A comparative study of McGrath and Airtraq videolaryngoscopes for tracheal intubation.

BACKGROUND AND AIMS: Many cases of difficult tracheal intubation remain unrecognized until after induction of anesthesia. McGrath and Airtraq videolaryngoscopes are among the novel laryngoscopes that have an advantage over the conventional laryngoscopes in case of unanticipated difficult airway. Thus, we did a comparative study between McGrath and Airtraq videolaryngoscopes to evaluate their efficacy in routine anesthesia practice. MATERIAL AND METHODS: Sixty anesthetized patients were divided into two groups using computer-based randomization, and tracheal intubation was performed using either McGrath or Airtraq laryngoscope. The primary outcome measures were duration and incidence of successful tracheal intubation. Hemodynamic response, glottic view (percentage of glottic opening score [POGO]), ease of intubation, and airway complications were also measured. RESULTS: Both McGrath and Airtraq groups were comparable in terms of incidence of successful tracheal intubation (93.3% vs. 96.6%), ease of intubation (70% vs. 77%), and POGO scoring. Intubation time was significantly shorter with Airtraq (13.5 vs. 17.8 s; P < 0.001). There were statistically significant changes in the heart rate and blood pressure after tracheal intubation in both the groups (P < 0.001); however, these parameters reached baseline within 5 min of intubation in both the groups. The incidence of injury was 10% with McGrath videolaryngoscope and 13.3% with Airtraq and was comparable. CONCLUSION: Both Airtraq and McGrath videolaryngoscope have high success rates of intubation. Airtraq is better than McGrath laryngoscope due to shorter tracheal intubation time.

Correlación y concordancia entre los valores de pH, PO2,PCO2 y HCO3− en sangre arterial y venosa de pacientes con ventilación mecánica en la unidad de cuidados intensivos: A prospective observational study / Correlation and agreement between arterial and central venous blood pH,PO2, PCO2 and HCO3− values of mechanically ventilated patients in intensive care unit

Antecedentes: El procedimiento de tomar las muestras de gases arteriales puede ser técnicamente difícil y tiene limitaciones y complicaciones. La colocación de un catéter venoso central es un procedimiento obligado en la unidad de cuidados intensivos (UCI). La toma de muestras de sangre venosa central es mucho más fácil y rápida, y menos complicada. Contexto: Correlación y concordancia entre los valores de pH, PO2, PCO2 y HCC3 en sangre arterial y venosa central de pacientes con ventilación mecánica. Objetivo: El objetivo era evaluar la correlación y la concordancia entre los valores de pH, PO2, PCO2 y HCC3 en sangre arterial y venosa central e inferir si los valores de los gases venosos centrales podían reemplazar la lectura de los gases arteriales. Lugar y diseño: UCI y estudio prospectivo de tipo observacional. Materiales y métodos: Se tomaron en total 100 muestras (50 gases arteriales y 50 gases venosos centrales) de 50 pacientes adultos con distintos procesos patológicos ingresados en la UCI de un hospital universitario. Se ingresaron en el estudio los pacientes normotensos y normotérmicos que requirieron ventilación mecánica y tenían arteria radial palpable. No se repitió ningún paciente en el estudio. En cada paciente se tomó primero la muestra de sangre arterial de la arteria radial y 2 min después se tomó la muestra de sangre venosa central. Se evaluaron la correlación y la concordancia entre los valores de pH, PO2, PCO2 y HCO3 - en sangre arterial y venosa central. Análisis estadístico utilizado: Correlación de Pearson y análisis de Bland Altman. Resultados: Se encontró una correlación significativa entre los valores venosos y arteriales de pH, PO2, PCO2 y HCO3 (r pH = 0,88, p< 0,001; rP02 = 0,358, p<0,05; rPC0(2) = 0,470, p< 0,001 y rHC03 = 0,714, p< 0,001). Se derivaron ecuaciones de regresión para predecir los valores en sangre arterial a partir de los valores en sangre venosa: pH arterial = 0,879 xpH venoso central +114,4 (constante), R² = 0,128, PC0(2) arterial = 0,429 x P0(2) venoso central + 24.627 (constante), R² = 0,2205 y HC0(3) arterial = 1.045 x HC0(3) venoso central+ 3.402 (constante), R² = 0,5101. La diferencia media de la lectura arterial menos la venosa para pH, P0(2), PC0(2), y bicarbonato fue de 0,053 ± 0,014, 56,04 ± 15,74, 2,20 ± 4,4 y 4,30 ± 1,64, respectivamente. Las gráficas de Bland-Altmanpara la concordancia de los valores de pH, P0(2), PC0(2) y bicarbonato mostraron límites de concordancia del 95% de -0,04 a 0,146, -52,51 a 164,59, -26,61 a 31,01 y -7,0 a 15,6, respectivamente. Conclusiones: Hubo una buena correlación entre los valores arteriales y venosos centrales de pH, P0(2), PC0(2) y HCO3 -. Sin embargo, solamente el valor venoso central del pH puede reemplazar el valor arterial del pH.

Background: The procedure for arterial blood sampling can be technically difficult with various limitations and complications. Central venous catheterization is a mandatory procedure in ICU. The sampling of central venous blood is much easier, quicker and less complicated. Context: Correlation and agreement between arterial and central venous blood pH, PO2, PCO2 and HCO3 − values of mechanically ventilated patients. Aims: Aim was to evaluate the correlation and agreement between arterial and central venous blood pH, PO2, PCO2 and HCO3 − values and infer whether central venous blood gas values could replace arterial blood gas values. Settings and design: Intensive Care Unit and prospective observational study. Materials and methods: A total of 100 samples (50 arterial blood gas and 50 central venous blood gas) were collected from 50 adult patients with varied disease process admitted in a medical college ICU. Patients requiring mechanical ventilation having palpable radial artery, normotensive and normothermic were enrolled for the study. No patient was repeated for the study. Arterial blood was collected from radial artery and within 2 minutes central venous blood was withdrawn from the same patient. Correlation and agreement were evaluated between arterial and central venous pH, PO2, PCO2 and HCO3 −. Statistical analysis used: Pearson's correlation and Bland-Altman analysis. Results: The pH, PO2, PCO2 and HCO3 − of CVBG correlated significantly with arterial values (r pH = 0.88, P < 0.001; rPO2 = 0.358, P < 0.05; rPCO2 = 0.470, P < 0.001 and rHCO3 = 0.714, P < 0.001). Regression equations were derived to predict arterial blood values from venous blood values as follows: arterial pH= 0.879×central venous pH+ 0.9422 (constant), arterial PO2 = 0.421×central venous PO2 + 114.4 (constant), R² = 0.128, arterial PCO2 = 0.429×central venous PO2 + 24.627 (constant), R² = 0.2205 and arterial HCO3 = 1.045×central venous HCO3 + 3.402 (constant), R² = 0.5101. The mean arterial minus venous difference for pH, PO2, PCO2, and bicarbonatewas 0.053±0.014, 56.04±15.74, 2.20±4.4 and 4.30±1.64 respectively. Bland-Altman plots for agreement of pH, PO2, PCO2, and bicarbonate showed 95% limits of agreement of −0.04 to 0.146, −52.51 to 164.59, −26.61 to 31.01 and −7.0 to 15.6, respectively. Conclusions: The arterial pH, PO2, PCO2 and HCO3 – values correlatedwell with central venous values. However, only the arterial pH value can replace the central venous pH value.

Symptomatic sinus bradycardia: A rare adverse effect of intravenous ondansetron.

Ondansetron is a serotonin receptor antagonist which has been used frequently to reduce the incidence of post-operative nausea and vomiting in laparoscopic surgery. It has become very popular drug for the prevention of post-operative nausea and vomiting due to its superiority in-terms of efficacy as well as lack of side effects and drug interactions. Although cardiovascular adverse effects of this drug are rare, we found a case of symptomatic sinus bradycardia in a 43-year-old female patient, going for laparoscopic cholecystectomy, who developed the same after she was given intravenous ondansetron in operation theater during premedication. Hence, we report this case, as the rare possibility of encountering bradycardia effect after intravenous administration of ondansetron should be born in mind.

Traumatic hemorrhage of occult phaeochromocytoma in a patient with septic shock.

Phaeochromocytoma can have a variety of presentations; however, traumatic hemorrhage into a phaeochromocytoma is a very rare presentation. Diagnosing and managing a critically ill, septic patient with a Phaeochromocytoma can be very challenging. We report a case of 53 years old man with a previously undiagnosed Phaeochromocytoma, who presented initially with bowel perforation following an assault. Following a laparotomy for bowel resection and anastomosis, whilst on the intensive care unit, he developed paroxysmal severe hypertension overlying septic shock. Phaeochromocytoma was confirmed using a computed tomography scan and urinary assay of metanephrine and catecholamines. We managed the haemodynamic instability using labetalol and noradrenaline infusions. As his septic state improved he was convention therapy and following control of his symptoms over the next few weeks, he underwent an uncomplicated right sided adrenalectomy. He made a full recovery.

Dexmedetomidine used to provide hypotensive anesthesia during middle ear surgery.

This study was carried out to assess the hypotensive effect of low dose dexmedetomidine (DEX) infusion during middle ear surgery. 42 ASA grades I and II patients of either sex aged 18-45 years undergoing elective middle ear surgery were randomly divided into two groups of 21 each. Group I received placebo bolus and infusion of saline at a rate similar to DEX in Group II. Group II received 10-15 min prior to induction of anesthesia 1 µg/kg IV bolus DEX diluted in 10 ml of normal saline over 10 min. Immediately thereafter an infusion of 0.4 µg/kg/hr of DEX commenced. Standard anesthetic technique was used. Halothane was titrated to achieve a mean arterial pressure 30% below the control value (value taken just after premedication). We observed that a statistically significant reduction in the percentage of halothane required to reduce MAP 30% below control value occurred in patients receiving DEX infusion (1.3 ± 0.4%) in comparison to those receiving placebo (3.1 ± 0.3%). Patients receiving DEX infusion had a better surgical field. The mean awakening time was significantly reduced in patients of Group II (9.1 ± 2.7 min) when compared to patients of Group I (12.8 ± 2.2 min).We conclude that DEX can be safely used to provide hypotensive anesthesia during middle ear surgery.