Spinal needle puncture pain can be one of the distressing factors for patient undergoing spinal anesthesia leading to refusal because of fear of puncture pain and postoperative backache [1]. Spinal needle puncture pain has both somatic and psychological components.

Different methods have been described in literature to minimize spinal puncture pain. Pharmacological methods like eutectic mixture of local anesthetic (EMLA) patch, local anesthetic infiltration reduces only somatic component of pain. Local anesthetic infiltration is itself a painful procedure [2,3,4]. EMLA patch and local anesthetic infiltration both do not alleviate psychological component of pain while non-pharmacological methods like attention-diverting measures (pressing ball, audio-visual distraction) minimizes only the psychological component of pain [4,5,6,7].

Valsalva maneuver decreases both somatic and psychological component of pain associated with venous cannulation [8,9]. Present study was planned to evaluate the efficacy of Valsalva maneuver on the attenuation of spinal needle puncture pain.

This prospective, randomized, placebo-controlled study was conducted between July to October 2014, following institutional ethics committee approval (Ref: 2014/114/IP/78) and written informed consent from patients. The study is registered at Clinical Trial Registry of India (Ref: CTRI: 2014:09:005037).

Total 90 patients were enrolled for eligibility, out of which 87 patients were posted for study following randomization and 82 patients i.e. 94% completed the study (Fig. 1). The reasons for patients not being randomized were refusal to participate in the study (3 patients opted for general anesthesia). Five patients were excluded from the study following initial randomization and were therefore not subjected for further analysis (2 could not perform Valsalva maneuver and 3 required second skin prick for successful dura puncture during spinal anesthesia). Total 82 patients were assessed for statistical analysis. There was no difference amongst the groups as regards to age, sex, weight and height distribution (P > 0.05) (Table 1).

Incidence of spinal puncture pain was reduced to 10% (3 of 27) in Valsalva group as compared to 100% (28 of 28 in Control group and 27 of 27 in Distraction group) observed in other two groups (P < 0.05, Table 2). Severity of lumbar puncture pain as assessed by VAS, presented as Median (interquartile range) were significantly reduced in the Valsalva group (0.0 [0.0]) as compared to other 2 groups (2.0 [0.0]) in Distraction group and 3.0 [0.8] in Control group (P < 0.001, Fig. 2).

Regarding time taken by CSF to fill spinal needle hub, there was no difference among the three groups (P > 0.05, Table 3). None patient of all groups had post dural puncture headache (P > 0.05).

In the present study we observed that Valsalva maneuver significantly reduced the incidence and severity of skin puncture pain associated with lumbar puncture (P < 0.05).

Skin puncture is a painful and distressing factor for any patient undergoing spinal anesthesia. Skin puncture gives a patient both physical as well as psychological trauma. Physiological and psychological factors, both determine the perception of skin puncture pain during any invasive procedure. Psychological factor of fear towards needle poke, unknown unanticipated events and anticipation of pain may affect the pain perception of patient. Pain felt during skin puncture can exaggerate anxiety and physiological reactions to further procedure [8]. Valsalva maneuver has been reported to be effective in attenuating venipuncture pain [9]. Pain attenuation observed during skin puncture in the Valsalva group could have been multifactorial. The observed reduction in venipuncture pain in Valsalva group could possibly because of both distraction component and the sinoaortic baroreceptor reflex arc mediated antinociceptive mechanism [9,10,11]. Therefore, we planned to evaluate efficacy of Valsalva maneuver to address both physiological and psychological aspect of skin puncture pain felt during spinal anesthesia.

The Valsalva maneuver is performed by forced expiration against the closed glottis and holding this for at least 16 seconds [10]. We therefore in the present study performed skin puncture for spinal anesthesia 20 seconds following Valsalva maneuver. Valsalva increases intrathoracic pressure leading to great vessels compression which in turn activates baroreceptor as well as distracts the subject from the immediate environment [8,9,10]. Valsalva attenuates pain perception through a complex mechanism as proven by pharmacological, neuro-anatomical, electrophysiological and behavioral data suggesting that systems regulating haemodynamics are closely linked to modulators of pain perception [9]. This has been supported by previous studies showing that activation of baroreceptor reflex arc triggers antinociception [9]. The observed reduction in skin puncture pain in Valsalva group could possibly because of both distraction component and the sinoaortic baroreceptor reflex arc mediated antinociceptive mechanism [9,10,11]. Sinoaortic baroreceptor reflex arc maintains circulatory homeostasis utilizing peripheral receptors and central nervous system through reflex adjustment of parasympathetic and sympathetic efferents to the cardiovascular system. Peripheral activation of sinoaortic baroreceptor reflex arc by cardiovascular stimuli simultaneously involves central nervous system which inhibits pain. Antinociceptive activity of sinoaortic baroreceptor reflex is mediated by three mechanisms like releasing opioid like substance-P into circulation, by secreting vasoconstrictor like noradrenaline increasing blood pressure and by distributing blood towards the heart leading to increased central blood volume [10,11].

Psychological component of pain can be dealt by distracting the patient from the surrounding. Distraction is a congnitive behavioral preparation which acts by manipulating attention framework and by diverting away from pain producing stimulus in the immediate environment [12,13]. Distraction not only reduces magnitude of fear, anxiety and pain but also maximizes coping capability of patient to procedural pain [13,14,15]. Different methods of distraction like cough trick, virtual reality, movies, and balloon inflation have been studied [6,7,8,13]. Ballon inflation technique in pediatric venipuncture utilizes advantage of both psychological and physiological methods of pain attenuation through performing valsalva manuever [8]. Distraction reduces pain by activating the segmental pain inhibitory pathways [16]. Distraction group utilizes direction of attention method but Valsalva mauever incorporates both attention diversion and physiological methods of pain reduction [8].

In our study, Valsalva group has shown significant reduction in incidence and severity of spinal puncture pain as compared to Distraction and Control group.

Limitations of the present study are lack of double blinding; Cerebrospinal fluid pressure wasn't measured during the study; local anesthetic infiltration of the skin and subcutaneous tissue was not done prior to skin puncture. We did not assess pain due to penetration of subcutaneous tissue, ligaments and ligamentum flavum during spinal puncture. We did not monitor duration of analgesic effect of Valsalva maneuver. Further studies are required in this direction.

In conclusion, we report that Valsalva maneuver performed before spinal anesthesia reduced both incidence and severity of spinal puncture pain as compared to Distraction and control group. This magnitude of reduction could be secondary to reduction in both psychological and physiological component of pain by performing Valsalva maneuver. Distraction group was found to be inferior to Valsalva group in reducing pain as it utilizes only attention diversion to reduce pain. Distraction group had shown reduction in severity of pain as compared to control group. We further suggest that Valsalva should be performed routinely in all ASA I and II patients undergoing spinal anesthesia as it is an inexpensive, easy to perform, painless and non-pharmacological method of pain attenuation during spinal puncture.