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Three Part Question

In [patients undergoing a lateral thoracotomy] is [intrathecal analgesia better than IV analgesia] for [complication free analgesia]?

Clinical Scenario

A patient requires a thoracotomy for resection of a lobe of their lung is worried about pain relief post-operatively. You wonder whether it might be pertinent to provide them with an spinal block rather than prescribe IV analgesia for the immediate post-operative period.

Search Strategy

Medline 1950-present and Embase 1980-present were searched using the nhs healthcare database information resources interface. The cochrane library was also searched on 8th October 2011.
Medline and embase:
"intrathecal morphine" OR "intrathecal opioids" OR "spinal morphine" OR "spinal opioids" OR "intrathecal analgesia" OR "spinal morphine").ti,ab AND ("thoractomy" OR "thorac*" OR "cardiothoracic" OR "cardio-thoracic" OR "thoracic surgery").ti,ab

Cochrane library:
("analgesia" OR "anal*" OR "morphine") AND "thorac*"

Search Outcome

Medline and embase:
133 abstracts were identified by the search of medline and Embase, of which 4 were suitable for this topic.

Cochrane library:
No results matched the search criteria

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Askar FZ, et al. 2007 USA	33 patients undergoing thoractomy randomised into 2 groups: The IV PCA morphine and intrathecal morphine group (n=17) and control group (IV PCA morphine only) (n=16).	1b - prospective randomised clinical trial	Post-operative VAS pain score	Reduced at rest, while coughing and while moving at 4 hours, 24 hours and 48 hours in the intrathecal morphine group (all p<0.01)	Small patient numbers meaning results may not be suitably reliable to draw firm conclusions from. The randomisation was not blinded and so may have had an impact by introcuding error. The patients were undergoing a heterogenous group of operations, which may have impacted on pain scores as the operations were not matched between groups.
			Peak expiratory flow rate (PEFR)	The best PEFR scores were 72% of pre-operative level in the intrathecal group and 61% in the control group (p<0.05)
			Morphine demand	Lower in intrathecal morphine group (8.82 (+/-6.82) mg) than non-intrathecal group (20.12 (+/- 15.78) mg) (p<0.05)
			Post-operative sedation	Higher in the intrathecal morphine group at 10 and 30 minutes post-operative (p<0.05), but lower at 24 hours post-operation (p<0.05)
			Mean arterial pressure	No significant difference
			Heart rate	No significant difference
			Respiratory rate	No significant difference
Liu N, et al. 2001 France	50 patients in total. 20 control patients receiving on IV PCA morphine. 10 patients each in the groups: Intrathecal morphine (group M), intrathecal sufentanil (group S), or intrathecal morphine and sufentanil (group M-S).	1b - prospective randomised double-blinded study	Post-operative IV PCA morphine usage	Higher in control group (71 +/- 30 mg) compared to group M (38 +/-31 mg, p<0.05), group S (46 +/-34 mg, p<0.05), and group S-M (23 +/-16 mg, p<0.01).	No use of a true placebo group (e.g. intrathecal saline injection). Only one dose of each of the drugs was used, so not able to distinguish between additive and supraadditive effect.
			Post-operative VAS pain score	Higher in control group than all three intervention groups at rest for first 0-11 hours post-operation (p<0.05 for all comparisons) and on coughing for the first 0-8 hours post-operation (p<0.05 for all comparisons).
Cohen E, et al. 1993 USA	24 patients, 12 received intrathecal injection of 12 micrograms/kg morphine sulphate, the remaining 12 acted as controls. Anaesthesia was maintained solely by enflurane for all patients, titrated to keep mean arterial pressure within 15% of the preoperative values.	2b - Individual randomised control trial.	Intraoperative mean end-tidal volume concentration of enflurane	Significantly reduced in the group receiving intrathecal morphine (0.73 +/- 0.08%) than the control group (1.19 +/- 0.45%) (p<0.05)	The number of patients was relatively low. The method of randomisation was not mentioned. The patients were randomised, but the researchers were not blinded to groups. The post-operative aspects of the intrathecal morphine were not investigated in this paper. Other parameters other than enflurane requirements were not measured.
Neustein SM, et al. 1993 USA	30 patients, 16 received 12 micrograms/kg of intrathecal morphine, the remaining 14 patients were controls.	1b - Individual randomised control trial.	Post-operative VAS pain score	Those receiving intrathecal morphine had lover pain scores (1.4 +/- 1.1) than controls (2.4 +/- 0.9) (p<0.05).	The number of patients was relatively low. The method of randomisation was not mentioned. The patients were randomised, but the researchers were not blinded to the groups.
			Total 24 hour dose of meperidine	Those receiving intrathecal morphine used significantly less meperidine (59 +/- 68 mg) compared to controls (167 +/- 97 mg) (p<0,05).

Comment(s)

While there have been many papers investigating the efficacy of different types of intrathecal analgesia in patients undergoing a thoractomy, most have not compared this to IV analgesia. Those that have have been prospective randomised clinical trials (one double-blind, three not) meaning that this data set can be seen to be reliable. The three papers investigating the post-operative parameters found that intra-operative intrathecal analgesia results in reduced pain, reduced IV PCA morphine use, and improved lung function. The paper by Cohen and Neustein identified that intrathecal analgesia results in reduced anaesthetic requirements. 4 patients in the study by Askar et al. complained of post-spinal headache which resolved following conservative treatment.

Clinical Bottom Line

The clinical outcomes of pain, morphine use and post-operative lung function are are improved by the use of intrathecal analgesia in patients receiving a thoracotomy. Intra-operative anaesthetic requirements were reduced by using intrathecal analgesia. Other outcomes including post-operative sedation and opioid-related complications are comparable between the groups. Therefore, any patient who is to undergo a thoracotomy and who is suitable for receiving intrathecal analgesia, should have this option made available to them.

References

1. Askar FZ, Kocabas S, Yucel S, Samancilar O, Cetin HY, Uyar M. The efficacy of intrathecal morphine in post-thoracotomy pain management J Int Med Res 2007 May-Jun;35(3):314-22.
2. Liu N, Kuhlman G, Dalibon N, Moutafis M, Levron JC, Fischler M. A randomized, double-blinded comparison of intrathecal morphine, sufentanil and their combination versus IV morphine patient-controlled analgesia for postthoracotomy pain Anesthesia and Analgesia 2001 Jan;92(1):31-6.
3. Cohen E, Neustein SM. Intrathecal morphine during thoracotomy, part I: Effect on intraoperative enflurane requirements. Journal of Cardiothoracic and Vascular Anaesthesia 1993;7(2):154-6
4. Neustein SM, Cohen E. Intrathecal morphine during thoracotomy, part II: Effect on postoperative meperidine requirements and pulmonary function tests Journal of Cardiothoracic and Vascular Anaesthesia 1993;7(2):157-9.