and evidence-based guidelines are essential in the prevention of such catastrophes.

 

Introduction

Pulmonary aspiration of gastric contents is one of the most feared complications of anesthesia. Prevention of aspiration by identification of patients at risk, preoperative fasting, drug treatment and various anesthetic maneuvers are cornerstones of safe anesthetic practice. The incidence, morbidity and mortality of pulmonary aspiration have been reported from South Africa, 1 Finland, 2 Sweden, 3 Canada, 4 France, 5 UK, 6 USA, 7,8 and Thailand. 9 with varying incidences, and different rates of morbidity and mortality. There are no similar reports from the Kingdom of Saudi Arabia. This study is looking at the incidence, morbidity and mortality of pulmonary aspiration in a surgical population as a result of general anesthesia over a 15-year period in a Saudi general hospital following adoption of series of approved guidelines for the prevention of pulmonary aspiration during anesthesia.

Methods

Following approval of the Hospital Scientific and Ethics Committee, anesthetic records of patients above 12 years old admitted for surgical procedure under general anesthesia from the day of commission of the hospital on 13.07.1992 until 31.10.2007 were examined. In addition to demographic data, the nature and type of surgery, whether elective or emergency, administration of antacids in risky patients, method used to maintain the airway by cuffed tracheal tube, laryngeal airway mask (LMA) or face mask were noted. The time of regurgitation in relation to the procedure whether at induction, maintenance, or recovery from anesthesia until the patient was fully awake, was recorded.

Results

A total of 12828 patients received general anesthesic during the 15-year period. They included surgical, trauma, obstetrics and gynecology, and pediatric patients above 12 year old. Their demographic details are listed in Table I, and the method of maintaining the airway during anesthesia in Table II.

Figure 1
Table 1: Demographic data of patients received General Anesthetic over 15- year period.

Figure 2
Table 2: Method of maintaining airway in patients received general anesthetic. CTT: cuffed tracheal tube, LMA: laryngeal mask airway, FM: face mask.

Out of the total, 451 patients have shown signs of regurgitation of stomach contents. Their details are shown in Table III.

Figure 3
Table 3: Number and time of patients regurgitated.

All patients who showed signs of regurgitation were managed by oropharyngeal suction, head-down tilt and by turning them on to one side, if allowed. None of the patients who were operated in a lateral or prone position regurgitated at extubation. More than half of the cases regurgitated in the elective group were female patients following laparoscopic cholecystectomy (46 patients), in spite of the fact that they were fasting and had orogastric tube introduced at induction and removed at end of procedure with active suction at the time of insertion and before removal, and free drainage through-out the operation. The number of patients in obstetrics and gynecology group who were operated upon under GA and showed obvious signs of regurgitation was 138; 120 patients of them were from the emergency group. Patients for emergency cesarean section constituted 74, that is 53.6% of this group. They regurgitated at or immediately after extubation and all managed by routine measures.

Out of all those regurgitated, portable chest x-ray was requested for 12 patients of them. Two patients showed signs of radiological pulmonary changes considered to be secondary to aspiration of stomach secretions. One of them was admitted to the intensive care unit for observation and was discharged 36 hrs later. None were reintubated and blood gases estimations were within normal limits. There was no mortality in this series of patients who received GA during the course of their operative intervention.

Discussion

Identification of predisposing factors for pulmonary aspiration is paramount in its prevention. Risk factors include increased gastric pressure, increased tendency to regurgitate, and laryngeal incompetence. 10,11,12,13 Contrary to vomiting, which is an active process, regurgitation is passive in nature. Pulmonary consequences of gastric aspiration fall into three groups: (i) particle-related, (ii) acid-related and (iii) bacterial. Particle-related complications may result in acute airway obstruction leading to arterial hypoxemia and may cause immediate death. The harmful effects of acid aspiration may occur in two phases: (i) immediate direct tissue injury and (ii) subsequent inflammatory response. 14,15,16 Gastric contents are not sterile and infection with bacteria following aspiration may result in pneumonia. 17 With understanding of risk factors in the surgical patient and laying down evidence-based guidelines to be strictly followed and rigorously applied by the surgical, anesthetic and nursing teams, such catastrophes could be avoided. These guidelines include: identification of patients at risk of pulmonary aspiration, period of fasting, the use of pharmacotherapy and the anesthetic technique used.

All patients for elective surgery should fast before administration of the anesthetic. However, it is known that prolonged fasting results in increased gastric pH. 18,19 Recommendations of well established anesthetic bodies in relation to preoperative fasting time for all age groups are applied. 20 Patients for emergency operations should fast the recommended period whenever possible, otherwise they have to be managed as patients at risk of pulmonary aspiration. They are given prophylactic antacid 21 and anesthetized by rapid sequence induction with application of cricoid pressure. 22 Patients admitted for elective procedures and considered at risk for regurgitation are also given prophylactic antacids as premedication.

The high incidence of regurgitation after laparoscopic cholecystectomy comes as no surprise even when patients are fasting and an orogastric tube is introduced at induction of anesthesia. This step is essential to empty the gas from the stomach to prevent gastric perforation during insertion of Verres needle. During surgery the stomach tube is kept open to drain, and at the end of procedure and before removal of tube suction is applied. In spite of all these measures, regurgitation may still occur, and this is due to the presence of pockets within the stomach far from reach of the tip of the gastric tube.

The laryngeal mask airway (LMA) is widely used nowadays in anesthetic practice, but it does not protect against pulmonary aspiration of gastric contents. 23,24 It is recommended that LMA should not be used in morbidly obese patients, and measures should be taken to ensure that the stomach is empty. 25,26

Armed Forces Hospital at Wadi Al-Dawasir, Kingdom of Saudi Arabia, provides both primary and secondary medical care to military personnel and their dependants, and receives entitled patients from the civilian population. It acts as a referral centre for other hospitals in the region including major trauma cases. It is the first hospital in the Kingdom of Saudi Arabia to obtain the ISO 9000 (International Standard Organization) Certificate in 1997. It is also the first hospital in Saudi Arabia and among all military hospitals in the Kingdom to apply Total Quality Management standards in 2003. The hospital has facilities for all types of surgery except open heart operations.

It is important when patient safety is considered that anesthetic staff and assistants must be properly selected, well experienced and closely trained. New members and trainees are adequately oriented and supervised before allowed to practice independently. We would like also to emphasize that regular meetings and the enforcement of the Total Quality Management roles which necessitate regular auditing of departmental activities are essential elements in persistently providing a quality patient service. It is worth mentioning that the vast majority of cases in our study received GA in which regurgitation of stomach contents are known to happen far more than other types of anesthetic techniques, but due to the meticulous application of all the factors mentioned before that such low incidence has been achieved.

References

1. Harrison GG. Death attributable to anesthesia. A ten year survey (1967-1976). Br J Anaesth 1978; 50: 1041-1046
2. Hovi-Viander M. Death associated with anesthesiain Finland. Br J Anesth 1980; 52: 483-489
3. Olsson GL, Hallen B, Hambraeus-Jonzon K. Aspiration during anaesthesia: a computer-aided study of 185,358 anaesthetics. Acta Anaesthesiol Scand 1986; 30: 84-92
4. Cohen MM, Duncan PG, Pope WDP, Wolkenstein C. A survey of 112,000 anaesthetics at one teachibg hospital (1975-83). Can Anaesth Soc J 1986; 33: 22-31
5. Tiret L, Hatton F. Complications associated with anaesthesia-a prospective survey in France. Can Anaesth Soc J 1986; 33: 336-344
6. Leigh JM, Tytler JA. Admissions to the intensive care unit after complications of anaesthestic techniques over 10 years. Anaesthesia 1990; 45: 814-820
7. Warner MA, Warner ME, Weber JG. Clinical significance of pulmonary aspiration during the perioperative period. Anesthesiology 1993; 8: 56-62
8. Sakai T, Planinsic RM, Quinlan JJ, Handley LJ, Kim TY, Hilmi IA. The incidence and outcome of perioerative pulmonary aspiration in a university hospital: a 4-year retrospective analysis. Anesth Analg 2006; 103: 941-947
9. Veerawatakanon T, Rungreungvanich M. The Thai Anesthesia Incidents Study (THAI Study) of pulmonary aspiration: a qualitative analysis. J Med
Assoc Thai 2005, 88 Suppl 7: S76-83
10. Harkness GA, Bentley DW, Roghmann KJ. Risk factors for nosocomial pneumonia in the elderly. Am J Med 1990; 89: 457-463
11. Ishihara H, Singh H, Giesecke AH. Relationship between diabetic autonomic neuropathy and gastric contents. Anesth Analg 1994; 78: 943-947
12. Manchikanti L, Colliver JA, Marrero TC, Roush JR. Ranitidine and metoclopramide for prophylaxis of aspiration pneumonitis in elective surgery. Anesth Analg 1984; 63: 903-910
13. Philips S, Daborn AK, Hatch DJ. Preoperative fasting for paediatric anaesthesia. Br J Anaesth 1994; 73: 529-536
14. Goldman G, Welbourn R, Kobzik L, Valeri CR, Shepro D, Hechtman HB. Synergism between leukotriene B4 and thromboxane A2 in mediating acid-aspiration injury. Surgery 1992; 111: 55-61
15. Kennedy TP, Johnson KJ, Kunkel RG, Ward PA, Knight PR, Finch JS. Acute acid aspiration lung injury in the rat: biphasic pathogenesis. Anesth Analg 1989; 69: 87-92
16. Knight PR, Druskovich G, Tait AR, Johnson KJ. The role of neutrophils, oxidants, and proteases in the pathogenesis of acid pulmonary injury. Anesthesiology 1992; 77: 772-778
17. Johanson WG jr, Harris GD. Aspiration pneumonia, anaerobic infections, and lung abscess. Med Clin North Am 1980; 64: 385-394
18. Manchikanti L, Colliver JA, Marrero TC, Roush JR. Assessment of age-related acid aspiration risk factors in pediatric, adult, and geriatric patients. Anesth Analg 1985; 64: 11-17
19. Hutchison BR, Merry BF. Acid aspiration risk factors. Anesth Analg 1986; 65: 210
20. Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: Application to healthy patients undergoing elective procedures. A report by the American Society of Anesthesiologists Task Force on preoperative fasting. Anesthesiology 1999; 90: 896-905
21. Kluger MT, Willemsen G. Anti-aspiration prophylaxis in New Zealand: A national survey. Aneasth Intensive Care 1998; 26: 70=77
22. Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia. Lancet 1961; 2: 404-406
23. Griffin RM, Hatcher IS. Spiration pneumonia and the laryngeal mask airway. Anaesthesia 1990; 45: 1039-1040
24. Pennant JH, White PF. The laryngeal mask airway: its uses in anesthesiology. Anesthesiology 1993; 79: 144-163
25. Brain AAJ. The Intavent Laryngeal Mask Instruction Manual, 2nd Edn.
26. Meek T, Vincent A, Duggan JE. Cricoid pressure: can protective force be sustained. Br J Anaesth 1998; 80: 672-674

Author Information

Farouk M. Messahel, DA, FRCA
Chief of Anesthesia, Intensive Care & Pain Medicine, Head of Medical Education Department, Armed Forces Hospital

Ali S. Al-Qahtani, DOL, KSUF
Chief of Surgery, Consultant ENT/Head and Neck Surgeon, Armed Forces Hospital

Download PDF

Your free access to ISPUB is funded by the following advertisements:

 

BACK TO TOP
  • Facebook
  • Google Plus

© 2013 Internet Scientific Publications, LLC. All rights reserved.    UBM Medica Network Privacy Policy