Early Mortality in Cardiac Surgery - Is Lactate Significant?

INTRODUCTION: Serum lactate is a consequence of tissue hypoperfusion and has been used routinely for patient management following cardiac surgery. This study aims to determine the association of lactate with early mortality and postoperative morbidity. METHODS: This is a prospective cohort study carried out in the Department of Cardiovascular and Thoracic Surgery, King George's Medical University (India), from January 2020 to December 2022. A total of 270 patients were included in this study. Serum lactate levels were measured preoperatively, intraoperatively on-pump, coming off-pump, and at six, 12, 24, and 48 hours postoperatively. RESULTS: Early mortality was noted in 17 cases (6.3%). While both lactate and lactate clearance correlated with duration of mechanical ventilation, vasopressor duration, and intensive care unit and hospital stay, correlation with early mortality was noted only with lactate at 24 hours. Logistic regression analysis demonstrated that lactate levels at preoperative period (adjusted odds ratio [OR] 4.76 [1.67-13.59], P=0.004) and at 24 hours after bypass (OR 1.21 [1.00-1.47], P=0.046) and vasopressor duration (OR 1.11 [1.04-1.19], P=0.002) are independent predictors of mortality. Receiver operating characteristic curve analysis showed that arterial lactate on-pump, off-pump, and at six, 12, and 24 hours after surgery had significant area under the curve for predicting mortality. CONCLUSION: Arterial lactate and lactate clearance show good correlation with duration of mechanical ventilation, vasopressor support, and intensive care unit and hospital stay and can serve as a good indicator to guide therapeutic decisions in postoperative period. However, it fails to be a sensitive predictor of mortality.

Comparison of Magnesium Pre-treatment With Two Different Doses of Rocuronium in Rapid Sequence Intubation: A Randomized Controlled Trial.

Introduction Magnesium is recognized for its ability to reduce the onset time of rocuronium while simultaneously extending its duration of action. This study aims to assess the efficacy of magnesium pre-treatment in decreasing the onset time with two different doses of rocuronium in patients undergoing rapid sequence intubation. Materials and methods This randomized prospective double-blind clinical study involved 50 patients classified as American Society Of Anesthesiologists (ASA) I/II, with no preoperative indications of difficult intubation, undergoing elective surgery under general anesthesia. The patients were divided into two groups: group A received 60 mg/kg of magnesium 15 minutes before intubation with 1.2 mg/kg of rocuronium, and group B received 60 mg/kg of magnesium before 0.6 mg/kg of rocuronium. Intubating conditions were assessed and graded at loss of last twitch after administration in both groups, considering ease of intubation, vocal cord position, and response to the insertion of the tracheal tube. Simultaneously, hemodynamic variations were recorded just before intubation, at one minute and five minutes post-intubation. Results Intubating conditions with 0.6 mg/kg of rocuronium were comparable or equally good compared to 1.2 mg/kg of rocuronium with magnesium pre-treatment. Conclusions Magnesium pre-treatment enhances the neuromuscular blocking effect of rocuronium, reducing its onset time without clinically significant prolongation of the duration of the block.

A Randomized Comparison of Intravenous Versus Nebulized Routes for Administering Dexmedetomidine and Ketamine Combination to Facilitate Awake Fibreoptic Intubation.

Introduction Awake fibreoptic intubation is a technique used to secure the airway of patients who are having predicted difficult intubation. We compared two routes, intravenous and nebulized, for administering a combination of ketamine and dexmedetomidine to patients requiring sedation for fibreoptic intubation. Methods and materials After approval of the institutional ethics committee, 64 patients between 18 and 60 years belonging to the American Society of Anesthesiologists physical status I or II and having predicted difficult airway were randomized to receive study medications through either intravenous (group I, n = 32) or nebulized (group N, n = 32) routes. Group I patients were given a combination of ketamine and dexmedetomidine through intravenous route. Group N patients were nebulized with a combination of ketamine and dexmedetomidine. The time required for awake fiberoptic intubation was the primary outcome variable. In addition, sedation score, cough severity, patient tolerance, intubating condition, hemodynamic changes, recall of events and discomfort during intubation, and any adverse events in the perioperative period were also compared. Results Compared to group N, the time needed to intubate the patients was significantly less in group I (75.69 ± 10.83 versus 49.19 ± 3.60 seconds, p < 0.001). Observer assessment sedation/alertness score (p < 0.001), cough severity (p < 0.001), patient tolerance (p < 0.001), and intubating condition (p = 0.001) were statistically significant, all conditions being better in group I. Patient discomfort and recall of the procedure were statistically similar between the groups. Conclusions The efficacy of a combination of dexmedetomidine and ketamine through the intravenous route is better than the nebulized route for patients undergoing awake fibreoptic intubation.

Effect of Deferasirox on Shunt Fraction During Thoracic Surgery With One-Lung Ventilation: A Randomized Controlled Study.

Context Deferasirox, an iron chelator, can potentially reduce intraoperative right-to-left shunt and improve oxygenation in patients undergoing thoracic surgery requiring one-lung ventilation (OLV) by potentiating hypoxic pulmonary vasoconstriction (HPV). Aim The aim was to determine the effect of deferasirox on the intraoperative shunt fraction (SF) of patients undergoing thoracic surgery using OLV. Study design and settings This was a prospective, single-blind, randomized, controlled study. The study was conducted at a tertiary-care hospital. Methods Before surgery, 64 patients were allocated to two groups comprising 32 patients each. Group D patients were administered deferasirox, while those in group C were given a placebo. We included patients with the American Society of Anesthesiologists physical status III or IV, aged 18-60 years, undergoing elective thoracic surgery needing OLV. SF was the primary outcome variable. Secondary outcome variables were arterial oxygen tension (PaO2), peripheral oxygen saturation (SpO2), the ratio of PaO2 and inspired oxygen concentration (P/F), and complications such as desaturation episodes, hypotension, and tachycardia. Results Baseline and postoperative values of outcome variables were statistically similar in both groups. Intraoperative values of SF were lower and PaO2, SpO2, and P/F were higher in group D. The incidence of intraoperative desaturation was lower in group D. Conclusion We conclude that pre-treatment with deferasirox reduces intraoperative SF and improves oxygenation during thoracic surgery using OLV.

Comparison of clinical performance of Baska mask and Ambu AuraGain in patients undergoing surgery: A single-blinded, randomised comparative trial.

Background and Aims: The Baska mask (BM) and the Ambu AuraGain (AAG) have shown promising results in recent trials but have not been compared. Therefore, we aimed to compare the clinical performance of the BM and the AAG for airway management of adult patients. Methods: In this randomised comparative study, patients aged 18-60 years and with an expected surgical duration of less than 2 h were enroled. Patients were randomly allocated to AAG (Group A, n = 37) and BM (Group B, n = 37) for airway management. After induction of anaesthesia, an allocated supraglottic airway device (SAD) was inserted. Oropharyngeal leak pressure (OLP), time taken to insert SAD, number of insertion attempts, leak fraction (LF), first-attempt success rate, overall success rate, ease of insertion, fiberoptic view of the glottis, and complications were compared. The data were analysed using Student's t-test, Mann-Whitney U test, and Fisher's exact tests. Results: Baseline and demographic characteristics were comparable. OLP (31.32 ± 2.59 versus 27.54 ± 1.32 cmH2O) was higher (P < 0.001), and LF (6.19% ± 1.20% versus 7.24% ± 1.72%) was lower (P = 0.003) in the BM group. First-attempt and overall success rate, time taken to insert, number of insertion attempts, ease of insertion, and fibreoptic view of glottis through the SADs were statistically similar between groups. However, the incidence of sore throat (P = 0.007) and cough (P = 0.028) was higher with AAG. Conclusion: Clinical performance of BM was better than AAG as the former had higher OLP, lower LF and complications.

Quadratus Lumborum Block for Patients Undergoing Percutaneous Nephrolithotomy: A Randomized Controlled Study.

Background: Recent studies have supported the use of quadratus lumborum block (QLB) for postoperative analgesia for patients undergoing renal surgery. Aims: The aim was to study the efficacy of posterior QLB for postoperative analgesia in patients undergoing percutaneous nephrolithotomy (PCNL). Settings and Design: This trial was a hospital-based, randomized, double-blind, controlled, prospective study. Materials and Methods: Forty patients aged from 18 to 60 years, belonging to the American Society of Anesthesiologists physical status I-III and scheduled for unilateral PCNL under spinal anesthesia were administered ultrasound-guided posterior QLB with 30 ml of either 0.2% ropivacaine (Group Q) or normal saline (Group C) after the subarachnoid block. Duration of analgesia was the primary outcome variable. Statistical Analysis Used: Data were compiled in Microsoft Excel, and analyses were performed in SPSS (version 24.0.0.0; IBM, Armonk, New York, USA). Unpaired t-test, Mann-Whitney U test, and Fisher's exact test were used for the comparison of continuous, ordinal, and categorical data, respectively. Results: Duration of analgesia was significantly longer in Group Q (1167.10 ± 89.74 vs. 290.25 ± 47.38 min), as compared to Group C. Except at the end of the surgery, visual analog scale at rest and on movement was significantly lower till 20th h in Group Q. Patient satisfaction was better, and analgesic consumption was lower in Group Q. Side effects were similar in both groups. Conclusions: QLB provides good quality, and prolonged duration of postoperative analgesia compared to placebo for PCNL, but more large-scale studies are needed to recommend it for routine use.

Comparison of I-gel for general anesthesia in obese and nonobese patients.

CONTEXT: I-gel is a second-generation supraglottic airway device. Despite several studies on i-gel, there are very few studies on the use of i-gel in obese patients. AIMS: The aim of the study was to compare the clinical performance of i-gel between obese and nonobese patients. SETTINGS AND DESIGN: Prospective, controlled, nonrandomized, hospital-based study. SUBJECTS AND METHODS: After obtaining informed consent, patients were divided into two groups of 16 patients each: group O consisted of patients with body mass index (BMI) >30 kg/m2 and Group C consisted of patients with BMI 18.5-29.9 kg/m2. I-gel was inserted after induction of anesthesia and muscle relaxation. Oropharyngeal leak pressure (OLP) (primary outcome variable), leak fraction, time taken to insert the device, ease of insertion, fiberoptic view of glottis through i-gel's airway tube, and adverse effects were recorded. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS 20. Continuous, ordinal, and categorical variables were analyzed using students t-test, Mann-Whitney U-test, and Fischer's exact test, respectively. RESULTS: OLP was slightly higher in Group O (25.38 ± 4.79 cm H2O) but was not statistically different than Group C (27.38 ± 4.38 cm H2O). Other parameters except weight and BMI (which were higher in Group O) were statistically similar in both groups. There was no statistical difference in side effects. CONCLUSIONS: We concluded that i-gel is as effective in obese patients as in nonobese patients when used for securing the airway for surgical procedures.