CLINICAL INVESTIGATION
Regional Anesthesia to Scalp for Craniotomy: Innovation With Innervation Kavitha Jayaram, DNB, Moningi Srilata, MD, Dilipkumar Kulkarni, MD, and Gopinath Ramachandran, MD, DA(UK), FFARCS Background: Effective management and pain prevention is of great importance to avoid postoperative complications such as hypertension, agitation, and vomiting. All these adverse events may lead to elevation in intracranial pressure and, in turn, unfavorable outcome and prolonged hospital stay. Development of multiple methods of analgesia may contribute to the alleviation of problems due to pain. We tested the effectiveness of bilateral maxillary block with greater and lesser occipital nerve block for providing analgesia to the scalp. Materials and Methods: This study was undertaken in 40 patients scheduled for craniotomy. Before skin incision, patients were assigned randomly to receive either bilateral maxillary (group M) or scalp block (group S). Data on intraoperative hemodynamics, postoperative analgesia, and sedation were collected and analyzed for statistical significance. Results: The primary outcome was the visual analog pain score. It was similar between the 2 groups at 1, 2, and 4 hours after extubation. At 12 hours, the maxillary block group had better analgesia (mean visual analog score: 3.4 cm for group M and 4.1 cm for group S with P-value of 0.0002) and sedation scores. Intraoperatively, there was no difference in the heart rate, blood pressure, and the anesthetic requirements between both the groups. Three patients in group S required fentanyl supplementation in the intraoperative period. There were no adverse events noted in the perioperative period among both the groups. Conclusions: Maxillary block along with greater and lesser occipital nerve block is an effective alternative to scalp block for craniotomy and has longer duration of analgesia. Key Words: craniotomy, maxillary nerve, scalp, nerve blockade (J Neurosurg Anesthesiol 2015;00:000–000)
S
everal clinical studies indicate poor postoperative pain management after craniotomy owing to lack of evidence-based guidelines and standardized management
Received for publication November 7, 2014; accepted March 9, 2015. From the Department of Anesthesiology and Critical Care, Nizam’s Institute of Medical Sciences, Hyderabad, India. K.J.: manuscript preparation, reference collection; S.M.: manuscript content and preparation; D.K. and G.R.: final script evaluation. The authors have no funding or conflicts of interest to disclose. Reprints: Kavitha Jayaram, DNB, Department of Anesthesiology, Nizam’s Institute of Medical Sciences, 500008 Hyderabad, India (e-mail: [email protected]). Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved.
J Neurosurg Anesthesiol
protocols.1–3 Postoperative pain has been described as superficial in the majority of patients, suggesting the role of pericranial muscles and soft tissue in its genesis. The highest incidence of headache was observed 12 hours after operation.4 The possible pathophysiological mechanisms are mechanical and chemical irritation of the muscles, periosteum, dura, and trigeminal nerves during surgery.4–6 Through unknown preemptive mechanisms, scalp block decreases postoperative headache and its effects lasts longer than expected.7,8 The scalp is innervated by the ophthalmic (supraorbital, supratrochlear) maxillary (zygomaticotemporal), and mandibular (auriculotemporal) divisions of the trigeminal nerve anterolaterally and greater and the lesser occipital branches of the deep cervical plexus posteriorly. The dura mater is innervated mainly by the major 3 branches of the trigeminal nerve, and hence blockade of these branches will provide analgesia to the dura as well.9 As per the pathophysiology of postoperative headache mentioned above, blockade of the nerves at the origin such as plexus blockade might reduce the incidence of acute postoperative headache after craniotomy. Maxillary nerve block given through intraoral approach has a higher success rate than the high tuberosity approach owing to precise anatomic points such as greater palatine foramen that leads to the infratemporal fossa. The pterygopalatine fossa contains the maxillary nerve and pterygopalatine ganglion, pterygoid artery and vein, and connective tissue.9,10 Anesthetic solution when injected into the pterygopalatine fossa diffuses into the infratemporal fossa through the pterygomaxillary fissure if the volume exceeds that of the fossa.11 This is likely to block all the 3 branches of the trigeminal nerve that produces analgesia in the anterolateral region of scalp. We have tried to base our block on this anatomic advantage of division of trigeminal nerve in the infratemporal fossa (Fig. 1). We designed this prospective randomized doubleblind controlled study to test the hypothesis that bilateral maxillary block along with greater and lesser occipital nerve block provides postoperative pain relief similar to scalp block. Secondarily, intraoperative anesthetic requirements were evaluated.
MATERIALS AND METHODS After institutional ethics committee approval and informed consent, 45 ASA grade I, II, and III patients scheduled for craniotomy were recruited for the study.
Volume 00, Number 00, ’’ 2015
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
www.jnsa.com |
1
Jayaram et al
J Neurosurg Anesthesiol
Volume 00, Number 00, ’’ 2015
FIGURE 1. Pterygopalatine fossa and its relation to the trigeminal nerve. The stippled area shows pterygopalatine fossa and the passage for drug spread to the infratemporal fossa.
(To account for loss of accrual from inability to complete the protocol or technical difficulty, we enrolled a total of 45 patients. A minimum sample size of 30 (15 per group) was determined statistically—see below.) The patients were randomly assigned into 2 groups based on computer-generated simple randomization of either group M (maxillary block) or group S (scalp block). Patients were premedicated with alprazolam 0.5 mg and ranitidine 150 mg orally on the night before and morning of the surgery. The patients were informed about the visual analog score (VAS) in centimeter and explained with pictorial representation for postoperative pain relief during the preanesthetic assessment. Exclusion criteria included inability to understand and incapacity to use VAS score, allergy to local anesthetics, and significant pathology at the sites of infiltration and patients who were chosen for elective postoperative ventilation and postinclusion postop ventilation. On arrival to the operating room, monitors (noninvasive blood pressure, electrocardiogram, pulse oximeter, entropy [GE healthcare, Helsinki, Finland]) were attached. After intravenous and arterial cannulation under local anesthesia, patients were administered intravenous fentanyl (2 mg/kg). Induction was with injection thiopentone 3 to 5 mg/kg titrated to the entropy of 50 to 60 and neuromuscular blockade with atracurium injection (0.5 mg/kg). After intubation, based on the randomization, patients were grouped and accordingly block was given using prepared solution of volume 30 mL (15 mL of 0.5% bupivacaine and 15 mL of 2% lignocaine).
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Group S The standard scalp block technique was performed by infiltrating 30 mL of local anesthetic solution at multiple sites with 23-G needle. First, the supraorbital and supratrochlear nerves were blocked as they emerge from orbit with 4 mL of the prepared solution. The auriculotemporal and greater auricular nerves were blocked anterior and posterior to the ear at the level of tragus with 3 mL each. Lastly, the greater and lesser occipital nerves were blocked by injection along the superior nuchal line with 5 mL.
Group M The greater palatine foramen was located using cotton applicator stick applying pressure to the palatal mucosa between the second and third molars. Using 25-G long needle, the palatal mucosa was entered at an angle of approximately 45 degrees to the long axis of hard palate. If the needle did not immediately enter the foramen, stepping of the needle around the region till it dips into the foramen was done. Then the needle is slowly advanced 2 to 3 mm depth to enter the pterygopalatine fossa (needle placement was confirmed using C-arm by taking lateral view of the head), and 10 mL of prepared solution was injected after negative aspiration. The common error of this technique is stepping the needle off of the posterior aspect of the hard palate that can be detected by the ease with which the needle enters the nasopharynx. This results in the drug entering the posterior nasal cavity and the antrum. Minimal resistance was encountered during Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
J Neurosurg Anesthesiol
Volume 00, Number 00, ’’ 2015
Regional Anesthesia to Scalp for Craniotomy
Statistical Analysis
injection as the volume of pterygopalatine fossa is less and oral cavity examined for seepage of drug that implies needle displacement. After blocking both sides of the maxillary nerve, the greater occipital and lesser occipital nerve were blocked bilaterally with 5 mL of drug on each side. A 16-G cavafix (B Braun, Germany) was placed in the right cubital fossa for peripherally inserted central venous access. Maintenance of anesthesia was achieved with air and oxygen mixture along with minimal alveolar concentration (MAC) of isoflurane upto 1%. Continuous infusion of atracurium (0.5 mg/kg/h) and fentanyl (2 mg/ kg/h) was used to maintain neuromuscular blockade and analgesia. The surgeons infiltrated the site of skin incision with normal saline combined with adrenaline. All the values during the intraoperative and the postoperative period were recorded by an independent observer who was blinded to the technique of block given.
The sample size was calculated using G-power version 3.1.9 on the basis of the effect size of the study performed by El-Dahab,12 in which scalp block was given before incision for postoperative analgesia. To achieve statistical power of 0.95 at a significance level of P < 0.05, a minimum sample size of 15 patients per group was calculated based on their data on pain scores after the first postoperative hour. Statistical analysis was performed using NCSS version 9 and MS-excel was used for graphical representation of the data. Normal distribution of the data was checked by Anderson Darling test, and variance by Levene’s imbalance test. All the continuous variables were given as mean and SD. Hemodynamic variables, postoperative VAS, and sedation were analyzed using repeated measures ANOVA. Tukey’s all-pair comparisons was used for post hoc analysis and the values between each of the conditions between and within groups were considered significant when P-value was 4 cm, patients were treated with 75 mg of diclofenac injection intramuscularly and the need for analgesic supplementation was recorded. Complications both due to local anesthetic and the blocks were addressed and recorded.
RESULTS Recruitment was done from July to September 2014. Of the recruited 45 patients, 4 were excluded as 1 had maxillary sinusitis, 2 patients had nasal bone fractures, and the other patient refused to participate. The remaining patients were randomly assigned into 2 groups. One patient in the maxillary block group was excluded from the study as he was not extubated due to prolonged surgery.
Demographic Data The data were found to be normally distributed without any variance with respect to the demographic parameters and baseline hemodynamics. The demographic data were comparable between the groups (Table 1).
Hemodynamics in the Intraoperative Period The mean of the heart rate, mean arterial pressure, and anesthetic concentrations at different time intervals are depicted in Figures 2–4, respectively. None of the hemodynamic variables in the intraoperative period were statistically significant both between and within the groups. There was a transient increase in the heart rate
TABLE 1. Comparison of Demographic Profile, Type of Surgery, Duration of Surgery, and Anesthesia in Both the Groups Age (y) Sex (M/F)* BMI Duration of surgery (min) Duration of anesthesia (min) Type of surgery supratentorial/infratentorial/retromastoid*
Group M (Mean ± SD)
Group S (Mean ± SD)
Probability
42.16 ± 12.74 11/9 25.41 ± 3.13 236.95 ± 72.68 283.33 ± 75.23 15/5/5
37.56 ± 10.96 12/8 25.83 ± 3.45 258.61 ± 46.04 299.72 ± 49.54 16/4/3
0.25 0.69 0.29 0.44
*Given as number of patients. BMI indicates body mass index; Group M, Maxillary block group; Group S, Scalp block group; M/F, male/female.
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2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
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3
Jayaram et al
J Neurosurg Anesthesiol
Volume 00, Number 00, ’’ 2015
Inhaled anesthetic requirement(MAC) 0.80 MAC value
0.70 0.60 0.50 0.40
Gr M
0.30
Gr S
0.20
FIGURE 4. Inhaled anesthetic requirement (MAC) in both the groups given as mean values. Base indicates baseline; Inci, incision; M, maxillary block; MAC, minimum alveolar concentration; S, scalp block.
retromastoid suboccipital craniotomy, but it was not statistically significant.
Postoperative Analgesia FIGURE 2. Comparison of heart rate (HR) changes in both the groups. M indicates maxillary block; S, scalp block.
and blood pressure at the time of incision, but was comparable in both the groups. The requirement of inhalational agent as measured by the MAC at different time periods was comparable between both the groups. Opioid supplementation in the intraoperative period was not required in any patients in the maxillary block group, whereas in the scalp block group 3 patients required boluses of fentanyl. All the 3 patients underwent
FIGURE 3. Comparison of intraoperative mean arterial pressure (MAP) changes in both the groups. M indicates maxillary block; S, scalp block.
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Postoperatively, the VASs were comparable at 1, 2, and 4 hours. At 12 hours, the mean value of VAS score was 3.4 cm for group M and 4.1 cm for group S with a P-value of 0.002 (Fig. 5; Table 2). The fraction of patients requiring supplemental diclofenac analgesia at 12 hours was greater in group S (P = 0.025). The results are depicted in Table 3. In total, 4 patients in group M and 14 patients in group S had received a dose of diclofenac injection in the postoperative period. Of these, 1 patient in group M who underwent retromastoid craniectomy received analgesia at 12
FIGURE 5. Comparison of postoperative VAS in both the groups. M indicates maxillary block; S, scalp block; VAS, visual analog score. Copyright
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2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
J Neurosurg Anesthesiol
Volume 00, Number 00, ’’ 2015
TABLE 2. Visual Analog Scores at Various Time Intervals Between the Groups in the Postoperative Period Given as Mean (SE of Mean) Group M (Mean [SEM]) 1h 2h 4h 12 h
2.25 2.9 3.15 3.4
(0.114) (0.114)* (0.114)* (0.114)*z
2.35 2.75 3.25 4.1
(0.114) (0.114) (0.114)* (0.114)*z
hours, whereas all the 4 patients of group S received analgesia at 2 and 4 hours.
Postoperative Sedation Sedation scores differed at 4 hours after extubation and at 12 hours. The mean values at 4 hours after extubation were 2.3 and 1.85 for group M and S, respectively (P = 0.005). Within the group there was a statistically significant difference between 4 and 12 hours values compared with 1 hour in both the groups (Table 4).
Adverse Events No adverse events were recorded in the intraoperative and the postoperative periods in either group.
DISCUSSION About 87% of the patients suffer from pain during the first 24 hours after craniotomy as per Mordhost et al.13 There has been reluctance to administer opioids owing to the risk of emesis and hypoventilation-induced hypercapnia with their attendant potential to increase intracranial pressure. Regional blocks have the advantage of blunting the hemodynamic responses during perioperative period and also facilitate more rapid and smooth emergence with lesser cognitive dysfunction in craniotomies.14 Prior clinical trials of scalp block for craniotomy patients have found it to be superior placebo and to provide similar postoperative pain relief to intravenous morphine8,15, with a lesser response to surgical stimulation as measured by ACTH, serum cortisol, and hemodynamic changes.16 Because we considered scalp block the gold standard, we compared it against maxillary block. TABLE 3. Comparison of Postoperative Analgesic Requirement Given as Number of Patients Received Analgesia (Percentage) Between the 2 Groups and Probability Group M (N [%])
Group S (N [%])
Probability
None 1 (5.56) 1 (5.56) 2 (11.11)
None 2 (11.11) 4 (22.22) 8 (44.44)
0.546 0.148 0.026
Group M indicates maxillary block group; Group S, scalp block group.
Copyright
r
TABLE 4. Ramsay Sedation Score at Different Time Intervals Between the Groups Given as Mean (SEM) Mean (SEM)
Group S (Mean [SEM])
*P-value
Regional Anesthesia to Scalp for Craniotomy: Innovation With Innervation Kavitha Jayaram, DNB, Moningi Srilata, MD, Dilipkumar Kulkarni, MD, and Gopinath Ramachandran, MD, DA(UK), FFARCS Background: Effective management and pain prevention is of great importance to avoid postoperative complications such as hypertension, agitation, and vomiting. All these adverse events may lead to elevation in intracranial pressure and, in turn, unfavorable outcome and prolonged hospital stay. Development of multiple methods of analgesia may contribute to the alleviation of problems due to pain. We tested the effectiveness of bilateral maxillary block with greater and lesser occipital nerve block for providing analgesia to the scalp. Materials and Methods: This study was undertaken in 40 patients scheduled for craniotomy. Before skin incision, patients were assigned randomly to receive either bilateral maxillary (group M) or scalp block (group S). Data on intraoperative hemodynamics, postoperative analgesia, and sedation were collected and analyzed for statistical significance. Results: The primary outcome was the visual analog pain score. It was similar between the 2 groups at 1, 2, and 4 hours after extubation. At 12 hours, the maxillary block group had better analgesia (mean visual analog score: 3.4 cm for group M and 4.1 cm for group S with P-value of 0.0002) and sedation scores. Intraoperatively, there was no difference in the heart rate, blood pressure, and the anesthetic requirements between both the groups. Three patients in group S required fentanyl supplementation in the intraoperative period. There were no adverse events noted in the perioperative period among both the groups. Conclusions: Maxillary block along with greater and lesser occipital nerve block is an effective alternative to scalp block for craniotomy and has longer duration of analgesia. Key Words: craniotomy, maxillary nerve, scalp, nerve blockade (J Neurosurg Anesthesiol 2015;00:000–000)
S
everal clinical studies indicate poor postoperative pain management after craniotomy owing to lack of evidence-based guidelines and standardized management
Received for publication November 7, 2014; accepted March 9, 2015. From the Department of Anesthesiology and Critical Care, Nizam’s Institute of Medical Sciences, Hyderabad, India. K.J.: manuscript preparation, reference collection; S.M.: manuscript content and preparation; D.K. and G.R.: final script evaluation. The authors have no funding or conflicts of interest to disclose. Reprints: Kavitha Jayaram, DNB, Department of Anesthesiology, Nizam’s Institute of Medical Sciences, 500008 Hyderabad, India (e-mail: [email protected]). Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved.
J Neurosurg Anesthesiol
protocols.1–3 Postoperative pain has been described as superficial in the majority of patients, suggesting the role of pericranial muscles and soft tissue in its genesis. The highest incidence of headache was observed 12 hours after operation.4 The possible pathophysiological mechanisms are mechanical and chemical irritation of the muscles, periosteum, dura, and trigeminal nerves during surgery.4–6 Through unknown preemptive mechanisms, scalp block decreases postoperative headache and its effects lasts longer than expected.7,8 The scalp is innervated by the ophthalmic (supraorbital, supratrochlear) maxillary (zygomaticotemporal), and mandibular (auriculotemporal) divisions of the trigeminal nerve anterolaterally and greater and the lesser occipital branches of the deep cervical plexus posteriorly. The dura mater is innervated mainly by the major 3 branches of the trigeminal nerve, and hence blockade of these branches will provide analgesia to the dura as well.9 As per the pathophysiology of postoperative headache mentioned above, blockade of the nerves at the origin such as plexus blockade might reduce the incidence of acute postoperative headache after craniotomy. Maxillary nerve block given through intraoral approach has a higher success rate than the high tuberosity approach owing to precise anatomic points such as greater palatine foramen that leads to the infratemporal fossa. The pterygopalatine fossa contains the maxillary nerve and pterygopalatine ganglion, pterygoid artery and vein, and connective tissue.9,10 Anesthetic solution when injected into the pterygopalatine fossa diffuses into the infratemporal fossa through the pterygomaxillary fissure if the volume exceeds that of the fossa.11 This is likely to block all the 3 branches of the trigeminal nerve that produces analgesia in the anterolateral region of scalp. We have tried to base our block on this anatomic advantage of division of trigeminal nerve in the infratemporal fossa (Fig. 1). We designed this prospective randomized doubleblind controlled study to test the hypothesis that bilateral maxillary block along with greater and lesser occipital nerve block provides postoperative pain relief similar to scalp block. Secondarily, intraoperative anesthetic requirements were evaluated.
MATERIALS AND METHODS After institutional ethics committee approval and informed consent, 45 ASA grade I, II, and III patients scheduled for craniotomy were recruited for the study.
Volume 00, Number 00, ’’ 2015
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
www.jnsa.com |
1
Jayaram et al
J Neurosurg Anesthesiol
Volume 00, Number 00, ’’ 2015
FIGURE 1. Pterygopalatine fossa and its relation to the trigeminal nerve. The stippled area shows pterygopalatine fossa and the passage for drug spread to the infratemporal fossa.
(To account for loss of accrual from inability to complete the protocol or technical difficulty, we enrolled a total of 45 patients. A minimum sample size of 30 (15 per group) was determined statistically—see below.) The patients were randomly assigned into 2 groups based on computer-generated simple randomization of either group M (maxillary block) or group S (scalp block). Patients were premedicated with alprazolam 0.5 mg and ranitidine 150 mg orally on the night before and morning of the surgery. The patients were informed about the visual analog score (VAS) in centimeter and explained with pictorial representation for postoperative pain relief during the preanesthetic assessment. Exclusion criteria included inability to understand and incapacity to use VAS score, allergy to local anesthetics, and significant pathology at the sites of infiltration and patients who were chosen for elective postoperative ventilation and postinclusion postop ventilation. On arrival to the operating room, monitors (noninvasive blood pressure, electrocardiogram, pulse oximeter, entropy [GE healthcare, Helsinki, Finland]) were attached. After intravenous and arterial cannulation under local anesthesia, patients were administered intravenous fentanyl (2 mg/kg). Induction was with injection thiopentone 3 to 5 mg/kg titrated to the entropy of 50 to 60 and neuromuscular blockade with atracurium injection (0.5 mg/kg). After intubation, based on the randomization, patients were grouped and accordingly block was given using prepared solution of volume 30 mL (15 mL of 0.5% bupivacaine and 15 mL of 2% lignocaine).
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Group S The standard scalp block technique was performed by infiltrating 30 mL of local anesthetic solution at multiple sites with 23-G needle. First, the supraorbital and supratrochlear nerves were blocked as they emerge from orbit with 4 mL of the prepared solution. The auriculotemporal and greater auricular nerves were blocked anterior and posterior to the ear at the level of tragus with 3 mL each. Lastly, the greater and lesser occipital nerves were blocked by injection along the superior nuchal line with 5 mL.
Group M The greater palatine foramen was located using cotton applicator stick applying pressure to the palatal mucosa between the second and third molars. Using 25-G long needle, the palatal mucosa was entered at an angle of approximately 45 degrees to the long axis of hard palate. If the needle did not immediately enter the foramen, stepping of the needle around the region till it dips into the foramen was done. Then the needle is slowly advanced 2 to 3 mm depth to enter the pterygopalatine fossa (needle placement was confirmed using C-arm by taking lateral view of the head), and 10 mL of prepared solution was injected after negative aspiration. The common error of this technique is stepping the needle off of the posterior aspect of the hard palate that can be detected by the ease with which the needle enters the nasopharynx. This results in the drug entering the posterior nasal cavity and the antrum. Minimal resistance was encountered during Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
J Neurosurg Anesthesiol
Volume 00, Number 00, ’’ 2015
Regional Anesthesia to Scalp for Craniotomy
Statistical Analysis
injection as the volume of pterygopalatine fossa is less and oral cavity examined for seepage of drug that implies needle displacement. After blocking both sides of the maxillary nerve, the greater occipital and lesser occipital nerve were blocked bilaterally with 5 mL of drug on each side. A 16-G cavafix (B Braun, Germany) was placed in the right cubital fossa for peripherally inserted central venous access. Maintenance of anesthesia was achieved with air and oxygen mixture along with minimal alveolar concentration (MAC) of isoflurane upto 1%. Continuous infusion of atracurium (0.5 mg/kg/h) and fentanyl (2 mg/ kg/h) was used to maintain neuromuscular blockade and analgesia. The surgeons infiltrated the site of skin incision with normal saline combined with adrenaline. All the values during the intraoperative and the postoperative period were recorded by an independent observer who was blinded to the technique of block given.
The sample size was calculated using G-power version 3.1.9 on the basis of the effect size of the study performed by El-Dahab,12 in which scalp block was given before incision for postoperative analgesia. To achieve statistical power of 0.95 at a significance level of P < 0.05, a minimum sample size of 15 patients per group was calculated based on their data on pain scores after the first postoperative hour. Statistical analysis was performed using NCSS version 9 and MS-excel was used for graphical representation of the data. Normal distribution of the data was checked by Anderson Darling test, and variance by Levene’s imbalance test. All the continuous variables were given as mean and SD. Hemodynamic variables, postoperative VAS, and sedation were analyzed using repeated measures ANOVA. Tukey’s all-pair comparisons was used for post hoc analysis and the values between each of the conditions between and within groups were considered significant when P-value was 4 cm, patients were treated with 75 mg of diclofenac injection intramuscularly and the need for analgesic supplementation was recorded. Complications both due to local anesthetic and the blocks were addressed and recorded.
RESULTS Recruitment was done from July to September 2014. Of the recruited 45 patients, 4 were excluded as 1 had maxillary sinusitis, 2 patients had nasal bone fractures, and the other patient refused to participate. The remaining patients were randomly assigned into 2 groups. One patient in the maxillary block group was excluded from the study as he was not extubated due to prolonged surgery.
Demographic Data The data were found to be normally distributed without any variance with respect to the demographic parameters and baseline hemodynamics. The demographic data were comparable between the groups (Table 1).
Hemodynamics in the Intraoperative Period The mean of the heart rate, mean arterial pressure, and anesthetic concentrations at different time intervals are depicted in Figures 2–4, respectively. None of the hemodynamic variables in the intraoperative period were statistically significant both between and within the groups. There was a transient increase in the heart rate
TABLE 1. Comparison of Demographic Profile, Type of Surgery, Duration of Surgery, and Anesthesia in Both the Groups Age (y) Sex (M/F)* BMI Duration of surgery (min) Duration of anesthesia (min) Type of surgery supratentorial/infratentorial/retromastoid*
Group M (Mean ± SD)
Group S (Mean ± SD)
Probability
42.16 ± 12.74 11/9 25.41 ± 3.13 236.95 ± 72.68 283.33 ± 75.23 15/5/5
37.56 ± 10.96 12/8 25.83 ± 3.45 258.61 ± 46.04 299.72 ± 49.54 16/4/3
0.25 0.69 0.29 0.44
*Given as number of patients. BMI indicates body mass index; Group M, Maxillary block group; Group S, Scalp block group; M/F, male/female.
Copyright
r
2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
www.jnsa.com |
3
Jayaram et al
J Neurosurg Anesthesiol
Volume 00, Number 00, ’’ 2015
Inhaled anesthetic requirement(MAC) 0.80 MAC value
0.70 0.60 0.50 0.40
Gr M
0.30
Gr S
0.20
FIGURE 4. Inhaled anesthetic requirement (MAC) in both the groups given as mean values. Base indicates baseline; Inci, incision; M, maxillary block; MAC, minimum alveolar concentration; S, scalp block.
retromastoid suboccipital craniotomy, but it was not statistically significant.
Postoperative Analgesia FIGURE 2. Comparison of heart rate (HR) changes in both the groups. M indicates maxillary block; S, scalp block.
and blood pressure at the time of incision, but was comparable in both the groups. The requirement of inhalational agent as measured by the MAC at different time periods was comparable between both the groups. Opioid supplementation in the intraoperative period was not required in any patients in the maxillary block group, whereas in the scalp block group 3 patients required boluses of fentanyl. All the 3 patients underwent
FIGURE 3. Comparison of intraoperative mean arterial pressure (MAP) changes in both the groups. M indicates maxillary block; S, scalp block.
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Postoperatively, the VASs were comparable at 1, 2, and 4 hours. At 12 hours, the mean value of VAS score was 3.4 cm for group M and 4.1 cm for group S with a P-value of 0.002 (Fig. 5; Table 2). The fraction of patients requiring supplemental diclofenac analgesia at 12 hours was greater in group S (P = 0.025). The results are depicted in Table 3. In total, 4 patients in group M and 14 patients in group S had received a dose of diclofenac injection in the postoperative period. Of these, 1 patient in group M who underwent retromastoid craniectomy received analgesia at 12
FIGURE 5. Comparison of postoperative VAS in both the groups. M indicates maxillary block; S, scalp block; VAS, visual analog score. Copyright
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2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
J Neurosurg Anesthesiol
Volume 00, Number 00, ’’ 2015
TABLE 2. Visual Analog Scores at Various Time Intervals Between the Groups in the Postoperative Period Given as Mean (SE of Mean) Group M (Mean [SEM]) 1h 2h 4h 12 h
2.25 2.9 3.15 3.4
(0.114) (0.114)* (0.114)* (0.114)*z
2.35 2.75 3.25 4.1
(0.114) (0.114) (0.114)* (0.114)*z
hours, whereas all the 4 patients of group S received analgesia at 2 and 4 hours.
Postoperative Sedation Sedation scores differed at 4 hours after extubation and at 12 hours. The mean values at 4 hours after extubation were 2.3 and 1.85 for group M and S, respectively (P = 0.005). Within the group there was a statistically significant difference between 4 and 12 hours values compared with 1 hour in both the groups (Table 4).
Adverse Events No adverse events were recorded in the intraoperative and the postoperative periods in either group.
DISCUSSION About 87% of the patients suffer from pain during the first 24 hours after craniotomy as per Mordhost et al.13 There has been reluctance to administer opioids owing to the risk of emesis and hypoventilation-induced hypercapnia with their attendant potential to increase intracranial pressure. Regional blocks have the advantage of blunting the hemodynamic responses during perioperative period and also facilitate more rapid and smooth emergence with lesser cognitive dysfunction in craniotomies.14 Prior clinical trials of scalp block for craniotomy patients have found it to be superior placebo and to provide similar postoperative pain relief to intravenous morphine8,15, with a lesser response to surgical stimulation as measured by ACTH, serum cortisol, and hemodynamic changes.16 Because we considered scalp block the gold standard, we compared it against maxillary block. TABLE 3. Comparison of Postoperative Analgesic Requirement Given as Number of Patients Received Analgesia (Percentage) Between the 2 Groups and Probability Group M (N [%])
Group S (N [%])
Probability
None 1 (5.56) 1 (5.56) 2 (11.11)
None 2 (11.11) 4 (22.22) 8 (44.44)
0.546 0.148 0.026
Group M indicates maxillary block group; Group S, scalp block group.
Copyright
r
TABLE 4. Ramsay Sedation Score at Different Time Intervals Between the Groups Given as Mean (SEM) Mean (SEM)
Group S (Mean [SEM])
*P-value
