|LETTER TO EDITOR
|Year : 2013 | Volume
| Issue : 1 | Page : 95
Patient position for spinal anaesthesia: Flexed-back versus straight-back
Department of Anaesthesia and Intensive Care, Vardhman Mahavir Medical College and Safdarjang Hospital, New Delhi, India
|Date of Web Publication||14-Mar-2013|
C 17 HUDCO Place, New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Prakash S. Patient position for spinal anaesthesia: Flexed-back versus straight-back. Indian J Anaesth 2013;57:95
I read with great interest the article "Patient position for spinal anaesthesia: Flexed-back versus straight-back" by Biswas et al. in which the authors determined the success of subarachnoid block performed in the optimal flexed position versus a straight-back posture in non-obese patients with palpable spinous processes. I would like to highlight some of my concerns about the study, as detailed below:
- I find the conclusions of the study misleading. The authors state that the overall success rate of correct spinal placement was comparable in the straight-posture group and flexed-posture group. However, this was achieved at the expense of an increased number of attempts and needle redirections. Perusal of their data in terms of straight-back and flexed-back groups shows that 4/80 patients in the straight-back group (sitting and lateral groups combined) had a failed block as compared with 0/80 patients in the flexed-back group; 12/80 patients required a second attempt in the straight-back group as compared with 4/80 in the flexed-back group; 53/80 patients in the straight-back group required needle-redirection as compared with 21/80 in the flexed-back group; 8/80 patients in the straight-back group experienced nerve root irritation as compared with 2/80 in the flexed-back group.
Filho et al. reported that the successful location of the subarachnoid or the epidural space at the first attempt is influenced by the quality of patients' anatomical landmarks, the adequacy of patient positioning, and the provider's level of experience. Incorrect posture resulting in multiple attempts may cause patient discomfort (thus rendering the technique unpleasant to the patient), a higher incidence of spinal hematoma, post-dural puncture headache, and trauma to neural structures.  Indeed, there are patients who are unable to adopt the ideal flexed posture due to arthritis, spondylosis, or pain due to limb trauma. In such patients, one has no option but to perform spinal anaesthesia in a sub-optimally flexed position, wherein the paramedian approach may be useful.
- The straight-back posture was preferred by 12.5% of the patients in the sitting-flexed position group because of discomfort over the neck. I have observed in my practice that often the assistant exerts considerable pressure on the patient's neck under the erroneous impression that success of the procedure depends on a flexed neck. Intrathecal puncture is performed at L3-4/L4-5 interspace; the patient simply needs to arch his/her back quite like the back of a crouched cat. The assistant should support the patient at the shoulders and not exert pressure on the neck.
- The authors state in the results that "patients in the lateral-flexed group did not require redirection of needles." However, the table in their article depicts that 20 patients required needle redirection in the lateral-flexed group.
Based on these considerations, I am not convinced that the findings of Dr. Biswas et al. could challenge the clinical usefulness of the flexed position for performance of spinal anaesthesia. I believe that the flexed position is still the optimal position for spinal position for reducing the number of attempts and needle-redirections.
| References|| |
|1.||Biswas BK, Agarwal B, Bhattarai B, Dey S, Bhattacharya P. Straight versus flex back: Does it matter in spinal anaesthesia? Ind J Anaesth 2012;56:259-64. |
|2.||de Oliveira Filho GR, Gomes HP, da Fonseca MH, Hoffman JC, Pederneiras SG, Garcia JH. Predictors of successful neuraxial block: A prospective study. Eur J Anaesthesiol 2002;19:447-51. |
|3.||Atallah MM, Demian AD, Shorrab AA. Development of a difficulty score for spinal anaesthesia. Br J Anaesth 2004;92:354-60. |