Anaesthesia

Fasting for anaesthesia: Less is more! Elizabeth M Elliott, Rebecca S Isserman, Paul Stricker, Sandhya Yaddanapudi, Rajeev Subramanyam Indian Journal of Anaesthesia 2020 64(2):87-89

Intraoperative hypotension: Pathophysiology, clinical relevance, and therapeutic approaches Karim Kouz, Phillip Hoppe, Luisa Briesenick, Bernd Saugel Indian Journal of Anaesthesia 2020 64(2):90-96 Intraoperative hypotension (IOH) i.e., low arterial blood pressure (AP) during surgery is common in patients having non-cardiac surgery under general anaesthesia. It has a multifactorial aetiology, and is associated with major postoperative complications including acute kidney injury, myocardial injury and death. Therefore, IOH may be a modifiable risk factor for postoperative complications. However, there is no uniform definition for IOH. IOH not only occurs during surgery but also after the induction of general anaesthesia before surgical incision. However, the optimal therapeutic approach to IOH remains elusive. There is evidence from one small randomised controlled trial that individualising AP targets may reduce the risk of postoperative organ dysfunction compared with standard care. More research is needed to define individual AP harm thresholds, to develop therapeutic strategies to treat and avoid IOH, and to integrate new technologies for continuous AP monitoring.

A study to evaluate and compare intubating laryngeal mask airway and air-Q intubating laryngeal airway for intubation using Parker Flex Tip tube Teena Bansal, Suresh Singhal, Himani Mittal Indian Journal of Anaesthesia 2020 64(2):97-102 Background and Aims: Though manufacturer recommendations suggest use of specific endotracheal tube (ETT) with intubating laryngeal mask airway (ILMA) and air-Q intubating laryngeal airway (ILA), Parker Flex Tip tube introduced by J D Parker has certain advantages and is also cost-effective. This study was conducted to compare ILMA and air-Q ILA for intubation using Parker Flex Tip tube. Methods: Patients of either gender, aged 18–60 years, scheduled for elective surgery requiring endotracheal intubation were included in this study. In group A (n = 55), blind intubation was done through ILMA using Parker Flex Tip tube and in group B (n = 55), blind intubation was done through air-Q ILA using Parker Flex Tip tube. Success rate, number of attempts, ease and a total time of intubation were recorded. Results: Intubation was successful in 54 patients (98.2%) in group A and in 46 patients (85.2%) in group B (P = 0.026). Intubation was significantly easy with ILMA (P = 0.048). Manoeuvres for intubation were used in 10.9% patients in group A while it was used in 27.8% patients in group B. Significantly, more manoeuvres were required with air-Q ILA for intubation (P = 0.026). Number of attempts for ETT placement (P = 0.092), insertion time of ETT (TT) (P = 0.472) and total time taken for successful intubation (P = 0.526) were comparable in both the groups. Conclusion: The intubating laryngeal mask airway was superior to the air-Q intubating laryngeal airway for blind intubation using Parker Flex Tip tube.

Correlation between correctly sized uncuffed endotracheal tube and ultrasonographically determined subglottic diameter in paediatric population Rekha Makireddy, Anusha Cherian, Lenin Babu Elakkumanan, Prasanna Udupi Bidkar, Pankaj Kundra Indian Journal of Anaesthesia 2020 64(2):103-108 Background and Aims: Conventional age-based formulae often fail to predict correct size of endotracheal tube (ETT). In this study, we evaluated usefulness of ultrasound in determining appropriate tube size and derived a formula which enables us to predict correct tube size. Methods: A total of 41 American Society of Anesthesiologists' physical status 1 and 2 children in the age group of 2–6 years, undergoing elective surgery under general anaesthesia with uncuffed ETT were included in the study. Ultrasonography (US) was used to measure the subglottic diameter after induction of anaesthesia. The trachea was intubated with an ETT that allowed an audible leak between 15–30 mmHg. Pearson's correlation was used to assess the correlation between US measured subglottic diameter (US-SD) with diameter of ETT used. Linear regression was used to derive a formula for predicting ETT size. Results: We found that US-SD and patient's age correlated well with actual ETT OD (r: 0.83 and 0.84, respectively). Age-based formula, ETT ID = (Age/3) +3.5 [r: 0.81] had better correlation with actual ETT OD than conventional age-based Cole's formula, i.e., ETT ID = Age/4 + 4 [r: 0.77]. Our results enabled us to derive a formula for selecting uncuffed ETT based on US-SD. Conclusion: Our study concludes that although US-SD correlates with actual tracheal tube used and may be useful in choosing appropriate size ETT, there was no difference in number of correct predictions of ETT size by US measurement, universal formula, and locally derived formula.

Outcomes of intrathecal analgesia in multiparous women undergoing normal vaginal delivery: A randomised controlled trial Gaballah M Khaled, Abdallah I Sabry Indian Journal of Anaesthesia 2020 64(2):109-117 Background and Aims: Although intrathecal analgesia is an effective option during labour, there is a need to establish sustainable and assured analgesia during the entire labour process. We aimed to assess the effect of adding dexmedetomidine, fentanyl or morphine to low-dose bupivacaine-dexamethasone for intrathecal labour analgesia in multiparous women. Methods: This was a triple-blind, randomised controlled trial that included 140 multiparous women. Eligible women were randomly allocated to have intrathecal bupivacaine-dexamethasone with dexmedetomidine (group D), fentanyl (group F), morphine (group M) or saline (placebo) (group C). The duration of analgesia, intrathecal block characteristics and maternal and foetal outcomes were assessed and analysed. Results: The longest analgesia duration and S1 regression time was recorded in group D followed by groups M, F and C, respectively, with statistical significance between all of them (P < 0.001). The shortest analgesia onset time and the highest sensory levels were recorded in group D followed by group F then group M with statistical significance between all of them (P < 0.001 and 0.003, respectively). Visual analogue scale values were comparable among groups M, F and D (P > 0.05) at most of the measurement time points and at the peak of the last uterine contraction before delivery while being significantly lower than those in group C (P < 0.001). However, there were similar motor block characteristics and normal neonatal outcomes in all groups. Conclusion: In comparison to morphine and fentanyl, dexmedetomidine addition to intrathecal bupivacaine-dexamethasone significantly prolonged the duration and accelerated the onset of labour analgesia, with a good maternal and neonatal outcome.

Erector spinae plane block for complete surgical anaesthesia and postoperative analgesia for breast surgeries: A prospective feasibility study of 30 cases Aman Malawat, Kalpana Verma, Durga Jethava, Dharam D Jethava Indian Journal of Anaesthesia 2020 64(2):118-124 Background and Aims: Several regional anaesthesia techniques have been described for carcinoma of the breast surgeries in the past but all of them failed to provide adequate surgical anaesthesia and are associated with multiple complications, thus limiting their use. This prospective study was designed to assess the efficacy of erector spinae plane (ESP) block to provide complete surgical anaesthesia without general anaesthesia (GA) and postoperative analgesia in patients undergoing modified radical mastectomy (MRM) surgery. Methods: Thirty females of the American Society of Anaesthesiologists physical status I, II or III scheduled for MRM were included in the study to receive unilateral ultrasound-guided ESP block preoperatively (25 ml of 0.5% bupivacaine with dexamethasone 8 mg on the operating side). The primary objective of the study was to evaluate the efficacy of ESP block to provide complete surgical anaesthesia in terms of total number of cases converted to GA. Results: Our study shows that ultrasound-guided single-shot ESP block provided complete surgical anaesthesia in all the patients within an average of 31.50 minutes and an average long-lasting postoperative analgesia of 41.73 hours following MRM. Conclusion: Our study proves that ESP block is a novel, predictable, secure, and safe option for carcinoma of the breast surgery. Thus, ESP block would surely provide a clinical advantage in these population group.

A study of effect of lateral position on oropharyngeal seal pressure of i-gel® and ProSeal™ LMA in children Deepali P Thakur, Anila D Malde Indian Journal of Anaesthesia 2020 64(2):125-130 Background and Aims: Supraglottic airways (SGAs) should have good oropharyngeal seal pressures (OSP) for adequate ventilation and prevention of aspiration. Our aim was to study the effect of lateral position on OSP and thereby on ventilatory parameters for i-gel® and ProSeal™ laryngeal mask airway (PLMA) in children. Methods: In this prospective observational study, 86 children of ASA I-II, aged 1 month to 12 years, scheduled for elective surgery under general anaesthesia using i-gel® or PLMA and requiring lateral position either for surgery or regional blocks were included. In both supine and lateral position OSP (constant flow method), expired tidal volume, fractional volume loss (%), and end-tidal carbon dioxide (ETCO2) were noted. Intragroup and intergroup difference in OSP from supine to lateral position was analyzed using paired and unpaired t-test respectively. Results: In lateral position, there was a significant decrease in the OSP (cm H2O) in both i-gel® (supine: 21.94 ± 5.82, lateral: 15.54 ± 5.37) and PLMA (supine: 17.53 ± 5.05, lateral: 12.76 ± 3.37) groups (P = 0.000). Percentage reduction in OSP from supine to lateral with i-gel® (28.14 ± 18.86) and PLMA (24.06 ± 19.75) were comparable (P = 0.339). With both i-gel® and PLMA significant increase in fractional volume loss and ETCO2were noted in lateral position. I-gel® group had higher OSP compared to PLMA in supine (P = 0.001) and lateral position (P = 0.009). Conclusion: In lateral position there was significant reduction in OSP compared to supine position with both i-gel® and PLMA.

Quantifying influence of epidural analgesia on entropy guided general anaesthesia using sevoflurane – A randomised controlled trial Murugesan Ravishankar, Dalena Merin Mathew, VR Hemanthkumar, Parthasarathy Srinivasan Indian Journal of Anaesthesia 2020 64(2):131-137 Background and Aims: Minimum alveolar concentration (MAC) of inhalational agent denotes the requirement of it to maintain adequate plane of general anaesthesia. The precision to the maintenance of anaesthesia can be further guided by use of entropy to titrate the depth of anaesthesia. Regional anaesthesia and the concomitant deafferentation will decrease the need of general anaesthetics. We conducted a randomised double-blind trial to quantify the effect of addition of regional anaesthesia to sevoflurane based general anaesthesia technique guided by entropy to achieve satisfactory depth of anaesthesia. Methods: Forty patients posted for elective laparotomies were randomised to two groups. All patients received a bolus followed by an epidural infusion. Group GE (general anaesthesia + epidural bupivacaine) received 0.25% epidural bupivacaine and Group GS received epidural saline. Both groups received narcotic, relaxant and sevoflurane anaesthesia guided by entropy monitoring. The state entropy (SE) was maintained at 40–60 by titrating end tidal sevoflurane concentration (ETsevo). Heart rate, blood pressure, SpO2, end tidal carbon dioxide (ETCO2) and sevoflurane were recorded. Results: Both groups were similar in heart rate and mean blood pressure during anaesthesia maintenance. The minimum ETSevorequired to maintain entropy between 40 and 60 in group GE was 0.53% compared to 0.95% in group GS the epidural saline group (P < 0.001). The end-tidal sevoflurane requirement to maintain adequate depth of anaesthesia dropped by 44.2% in group GE.Conclusion: Lower concentrations of volatile anaesthetic are required when entropy-guided general anaesthesia is combined with regional blockade.

A negative preoperative 99mTechnetium tetrofosmin myocardial perfusion imaging scan with postoperative acute coronary syndrome - A case of balanced ischaemia Indira Gurajala, Padmaja Durga Indian Journal of Anaesthesia 2020 64(2):138-140 Perioperative myocardial infarction (PMI) is an important indicator of outcome after noncardiac surgery. Identifying patients at risk of PMI helps in risk stratification and modification. Myocardial perfusion imaging (MPI) is an established diagnostic modality for detection and prognostication of coronary artery disease (CAD). We report a case wherein preoperative MPI was negative for CAD but patient presented with acute coronary event in the postoperative period. We identify and evaluate the reasons for the failure of MPI in detection of CAD in our patient.

Haemodynamic and analgesic control in a perioperative opioid-free approach to bariatric surgery – A case report Ana Veiga de Sá, Carla Cavaleiro, Manuel Campos Indian Journal of Anaesthesia 2020 64(2):141-144 New approaches to bariatric surgery aim to achieve stress-free anaesthesia with sympathetic stability to protect organs and provide sufficient tissue perfusion, analgesia and rapid emergence. Opioid-free and multimodal approaches to anaesthesia provide intra- and post-operative sedation and analgesia, particularly advantageous in morbidly obese patients, but their feasibility and efficacy are still disputed. We describe the case of a female patient proposed for laparoscopic bariatric surgery, conducted under an opioid-free anaesthesia protocol, the haemodynamic, ventilatory and analgesic control, and intra- and post-operative monitoring and complications.