Techniques of detecting recurrent laryngeal nerve palsy in patients undergoing thyroid surgery: Pearls and pitfalls.

Though permanent vocal cord palsy consequent to recurrent laryngeal nerve (RLN) injury is rare following thyroidectomies, its consequences are grave enough for it to be the most feared complication postoperatively. Anesthesiologists and surgeons take various precautions to prevent its occurrence and employ various methods for its early detection. They include direct visualization of the nerve intraoperatively, use of intraoperative nerve monitoring, and post-extubation visualization of vocal cord mobility by use of direct or indirect methods. In the present narrative review, we aim to discuss the clinical evidence pertaining to the various methods adopted for the prevention and early detection of RLN palsy during thyroidectomy.

Weight-based oxytocin infusion for preventing uterine atony during caesarean delivery in non-labouring patients: A dose-response study.

Postpartum haemorrhage remains a significant cause of maternal morbidity and mortality with the commonest reason being uterine atony. For prevention of uterine atony during caesarean delivery, oxytocin is advocated as a first line drug. There is however no published data regarding utility of a weight-based oxytocin infusion. The present study evaluated dose-response relationship for oxytocin infusion when used as weight-based regimen. A total of 55 non-labouring patients without risk factors for uterine atony and scheduled for caesarean delivery under spinal anaesthesia were enrolled. Randomization was done to receive oxytocin infusion in a dose of 0.1, 0.15, 0.2, 0.25 or 0.3 IU kg-1  h-1 (n = 11 each), initiated at the time of cord clamping and continued until the end of surgery. Successful outcome was defined as attaining an adequate uterine response at 4 min of initiation of infusion and maintained till end of surgery. Oxytocin associated hypotension, tachycardia, ST-T changes, nausea/vomiting, flushing and chest pain were also observed. A significant linear trend for adequate intraoperative uterine tone was seen with increasing dose of weight-based oxytocin infusion (P < 0.001). The effective dose in 90% population (ED90) was 0.29 IU kg-1  h-1 (95% CI = 0.25-0.42). Amongst the oxytocin associated side effects, a significant linear trend was seen between increasing dose of oxytocin infusion and hypotension as well as nausea/vomiting (p = 0.016 and 0.023 respectively). Thus, oxytocin infusion during caesarean delivery may be used as per the patient's body weight.

Effect of timing of intraoperative administration of paracetamol on postoperative shivering: A randomised double-blind controlled trial.

Background and Aims: Paracetamol (PCM) has an anti-shivering effect and may also exacerbate intraoperative hypothermia. This study compares the incidence of shivering as the primary outcome and the incidence of perioperative hypothermia (<36°C) and the time to the analgesic requirement as secondary outcomes when PCM was administered after induction of anaesthesia or towards the end of surgery. Methods: In this randomised study, 225 adult patients of either gender undergoing elective surgical procedures under general anaesthesia with an expected duration of surgery of 1-4 h were studied. They received intravenous (IV) PCM 15 mg/kg (maximum 1 g) immediately after anaesthesia induction (Early PCM group), 30 min before completion of surgery (Late PCM group) or no PCM (Control group). IV morphine 0.1 mg/kg was administered for analgesia in all three groups. The Chi-square test and repeated measures analysis of variance followed by Tukey's test were used for statistical analysis. Results: The incidence of shivering was lower in Late PCM (12%) than in Early PCM (29.3%) (P = 0.009) and Control groups (30.6%) (P = 0.005). The incidence of postoperative hypothermia was also significantly lower in the Late PCM group than in the Early PCM (P = 0.002) and Control groups (P = 0.016). Early PCM and Control groups did not significantly differ. The number of patients requiring postoperative analgesia was smaller, and the time to the analgesic requirement was longer in Late PCM compared to other groups. Conclusion: Administration of IV PCM 30 min before completion of surgery results in a lower incidence of postoperative shivering and hypothermia when compared to PCM administered after induction of anaesthesia or no PCM.

Oxytocin infusion rates for maintaining uterine tone during non-elective cesarean section in laboring patients: a randomized, controlled trial.

PURPOSE: Oxytocin infusions for uterine tone maintenance are recommended following initial low oxytocin doses during cesarean section. Very limited literature is available on the optimal infusion rates in laboring patients who have been earlier exposed to oxytocin. METHODS: 105 patients, having received oxytocin for induction/augmentation of labor, received oxytocin infusions at rates of 2.5 IU/h (Group 2.5), 5 IU/h (Group 5) or 10 IU/h (Group 10) following 3 IU slow bolus. The primary outcome measure was estimated intraoperative blood loss; secondary outcome measures included uterine tone adequacy, requirements for additional uterotonics, and any side effects. Minor postpartum hemorrhage (PPH) was defined as blood loss > 500 ml and major/severe hemorrhage as blood loss > 1000 ml. RESULTS: Group 10 had minimum blood loss (311.1 ± 44.9 ml) and uterotonic requirements compared to other groups (p < 0.001). Group 2.5 had maximum blood loss (549.4 ± 74.3 ml) and uterotonic requirements; Group 5 had intermediate values (402.0 ± 49.5 ml). Twenty-six patients in group 2.5 had minor PPH against only one in group 5 and none in group 10 (p < 0.001). No patient in either group had major PPH. The incidence of hypotension was higher in group 10 than in group 2.5 (p = 0.004). Nausea and vomiting were also more frequent in group 10 than in the other two groups. CONCLUSION: Oxytocin infusions at 5 IU/h and 10 IU/h are more effective in reducing blood loss and preventing PPH than 2.5 IU/h. The dose of 10 IU/h, although the most efficacious, is associated with a high incidence of side effects. Hence, further studies are needed to find out the optimal maintenance infusion rate of oxytocin during cesarean section in laboring patients who have received oxytocin earlier.

Clinical utility of epidural volume extension following reduced intrathecal doses: a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Epidural Volume Extension (EVE) involves instillation of normal saline into the epidural space soon after an intrathecal injection, with the aim to augment the sensory block height. Its clinical relevance lies in the possibility of using reduced intrathecal dose and yet achieving the desired sensory block level. Intrathecal dose is a known determinant of the level of sensory block. Whether EVE is dependent on intrathecal dose is not known. METHODS: We conducted a randomized, controlled, double-blind study to compare the maximum sensory level (Smax) achieved with or without application of EVE to two different reduced intrathecal doses. Eighty four adult male patients of ASA status I or II with body weight between 50-70kg and height in the range of 150-180cm, scheduled for orthopedic lower limb surgery using combined spinal epidural anesthesia were randomized to receive, either intrathecal dose (5 or 8mg) with or without EVE, in accordance to group allocation. RESULTS: Smax was lowered by application of EVE to 5mg intrathecal bupivacaine (T8.9±4.3 vs. T6.4±1.9 with and without EVE respectively; p = 0.030). Smax was similar when EVE was applied to 8mg intrathecal bupivacaine than without it (T5.8±1.8 vs. T6.4±2.2 respectively; p= 0.324). CONCLUSION: EVE should not be applied to 5mg plain bupivacaine during a combined spinal epidural block in patients undergoing lower limb orthopedic surgery as it may result in a decrease in the maximum sensory level.

Perioperative concerns in Pott's spine: A review.

Pott's disease is the most common granulomatous spine infection caused by tubercle bacilli and is a common site of osseous tuberculosis, accounting for 50-60% of cases. The delay in establishing diagnosis and management results in complications such as spinal cord compression and spinal deformity. The aim of this narrative review is to discuss the perioperative concerns in patients for spine surgery. The literature source for this review was obtained via PubMed, Medline, Google Scholar, Cochrane database of systematic reviews, and textbooks until December 2019. On the literature search, we could not retrieve any review article specifically discussing the perioperative concerns of spinal tuberculosis. Therefore, the aim of the present narrative review is to discuss the perioperative concerns of patients for spine surgery along with the specific concerns related to spinal tuberculosis.

Efficacy of local wound infiltration analgesia with ropivacaine and dexmedetomidine in tubercular spine surgery - A pilot randomised double-blind controlled trial.

BACKGROUND AND AIMS: Regional analgesic techniques are difficult to use in tubercular spine patients due to distorted spinal anatomy and presence of infection. This study was conducted with the aim to evaluate analgesic efficacy of local wound infiltration before wound closure in tubercular spine patients. METHODS: This pilot randomised double-blind controlled study was conducted in 32 American Society of Anesthesiologists I-III patients, age ≥15 years, undergoing elective surgery for spinal tuberculosis. All the patients received general anaesthesia using standard technique and intravenous morphine for intraoperative analgesia. They received wound infiltration with either normal saline (group C) or local infiltration analgesia with 0.375% ropivacaine 3 mg/kg, adrenaline 5 µg/mL and dexmedetomidine 1 µg/kg in a total volume of 0.8 mL/kg (group LIA) before wound closure. Patient-controlled analgesia using intravenous morphine provided postoperative analgesia. The primary objective was to study 24-h morphine consumption, whereas the secondary objectives included pain scores, complications and patient satisfaction. Repeated measures analysis of variance, Chi-square test and Mann-Whitney U test were used for statistical analysis. RESULTS: Morphine requirement was lower in group LIA (6.7 ± 2.7 mg) than in group C (27.7 ± 7.9 mg);P < 0.001. Group LIA also had lower pain scores (P < 0.001), longer time to rescue analgesic (P < 0.001), better patient satisfaction to pain relief (P = 0.001) and lower incidence of postoperative nausea and vomiting than group C. CONCLUSION: Wound infiltration with ropivacaine, adrenaline and dexmedetomidine before wound closure provided good postoperative analgesia with lower morphine requirement.

Efficacy of dexmedetomidine as an adjuvant in paravertebral block in breast cancer surgery.

PURPOSE: This study evaluated the analgesic efficacy of dexmedetomidine in combination with bupivacaine for single-shot paravertebral block (PVB) in patients undergoing major breast cancer surgery. METHODS: This prospective, randomized double blind study was conducted in 45 ASA I/II/III females, aged ≥18 years, undergoing modified radical mastectomy or breast conservation surgery with axillary lymph node dissection. Patients in group PB (paravertebral-bupivacaine) received PVB with 0.5 % bupivacaine 0.3 ml/kg with 1 ml normal saline; group PBD (paravertebral-bupivacaine-dexmedetomidine) received PVB with 0.5 % bupivacaine 0.3 ml/kg and dexmedetomidine 1 µg/kg in a volume of 1 ml; and group C (control) patients were given a sham block (a subcutaneous injection with 2 ml normal saline) before receiving general anesthesia (GA). All patients received analgesia by fentanyl intraoperatively and morphine patient-controlled analgesia postoperatively. RESULTS: The control group patients required more intraoperative fentanyl than the other two groups. Patients receiving dexmedetomidine had lower morphine consumption (p < 0.001), pain scores and incidence of postoperative nausea/vomiting (p = 0.011); longer time to first analgesic request; earlier time to mobilize; and better satisfaction scores. Heart rate and blood pressure values during the intraoperative period were also lower at many time points in this group. However, the incidence of hypotension and bradycardia were statistically similar in all groups. CONCLUSIONS: PVB using dexmedetomidine 1 µg/kg added to 0.5 % bupivacaine in patients undergoing major breast cancer surgery under GA provides analgesia of longer duration with decreased postoperative opioid consumption and lower incidence of nausea/vomiting compared to PVB with bupivacaine alone or no PVB.

Does unilateral hip flexion increase the spinal anaesthetic level during combined spinal-epidural technique?

Needle-through-needle combined spinal-epidural (CSE) may cause significant delay in patient positioning resulting in settling down of spinal anaesthetic and unacceptably low block level. Bilateral hip flexion has been shown to extend the spinal block by flattening lumbar lordosis. However, patients with lower limb fractures cannot flex their injured limb. This study was conducted to find out if unilateral hip flexion could extend the level of spinal anaesthesia following a prolonged CSE technique. Fifty American Society of Anesthesiologists (ASA) I/II males with unilateral femur fracture were randomly allocated to Control or Flexion groups. Needle-through-needle CSE was performed in the sitting position at L2-3 interspace and 2.6 ml 0.5% hyperbaric bupivacaine injected intrathecally. Patients were made supine 4 min after the spinal injection or later if epidural placement took longer. The Control group patients (n=25) lay supine with legs straight, whereas the Flexion group patients (n=25) had their uninjured hip and knee flexed for 5 min. Levels of sensory and motor blocks and time to epidural drug requirement were recorded. There was no significant difference in sensory levels at different time-points; maximum sensory and motor blocks; times to achieve maximum blocks; and time to epidural drug requirement in two groups. However, four patients in the Control group in contrast to none in the Flexion group required epidural drug before start of surgery. Moreover, in the Control group four patients took longer than 30 min to achieve maximum sensory block. To conclude, unilateral hip flexion did not extend the spinal anaesthetic level; however, further studies are required to explore the potential benefits of this technique.

Role of repeated epidural injections in preventing post-spinal hearing loss.

STUDY OBJECTIVE: To determine if epidural volume extension and continued postoperative epidural injections prevent hearing loss associated with a 23-gauge (G) Quincke spinal needle. DESIGN: Prospective, double blinded trial. SETTING: Operating rooms. PATIENTS: 30 adult patients scheduled for lower abdominal or perineal surgery during spinal anesthesia. INTERVENTIONS: Patients were divided into two groups of 15 each. All patients received subarachnoid injection with a 23-G Quincke needle. While patients in Group S received a single-shot spinal, Group E patients underwent epidural catheter placement one intervertebral space above. The epidural catheter was bolused with 10 mL of normal saline followed by postoperative epidural boluses of local anesthetic for analgesia as needed. MEASUREMENTS: Patients' auditory function was evaluated by pure tone audiometry (frequencies of 250-8,000 Hz) on the day before and two days after receiving the spinal anesthesia. MAIN RESULTS: Unilateral low-frequency hearing loss (500 Hz) was seen in Group S (P < 0.05). It was prevented by the repeated epidural injections as used in Group E. CONCLUSION: Following spinal anesthesia, epidural volume extension with 10 mL of normal saline followed by epidural local anesthetic boluses titrated to adequate postoperative analgesia (6-8 mL each time) prevents post-spinal hearing loss.

Epidural volume extension and intrathecal dose requirement: plain versus hyperbaric bupivacaine.

BACKGROUND: Epidural volume extension leads to an increase in sensory spread of local anesthetic, but whether this translates into lower dose requirements during combined spinal epidural (CSE) remains undetermined. Likewise, the influence of intrathecal drug baricity on the dose-sparing effect of epidural volume extension has not been investigated. We studied the dose-sparing effect of epidural volume extension and its relation to intrathecal drug baricity by comparing the ED(50) of plain and hyperbaric bupivacaine with and without epidural volume extension. METHODS: Eighty-eight adult male patients scheduled for lower limb orthopedic surgery under CSE in the sitting position were randomized to four groups (n = 22 each); intrathecal injection was made with plain bupivacaine in groups plain bupivacaine (PB) and plain bupivacaine with epidural volume extension (PBE), and hyperbaric bupivacaine in groups hyperbaric bupivacaine (HB) and hyperbaric bupivacaine with epidural volume extension (HBE). Fentanyl, 25 microg, was added to the intrathecal drug in all groups. Among these four groups, epidural volume extension was performed with 10 mL normal saline only for groups PBE and HBE. The dose of spinal bupivacaine was varied using the up-and-down sequential allocation method. The first patient of each group received 10 mg bupivacaine. A successful spinal block was defined as attainment of sensory level of at least T10 along with complete motor blockade within 20 min of the intrathecal injection. The dose of bupivacaine was sequentially increased or decreased by 1 mg depending on whether spinal block was a failure or success in the previous patient. RESULTS: The addition of epidural volume extension to plain bupivacaine, i.e., group PBE versus group PB, resulted in a significant decrease in ED(50) (relative potency estimate: 1.2, 95% CI: 1.04-1.64) and increase in maximum sensory level (T6 vs T8, respectively, P < 0.05). These differences were not seen with hyperbaric bupivacaine (group HB vs HBE). Independent of the effect of epidural volume extension, the ED(50) of plain bupivacaine when compared with hyperbaric bupivacaine was significantly lower (relative potency estimate of group PB vs group HB: 0.78, 95% CI: 0.54-0.93; and for group PBE vs group HBE: 0.68, 95% CI: 0.37-0.87). CONCLUSIONS: Administered with or without epidural volume extension, plain bupivacaine appears to be more effective, requiring a smaller dose and producing a higher sensory block with an earlier onset in comparison to hyperbaric bupivacaine. Epidural volume extension, when applied to intrathecal hyperbaric bupivacaine, fails to decrease the dose or raise the level of block.

Autonomic dysfunction and adrenal insufficiency in thoracic spine tuberculosis.

While autonomic dysfunction has been reported in patients with spinal TB, little is known of the consequences. We matched 25 paraplegic patients with thoracic spine tuberculosis scheduled for spinal surgery (Group S) with 25 nontubercular American Society of Anesthesiologists Grade I patients scheduled for nonspinal surgeries (Group C) under identical operative conditions. All patients underwent four autonomic tests in the operating room, and a preoperative adrenocorticotropic hormone stimulation test was performed for patients in Group S. Compared to Group C, Group S had higher resting heart rate (103 +/- 20 beats/minute versus 81 +/- 10 beats/minute), lower expiratory:inspiratory ratio (1.14 +/- 0.11 versus 1.22 +/- 0.10), and higher heart rate variability (20 +/- 12 beats/minute versus 14 +/- 7 beats/minute), indicating probable parasympathetic dysfunction along with a relative sympathetic overactivity. Eight of the 17 patients who received an adrenocorticotropic hormone stimulation test had evidence of adrenal insufficiency. Incidence of hypotension in Group S and Group C was 100% and 44%, respectively. Mean systolic and diastolic blood pressure in Group S showed substantial decrease after induction and positioning of patients not associated with compensatory tachycardia. Coexisting pulmonary tuberculosis appears an important determinant of surgical approach as well as postoperative respiratory morbidity.